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Functionalized Carbon Nanotubes and Nanodiamonds for Engineering and Biomedical Applications
Abstract
Chemical “toolbox” methods for the covalent functionalization of single-wall carbon nanotubes (SWNTs) and nanosize (∼2–10 nm) diamond powders have been developed. These methods involve direct fluorination, organic free radical additions, fluorine displacement reactions in fluoronanotubes, and fluoronanodiamond producing amino, hydroxyl, and carboxyl group-terminated derivatives. By using this chemistry, a variety of biologically active molecules can be covalently attached to carbon nanostructures, including a shortened nanotubes. The incorporation of amino-terminated SWNTs into epoxy polymer matrices has been achieved and substantial mechanical reinforcement demonstrated. The overview of these recent results is presented.
... The prepared composites have high mechanical properties due to good dispersion of DND content in a PVA matrix [15-16-17]. Liu et al. reacted mixture of hydrogen/fluorine at temperatures varying from 150 to 470°C with DND powder which resulted in the formation of fluoro-nanodiamond [18][19][20][21][22][23][24][25][26]. Salvadori et al. bombarded the surface of polycrystalline diamond films with the ions of hydrogen, oxygen and fluorine by using small, simple and novel plasma gun to produce their surface terminations [19][20]. ...
... Liu et al. reacted mixture of hydrogen/fluorine at temperatures varying from 150 to 470°C with DND powder which resulted in the formation of fluoro-nanodiamond [18][19][20][21][22][23][24][25][26]. Salvadori et al. bombarded the surface of polycrystalline diamond films with the ions of hydrogen, oxygen and fluorine by using small, simple and novel plasma gun to produce their surface terminations [19][20]. Krueger et al. used bead-assisted sonic disintegration (BASD) for the production of primary particles from strong clusters of DND. ...
... As received DND was placed in a crucible and oxidized in a furnace at 440°C for 5 h to remove the impurities like traces of metal and non-carbon content present in the powder [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Metal oxides are burnt even at less temperature while the burning temperature of diamond is about 600°C which is above 440°C. ...
We applied acid treatment for the surface modification of detonation nanodiamond (DND) powder by minimizing their surface energy to overcome agglomeration and improve dispersion of DNDs. Different concentrations of acid modified DND in 828 epoxy matrix were fabricated to check their mechanical and electromagnetic properties. Mechanical properties were checked in terms of ultimate tensile strength (UTS), toughness, energy to break, percent strain break and Young's modulus while electromagnetic shielding properties were studied in frequency range of 11–17 GHz. To analyze electrical and magnetic properties of the nanocomposites, relative permittivity and permeability tests were performed. Excellent interactions among acid modified DND and epoxy resin was observed due to carboxyl and hydroxyl functional groups that results in the formation of efficient load transfer interface, which in turn enhance the mechanical and electromagnetic properties of epoxy nanocomposites. During investigation it was observed that mechanical properties and relative permittivity showed enhancements when, 0.2 wt% acid modified DND were used as a nano-filler, while on further increment of modified DND these properties start decreasing. Unlike this, the relative permeability, reflection and transmission loss values were increased with the increase of acid modified DND content.
... Sidewall fluorination is one of the most practical ways to modify the CNTs surfaces. These fluorinated surfaces can be applied as sensors [6,7], supercapacitor electrodes [8], nanocomposites [9,10], solid lubricants [6,11], engineering and biomedical applications [9], and lithium and sodium ion storage [12]. Many fluorinating agents have been involved in CNT fluorination experiments such as fluorine gas (F 2 ) [3,13,14], CF 4 -plasma [14][15][16][17][18], SF 6 -plasma [19], bromine trifluoride BrF 3 [14,20], and xenon difluoride XeF 2 [3]. ...
... Sidewall fluorination is one of the most practical ways to modify the CNTs surfaces. These fluorinated surfaces can be applied as sensors [6,7], supercapacitor electrodes [8], nanocomposites [9,10], solid lubricants [6,11], engineering and biomedical applications [9], and lithium and sodium ion storage [12]. Many fluorinating agents have been involved in CNT fluorination experiments such as fluorine gas (F 2 ) [3,13,14], CF 4 -plasma [14][15][16][17][18], SF 6 -plasma [19], bromine trifluoride BrF 3 [14,20], and xenon difluoride XeF 2 [3]. ...
With the growing demand of incorporating inherently hydrophobic carbon-based materials including carbon nanotubes (CNTs) with the surrounding medium (air, water, biofluids, etc.), it is inevitable to modify their surface chemistry and wettability with functionalization. Sidewall fluorination of the CNTs has attracted a lot of interest for its effectiveness in surface modification and switching surface wettability. Along with characterization techniques such as Raman and FESEM performed on the as-grown fluorinated CNTs surfaces, surface free energies were calculated based on the contact angle results. Detecting the proficiency of the fluorination treatments on wettability requires reliable water contact angle measurements on non-ideal solid surfaces where local energy minima are separated by energy barriers and the deposited static drop can be in any free energy minimum. Advancing contact angle (ACA) and receding contact angle (RCA) methods were applied to the fluorinated CNTs as well as static contact angle measurements. The former with higher reliability, to date, have not been used on nanotube-covered surfaces. Both methods confirmed the efficiency of tuning wettability of CNTs surfaces with fluorination while ACA–RCA method presented benefits on understanding the surface properties over the static contact angle measurements.
... Unmodified carbon nanotubes (CNT) are hardly soluble in water, which restricts their medicinal use. To avoid this problem, the graphene sheets are functionalised in different ways [13][14][15][16]. In general the methods of CNT functionalization are divided into endohedral and exohedral ones. ...
... It can be also performed by adsorption of chemical compounds through pyridine rings. Modification with pyrrolidine rings gives the species soluble in certain organic solvents [16]. Improvement in nanotubes solubility can also be achieved by introduction of certain biochemical compounds, e.g. ...
... Except for porosity and morphology, the addition of nanostructures can promote the sorption properties of chitosan membrane adsorbents. Incorporation of inorganic nanoparticles can also improve the mechanical properties of the membranes [11][12][13][14][15][16][17]. Acid functionalized CNTs embedded into CS/PVA adsorptive membranes were studied by Zarghami et.al for adsorption of Pb(II) and Zn(II) ions [17]. ...
... Nanodiamonds have emerged as promising nanoparticles because of their remarkable mechanical, thermal and biological properties together with its large specific surface area (larger than 200 m 2 /g) and hydrophilic surface owing to the presence of many oxygenated functional groups [12]. Khabashesku et.al [14] showed that nanotubes and nanocrystalline diamond powders need some surface modifications due to lack of interfacial bonding and nonreactive surface. ...
Detonation nanodiamonds (DNDs), for the first time, were utilized to modify chitosan/polyvinyl alcohol (CS/PVA) thin membrane adsorbents. For this purpose, different contents of DNDs, from nil to 1.5 wt%, were embedded in the polymer matrix of the membranes to obtain the optimum content. Static adsorption of Pb(II) on the prepared membrane adsorbents was studied. The fabricated membranes were characterized in terms of morphology and performance using scanning electron microscopy (SEM) micrographs and Fourier transform infrared (FTIR) spectrum analyses. Langmuir and Freundlich isotherms were used to model the equilibrium adsorption. The effects of pH, temperature, and initial metal concentration on the adsorption capacity were investigated. Results showed that adsorption of lead ion is more favorable at pH = 6. Thermodynamic parameters including ΔHo, ΔSo and ΔGo revealed endothermic, entropy-driven and spontaneous nature of the adsorption. Adsorption capacity for Pb(II) increased from 29.5 mg g⁻¹ (for the plain membrane) to 121.3 mg g⁻¹ by the addition of 1.5 wt% DNDs; however, the optimal content was 1 wt% DNDs considering both mechanical stability and adsorption capacity. Results revealed that the ultra-thin CS/PVA membrane adsorbents modified with DNDs are very potential candidates for heavy metal adsorption.
... The incorporation of amino-terminated SWCNT into epoxy polymer matrices has been achieved and substantial mechanical reinforcement was demonstrated. Table 3 shows tensile properties of epoxy composites [22] . For the nano and biotechnology integration, nanometer-sized diamond becomes an interesting material recently. ...
