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| TEM images of SiO 2 @PS core-shell precursors with different DVB contents. (a) SiO 2 @PS-0.5% DVB, (b) SiO 2 @PS-1% DVB, (c) SiO 2 @ PS-2.5% DVB, (d) SiO 2 @PS-5% DVB, (e) SiO 2 @PS-10% DVB, (f) SiO 2 @ PS-15% DVB. Styrene is 10 ml. The SiO 2 nanoparticles core is 130 nm. The mass of SiO 2 nanoparticles is 1.2 g. The scale is 200 nm.
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Fabrication of hollow microporous organic capsules (HMOCs) could be very useful because of their hollow and porous morphology, which combines the advantages of both microporous organic polymers and non-porous nanocapsules. They can be used as storage materials or reaction chambers while supplying the necessary path for the design of controlled upta...
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... from macro to microscale by changing the DVB contents 44 . Hence, to vary the porous structure of HMOCs, a series of precursor NPs (SiO 2 @PS- DVB) were prepared with different DVB contents (0.5, 1, 2.5, 5, 10 and 15 wt.% of styrene). It was observed that co-monomer (DVB) has a significant effect on the core-shell morphology of SiO 2 @PS-DVB NPs (Fig. 2). The SiO 2 @PS-DVB NPs with 0.5, 1 and 2.5% DVB exhibited eccentric SiO 2 cores, while the SiO 2 cores in SiO 2 @PS- DVB NPs with 5, 10 and 15% DVB were centric. By increasing the DVB contents, the SiO 2 @PS-DVB tended to have concentric core - shell morphology. By decreasing the DVB contents were low, the PS chains were weakly ...
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... of micelles which in turn decreases the number of polymer particle nuclei formed early in the reaction per unit time resulting in formation of polymer particles with smaller in numbers but larger in size 4 . It was also possible to change the size of hollow cavities of HMOCs (Fig. 3k and 3l) by using SiO 2 cores with different sizes (e.g. 200 nm, Fig. S19 and S20). The mass of SiO 2 nanoparticles is 1.2 ...
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... were also evaluated for their possible potential biomedical applications. Prior to that, the toxicity of HMOCs was investigated through an MTT assay, and cell viability of HepG2 cells was deter- mined in the presence of HMOCs (Fig. S21). HMOCs showed almost no cytotoxicity over the range of concentrations studied (0, 15.6, 62.5, 125, 250 and 500 mg/mL). As HMOCs are around 250 nm in diameter, usually they will be sequestered by phagocytotic cells of the spleen and eliminated from the body eventually 47 . Interestingly, these HMOCs were also found to be fluorescent, ...
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... found to be fluorescent, which may be useful for their applications in bio-imaging and bio-labeling. The origin of fluorescence in these HMOCs is not clear yet but it may be due the stacking of benzene rings and nanoscale size effect. The optical images of HMOCs under UV light in simulated body fluid (PBS, pH 5 7.4, buffer solution) are shown in Fig. S22. The emission Surface area calculated from nitrogen adsorption isotherms at 77.3 K using BET ...
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... micropore area./BET surface area*100%. spectra of HMOCs (Fig. S23-S28) indicate the emission peak at 590 nm when excited at 440 nm. In order to evaluate their applica- tion in a drug delivery system, in vitro drug loading and release experiments were performed with HMOCs having different pore structures using ibuprofen (IBU) as a model drug. Loading of the drug was achieved in IBU hexane solution, and ...
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... a model drug. Loading of the drug was achieved in IBU hexane solution, and the drug release rate was obtained by soaking the drug-loaded HMOCs in simulated body fluid (PBS, pH 5 7.4, buffer solution). The drug loading efficiency of HMOCs was calculated from the data obtained with UV-vis spectro- photometric and thermogravimetric (TG) analysis. In Fig. S29-S39, the weight loss at and above 450uC corresponds to the decomposition of HMOCs itself. But prior to that, the weight loss observed in the range of 180-230uC can be attributed due to the removal of IBU. As summarized in Table S2, HMOCs can uptake 1.68 to 2.04 g of ibu- profen/g, which is much higher than that (0.80 g of ibuprofen/g) ...
