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The hydrophobic and spherical PDVB-x-MeCN (x: molar ratio of p-styrene sulfonate/divinylbenzene; x=0.0, 0.1, 0.3, 0.5, and 1.0) catalyst was synthesized via polymerization and the ion-exchange process. Moreover, the hydrophobic property of PDVB-x-MeCN with high contact angles (> 124.0∘) was directly observed with a contact angle analyzer. The most appropriate x value of PDVB-x-MeCN for free fatty acid (FFA) removal and biodiesel production was 0.5, which was identified with gas chromatography (GC). During a 6-h transesterification-esterification, FFA removal and biodiesel yield of PDVB-0.5-MeCN reached 83.2% and 83.3%, respectively, at a ratio 45/1 (v/v) of methanol/palmitic acid mixture, approaching that of the Amberlyst 15 ones (83.4%). On the basis of these results, waste oils containing FFA can be transesterified efficiently from triglycerides and FFA into biodiesel.

In the present work, the effect of divinylbenzene (DVB) on the kinetics of post-radiation chemical graft polymerization styrene (St) on polyethylene (PE) film and its structural and morphological features were investigated. It has been found that the dependence of the degree of polystyrene (PS) grafting on the DVB concentration in the solution is extreme. An increase in the rate of graft polymerization at low concentrations of DVB in the solution is associated with a decrease in the mobility of the growing chains of PS. A decrease in the rate of graft polymerization at high concentrations of DVB is associated with a decrease in the rate of diffusion of St and iron(II) ions in the cross-linked network structure of macromolecules of graft PS. A comparative analysis of the IR transmission and multiple attenuated total internal reflection spectra of the films with graft PS shows that graft polymerization of St in the presence of DVB leads to the enrichment of the film surface layers in PS. These results have been confirmed by the data on the distribution of sulfur in these films after sulfonation. The micrographs of the surface of the grafted films show the formation of cross-linked local microphases of PS with fixed interfaces.

In this work, we successfully synthesize the core-shell structure carbon@titanium dioxide (C@TiO2) composite microspheres with wrinkled surface through a three-step method and build up the relationship between the TiO2 layer thickness and the microwave absorption property. The absorbing mechanism of the novel microsphere is revealed. Interface polymerization is applied for preparation of wrinkled poly glycidyl methacrylate/divinylbenzene polymer microspheres (PGMA/PDVB); Then, TiO2 layer is controllably coated on the surface of PGMA/PDVB microspheres by hydrolysis of tetrabutyl titanate (TBT); C@TiO2 composite microspheres are obtained by vacuum carbonization with PGMA/PDVB@TiO2 microspheres as the precursor. TiO2 layer thickness on the surface of C@TiO2 composite microspheres can be effectively adjusted by controlling the amount of TBT. When the amount of TBT is 0.75 mL, C@TiO2 composite microspheres exhibit the outstanding electromagnetic loss performance. The maximum reflection loss value (RLmax) reaches -49.21 dB at the thickness of 2 mm, corresponding effective absorption bandwidth is 5.27 GHz. The maximum effective absorption bandwidth is 5.5 GHz at 2.2 mm. The results show that the introduction of TiO2 can regulate electromagnetic parameters and enhance interface polarization ability. Meanwhile, the surface wrinkle structure offers more opportunities for multiple reflections of electromagnetic and introduces a large number of defective skeleton structure. The synergy of multiple advantages makes the absorbing performance of C@TiO2 composite microspheres significantly improved. This work plays a guiding role for the composition and the structure optimization of existing microwave absorbers.

The fabrication of chemically stable and high-permeance polymeric membranes, compatible with both polar and nonpolar solvents, for use in solvent filtration is reported. Herein, poly(divinylbenzene...

The synthesis of glycerol carbonate from glycerol and dimethyl carbonate in the presence of strongly basic styrene-divinylbenzene anionites Dowex 1×2, Dowex 1×4 and Dowex 1×8 in the –OH form with different cross-linking degree of polystyrene matrix (the divinylbenzene content of 2, 4 and 8 wt.%) at 90–105 °C and a dimethyl carbonate/glycerol molar ratio equal to 2 was studied. The yield of glycerol carbonate was shown to decrease with an increase in the cross-linking degree of the anion-exchange resin. The maximum conversion of glycerol (95 %) and selectivity to glycerol carbonate (45.5 %) were observed in the presence of Dowex 1×2 at 105 °C after 5 h of the reaction. Advantages of the studied systems were demonstrated in comparison with the anion-exchange and cationexchange resins proposed in the literature.

