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![Molecular structure of a cellulose unit, showing the β 1-4 glucosidic bond and the intrachain hydrogen bonding (dotted line) (Adapted from [3]).](profile/Matheus-Poletto/publication/270646609/figure/fig1/AS:295069560131584@1447361473409/Molecular-structure-of-a-cellulose-unit-showing-the-b-1-4-glucosidic-bond-and-the.png)
Molecular structure of a cellulose unit, showing the β 1-4 glucosidic bond and the intrachain hydrogen bonding (dotted line) (Adapted from [3]).
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Context 1
... is a natural polymer consisting of ringed glucose molecules. The repeat unit showed in Figure 1 is comprised of two anhydroglucose rings (C6H10O5)n, linked together through an oxygen covalently bonded to the C1 of one glucose ring and the C4 of the adjoining ring (1 → 4 linkage) and so called the β 1-4 glucosidic bond [2][3]. The degree of polymerization, n, varies between 10 000 and 15 000, where n is dependent on the cellulose source material [3,7]. ...
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... can be seen in Figure 1, each repeating unit contains three hydroxyl groups. These hydroxyl groups and their ability to make hydrogen bonds between cellulose chains govern the physical properties of cellulose [7]. ...
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... the hydroxyl groups being equatorial to the cellulose ring plane, intra-and inter-chain hydrogen bonding is most prevalent within the (110) plane in the triclinic structure and within the (200) plane in the monoclinic structure, hence the name " hydrogen-bonded" plane [3]. On the other hand, intrachain hydrogen bonding is dominated by strong O3- H···O5 bonds [1,3], as shown in Figure 1. ...
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... linear fits showed correlation coefficient (r) values close to unity (minimum 0.9878 and maximum 0.9998) with a confidence interval of 95%. Figure 10 shows the activation energy values for the CEG and CPT samples in the conversion range of 0.2-0.8. In Figure 10 it is seen that the Ea values decrease progressively as the degradation process occurs for both celluloses studied. ...
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... linear fits showed correlation coefficient (r) values close to unity (minimum 0.9878 and maximum 0.9998) with a confidence interval of 95%. Figure 10 shows the activation energy values for the CEG and CPT samples in the conversion range of 0.2-0.8. In Figure 10 it is seen that the Ea values decrease progressively as the degradation process occurs for both celluloses studied. The activation energy Ea varies between 210-165 and 178-140 kJ/mol for the CEG and CPT samples, respectively. ...
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... determine the Z(α) experimental values the heating rate (β) of 10 °Cmin -1 was used. The theoretical and experimental curves corresponding to these mechanisms are shown in Figure 11. The experimental data for the CEG sample in the conversion range of α = 0.2 -0.4 overlapped on the Dn mechanism and according to the literature these degradation mechanisms refer to the diffusion processes in one, two and three dimensions, respectively [23,28]. ...
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Citations
... X-ray diffraction (XRD) patterns of all samples were collected using a Philips PW 1050 powder diffractometer (scanning technique: step size = 0.05, counting time = 5 s/step) with Ni filtered Cu Kα radiation (λ = 0.1542 nm). The average crystallite size D (nm) was determined from XRD patterns according to the Scherrer equation Eq. 1 [13]: ...
... where k is a constant equal to 0.94, λ is the wavelength of the X-rays equal to 0.1542 nm, ꞵ is the fullwidth at half-maximum of the X-ray diffraction peak at θ, the Bragg angle of the peak. The Z-value which indicates whether cellulose is Iα (Z>0) or Iβ (Z<0) was calculated from Eq. 2 [13]: ...
... where d1 is the d-spacing of the Iβ (1-10) lattice plane and d2 is the d-spacing of the Iβ (110) lattice plane. The crystalline index (Cr.I.) was calculated using the empirical method proposed by Segal Eq. 3 [13]: ...
Non-woven jute (NWJ) produced from the carpet industry waste was oxidized by H2O2 or alkali treated by NaOH and compared with water-washed samples. Changes in the structure of the NWJ, tracked by XRD, showing that both chemical treatments disrupt hydrogen bond networks between cellulose Iβ chains of the NWЈ fibers. Thereafter, nano carbon nitride (nCN) was impregnated, using layer-by-layer technique, onto water washed jute sample (nCN-Jw), NaOH treated sample (nCN-Ja) and H2O2 treated sample (nCN-Jo). Analysis of the FTIR spectra of the impregnated samples, revealed that nCN anchors to the water washed NWЈ surface through hemicellulose and secondary hydroxyl groups of the cellulose. In the case of chemically treated samples nCN is preferentially bonded to the hydroxymethyl groups of cellulose. The stability and reusability of nCN-J samples were assessed by tracking the photocatalytic degradation of Acid Orange 7 (AO7) dye under simulated solar light irradiation. Results from up to ten consecutive photocatalytic cycles demonstrated varying degrees of effectiveness across different samples. nCN-Jo and nCN-Ja samples exhibited declining effectiveness over cycles, attributed to bond instability between CN and jute. In contrast, the nCN-Jw sample consistently maintained high degradation rates over ten cycles, with a dye removal percentage constantly above 90%.