... 2. Classification of particle assemblies in detonation nanodiamond [21] . Table 3. Tensile properties of epoxy composites [22] . carbon nanofibers were synthesized at 450-800°C by using alumina plate-supported nickel catalyst and acetylene as carbon source. ...
Recent technological advancements in polymeric buckypaper materials have brought spotlight on polymer/nanodiamond buckypaper. This review is designed as systematic and comprehensive source of information and research on nanodiamond, polymer/nanodiamond nanocomposite and buckypaper, and technological advancement in this field. Structure, properties, and manufacturing techniques of polymer/nanodiamond buckypaper are reviewed. Because of outstanding physical properties, polymer-based buckypaper has been employed as potential contenders in nanofilter, supercapacitor, fuel cell, electrical components, and biomedical devices. However, property dependence in relation to chemical structure is not fully identified in literature. To find out further technical suitability of polymer/nanodiamond materials are still among predominant research challenges.
... During the last 10 years, carbon nanotubes (CNTs) have been applied to many biomedical fields including biosensors, tissue engineering, and drug delivery because of their excellent electrochemical, mechanical, and electrical characteristics [1]. Many researchers have shown that the functionalization of CNTs (f-CNTs) enhances the non-toxicity, wettability, and biocompatibility of the near extra-cellular matrix (ECM) for application in biomedical fields [2][3][4]. Also, for application of CNTs to scaffolds and devices to regenerate neuronal tissue engineering, it is known that the functionalized CNTs (f-CNTs) can be used to control the number of growth cones, neurite outgrowth, length, and branching during neuronal cell growth on f-CNTs [5]. The neuronal environment with positively charged multi-walled carbon nanotubes (MWCNTs) has improved neurite outgrowth and branching compared to neutral or negatively charged MWCNTs [6,7]. ...
... To investigate and compare the effects of the plasma treatments on the morphological and chemical properties of the SWCNT paper scaffolds for enhancement of neuronal activity, we prepared an untreated sample and four samples treated under various plasma conditions. The treated samples are denoted as samples No. [1][2][3][4] in Table 1. Even if some negatively charged functional groups occurred during the purification process of the untreated SWCNT paper, the SWCNT paper can be considered to be neutrally charged due to the small density of negative charges. ...
Effects of O2 and N2/H2 plasma treatments on the neuronal cell growth on
single-walled carbon nanotube paper scaffolds
... Regardless of the observed decreased conductivity for fluorinated nanotubes [16][17][18], axial fluorine addition pattern predicts the band gap not to vanish for metallic nanotubes [13,14]. Potential applications of FSWCNT include its use in supercapacitors [15][16][17][18][19][20][21][22], Lithium-ion batteries [23][24][25][26] and as lubricants [27][28][29][30][31]. Recent investigations for FSWCNT as a modern approach for polymer reinforcement, predicts it to improve the physical properties of polymers in comparison to undoped nanotube fillers [31,32]. ...
In a nondegenerate fluorinated single-walled carbon nanotube (FSWCNT) in
the hypersound domain, ql>>1, where q is the acoustic wavenumber and ` is
the carrier mean free path, a theoretical study of semiclassical carrier miniband
Transport across a periodic potential was carried out. First, the effect of an
acoustic wave on FSWCNT was investigated, and it was discovered that
high-frequency carrier dynamics can be created, though the wavenumber or
Wave amplitude is critical. Depending on the wave amplitude and the carrier’s
In the initial position of the acoustic wave, there were two dynamical regimes.
Bloch-like oscillations could be induced by applying a large enough potential
amplitude/wavenumber, resulting in ultra-high negative differential velocity, or
the carrier could be dragged through the FSWCNT and permitted to drift in
periodic orbits with frequencies far above the gigahertz frequencies (GHz) of
the acoustic wave. A high negative differential velocity induces charge
domains in FSWCNT at transitions between these two carrier dynamic
regimes, which generated extra features in the current oscillations. Secondly,
invoking an analytical technique which is traceable and the phonon LBM, the
The dimensionless figure of merit (ZT) for FSWCNT was explored.
... Mechanical, optical, electrical, and magnetic properties of nano hydroxyapatite biomaterials [6] are also present. CNTs are interesting in the field of material science because of their noble mechanical qualities such as high resilience, flexibility, and tensile strength, as well as other unique structural, electrical, and physicochemical features [7] [8] [9]. Many papers are reported on the preparation and mechanical characterization of composites, its poor dissolution property restricts the application of CNTs [10]- [14]. ...
... The blend of CS with an appropriate polymer (such as cellulose acetate, poly vinyl pyrrolidine and polyvinyl alcohol) results in the formation of highly reactive and mechanically stable film (Jayakumar et al. 2011;Shawky 2009). The mechanical stability of the membrane is also enhanced by incorporating nanoparticles into it (Ashori and Bahrami 2014;Delavar and Shojaei 2017;Ghaeeet al. 2010;Khabashesku et al. 2005;Khan et al. 2017;Vatanpour et al. 2012). ...
By integrating the benefits of poly vinyl alcohol (PVA) and chitosan (CS) with α-MnO2 nanoparticles (MNPs), a novel type of nano-polymer composite (PVA/CS-MNP) membrane was synthesized through a simple and facile casting method. In this proposed work, the membrane prepared was used for removal of organic textile dyes from their aqueous solutions. The as-synthesized PVA/CS-MNP membrane was examined using different analytical techniques such as Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM), and mechanical properties of material was also studied. Two cationic dyes, methylene blue (MB) and eosin yellow (EY), were chosen as template dyes to be removed from industrial waste water. These dyes were degraded by carrying out a reaction in which the synthesized membrane was used as a photocatalyst. The study of kinetics revealed that the reaction process followed pseudo-first-order kinetics. The efficiency of catalyst and the rate of reaction were also examined by varying parameters such as pH, initial concentration of dyes, and composition of membrane. The maximum efficiency of catalyst was observed at pH 12 as more than 95% of dyes degraded within 1 h of time span. The catalyst was found to be reusable as its efficiency did not deteriorate even after using it for several times. Such functional membrane having higher stability, low production cost, excellent efficiency to degrade dyes, and good recyclability are promising material for distinctly effective deletion of organic dyes from waste water.
Graphical Abstract
... Nanodiamond (ND) particles are small diamond particles with the diameter of ∼5 nm, which also possess biocompatibility as well as chemical stability [6][7][8][9][10][11][12]. Furthermore, ND particles can be chemically modified to functionalize their surface in various ways [13][14][15]. Thus, taking advantage of these characteristics and applying ND particles as a platform for biological purposes such as drug delivery and targeted imaging have been attracting major attention recently [16][17][18][19]. ...
Magnetic resonance imaging (MRI) contrast agents with the particle diameter of around 3-10 nm hold the potential to be selectively uptaken by lymphatic vessels and be filtered in the kidney for final excretion. However, there are no existing MRI contrast agents based on gadolinium (Gd) complexes within the size of this range, and thus the selective imaging of the lymphatic system has not yet been achieved. In our previous report, we succeeded in fabricating nano-scale MRI contrast agents by complexing ordinary contrast agents (Gd-diethylenetriaminepentaacetic acid (DTPA)) with carboxylated nanodiamond (CND) particles to conquer this problem. However, DTPA has recently been reported to release Gd ions in the course of time, leading to the potential danger of severe side effects in the human body. In this study, we utilized cyclic-chained DOTA as an alternative chelating material for DTPA to fabricate CND-based MRI contrast agents for the selective lymphatic imaging. The newly fabricated contrast agents possessed the diameter ranging from 3 nm to 10 nm in distilled water and serum, indicating that these particles can be selectively uptaken by lymphatic vessels and effectively filtered in the kidney. Furthermore, the DOTA-applied CND contrast agents exhibited stronger MRI visibility in water and serum compared to DTPA-applied CND contrast agents. These results indicate that DOTA-applied CND contrast agents are promising materials for the selective MR imaging of lymphatic systems.