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... of Fe 3 O 4 nanoparticles within HMOCs cavities. It also implies that the HMOCs-Fe 3 O 4 NPs can retain magnetic properties in body fluid. Interestingly, 10% -HMOCs -2.5 ml -Fe 3 O 4 NPs also showed high drug uptake (2.04 of ibuprofen/g) and zero order kinetic model for drug release (Fig. S41), similar to 10% -HMOCs -2.5 ml (2.06 of ibuprofen/g, Fig. S42). The super-paramagnetic properties of 10% -HMOCs-2.5 ml-Fe 3 O 4 NPs were also maintained after drug loading, promising their potential application in the development of magnetically controlled drug delivery ...
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Citations
... Photocatalytic behavior of Knitted microporous polymer was observed by Zhang et al for-bromination reaction of electron enriched species [22] and showed efficient catalytical performance with ability of reutilization. Tan and its coworker studied the characteristics of HMOCs for IBU to investigate the loading capacity and found amount 1.68 to 2.04 of IBU per HMOCs from TGA and UV Visible spectrophotometry [23,24]. HCP is also used in sensing technology i.e. electrochemical humidity sensors (KAPs) was synthesized by Zhang et al by utilizing 3-hydroxybenzoic acid monomer [24]. ...
New Hyper cross-linked polymer (HCP) of Resorcinol (1, 3-dihydroxybenzol) “R-HCP” is synthesized using Friedel-Craft Reaction for the removal of cadmium metal ions from industrial wastewater. Real industrial wastewater samples are used to evaluate the adsorption capability of R-HCP. Fabricated R-HCP is characterized through Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), EDX (Energy dispersive x-ray spectroscopy) and BET (Brunauer–Emmett–Teller). The BET surface area of R-HCP is 221.5848m ² g − 1 .Through salt addition method, the point of zero charge (PZC) was also determined, and its value is 2.0 pH. The greatest adsorption value of 93% was obtained at pH 10 with 0.5 g of adsorbent, 9-minute contact time and favors exothermic reaction. Langmuir, Freundlich and Temkin isotherms were studied and results shows that Freundlich model is the best fit. Adsorption kinetics investigation shows that it follows pseudo first order kinetic model. Study of the effect of interfering ions including calcium, magnesium, sodium, and potassium demonstrate the decrease in adsorption capacity to little extent. R-HCP can be recycled and have regeneration capacity which is novel and distinguished feature of this adsorbent.
... However, these methods usually generate large spheres; thus, research to reduce the size of HCP spheres has become important. The Wu group [73] proposed an effective method for the fabrication of relatively small and monodisperse porous polymeric spheres. Solid spheres as small as 190 nm were prepared by the emulsion polymerization of divinylbezene (DVB) and styrene (St) followed by hypercrosslinking. ...
... The HCP based hollow spheres were firstly reported by the Tan's group [73] . The hollow HCP capsules were fabricated by using the SiO 2 as the template, and PS and DVB monomer were coated on the template by the emulsion polymerization followed by hypercrosslinked ( Fig. 5 a ). ...
... In this approach, the final morphologies are largely affected by the size and morphologies of the templates; however, the surface organic groups, hydrophilicity/hydrophobicity of the templates, and dosage and ratio of monomers are also important. For example, Tan et al. showed [73] that silica nanoparticles with a diameter of 130 or 200 nm could be used to generate HCPs with different interior cavities. In this method, the presence of 3-(trimethoxysilyl)propyl methacrylate moieties on the silica is important to ensure its further bonding with styrene and DVB to initiate polymerization on the surface. ...
... The hollow microporous capsules with meso-and microporous structures (Fig. 15c) displayed a regular first-order kinetic model, which indicated the release mechanism was adjusted by diffusion and the release rate was positively correlated to the amount of drug remaining in the cavity. In addition, they exhibited good biocompatibility and fluorescence feature, which ensured them as promising capsules for drug delivery [187]. ...