... Inside the crystalline regions, cellulose chains form robust and complex intra-and intermolecular hydrogen bonds acting as the cohesion among cellulose molecules, while in the amorphous 2 domains, distribution occurs uniformly along fascinatingthe microfibers. [9,10]. The stability and compactness of the cellulose fiber arise from intra-and interchain hydrogen bonds, forming a network that significantly contributes to cellulose's insolubility in both organic and non-organic solvents. ...
Molecular dynamics simulations were performed to examine the impact of temperature (ranging from 250K to 350K) on the structural behavior of cellulose chains when dissolved in an aqueous cuprammonium hydroxide Cuam solvent system. By monitoring the root mean square deviation (RMSD) and radius of gyration (Rg) values at each temperature, we found that the geometric deformation of the cellulose chains changed significantly at T=300K. In contrast, Rg and RMSD values remained stable at temperatures in the range of 250K, 270K and the range of 330K, 350K. Calculating the interaction energy between the solvent and cellulose chains revealed that temperature significantly influences the cellulose dissolution process in the Cuam solvent system and that T=300K is an efficient temperature for its dissolution. The number of intra- and interchain hydrogen bonds was also calculated as a function of temperature, and the analysis confirmed that there is no breakage of these bonds at temperatures below 300 K (i,e: 250K, 270K) and above 310 K (I,e, : 330K and 350K) either between two native chains or between a native chain and another derivative.
... In the crystalline regions, the cellulose chains are joined together by complex intraand intermolecular hydrogen bonds, forming the basis of cohesion between the cellulose chains. In contrast, in the amorphous domains, the cellulose chains are distributed homogeneously along the microfibers [9,10]. The intra-and interchain hydrogen bonds give the cellulose fiber a stable and compact structure, while the network of hydrogen bonds is one of the main factors of its insolubility in organic and inorganic solvents and its resistance to decomposition by microbial and enzymatic agents [1,11]. ...
... On the other hand, the In the crystalline regions, the cellulose chains are joined together by complex intra-and intermolecular hydrogen bonds, forming the basis of cohesion between the cellulose chains. In contrast, in the amorphous domains, the cellulose chains are distributed homogeneously along the microfibers [9,10]. The intra-and interchain hydrogen bonds give the cellulose fiber a stable and compact structure, while the network of hydrogen bonds is one of the main factors of its insolubility in organic and inorganic solvents and its resistance to decomposition by microbial and enzymatic agents [1,11]. ...
Cellulose is a biopolymer with numerous advantages that make it an ecological, economical, and high-performing choice for various applications. To fully exploit the potential of cellulose, it is often necessary to dissolve it, which poses a current challenge. The aqueous zinc oxide/sodium hydroxide (ZnO/NaOH/Water) system is a preferred solvent for its rapid dissolution, non-toxicity, low cost, and environmentally friendly nature. In this context, the behavior of cellulose chains in the aqueous solution of ZnO/NaOH and the impact of temperature on the solubility of this polymer were examined through a molecular dynamics simulation. The analysis of the root means square deviation (RMSD), interaction energy, hydrogen bond curves, and radial distribution function revealed that cellulose is insoluble in the ZnO/NaOH solvent at room temperature (T = 298 K). Decreasing the temperature in the range of 273 K to 268 K led to a geometric deformation of cellulose chains, accompanied by a decrease in the number of interchain hydrogen bonds over the simulation time, thus confirming the solubility of cellulose in this system between T = 273 K and T = 268 K.
... Figure 5a shows that Iα is a monoclinic structure containing one cellulose chain, and Figure 5b shows that Iβ is a triclinic structure with two cellulose chains. The main difference between Iα and Iβ is the relative displacement of cellulose along the (101) lattice plane in the triclinic structure and the (200) monoclinic structure, called the hydrogen bond [24,39]. ...