... The work [14] achieved a tensile strength of 90 ± 6.8 MPa, which is equal to that obtained in this application, however, for this, 6.4 wt% CNF functionalized with aminobenzoyl, i.e. the concentration of the introduced additive was 64 times higher than the concentration of the additive that we injected, which makes the use of this supplement economically inefficient. The work [21] achieved a tensile strength of 95 MPa, however, in this work, Resin 862 epoxy resin of the Bisphenol-F type based on fluorinated compounds was used, which has a significantly higher initial strength compared to the ED-22 resin, type Bisphenol-A, used by us. This means that the results of this work cannot be compared with the results obtained by the authors of the application. ...
Epoxy resin (diglycidyl ether bisphenol-A type) polymer composites with added pristine and fluorinated carbon nanotubes (CNTs) were studied by FTIR, TGA and electron microscopy. The tensile and flexural strengths of these composites were measured. The specific surface value of the fluorinated CNTs was found to be about 2.26 times higher than that of the one containing the pristine CNTs. The fluorination did not affect the thermal stability of the CNTs below 260 °C and did not worsen the thermal stability of the filled composites. The introduction of 0.1 wt% CNTs fluorinated at 150 °C into the polymer matrix resulted in the increase of the tensile strength of the composite to 89.6 ± 4.1 MPa (35% increase when compared to the unfilled composite). The flexural strength of the composite filled with 0.2 wt% CNTs fluorinated at 150 °C was increased to 199.7 ± 4.8 MPa (+58% when compared with the unfilled composite). The pristine CNTs were less effective in improving the tensile and flexural strengths of the composite when compared with the fluorinated CNTs. The introduction of the fluorinated CNTs into the polymer matrix did not influence the thermal stability of the composite. The reinforced composites can be applied in several areas: aviation, automotive, wind turbine propeller blades, for producing yachts and boats, etc.
... Also, they showed that DOX could be absorbed by the composite with high efficiency [116]. Other research group showed that it could be produced NDs that includes amino acid, peptides, oligonucleotides, sugars, etc., for drug delivery [117]. ...
Carbon based nanomaterials have unique advantages in several areas due to its electronic, optical, thermal, and mechanical properties. In these terms, nanodiamonds have attracted considerable attention in recent years in different research areas such as biological sensing, medical therapy, fluorescent markers, enzyme immobilization and so on. Nanodiamond (ND) is a new member of carbon nanoparticle family with a truncated octahedral architecture that showed superior characteristics of diamond. This review is focus on synthesis methods, dispersion, functionalization, medical applications and toxicity of nanodiamonds.
... Fluorination is an efficient way to modify and control the surface properties of NDs. Fluorinated ND can be further subjected to modification with the selected reagents, such as alkyllithium, diamines, aminoacids, etc. [99]. It is worth noting that the direct fluorination does not require hydrogen pretreatment at substantially higher temperatures [100]. ...
... Received 24 July 2018; Received in revised form 12 November 2018; Accepted 18 November 2018 polymeric matrix. In addition, NDs possesses rich functional sites on their surfaces; hence ND surfaces can be functionalized to any extent without compromising the useful properties of their nanodiamond cores using simple chemistry for the grafting of chemical moieties or polymer structures [21,22]. Poly(ε-caprolactone)-click coupled NDs have recently been reported to significantly contribute to the mechanical and shapememory properties of polyurethane composites [23]. ...
Nanodiamond-grafted hyperbranched polyurethanes (HPU-g-NDs) with various nanodiamond (ND) loadings were synthesized and composites with multi-walled carbon nanotubes (MWNTs) were prepared. The HPU-g-ND/MWNT composites showed significantly improved mechanical, thermal, and photothermal shape-recovery properties, compared to the HPU-g-NDs. Scanning electron microscopy of fractured surfaces revealed that the HPU-g-NDs are highly compatible with the polymer matrix as well as the highly dispersed MWNTs. The mechanical properties of the HPU-g-NDs were profoundly enhanced by the addition of MWNTs. The breaking stress and modulus of the HPU-g-ND (1 wt% ND) composite were enhanced by 29% and 42%, respectively, with the incorporation of only 1 wt% MWNTs. An exceptional increase in thermal stability, of about 60 °C at a weight loss of 50%, was observed for HPU-g-ND at 1 wt% ND, compared with that of pure HPU; this composite also exhibited better shape recovery and faster actuation behavior during laser-driven photothermal actuation.
... The effective utilization of CNT in composite applications depends strongly on the ability to disperse CNT homogeneously throughout the matrix without destroying the integrity of CNT. Furthermore, good interfacial bonding is required to achieve the load transfer across the CNT-matrix interface, a necessary condition for improving the mechanical properties of polymer composites [7]. Although several studies have focused on producing polymer CNT composites, many practical challenges remain before their potential can be fully realized [4,5,[8][9][10][11]. ...
Carbon nanocomposites have received a great deal of attention in recent years in view of their special properties such as low density, superior thermal and mechanical properties. However, poor dispersion and poor interfacial bonding limit the full utilization of carbon nanotubes as reinforcing agent in polymer nanocomposites. This paper presents an approach developed for production of polymer matrix nanocomposites with uniformly distributed multi-walled carbon nanotube (MWCNT). This approach involves preparation of a stable MWCNT in Nafion ® polymer matrix followed by fabrication of MWCNT-Nafion ® nanocomposite via a novel electrochemical co-deposition process (ECD). The ECD process introduced here follows the similar basic principles of traditional electrophoretic deposition. Morphology and microstructure of fabricated MWCNT-Nafion ® nanocomposite sheets were evaluated through scanning electron microscopy(SEM). The mechanical performance of the nanocomposite was assessed by tension tests per ASTM D3039. Deposition of the MWCNT-Nafion ® nanocomposite on an aluminum sheet produced significant gains in the tensile properties of the sheet. This finding confirms that uniform dispersion of MWCNT in a polymer matrix can produce nanocomposites with desired mechanical properties.
... 3 ND applications may range from composites/nanocomposites in aerospace and electronics to biomedical applications. [4][5][6] Polymer-based nanocomposites are promising materials that combine the polymer matrix and nanofiller properties. 7 Including ND in thermoplastic polymers significantly improves the mechanical and other physical properties. ...
Nanodiamond is an emerging nanocarbon material having several advantageous properties (high surface area, mechanical properties, optical features, wear resistance, low friction coefficient, etc.) as a nano-sized filler for polymer matrices. Polyamides and polyimides are two important thermoplastic polymers which are among important matrices for nanodiamond composites. Polyamides have high thermal stability, mechanical strength, wear resistance, superior tribological properties, and fine processability. Many aliphatic polyamides, such as polyamide 6, polyamide 6,6, polyamide11, polyamide 12, and several aromatic polyamides have been reinforced with nanodiamond to further enhance their engineering properties. Similarly, outstanding mechanical, thermal, optical, and electrical properties of aromatic polyimides have been enhanced by using nanodiamond particles. Surface nanodiamond modification with various functional groups has been achieved to enhance interfacial adhesion with the matrix, which in turn, improved the physical properties. Polyamide/nanodiamond nanocomposites and polyimide/nanodiamond nanocomposites have been prepared using in situ reactive polymerization, melt extrusion, solution processing, and other techniques. The improved electrical, mechanical, thermal, and biomedical properties render them potentially important materials for various technical applications including energy storage, membrane technology, coatings, and biomedical.
... A significant volume of research is currently under way on the biomedical applications of DNDs, including targeted drug delivery and biocompatibility of DNDs with various types of tissue [3]. Fluorinated-surface DNDs are a promising precursor for novel hybrid and composite materials and can be used as an intermediate link in their synthesis [4][5][6]. Liu et al. [6], Ando et al. [7], and Dubois et al. [8] have used infrared spectroscopy to study surface conditions and the composition of functional groups in fluorinated powders of micro-and nano-crystalline diamonds, including DNDs. Nakaura et al. ...
Infrared spectroscopy was used to analyze detonation nanodiamond powder with surfaces functionalized by fluorine- or oxygen-bearing groups before and after heat treatment in air. Fluorination at T=500°C has a significant effect on the actual condition of the diamond surface. The infrared absorption bands associated with the fluorocarbon groups occur at 1092, 1156, 1248, and 1340 cm−1. We show that heat treatment does not have any qualitative effect on the broad infrared absorption band between 1000 and 1400 cm−1 characterizing the fluorinated surface when the sample is heat treated at temperatures up to 520°C. This can be attributed to the entire surface of the detonation nanodiamond particles being covered by saturated, strong, covalent C–F bonds arising from the use of an element more electronegative than oxygen.