... The research hotspots mainly focus on two aspects as following: some new preparation approaches have been developed to control their porous structures and morphologies; introducing functional groups can enhance their adsorption performance and selectivity, such as polar group can adjust the selectivity of the HCMPS towards the adsorption of polar molecules. Of course, there are also numerous efforts focused on the different morphologies of HCMPS systems (e.g., monoliths [131,200], microparticles [201,202], nanoparticles [203,204], microspheres [193,205], hollow microporous organic capsules [187,199], membranes [60], etc), in this case, which is beneficial for enlarging their applicability and realizability in various fields. ...
... (c) Simulated ibuprofen molecules and different diffusion processes of release in micropores and mesopores. Reprinted with permission from Ref.[187]. ...
Hypercrosslinked microporous polystyrene (HCMPS) have recently achieved growing attention because of their advantages of diverse preparation methods, easily to be functionalized, large specific surface area, cheap reagents, mild reaction conditions, high chemical and thermal stability, and so on. Reasonable selection of polystyrene precursors, suitable length crosslinkers, and optimal reaction conditions can produce an advanced hypercrosslinked polymers with a controllable porous topology. In this review, we systematically summarize the fundamentals and synthetic strategies of HCMPS materials, outline their recent advances in various applications including gas storage, removal of pollutants, chromatographic separation, supports, and so on, and exhibit their diverse properties including porous structure, physi-cochemical properties, and positronium annihilation properties. In addition, the state-of-the-art advances , opportunities, challenges, and perspectives of HCMPS materials are also in-depth discussed. It is believed that the advanced HCMPS-based materials can realize diverse applications via unremitting efforts of scientific researchers.
... The nitrogen adsorption-desorption isotherm and corresponding pore size value were carried out to confirm the mesoporous nature of the Zein/M41. The lowest pore diameter value of Zein/M41 demonstrated that the pores on the bare materials had been packaged, further confirming the coexistence of Zein in the material [63]. However, the surface area of Zein/M41 continued to decrease to 290.32 m 2 · g −1 , lower than that of previously reported ordered NH2/M41, as showed in Table 1, indicating that the NH2/M41 was filled by or covered with the pore space of Zein. ...
This research provided a novel enzyme-responsive antimicrobial carrier aiming at overcoming the volatile loss of active antibacterial components, by employing mesoporous silica nanoparticles (MCM-41) as the matrix of encapsulation and Zein as the molecular gate. Since Zein could be consumed by bacteria, Zein-functionalized MCM-41 acted as an enzyme-responsive gate and improved the controlled-release capacity. The results showed that the amount of capsaicin released from Zein-functionalized MCM-41 without bacteria was quite low compared with the essential oils liberated with bacteria. This validated that the delivery of capsaicin was hampered by Zein and the existence of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) promoted the release of encapsulated cargo. The release rate of capsaicin in Zein-functionalized MCM-41 climbed with the growth velocity of bacteria. These functions were realized in the form of controlled diffusion of essential oils encapsulated in MCM-41 by electrostatic interaction, and Zein was performed by both covalent bonding interaction and electrostatic interaction. Zein-functionalized MCM-41 was 2.4 times more effective in killing E. coli and 1.2 times more effective in inhibiting S. aureus than an equal amount of free capsaicin, and possessed a long-lasting antibacterial activity. The responsive antimicrobial material might be used as a promising preservative in the food industry for antimicrobial activity enhancement.
... The highly porous structure of HCPs can allow drugs to be appropriately confined within the polymeric backbone, making them promising carriers for drug delivery. In this sense, HCP-based hollow microspheres containing silica nanoparticles were developed by Li et al., 90 using both polystyrene and divinylbenzene as precursors, which were able to tune the adsorption and thus the drug delivery capacity by carefully choosing the concentration of the silica nanoparticles (see the schematic preparation process of these hollow microspheres in Figure 8F and the actual SEM image in Figure 8G). Thus, the release of ibuprofen in simulated body fluid (37°C, pH 7.4) was evaluated, showing that at low concentrations of silica nanoparticles (0.5%−5%), ibuprofen can be released almost completely within a period of 25 h, whereas it is much faster (around 12 h) for higher concentrations (10%−15%), due to the presence of much smaller pores. ...