Nanocrystalline cellulose (NCC) from natural Agave sisalana (Sisal) fibers were isolated using a combination of chemical and mechanical processes. The chemical treatment begins with soaking the fiber in a sodium hydroxide (NaOH) solution with a concentration of 5 wt.% at a temperature of 90°C for 60 minutes. Then following by bleaching (fiber refining) using a hydrogen peroxide solution (H2O2) with a concentration of 3 wt.% (weight), at a temperature of 60°C, and pH of 10 for 30 minutes. It aims to eliminate the presence of hemicellulose and lignin contained in the fiber. Fibrillation Micro into nano Sisal fibers using sulfuric acid (hydrolysis process). Sulfuric acid (H2SO4) with 55 wt.% at temperature 60°C for 30 minutes produced NCC with a diameter of 5±1 nm (D) and a length of 260±10 nm (L), as seen using a TEM (transmission electron microscope). The web-like network structured shape of NCC results in a high aspect ratio (L/D) value is 52. The acid hydrolysis-ultrasonication process produced a high crystallinity index of 78.82% through the XRD (x-ray diffraction) test. The crystallinity and aspect ratio of NCC show that Sisal fiber is a suitable material as a filler for bio-nanocomposite materials. The maximum temperature (Tmax) of NCC decreased by 10°C due to sulfate ions attached to the cellulose structure, causing the thermal stability to drop from 348°C to 338°C.
... This is likely because there are more hydrogen bonds between the chains of cellulose, which can result in more organized and packed cellulose areas. This could raise the temperature at which cellulose decomposes [17]. Jackfruit peel-derived cellulose started to degrade at 188ºC which is comparable to the result of Gajera and Panwar [18], where the decomposition started at 180ºC.However, if compared, it can be seen that commercial cellulose has a higher degradation temperature, which can be attributed to the absence of hemicellulose and lignin, thus indicating the lower purity of the extracted cellulose. ...
... Depending on the antioxidant used, the fabric samples became hydrophilic or hydrophobic. It is also of importance that cotton decomposition occurs above 240-250 • C [24]. ...
Cotton and poly(ethylene terephthalate) (PET) woven fabrics were coated with graphene oxide (GO) using a padding method and the GO deposited on the fiber surfaces was thermally reduced to impart electrical conductivity to the fabrics. To assist the thermal reduction of GO, quercetin (Q)—a natural flavonoid—was used. To this end, before the reduction, the GO-padded fabrics were immersed in Q solutions in ethanol with different Q concentrations. Q enhanced the thermal reduction of GO. Depending on the Q concentration in the solutions, electrical surface resistivities of the cotton fabric of 750 kΩ/sq to 3.3 MΩ/sq and of the PET fabric of 240 kΩ/sq to 730 kΩ/sq were achieved. The cotton and PET fabrics also became hydrophobic, with water contact angles of 163° and 147°, respectively. In addition to the electrical conductivity, the presence of Q resulted in antibacterial activity of the fabrics against Escherichia coli and Staphylococcus aureus.
... All of the polymers tested in this study contain cyclic structures. The cellulose-based polymers contain an anhydroglucose ring [26][27][28], while polysulfone contains an aryl functional group that is derived from an aromatic hydrocarbon ring (C 6 H 6 ) [29]. It is noteworthy that the aryl group has an intrinsically higher chemical resistance to modification, thus allowing one to assess the plasma capability in altering such materials. ...
This study’s aim is a comparison of the plasma-induced effects on polymers exposed in helium and argon gaseous environments in a pulsed dielectric barrier discharge at atmospheric pressure. Cellulose-based and synthetic polymers are tested with regard to a range of parameters, such as wettability, adhesion, surface energy and polarity, the oxygen amount in their structure, and surface morphology. The surface properties are analyzed by contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy images. The results point to the efficient and remarkably stable modifications of the plasma-exposed surfaces, such as their enhanced adhesion, surface energy, and oxygen incorporation. Additionally, plasma provides significant oxygen uptake in cellulose-based materials that bear already prior to treatment a high amount of oxygen in their structure. The comparison between the properties of the non-permeable, homogeneous, smooth-surface synthetic polymer and those of the loosely packed, porous, heterogeneous cellulose-based polymers points to the different rates of plasma-induced modification, whereby a progressive alteration of cellulosic surface properties over much larger ranges of exposure durations is noted. Present experimental conditions ensure mild treatments on such sensitive material, such as paper, and this is without alterations of the surface morphology and the physical degradation of the material over a large range of treatment duration.