... For the case with two -OH groups at different carbon rings of the graphene, it was observed that the most stable system is Gr-OH-I_V; the energy values and the transfer of charge are very close to those of the Gr-OH-ab system. Some theoretical studies of the functionalization of SWCNTs with -OH are described in the literature, 18,56,57 showing that the binding energy SWCNT increase for -OH adsorption, especially for finite SWCNTs. In the study by Milowska and Majewski, 18 they evaluated SWCNT (10,0) with different functional groups including -OH. ...
Carbon nanomaterials are one of the most promising nanostructures for adsorption of chemical species due to the high superficial area and possible interesting applications. In this way, a systematic study of chemical groups attached on the graphene surface is necessary in order to evaluate the influence of the type and number of functionalizations on the resulting properties of the derived system. In this work, first principles simulations were used to evaluate the physical effects of different concentrations of the chemical groups -COOH, -COH, -OH, -O- or -NH2 adsorbed on the graphene surface. The functionalizations occur from one up to three chemical groups and either in the same or different carbon rings. It is observed that significant changes occur in the adsorption and electronic properties due to the hybridization and symmetry points of interaction of the chemical groups. Then, the results indicate that it is possible to control the properties of the desired system through the type, concentration and binding site of the functional groups attached to the graphene monolayer.
... deposition technique. Nanodiamonds have high mechanical and thermal properties, excellent corrosion resistance, microstructural stability at extreme anodic and cathodic potentials, wide working potential window, low and stable background current [107][108][109][110]. ...
Nanotechnology has become very popular in the sensor fields in recent times. It is thought that the utilization of such technologies, as well as the use of nanosized materials, could well have beneficial effects for the performance of sensors. Nano-sized materials have been shown to have a number of novel and interesting physical and chemical properties. Low-dimensional nanometer-sized materials and systems have defined a new research area in condensed-matter physics within past decades. Apart from the aforesaid categories of materials, there exist various materials of different types for fabricating nanosensors. Carbon is called as a unique element, due to its magnificent applications in many areas. Carbon is an astonishing element that can be found many forms including graphite, diamond, fullerenes, and graphene. This review provides an overview of some of the important and recent developments brought about by the application of carbon based nanostructures to nanotechnology for both chemical and biological sensor development and their application in pharmaceutical and biomedical area.
... Nanodiamond which is a significant member in carbon nanomaterials family has been discovered before fullerene in 1963– 1982. Indeed, fullerene could be considered as the first discovery among symmetric carbon nanostructures[6][7][8], and its discovery revealed new perspectives in carbon-based materials that resulted in research on carbon nanotubes, cylindrical cousin of buckyball, and rapid developments in advanced materials field. Although the emergence of 2D carbon nanomaterials, as graphene reported by Geim and Novoselov in 2004, who were awarded the Noble Prize in 2010, marginalized fullerenes and moved the majority of the studies towards other carbon nanostructures[9,10], the incredible properties of fullerene could not be underestimated. ...
In 1985, the serendipitous discovery of fullerene triggered the research of carbon structures into the world of symmetric nanomaterials. Consequently, Robert F. Curl, Harold W. Kroto and Richard E. Smalley were awarded the Noble prize in chemistry for their discovery of the buckminsterfullerene (C60 with a cage-like fused-ring structure). Fullerene, as the first symmetric nanostructure in carbon nanomaterials family, opened up new perspectives in nanomaterials field leading to discovery and research on other symmetric carbon nanomaterials like carbon nanotubes and two-dimensional graphene which put fullerenes in the shade, while fullerene as the most symmetrical molecule in the world with incredible properties deserves more attention in nanomaterials studies. Buckyball with its unique structure consisting of sp2 carbons which form a high symmetric cage with different sizes (C60, C70 and so on); however, the most abundant among them is C60 which possesses 60 carbon atoms. The combination of unique properties of this molecule extends its applications in divergent areas of science, especially those related to biomedical engineering. This review aims to be a comprehensive review with a broad interest to the biomedical engineering community, being a substantial overview of the most recent advances on fullerenes in biomedical applications that have not been exhaustively and critically reviewed in the past few years.
... Carbon-based nanoparticles (CNPs), such as carbon nanotube, fullerene, graphene, and nanodiamond (ND), have attracted great attention due to their favorable chemical and physical properties, including a large surface area, outstanding strength, and good biocompatibility. 1,2 CNPs have been greatly studied with a view to being exploited in biomedical and pharmaceutical areas, with ND, in particular, gaining widespread interest in the recent years. ND is known to exhibit lower toxicity and improved cell tolerance compared with other CNPs. ...
The best strategy in the development of topical drug delivery systems may be to facilitate the permeation of drugs without any harmful effects, while staying on the skin surface and maintaining stability of the system. Nanodiamonds (NDs) play a key role with their excellent physicochemical properties, including high biocompatibility, physical adsorption, reactive oxygen species (ROS) scavenging capability, and photostabilizing activity. Z-average sizes of carboxylated ND (ND–COOH) agglutinate decreased significantly as the pH increased. Fluorescein-conjugated ND was observed only on the stratum corneum, and no sample diffused into the dermal layer even after 48 hours. Moreover, ND–COOH and ND–COOH/eugenol complex did not show significant toxic effects on murine macrophage cells. ND improved in vitro skin permeation >50% acting as a “drug reservoir” to maintain a high drug concentration in the donor chamber, which was supported by quartz crystal microbalance results. Moreover, ND–COOH could adsorb a drug amount equivalent to 80% of its own weight. A photostability study showed that ND–COOH increased the photostability ~47% with regard to rate constant of the eugenol itself. A significant decrease in ROS was observed in the ND–COOH and ND–COOH/eugenol complex compared with the negative control during intracellular ROS assay. Moreover, ROS and cupric reducing antioxidant capacity evaluation showed that ND–COOH had synergistic effects of antioxidation with eugenol. Therefore, ND–COOH could be used as an excellent topical drug delivery system with improved permeability, higher stability, and minimized safety issue.
... CNTs are classified in the three types based on the pair of integers of (n, m) that is related to the chiral vector. Hence, the types of CNTs are chiral (n = m), armchair (n = m) and zigzag (n, m = 0) (4)(5)(6)(7)(8)(9). Previous studies illustrated that SCNTs because of their molecular size, electronic structure and electrical conductivity are considered as a compatible candidate for binding to the polymers and biomolecules such as DNA (10)(11)(12)(13). ...
Background:
To explore practical applications of carbon nanotubes (CNTs) in biomedical fields the properties of their interaction with biomolecules must be revealed. Recent years, the interaction of CNTs with biomolecules is a subject of research interest for practical applications so that previous research explored that CNTs have complementary structure properties with single strand DNA (ssDNA).
Objectives:
Hence, the quantum mechanics (QM) method based on ab initio was used for this purpose. Therefore values of binding energy, charge distribution, electronic energy and other physical properties of interaction were studied for interaction of nucleic acid bases and SCNT.
Materials and methods:
In this study, the interaction between nucleic acid bases and a (4, 4) single-walled carbon nanotube (SCNT) were investigated through calculations within quantum mechanics (QM) method at theoretical level of Hartree-Fock (HF) method using 6-31G basis set. Hence, the physical properties such as electronic energy, total dipole moment, charge distributions and binding energy of nucleic acid bases interaction with SCNT were investigated based on HF method.
Results:
It has been found that the guanine base adsorption is bound stronger to the outer surface of nanotube in comparison to the other bases, consistent with the recent theoretical studies. In the other words, the results explored that guanine interaction with SCNT has optimum level of electronic energy so that their interaction is stable. Also, the calculations illustrated that SCNT interact to nucleic acid bases by noncovalent interaction because of charge distribution an electrostatic area is created in place of interaction.
Conclusions:
Consequently, small diameter SCNT interaction with nucleic acid bases is noncovalent. Also, the results revealed that small diameter SCNT interaction especially SCNT (4, 4) with nucleic acid bases can be useful in practical application area of biomedical fields such detection and drug delivery.