Hyper-crosslinked polymers (HCPs) are receiving great attention due to their high specific surface area, allowing them to offer high performance in many different applications. However, most of the time, their synthesis requires hazardous and time-consuming protocols, making their implementation and scaling up difficult. To overcome this problem, a relatively old technology such as mechanosynthesis (MS) has gained renewed interest as a greener and faster technology to produce HCPs, which involves much lower energy consumption during the reaction process. In this review, the latest advances on the performance of HCPs based on MS protocols are compiled and analysed, subdivided into those based on Friedel-Crafts alkylation, Scholl coupling reactions and other less common procedures. An analysis of MS versus solvent-based protocols regarding the twelve principles of green chemistry is also reported, as well as a section including a summary of the most recent applications of HCPs. Finally, the use of bio-based precursors for the formulation of HCPs is discussed, thus pooling knowledge for a greener, faster and more widely applicable future development of HCPs.
... So far, various adsorbent materials have been made with various properties and applications [3,19,22,23]. In the past few decades, microporous and mesoporous organic polymers have been widely used in gas separation and storage [24], sensor and catalytic reactions [25], chromatography [26], and drug delivery [27]. Porous organic polymers (POPs) are classified into different categories such as conjugated microporous polymers (CMPs) [28], covalent organic frameworks (COFs) [29], hypercrosslinked polymers (HCPs) [26], covalent triazine frameworks (CTFs) [30], and porous aromatics frameworks (PAFs) [31]. ...
In this investigation, a hypercrosslinked polymer based on polystyrene as an adsorbent was used for CO2 adsorption. Design of experiment with response surface methodology is considered to optimize the synthesis parameters for obtaining the maximum carbon dioxide adsorption capacity. The independent parameters including the crosslinker amount (mmol), synthesis time (h) and catalyst type (FeCl3 and AlCl3) and adsorption capacity (mg/g) are considered as the dependent parameter in design of experiment method. The optimum values of crosslinker amount, synthesis time, and catalyst type to maximize adsorption capacity achieved 17.7 mmol, 14.6 h, and FeCl3, respectively. Additionally, isotherm and kinetic modeling were carried out to determine the adsorbent behavior. The results showed that Hill and Elovich models have a better precision between other isotherm and kinetic models. Finally, thermodynamic modeling was accomplished using the optimized adsorbent and the results show that physisorption is the main of CO2 adsorption by polystyrene-based adsorbent. The values of − 13.498 kJ/mol, − 0.018 kJ/mol.K, and − 8.224 kJ/mol were obtained for enthalpy differences, entropy differences, and Gibbs free energy change at 293 K and 5 bar, respectively.
... MSN are a class of materials widely investigated for several applications, ranging from energy storage, 7,8 water and air purification, [9][10][11][12][13][14] catalysis 15,16 optoelectronics, 17 drug delivery 18,19 or smart release of active agents. [20][21][22] For coating applications, MSN have several advantages, such as a chemically stable structure, low reactivity and compatibility with numerous matrices. ...
Mesoporous silica nanoparticles (MSN) have attracted increasing interest for their applicability as smart nanocarriers of corrosion inhibitors, due to their porous structure, resistance to main corrosive environments and good compatibility with polymer coatings. In this review, the main synthetic routes to obtain MSN with tailored textural properties, the design of different loading and stimuli-induced release strategies, the development of advanced organic nanocomposite coatings with MSN and the validation of their anticorrosive performances are reviewed and compared. Through a critical analysis of the literature, the most promising research trends and perspectives to exploit the highly interesting properties of MSN in advanced organic coatings are proposed.