In this work, we develop a novel synthetic strategy for wrinkled magnetic composite microspheres (Fe3O4@C). Firstly, hydrophobic oleic acid modified Fe3O4 (OA-Fe3O4) nanoparticles acted as the magnetic component are prepared by synchronous modification coprecipitation method. The macromolecular emulsifier with initiating activity is obtained by means of soap-free emulsion polymerization under the presence of 1,1-diphenylethylene (DPE). Then, interfacial polymerization is employed to synthesis Fe3O4@polymethylglycidyl ester/divinylbenzene composite microspheres (Fe3O4@PGMA/DVB). Fe3O4@C composite microspheres are obtained by vacuum carbonization of the microspheres. The effect of magnetic content on the microwave absorbing properties of Fe3O4@C composite microspheres is explored. The results show that Fe3O4@C composite microspheres exhibit the excellent application performance at the Fe3O4 content of 0.15 g. The reflection loss can reach −53.7 dB at only thickness of 1.7 mm. The Maximum effective absorption bandwidth is up to 5.26 GHz with a thickness of 1.9 mm. The microwave attenuation mechanism of Fe3O4@C composite microspheres is revealed. The excellent absorbing performance is attributed to the enhanced interfacial polarization ability, the surface wrinkled structure and the good synergy between dielectric and magnetic losses. This work provides an effective strategy for the design and preparation of new magnetic composite materials.

INTRODUCTION Hydrogen is the most efficient and economical carrier gas for gas chromatography (GC). However, there are rare reports of artefact formation by hydrogenation of unsaturated compounds on GC. Head space solid-phase microextraction (HS-SPME) GC conditions for hydrogenation were studied. METHODOLOGY HS-SPME-GC-mass spectrometry (MS) analyses of common classes of plant volatiles were carried out using hydrogen (H2 ) and helium (He) carrier gases with different SPME fibre coatings, GC inlet temperatures, and desorption times. RESULTS Common phenylpropanoids, monoterpenes, and green leaf volatiles were hydrogenated to varying degrees on HS-SPME-GC with H2 carrier gas and SPME fibres coated with polydimethylsiloxane (PDMS)/Carboxen (CAR), PDMS/divinylbenzene (DVB), and PDMS/CAR/DVB. No artefacts were detected using PDMS-only coated fibres or He carrier gas. CONCLUSION Unsaturated plant volatiles may be hydrogenated on HS-SPME-GC when using H2 carrier gas with SPME fibre coatings containing DVB polymer or CAR porous particles. Parallel analyses with He and H2 carrier gases are recommended when developing HS-SPME-GC methods for plant volatiles, or use of PDMS-only coated fibres.

Volatile compounds produce the aroma of fruits such as melons (Cucumis melo) and therefore play a key role in fruit quality. Here, we optimized experimental parameters to evaluate the effect of blending time, extraction temperature and time, different fibers, sample weight, different columns, and salt on the volatile composition of melons was performed using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC–MS). In general practice, samples are queued up for GC–MS analysis at room temperature (25 °C) for 12–24 h; during this time, the volatile concentrations in samples may vary. To address this, we examined the effect of storage at 4 and 25 °C for 0, 12, 24, 48, and 72 h on samples with and without salt added. Overall, the addition of salt to the sample enhanced the volatile concentration in the headspace and helped preserve the sample at 4 and 25 °C without any significant changes up to 72 h. Our results showed that blending the sample for 1 min, the addition of 1 mL 30% NaCl in a 1 g sample, followed by the adsorption of volatiles with 50/30 µm divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) coated 2-cm SPME fiber, and extraction at 80 °C for 30 min were optimal for the detection of melon volatile organic compounds (VOCs). These optimized conditions were employed for the analysis of VOCs from seven melon varieties. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and variable importance on projection (VIP) analyses were performed to identify markers responsible for melon variety discrimination. A total of twenty volatile compounds with VIP > 1.4 are considered as potential markers for the separation of melon varities studied. The combination of HS–SPME–GC–MS and chemometric classification offers a valuable tool for the identification of type-specific volatile markers in melons.