... Carbon nanotubes (CNTs) are an example of a carbon-based nanomaterial, whose unique properties have sparked enormous popularity in nanotechnology since the first radix carbon nano-tube was found in 1991 [1]. Nowadays, Much attention has been paid on CNTs, due to their small size and extraordinary physicochemical properties, in combination with their unique tubular morphology, not only for their huge potential industrial application, but also in biological application including biosensors, drug and vaccine delivery and the preparation of novel biomaterials for bone tissue engineering [2][3][4][5][6][7][8]. However, there are two obstacles to overcome in its application: First, CNTs are prone to aggradation in animals lung, which is harmful to their health [9], Secondly, the poor wettability of the CNTs surface often induces weak interfacial bonding, hence the improvement of the composites mechanical properties is limited [6]. ...
In this paper, multi-walled carbon nanotubes (CNTs) were first purified and oxidized by blend acid composed of vitriol and nitric acid, and then surface decorated with biopolymer chitosan via a controlled surface deposition and crosslinking process. The results showed that the diameter of CNTs became thicker because the surface of CNTs was covered with chitsoan, and the dispersion of CNTs was improved.
... To enhance the mechanical properties of the brittle ceramic matrix, without sacrificing its biocompatibility, different dopants like zinc, magnesium, silver (Webster et al., 2004) or secondary phases like zirconia, alumina, titania, carbon fibers, carbon nanotubes etc. have been widely used as reinforcing materials (Kong et al., 1999;Lopes et al., 1999;Park and Vasilos, 1997;Shen et al., 2001;Zhang et al., 1997). Carbon nanotubes (CNTs) are getting considerable attention in recent past owing to their good mechanical properties together with high tensile strength, high resilience, flexibility and other unique structural and physicochemical properties (Iijima, 1991;Khabashesku et al., 2005;Sambarkar et al., 2012). CNTs have widely applied as a reinforcement material to improve the strength and toughness of the HAp matrix (Kaya, 2008;Najafi et al., 2009). ...
... Nanodimonds (NDs)232425, which is other carbon nanoallotrope, exhibit interesting mechanical and optical properties, high surface areas and tuneable surface structures [25]. Moreover, they are non-toxic, which makes them suitable to biomedical applications, a feasible alternative as nanocarriers for addressed delivery of drugs and biolabeling [26,27]. Despite their toxicity, CNTs find various applications since their discovery due to their structural properties, stability and high electrical and thermal conductivities. ...
Epoxies are a versatile class of resins, well-known for its excellent combination of properties like light weight, chemical resistance, fatigue strength, custom-made impact resistance, and can be tailored to be biocompatible. Although ceramic and metallic composites are widely accepted for the development of biomaterials, their heaviness, non-resorbability, and necessity of second surgical operation to remove the implant after healing induces extra pain for the patients; hence, they were gradually replaced by polymer composites. Epoxies can be self-cross-linked or cross-linked with external curatives at stoichiometric ratio to achieve desired properties and purity. Advances in epoxy-based biomedical composites have been focused on the design of implants with concerns on comfort, biocompatibility, precise property matching, light weight, and closely mimicking natural structures in performance. Epoxy-based materials are also having footprints in drug delivery and tissue engineering. The chapter highlights epoxy usage in the biomedical field for various advanced applications.
Background: Nanodiamonds (ND) have attracted significant interest for use in several biomedical applications. These applications can be very useful if safety and compatibility of ND have been proved.
Results: We assessed the effects of ND (100 nm, Carboxylated) on primary macrophages and a macrophage-like cell line and found that these particles are not toxic to these cells at the lower concentrations, but they may interfere with cell’s functions and differentiation. Internalization of ND by these cells in a time- and dose-dependent manner were mostly via phagocytosis and clathrin-dependent endocytosis and localized to the cytoplasm but not into the nucleus. No significant induction of inflammatory cytokines and no reduction in the ability of these cells to respond to lipopolysaccharides (LPS) were noted. However, the endocytic activity of these cells was significantly reduced. In addition, ND exposure reduced the ability of differentiating bone marrow cells to express macrophage surface markers.
Conclusions: Our findings suggest that ND are not cytotoxic to macrophages at the tested concentrations, but they can interfere with macrophage functions and differentiation.
By integrating the benefits of poly vinyl alcohol and chitosan with bio fabricated α-MnO 2 nanoparticles, a novel type polymer-nanocomposite membrane was synthesized through a simple and facile casting method. In this proposed work, the membrane prepared was used for removal of organic textile dyes from their aqueous solution. Two cationic dyes, methylene blue and eosin yellow were chosen as template dyes to be removed from industrial waste water. These dyes were degraded by carrying out a reaction in which the synthesized membrane was used as a photocatalyst. The photocatalyst was found to be highly efficient for removal of these dyes from their aqueous solutions. The efficiency of catalyst and the rate of reaction were also examined by varying parameters such as pH, initial concentration of dyes and composition of membrane. The catalyst was found to be reusable as its efficiency did not deteriorate even after using it for 5 times. Such functional membrane having higher stability, low production cost, excellent efficiency to degrade dyes and good recyclability are promising material for distinctly effective deletion of organic dyes from waste water.
Some of the challenges and specific outcomes of the doped carbon nanotubes have been reviewed in detail. In particular, the doping techniques and the implementations of doped CNTs depending on the specific applications such as sensors, electronic devices, nanorobots, composites, and so on have been reported. Various synthetic approaches have been utilized to dope the novel CNT materials. Recently, the transport behavior of doped CNTs was explored by several researchers. In this chapter, the current advancement on carbon nanotubes doping has been highlighted. The recent progress of the functionalization, fluorination, and electrochemical modifications of doped CNTs have been briefly discussed.
KeywordsDefected carbon nanotubesFunctionalization of carbon nanotube and applications
This book presents an analysis of the techniques used for the synthesis of innovative functional carbon nanostructures. The chapters describe the research and development of various layered carbon nanostructures. Emphasis is given to the impact of defects on carbon nanostructures. The application of carbon nanostructured materials in biomedical field and energy storage is described.
This is my thesis work on protein folding structure, dynamics, and associated solvent properties
MRI contrast agents with a size of 3-10 nm are considered to be an effective pathway for selective MR lymphatic imaging. In our previous study, we fabricated nanosized MRI contrast agents (Gd-DTPA-ND) with the condensation of nanodiamond (ND) particles and gadolinium chelates (Gd-DTPA). However, these Gd-DTPA-ND particles formed microscale aggregates in distilled water, exceeding the size required for selective lymphatic MR imaging. In this study, carboxylated nanodiamond (CND) particles were utilized as alternative platforms for condensation with gadolinium complexes. The carboxyl groups introduced by oxidation were expected to induce hydrophilicity with a negative charge on the ND surface, resulting in the high dispersity of gadolinium-complexed CND particles. The fabricated Gd-DTPA-CND particles possessed a hydrodynamic diameter of around 4-5 nm without any signs of aggregation in distilled water and human serum. Furthermore, the T1-weighted image of Gd-DTPA-CND particles in distilled water and human serum presented strong contrast, indicating the excellent MRI visibility of the particles. Therefore, the Gd-DTPA-CND particles can become practical MRI contrast agents for the achievement of selective MR imaging of the lymphatic system.
The currently observed development of medical science results from the constant search for innovative solutions to improve the health and quality of life of patients. Particular attention is focused on the design of a new generation of materials with a high degree of biocompatibility and tolerance towards the immune system. In addition, apart from biotolerance, it is important to ensure appropriate mechanical and technological properties of materials intended for intrabody application. Knowledge of the above parameters becomes the basis for considerations related to the possibilities of choosing the appropriate polymer materials. The researchers' interest, as evidenced by the number of available publications, is attracted by nanobiocomposites based on chitosan and carbon nanotubes, which, due to their properties, enable integration with the tissues of the human body. Nanosystems can be used in many areas of medicine. They constitute an excellent base for use as dressing materials, exhibiting antimicrobial properties. In addition, they can be carriers of drugs and biological macromolecules, and can be used in gene therapy, tissue engineering and construction of biosensors. For this reason, potential application areas of chitosan-carbon nanotube nanocomposites in medical sciences are presented in this publication, considering the characteristics of the system components.