... In the template method for fabricating of the HCPs, we should precisely choose a suitable template with the ordered and qualified shapes. Thus far, various materials such as silica [26][27][28], graphene [29], Fe 3 O 4 [30,31], gold [32], and ZnO [33] are all used as the hard template to control the morphologies of HCPs. The hollow structure is the most fascinating morphologies. ...
... Tan et al. firstly reported synthesizing of the hollow spheres and hollow rods by using the template method ( Figure 3a). The spherical and rod-liked silica were firstly synthesized and modified with characteristic groups, the polymerization and crosslinking process were further induced to the surface of modified silica [27,28]. The spherical and rod-liked HCPs were generated by etching with the HF to remove the silica template, main problems with this method are the waste of hard templates, and the possible danger in the use of toxic HF acid. ...
... With the advancement of synthetic approaches, a fine-tuning over the morphology and molecular orientation in POPs synthesis are increasingly receiving attention owing to their significant influence on the porosity and functionality. Most of the studies on the morphology controlled molecular design of hyper-cross-linked POPs have resulted in nanobead or nanosphere morphologies [25,26]. Recently, Jiang and coworkers proposed a series of 1D HCP nanotubes [23] and our group designed a guided assembly of well-defined nanoporous polymers by the acid-base interaction, facilitating the morphologies from nanotubes to hollow nanospheres and even polymeric nanosheets [27]. ...
Morphological diversity and porosity of porous organic polymers (POPs) exert vital influence on their potential applications. Herein, we demonstrate the morphology and porosity design of biphenyl-based hyper-cross-linked porous organic polymers by using a Lewis acid catalyzed Friedel–Crafts polymerization in the presence of formaldehyde dimethyl acetal (FDA) as cross-linker. The chemical composition of POPs is tunable by simply varying monomer to FDA ratio, leading to considerable morphological diversity such as the nanospheres, nanofibers, and flower-like nanostructures. High specific surface areas with mostly microporous nature, stable organic frameworks and tunable morphologies coupled with facile synthetic protocol let the hyper-cross-linked polybiphenyl (HCPbPh) based POPs exhibit the outstanding adsorption capacity and efficiency towards p-cresol based pollutant. The obtained carbon materials by direct pyrolysis of corresponding POPs can be used as the electrode materials for supercapacitors, exhibiting outstanding electrochemical performance with specific capacitance up to 421 F g⁻¹ at 1 A g⁻¹, and capacitance retention of 97% even after 10,000 cycles at 12 A g⁻¹. This methodology delivers a new platform for the fabrication of microporous and mesoporous materials for various potential applications including energy storage, adsorption, and catalysis.
... 36−44 However, generation of hollow porous polymers is challenging; for example, initial template synthesis (e.g., silica) and postcorrosive liquid removal (e.g., HF and NaOH) are requisite processes for generating hollow polymer structures using the hard template approach. 45,46 Further, the soft-template strategy involves a tedious precursor synthesis procedure. 47,48 Although some template-free methods have been reported, they require harsh conditions such as extreme pressure and temperature for generating HPCs. ...
This study presents an efficient and systematic approach to synthesize bioapplicable porous hollow polymeric capsules (HPCs). The hydroxyl-functionalized nanoporous polymers with hollow capsular shapes could be generated via the moderate Friedel-Crafts reaction without using any hard or soft template. The numerous primitive hydroxyl groups on these HPCs were further converted to carboxyl groups. Owing to the abundance of highly branched carboxyl groups on the surface of the HPCs, biomolecules [such as folic acid (FA)] could be covalently decorated on these organic capsules (FA-HPCs) for drug delivery applications. The intrinsic hollow porosities and specific targeting agent offered a maximum drug encapsulation efficiency of up to 86% and drug release of up to 50% in 30 h in an acidic environment. The in vitro studies against cancer cells demonstrated that FA-HPCs exhibited a more efficient cellular uptake and intracellular doxorubicin release than bare HPCs. This efficient approach to fabricate carbonyl-functionalized hollow organic capsules may open avenues for a new type of morphological-controlled nanoporous polymers for various potential bioengineering applications.