... The Iβ unit cell parameters are a = 0.778 nm, b = 0.820 nm, c = 1.038 nm and γ = 96.5° (Poletto et al. 2013). As shown in the Fig. 10 b, there are two cellulose chains in one Iβ unit cell. ...
... XRD pattern of milled UC. Insert pictures are a a schematic diagram of the unit cell for cellulose Iβ (cotton) and b displacement of cellulose sheets within the crystal structure (Fig. 9bis republished from Poletto et al.(Poletto et al. 2013) ...
Rather than landfilling or incineration, value exists in textile wastes that should be recovered. Cotton is a major component of apparel and other textile materials that could find new value by extracting it from textile waste in the form of cotton fiber fragments (CFFs). To explore this potential, CFF properties were analyzed and compared after producing them from model undyed and fiber reactive dyed textile waste fabrics by mechanical milling or enzymatic degradation. Characterization methods included scanning electron microscopy (SEM), optical microscopy, fiber quality analysis, degree of polymerization (DP), X-ray diffraction, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. Enzyme-treated undyed CFFs exhibited distinct properties of flattened fiber fragment dimensions, a more uniform fiber length distribution compared to other CFFs, a DP comparable to solvent-spun regenerated cellulose fibers from cotton, the highest crystallinity of all CFFs tested, greater hydrophobicity than milled cotton reference material, and better thermal stability than milled reference cotton. The effects of mono-functional and bi-functional reactive dyes on enzyme degradation behavior and final product characteristics were also evaluated and discussed. Both dyed and undyed CFFs show good potential for being utilized in diverse applications. This analysis of the properties of partially degraded cotton fibers provides a necessary technical foundation for promoting CFF recycling for use in applications such as composites and regenerated fibers, and provides insights on the mechanism by which cotton disintegrates in the presence of enzymes to potentially inspire new strategies for dyeing cotton that takes a designed for recycling perspective into account.
Graphical Abstract
... The findings demonstrated a substantial connection between the nanoclay and the wood's chemical components. Looking at the peaks of FTIR spectroscopy, cellulose, hemicellulose, and lignin were changed by the processing (Wada 1967;Poletto et al. 2013). When compared to the control group, the peak created in the 2910 cm -1 band was lower. ...
This study aimed to evaluate the effects of brutian pine (Pinus brutia Ten.) wood impregnation with nanoclay in different concentrations on the chemical and thermal changes, and their impact on the physical and mechanical properties. The samples were impregnated with nanoclay in concentrations of 1%, 3%, and 5%, for 2, 24, and 48 h. Fourier transform infrared spectroscopic analysis revealed a shift in the typical peaks of cellulose, hemicellulose, and lignin depending on the impregnation time and nanoclay ratio. Thermogravimetric analysis and the limiting oxygen index indicated that the samples impregnated with clay solutions exhibited higher thermal stability than the unimpregnated wood. Impregnation with nanoclay caused a decrease water absorption and thickness swelling of the sample groups. The modulus of elasticity, modulus of rupture, and compression strength strength values of samples were improved via impregnation. In conclusion, the applied nanoclay are suitable substances to increase the durability and thermal stablity of brutian pine wood.
... Another central structural aspect is related to the size of the crystalline domains, since the different crystallite sizes affect the thermal degradation temperature of natural fibers (Poletto et al. 2013). One of the most common ways to evaluate the crystal quality is based on the Scherrer's equation on the (200) main reflection that gives the correlation between the size of the crystalline domains and the Full Width at Half Maximum (FWHM) (Patterson 1939): ...
This study aimed to exploit two invasive plant species to develop a novel, multifunctional, bioactive wound dressing based on a microporous cellulosic sponge (CS) from Gleditsia triacanthos pods and functionalizing them with Phytolacca americana fruit extract. The CS was functionalized, lyophilized, and characterized by Attenuated total reflectance–Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, contact angle, water absorption, and retention capacity. In addition, two parameters were evaluated in temporal dynamics: controlled release of phenolic compounds and antioxidant activities. The hemolytic index, blood clotting kinetics, lactate dehydrogenase release, and wound scratch assays proved their hemo- and biocompatibility, as well as their ability to promote cell proliferation and migration promoting-activity and to inhibit microbial growth. Furthermore, the obtained spongious material exhibited an anti-inflammatory effect by modulating the macrophages’ secretion profile of IL-6 and IL-10. In conclusion, the microporous cellulosic sponge obtained from G. triacanthos could be used as a vehicle to ensure the controlled release of bioactive principles with pro-wound healing activities extracted from invasive plants.
Graphical abstract