Exposure of genomic, single-stranded DNA (ssDNA) during transcription and replication creates opportunities for the formation of inappropriate secondary structures. CTG repeat has been shown to form stable secondary structures that are the cause of inherited human genetic disease related to the myotonic dystrophy. Here, we investigated the role of SWCNT and BNNT in preventing CTG repeat using molecular dynamics (MD) simulations. The assessment of the simulations reveals that the ssDNA undergoes rapid conformational changes and wrap around the SWNTs via π-stacking interactions between SWNT’s wall and the nucleobases of the ssDNA. The ssDNA is observed to spontaneously wrap around SWNTs into compact right-handed helice within a few nanoseconds. Helical wrapping is driven by the electrostatic and torsional interactions within the sugar−phosphate backbone that result in ssDNA wrapping from the 3′end to the 5′end. Our computations demonstrate that the binding strength of the ssDNA to the SWCNT is substantially greater than to the BNNT. These findings would enable providing new avenues for therapeutic interventions in of myotonic dystrophy and potentially other triplet repeat disorders.
Polymer nanocomposites formed by carbon nanofillers have many potential applications such as thermal energy management in high-density electronic packing. Although carbon nanofillers have excellent thermal and mechanical properties compared to the polymeric materials, in practice, the properties of PNCs exhibit only a minor enhancement compared to those of the neat polymer matrix. Previous literature has indicated that the weak interphase region between the carbon nanofiller and the polymer matrix leads to poor thermal conduction and hence the lack of significant property enhancement in nanocomposites. In this chapter, we will describe the use of atomistically detailed molecular dynamics (MD) simulations for investigating the effect of the carbon nanofiller–polymer interfacial region on the thermal properties of the PNCs. The use of finite-sized nanofillers in molecular simulations (compared to experiments) results in additional interfacial regions at the ends of the nanofillers and hence exacerbates the effects of the interphase in simulations. The discussion is presented in the context of two systems: (1) cross-linked epoxy–graphene nanosheet (epoxy-GNS) nanocomposite, and (2) cross-linked epoxy–carbon nanotube (epoxy-CNT) nanocomposite consisting of both infinite (no interphase at CNT end) and finite (interphase at both ends) CNTs. The thermal conductivities of these nanocomposite systems were determined using molecular simulations and were compared with the thermal conductivity of the neat cross-linked epoxy system. These thermal conductivity results are analyzed in the context of the volume fraction of the polymer–nanofiller interphase. A model is presented for quantifying the effect of the interfacial region on the overall rate of heat transfer in the polymer nanocomposite.
Nanodiamond (ND) surfaces were successfully modified using the ozone treatment and tetraethylenepentamine (TEPA) solution for use as reinforcement in epoxy nanocomposites. The main purpose of the project was to introduce ozone/TEPA-functionalized NDs within the epoxy matrix to improve its thermal conductivity and fracture resistance by enhancing interfacial interactions. To confirm the efficacy of the proposed method, ND/epoxy nanocomposites were fabricated with three types of ND (pristine ND, ozone-functionalized ND, and ozone/TEPA-functionalized ND) at different amounts; the ND contents were found to be optimal at 0.50 wt% for all of the nanocomposites developed in this work. With the addition of this amount of the ozone/TEPA-functionalized NDs, the thermal conductivity and fracture toughness of the nanocomposite were enhanced by 34.1 and 121.4%, respectively, compared with pristine ND. The related ND reinforcing mechanisms were also analyzed, and the enhancements of dispersion and interfacial properties can mainly be attributed to thermal and mechanical interlocking effects. The obvious advantage of this approach is that the ozone/TEPA-functionalized NDs can prevent the aggregation process of nanostructures, thereby demonstrating interface synergism within nanocomposites with the final outcomes of better thermal conductivity and fracture resistance within the epoxy matrices under an equivalent load.
The published and the authors’ own data on the methods of chlorination of the surface of diamond micropowders are critically assessed. The features of different methods of chlorination of detonation nanodiamond (DND) are compared; the optimum process conditions are revealed. The method of gas-phase chlorination with molecular chlorine at elevated temperatures is preferable when using DND in biomedical applications; this method also helps lower the concentration of metal impurities. The use of thionyl chloride and sulfuryl chloride results in the contamination of DND-Cl samples with sulfur. It is shown that the DND-Cl samples have satisfactory hydrolytic stability.
P>Background: In spite of considerable efforts of researchers the cancer deseases remain to be incurable and a percentage of cancer deseases in the structure of mortality increases every year. At that, high systemic toxicity of antitumor drugs hampers their effective use. Because of this fact, the development of nanosystems for targeted delivery of antitumor drugs is one of the leading problem in nanomedicine and nanopharmacy.
Objective: To critically examine the modern strategies for carbon nanotubes (CNTs)-based delivery of anticancer quinones and to summarize the mechanisms which can provide high effectiveness and multifunctionality of the CNT-based quinone delivery platform.
Results: Quinones, including anthracycline antibiotics – doxorubicin and daunorubicin, are among the most prospective group of natural and syntetic compounds which exhibit high antitumor activity against different type of tumors. In this review, we focus on the possibilities of using CNTs for targeted delivery of antitumor compounds with quinoid moiety which is ordinarily characterized by high specific interaction with DNA molecules. Quinones can be non-covalently adsorbed on CNT surface due to their aromatic structure and π-conjugated system of double bonds. The characteristic features of doxorubicine-CNT complex are high loading efficiency, pH-dependent release in acidic tumor microenviroment, enough stability in biological fluid. Different types of CNT functionalization, targeting strategies and designs for multifunctional CNT-based doxorubicine delivery platform are disscussed.
Conclusion: Nanosystems based on functionalized CNTs are very promising platform for quinone delivery resulting in significant enhancement of cancer treatment efficiency. Functionalization of CNTs with the polymeric shell, especially DNA-based shells, can provide the greatest affinity and mimicry with biological structures.</P
The era of carbon-based nanotechnology, as it is well-known, started from 1985 when the fullerene C60 was discovered. The rediscovery of carbon nanotubes and unexpected discovery of graphene gave a powerful impulse to the further development of carbon nanostructures. At present, these nanocarbons, as well as nanodiamonds or nanofibers, can already be considered as “conventional” carbon nanostructures.
Nanodiamond exhibits several unique properties of diamond on nanoscale and is
becoming one of the widely studied nanomaterials. Modification/functionalization
of nanodiamond and incorporation in polymers has opened several new doors for
advanced applications. Consequently, nanodiamond has been introduced in polymer
coatings to harness its valuable properties. Epoxy is one of the indispensable polymers
explored as coating materials. Epoxy/nanodiamond composite has been used
for producing thin and transparent nanodiamond-containing coatings. Several techniques
have been focused for manufacturing epoxy/nanodiamond nanocomposite
coatings such as solution casting, spraying, Doctor Blade, dip coating, spin coating,
or other approaches. One foremost hindrance for casting nanocomposite coatings is
the fine dispersion in epoxy matrix. Incidentally, nanodiamond particles have been
incorporated in epoxy resin using various mechanical, physical, and chemical methods.
A significant upsurge in mechanical properties (Young’s modulus, hardness,
toughness, abrasion), weatherability, corrosion resistance, scratch opposition, heat
stability, thermal conductivity, and other physical features of epoxy/ND composites
has been observed as compared to neat epoxy. Consequently, thin transparent
coatings with optimum loads of nanodiamond are well suited for high-performance
applications where a fine mishmash of mechanical, thermal, and dielectric properties
is required. Nanodiamond-modified epoxy nanocomposites have also been
employed in microwave absorbing, thermally conducting, and bioactive coatings.
Nanodiamonds (NDs) are specific carbon nanoparticles approximately 5 nm in diameter with a large and accessible surface containing functional groups. Poly(phenylene–isophtalamide) (PA)–ND composites were prepared by solid-phase dispersal and used for dense film formation. The PA–ND composites were analyzed by Fourier transform infrared spectroscopy. The membrane structure was determined on the basis of density measurement and morphological study by atomic force microscopy. The gas-transport properties were measured over a wide range of temperatures from 30 to 100 °C for the following series of penetrants: H2, N2, O2, and CO2. The experimental data of gas permeability were compared with the permeability values calculated from Maxwell's model. Data on the permeability and diffusion coefficients were used to calculate the activation energies. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46320.