Colloidal molecules (CMs), nonspherical clusters of a small number of particles, can be used as building blocks for self-assembly applications. Here, we propose a novel one pot method for CMs synthesis. First, poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) microgels were prepared by soap-free emulsion polymerization as seed particles, then monomer styrene and cross-linking agent divinylbenzene (DVB) were added, which could be polymerized by the remaining free radicals on the seed surface in situ. P(NIPAM-co-AA)-PS colloidal molecules with a series of morphologies such as popcorn-like, CO2-like, NH3-like, CH4-like and so on could be obtained. The effects of satellite colloid viscosity, interfacial tension, and polymer chain mobility on the number of satellite colloid have been investigated, and the formation mechanism of CMs is proposed based on morphology evolution investigation. Compared with the existing CM synthesis techniques, our method enables fabricating CMs from vinyl monomer in a facile and efficient way, and the scientific finding regarding the CMs formation will guide the CMs fabrication toward salable and reliable direction.

Nanostructured tricontinuous block polymers allow for the preparation of single-component materials that combine multiple properties. We demonstrate the synthesis of a mesoporous material from the selective orthogonal etching of a microphase-separated tricontinuous block polymer precursor. Using the synthetic approach of polymerization-induced microphase separation (PIMS), divinylbenzene (DVB) is polymerized from a mixture of poly(isoprene) (PI) and poly(lactide) (PLA) macro-chain transfer agents. In the PIMS process in situ cross-linking by the DVB arrests structural coarsening, resulting in a disordered block polymer morphology that we posit exhibits three nonintersecting continuous domains. Selective etching of the PI domains by olefin cross metathesis and PLA domains by hydrolytic degradation produces a mesoporous polymer with two independent pore networks arising from the different etch mechanisms.

A novel type of hyper-cross-linked organic microporous polymer (HOMP) has been successfully prepared based on the radical copolymerization of bismaleimides and divinylbenzene. In comparison with the HOMPs prepared with cross-linking techniques, the new radical strategy circumvents some intractable problems, such as low atom economy, structure irregularity and corrosive byproducts. The obtained HOMPs have defined molecular structures due to the intrinsic alternating copolymerization properties of the two monomers. A maximum BET surface area of 841 m2 g–1 and high gas capture capacity (CO2, 11.22 wt %, 273 K/1.0 bar; H2, 0.82 wt %, 77.3 K/1.0 bar; benzene, 545 mg g–1, room temperature/0.6 bar; and cyclohexane, 1736 mg g–1, room temperature/0.6 bar) were achieved. In addition, the polymers also displayed good chemical and thermal stability, which is critical for the practical application.

Dissolved organic matter (DOM) is an important component in marine and freshwater environments and plays a fundamental role in global biogeochemical cycles. In the past, optical and molecular-level analytical techniques evolved and improved our mechanistic understanding about DOM fluxes. For most molecular chemical techniques, sample desalting and enrichment is a prerequisite. Solid-phase extraction (SPE) has been widely applied for concentrating and desalting DOM. The major aim of this study was to constrain the influence of sorbent loading on the composition of DOM extracts. Here we show that increased loading resulted in reduced extraction efficiencies of dissolved organic carbon (DOC), fluorescence and absorbance, and polar organic substances. Loading-dependent optical and chemical fractionation induced by altered adsorption characteristics of the sorbent surface (PPL) and increased multilayer adsorption (DOM self-assembly) can fundamentally affect biogeochemical interpretations, such as the source of organic matter. Online fluorescence monitoring of the permeate flow allowed to empirically model the extraction process, and to assess the degree of variability introduced by changing the sorbent loading in the extraction procedure. Our study emphasizes that it is crucial for sample comparison to keep the relative DOC loading (DOCload [wt%]) on the sorbent always similar to avoid chemical fractionation.

A novel analytical methodology for the extraction and determination of catecholamines (dopamine, epinephrine and norepinephrine) and their metabolites DL-3,4-dihydroxyphenyl glycol and DL-3,4-dihydroxymandelic acid by LC-MS is developed and validated for its application to human and animal urine and hair samples. The method is based on the preliminary extraction of the analytes by a magnetic multi-walled carbon nanotube poly(styrene-co-divinylbenzene) composite. This is followed by a 90%. Accuracy values comprised the range 79.5-109.5% when the analytes were extracted from deer urine samples using the selected MMWCNT-poly(STY-DVB) sorbent. This methodology was applied to real red deer urine and hair samples, and concentrations within range from 0.05 to 0.5 µg mL-1 for norepinephrine and from 1.0 to 44.5 µg mL-1 for its metabolite 3,4-dihydroxyphenyl glycol were calculated. Analyses of red deer hair resulted in high amounts of 3,4-dihydroxyphenyl glycol (0.9-266.9 µg mL-1).