Nanodiamond (ND)-based fluorescent probes have been extensively researched in cell imaging applications. Several outstanding properties of fluorescent NDs (FNDs), such as their excellent biocompatibility, intensive fluorescence and chemical stability in organisms, have made them the most promising carbon materials in biomedicine. However, the production of FNDs with nitrogen-vacancy defect centers was rather complicated and costly, which limited their wide application in the biomedical field. Moreover, the particle size of these types of FNDs was much larger than that of NDs produced by the detonation method; thus, it is difficult for them to penetrate the cell membrane. In this present work, a facile and ultrafast photo-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization was introduced for the fabrication of FND-based polymer composites. The photo-initiated RAFT polymerization is time saving, environmentally friendly and highly efficient. To prepare these FNDs, fluorescein was converted into diacryloyl fluorescein (AcFl), which was used not only as the photocatalyst but also a fluorescent comonomer. The functional monomer 2-methacryloyloxyethyl phosphorylcholine (MPC) was introduced to improve the water dispersibility of the FNDs. The successful fabrication of FNDs-polyMPC composites was proven by a series of characterization methods. These FNDs-polyMPC composites show high water dispersibility, strong fluorescence and low toxicity. The cell uptake behavior suggested that FNDs-polyMPC composites can be facilely internalized by cells. Taken together, FNDs-polyMPC composites can be fabricated by a photo-initiated RAFT polymerization. These FNDs-polyMPC composites possess excellent physicochemical and biological properties and are promising candidates for cell imaging applications.
The outstanding optical properties of diamond have enabled the development of waveguide materials with low absorption and scattering losses and transparency over a wide spectral window. Furthermore, diamond features a high refractive index, high thermal conductivity, high density, low thermal expansion, and extreme hardness and chemical resistance enabling harsh operating conditions, which render diamond a suitable material for a wide variety of optical sensing applications. In addition, the versatility in functionalization of diamond surfaces expands its utility toward optical chem/biosensors. In this chapter, different strategies for the fabrication and structuring of diamond waveguides are presented, as well as surface functionalization strategies. Finally, the applications of such waveguides in analytical spectroscopy are highlighted revealing the potential of this material for advanced chemical sensor and biosensor schemes.
Diamond, because of its electrical and chemical properties, may be a suitable material for integrated sensing and signal processing. But methods to control chemical or biological modifications on diamond surfaces have not been established. Here, we show that nanocrystalline diamond thin-films covalently modified with DNA oligonucleotides provide an extremely stable, highly selective platform in subsequent surface hybridization processes. We used a photochemical modification scheme to chemically modify clean, H-terminated nanocrystalline diamond surfaces grown on silicon substrates, producing a homogeneous layer of amine groups that serve as sites for DNA attachment. After linking DNA to the amine groups, hybridization reactions with fluorescently tagged complementary and non-complementary oligonucleotides showed no detectable non-specific adsorption, with extremely good selectivity between matched and mismatched sequences. Comparison of DNA-modified ultra-nanocrystalline diamond films with other commonly used surfaces for biological modification, such as gold, silicon, glass and glassy carbon, showed that diamond is unique in its ability to achieve very high stability and sensitivity while also being compatible with microelectronics processing technologies. These results suggest that diamond thin-films may be a nearly ideal substrate for integration of microelectronics with biological modification and sensing.
This is an introductory textbook for graduate students and researchers from various fields of science who wish to learn about carbon nanotubes. The field is still at an early stage, and progress continues at a rapid rate. This book focuses on the basic principles behind the physical properties and gives the background necessary to understand the recent developments. Some useful computational source codes which generate coordinates for carbon nanotubes are also included in the appendix.
Fluorinated armchair (10,10) and zigzag (18,0) single-wall carbon nanotubes (F-SWNT) of C2F stoichiometry with five different fluorine atom decorations are studied using density-functional theory and periodic boundary conditions. The most stable armchair F-SWNT isomers (1a and 5a) are metallic and have pi bond chains parallel to the tube axis. Isomer 5a carries every second fluorine atom inside the tube and is 5 kcal mol-1 more stable than 1a. Fluorinated zigzag tubes are not metallic. The isomer with helical zigzag conjugated pi bonds is the most stable zigzag F-SWNT, but is less stable than 1a. Depending on the fluorination pattern and the tube chirality, the band gaps of the F-SWNT's vary from 2.7 to 0 eV.
Carbon nanotubes were discovered soon after the successful laboratory synthesis of fullerenes. Since their discovery in 1991, there has been intensive research activity in the area of carbon nanotubes, not only because of their fascinating structural features and properties, but also because of their potential technological applications. There is increasing experimental evidence to show that carbon nanotubes may find use in nanoelectronic devices, displays, and in hydrogen storage. In this article, we discuss various important aspects related to the synthesis, structure, characterization, and mechanism of formation of multi-walled and single-walled carbon nanotubes, followed by a presentation of the important electronic, mechanical, hydrogen storage, and other properties of the nanotubes. Doping, as well as other chemical manipulations with boron and nitrogen, bring about significant changes in the properties of the nanotubes. Carbon nanotubes also serve as useful templates to make other nanostructures. Layered metal chalcogenides, boron nitride, and other materials form nanotubes and provide considerable scope for study.
Considerable improvement in the dispersion of purified single-walled carbon nanotubes (SWNTs) in an epoxy composite was obtained through functionalization of the SWNTs by using an optimized H2SO4/70% HNO3 acid treatment and subsequent fluorination. Epoxy composites containing 1 wt % nanotubes were processed by dissolving the functionalized SWNTs in dimethylformamide and mixing with the epoxy resin thereafter. The functionalized nanotubes were observed to be highly dispersed and well integrated in the epoxy composites. The enhancement of mechanical properties of the latter was indicated by a 30% increase in modulus and 18% increase in tensile strength. This work demonstrates the practical use of combining acid treatment and fluorination to achieve functionalization and unroping of SWNTs. The functionalized SWNTs can be integrated into epoxy composites through the formation of strong covalent bonds in the course of epoxy ring-opening esterification and curing chemical reactions.
Single-walled carbon nanotubes (SWNTs) with the N-alkylidene amino groups covalently attached to their side walls have been prepared starting from colloidal solutions of fluorinated SWNTs (fluoronanotubes) in terminal alkylidene diamines followed by heating at 70−170 °C. On the basis of data from thermal gravimetric and energy-dispersive X-ray analyses, the degree of SWNT functionalization achieved was estimated to be as high as 1 in 8 to 12 sidewall carbons. The demonstrated new C−N functionalization method provides a synthetic tool for binding amino acids, DNA, and polymer matrices to the side walls of the SWNTs as well as yields sidewall amino-functionalized nanotube precursors for the preparation of nylon−SWNT polymer materials.
Although boron-doped diamond (BDD) is itself quite stable and chemically inert, some electrochemical applications could require further improvement, and fluorination could be one of the most promising methods. In the present paper, a characterization of diamond film electrodes surface-modified by fluorine insertion, through CF4 plasma treatment, has been carried out. X-ray photoelectron spectroscopy (XPS) analysis showed that the above preparation method most probably leads to the fluorination of the near-surface region of the diamond film. The electrochemical characterization showed that the fluorination of BDD shifts the cathodic water decomposition by about 2 V in the negative direction; this behavior could not be ascribed to problems of film conductivity and/or to a decrease in electronic density of states. The electron-transfer kinetics for model redox couples such as the Eu3+/ Eu2+, Fe3+/Fe2+, and ferri/ferro cyanide redox systems has been found to be quite significantly affected by the surface modification, while the electrochemical behavior of methyl viologen remains practically unchanged. The exchange current densities for the aquo complexes are decreased about five times, while for the cyano complex of more than 3 orders of magnitude.
The reaction of nanoscale diamond (ND) powder with an elemental fluorine/hydrogen mixture at temperatures varying from 150 to 470 °C resulted in the high degree of ND surface fluorination yielding a fluoro-nanodiamond with up to 8.6 at. % fluorine content. The fluoro-nanodiamond was used as a precursor for preparation of the series of functionalized nanodiamonds by subsequent reactions with alkyllithium reagents, diamines, and amino acids. The fluoro-nanodiamond and corresponding alkyl-, amino-, and amino acid-nanodiamond derivatives were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), and thermal gravimetry-mass spectrometry (TG-MS) measurements. In comparison with the pristine nanodiamond, all functionalized nanodiamonds show an improved solubility in polar organic solvents, e.g., alcohols and THF, and a reduced particle agglomeration. The developed methodology provides an efficient method for the chemical modification of nanodiamond powder, which enables a variety of engineering and biomedical applications of ND derivatives.
Single-walled carbon nanotubes functionalized with the OH group-terminated moieties (“hydroxyl nanotubes”) have been prepared by fluorine displacement reactions of fluoronanotubes with a series of diols and glycerol in the presence of alkali, LiOH, NaOH, or KOH or with amino alcohols in the presence of Py as a catalyst. The “hydroxyl nanotubes” were characterized by optical spectroscopy (Raman, ATR-FTIR, UV−vis−NIR), electron microscopy (TEM), atomic force microscopy (AFM), and thermal degradation (TGA and VTP-MS) materials characterization methods. The degree of sidewall functionalization in the prepared SWNT derivatives was estimated to be in the range of 1 in 15 to 25 carbons, depending on derivatization method and alcohol reagent used. The hydroxyl nanotubes form stable suspension solutions in polar solvents, such as water, ethanol, and dimethylformamide, which facilitate their improved processing in copolymers and ceramics nanofabrication and provide for compatibility with biomaterials.
Strong interfacial bonding and homogenous dispersion have been found to be necessary conditions to take full advantage of the extraordinary properties of nanotubes for reinforcement of composites. We have developed a fully integrated nanotube composite material through the use of functionalized single-walled carbon nanotubes (SWNTs). The functionalization was performed via the reaction of terminal diamines with alkylcarboxyl groups attached to the SWNTs in the course of a dicarboxylic acid acyl peroxide treatment. Nanotube-reinforced epoxy polymer composites were prepared by dissolving the functionalized SWNTs in organic solvent followed by mixing with epoxy resin and curing agent. In this hybrid material system, nanotubes are covalently integrated into the epoxy matrix and become part of the crosslinked structure rather than just a separate component. Results demonstrated dramatic enhancement in the mechanical properties of an epoxy polymer material, for example, 30-70% increase in ultimate strength and modulus with the addition of only small quantities (1-4 wt.-%) of functionalized SWNTs. The nano tube-reinforced epoxy composites also exhibited an increased strain to failure, which suggests higher toughness.
Since their first observation nearly a decade ago by Iijima (Iijima S. Helical microtubules of graphitic carbon Nature. 1991; 354:56–8), carbon nanotubes have been the focus of considerable research. Numerous investigators have since reported remarkable physical and mechanical properties for this new form of carbon. From unique electronic properties and a thermal conductivity higher than diamond to mechanical properties where the stiffness, strength and resilience exceeds any current material, carbon nanotubes offer tremendous opportunities for the development of fundamentally new material systems. In particular, the exceptional mechanical properties of carbon nanotubes, combined with their low density, offer scope for the development of nanotube-reinforced composite materials. The potential for nanocomposites reinforced with carbon tubes having extraordinary specific stiffness and strength represent tremendous opportunity for application in the 21st century. This paper provides a concise review of recent advances in carbon nanotubes and their composites. We examine the research work reported in the literature on the structure and processing of carbon nanotubes, as well as characterization and property modeling of carbon nanotubes and their composites.
An overview of the various carbon structures with characteristic sizes
in the nanoscale region is presented, with special attention devoted
to the structures and properties of nanodiamond and carbon nanotubes.
The term nanodiamond is used broadly for a variety of diamond-based
materials at the nanoscale ranging from single diamond clusters to
bulk nanocrystalline films. Only selected properties of carbon nanotubes
are discussed, with an aim to summarize the most recent discoveries.
Current and potential applications of carbon nanostructures are critically
analyzed.
Published data on the properties of a novel nanomaterial viz., detonation
synthesis ultradispersed diamonds (UDD), are summarised and systematised
for the first time. Certain properties of UDD synthesised under different
conditions are compared. Particular attention is drawn to substantiation
of the cluster model of UDD and the fractal nature of their aggregates.
The potential application fields of UDD are considered. Operating
parameters of new materials are presented. The bibliography includes
110 references.
Nanophase materials — metals or ceramics with very small grain sizes — have been fairly disappointing. It was thought that small grains should result in much harder metals. It turns out that they are harder but also more brittle. We also hoped that ceramics with very small grains would be much stronger but that hasn't really been demonstrated yet. Yet there is still reason to expect that nanometre-scale composite materials might turn out to be better than conventional composites, such as the carbon fibre-epoxy composites used in high-performance aircraft. For example, we could use nanometre-sized fibres to strengthen a polymer matrix, and carbon nanotubes are now available in sufficient quantities to test this idea. When researchers met at a conference in Alaska, to discuss the challenge of making nanocomposites, it became clear that inputs from several fields will be needed to make it work.
This Account focuses on the most recent and systematic efforts in the area of functionalization chemistry of the single-wall carbon nanotubes (SWNTs) which utilizes direct fluorination for the preparation of "fluoronanonotubes" and their subsequent derivatization. The results obtained prove that the addition of fluorine drastically enhances the reactivity of the nanotube side walls. The use of this strategy as a versatile tool for preparation and manipulation of SWNTs with variable side-wall functionalities has been demonstrated. The functionalized SWNTs have shown an improved solubility in selected solvents and significantly altered electrical, mechanical, and optical properties. An overview of new synthetic methods for preparation and a discussion of characterization data for the functionalized SWNTs are provided.
Single-wall carbon nanotubes (SWNTs) and their fluorinated derivatives (F-SWNTs) were reacted with organic peroxides including benzoyl and lauroyl peroxide to produce phenyl and undecyl sidewall functionalized SWNTs, respectively, which were characterized by Raman, FTIR, and UV-Vis-NIR spectra as well as TGA/MS, TGA/FTIR, and TEM data.
The reactions of single-walled carbon nanotubes (SWNTs) with succinic or glutaric acid acyl peroxides in o-dichlorobenzene at 80-90 degrees C resulted in the addition of 2-carboxyethyl or 3-carboxypropyl groups, respectively, to the sidewalls of the SWNT. These acid-functionalized SWNTs were converted to acid chlorides by derivatization with SOCl(2) and then to amides with terminal diamines such as ethylenediamine, 4,4'-methylenebis(cyclohexylamine), and diethyltoluenediamine. The acid-functionalized SWNTs and the amide derivatives were characterized by a set of materials characterization methods including attenuated total reflectance (ATR) FTIR, Raman and solid state (13)C NMR spectroscopy, transmission electron microscopy (TEM), and thermal gravimetry-mass spectrometry (TG-MS). The degree of SWNT sidewall functionalization with the acid-terminated groups was estimated as 1 in 24 carbons on the basis of TG-MS data. In comparison with the pristine SWNTs, the acid-functionalized SWNTs show an improved solubility in polar solvents, for example, alcohols and water, which enables their processing for incorporation into polymer composite structures as well as for a variety of biomedical applications.
Heavily doped diamond films are quite actively studied for their promising applications in industrial as well as in fundamental electrochemistry (both for physicochemical studies and in the field of electroanalysis), because of their very high stability toward chemical and electrochemical oxidative attacks. Fluorinated diamond electrodes exhibit an exceptionally lower electrocatalytic activity toward reactions involving adsorbed intermediates, as a result of the F-termination of the surface dangling bonds. This feature allows the investigation of the widest range of potentials for an electrode material in aqueous solution, being limited only by the formation of free hydrogen [E degrees (H*/H2) = -2.3 V(SHE)] and hydroxyl [E degrees (*OH,H+/H2O) = 2.74 V(SHE)] radicals, at the two boundaries of the approximately 5-V polarization window.
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