A wide series of copolymer materials with various contents of 4-vinyl-diisopropyl-phtalate ester (10–90 mol%), divinylbenzene (1–11 mol%) and styrene, as monomers, were obtained by radical copolymerization. In the last steps of the synthesis, diisopropyl ester functionalities were converted into the form of N-hydroxyphthalimide (NHPI) rings. The obtained materials with the NHPI groups immobilized in the copolymer structure were studied by various physicochemical techniques, including FT-IR, UV-Vis-DR, XPS, elemental analysis, and tested as catalysts in aerobic oxidation of p-methoxytoluene in the presence of Co(II) acetate co-catalyst. Conversion of the aromatic substrate was correlated with the NHPI content and cross-linking degree. The best catalytic performance (conversions higher than 23%) was achieved for the copolymer catalysts containing 60% and 30% of 4-vinyl-diisopropyl-phtalate ester. At too high concentrations of NHPI and DVB, some of the NHPI groups were transformed into inactive (C=O)-N=O species or not available due to embedding inside the copolymer structure. The mechanism of the process involving both NHPI centers, forming phthalimide N-oxyl (PINO) radicals, and Co(II) cations was discussed. Stability of the developed catalysts was also tested. The opening of imide rings took place during the catalytic process, resulting in the formation of carboxyl groups and the release of hydroxylamine molecules. The deactivated catalyst could be easily regenerated by repeating two last steps of closing imide ring.

Anisotropic colloidal particles with concave and convex structures are useful in both theoretical studies and applications. In this work, we mass-produced polystyrene (PS) colloidal particles with multiple concavities through dispersion polymerization techniques. By increasing the delayed feeding time td of the cross-linker divinylbenzene (DVB), the morphological evolution of particles can be classified into two stages, during which the formation of different concavities is consistent with either the buckling mechanism or phase separation mechanism. By varying the DVB dosage, we found that the size of the big chamber formed on the particle surfaces decreases as the DVB dosage increases. Then, using these concave particles as seeds, 2-5 μm anisotropic colloids with various shapes, including spherical, ellipsoidal, snowman and multi-protrusion, were synthesized by seeded emulsion polymerization. Moreover, our results show that both the chambers and long narrow ditches on the surface of seeds can be the active sites for monomers to gather and polymerize, but monomers in the big chamber have a priority to polymerize first when big and small concavities both exist on seeds. The results of this study could mean great potential in synthesizing a variety of anisotropic particles with well-controlled concave morphologies.

Microfluidic techniques allow for the tailored construction of specific microparticles, which are becoming increasingly interesting and relevant. Here, using a microfluidic hole-plate-device and thermal-initiated free radical polymerization, submicrometer polymer particles with a highly textured surface were synthesized. Two types of monomers were applied: (1) methylmethacrylate (MMA) combined with crosslinkers and (2) divinylbenzene (DVB). Surface texture and morphology can be influenced by a series of parameters such as the monomer–crosslinker–solvent composition, surfactants, and additives. Generally, the most structured surfaces with the simultaneously most uniform particles were obtained in the DVB–toluene–nonionic-tensides system. In a second approach, poly-MMA (PMMA) particles were used to build aggregates with bigger polymer particles. For this purpose, tripropyleneglycolediacrylate (TPGDA) particles were synthesized in a microfluidic co-flow arrangement and polymerized by light- irradiation. Then, PMMA particles were assembled at their surface. In a third step, these composites were dispersed in an aqueous acrylamide–methylenebisacrylamide solution, which again was run through a co-flow-device and photopolymerized. As such, entities consisting of particles of three different size ranges—typically 0.7/30/600 µm—were obtained. The particles synthesized by both approaches are potentially suitable for loading with or incorporation of analytic probes or catalysts such as dyes or metals.

This work presents the results of the synthesis of granular copolymers of acrylonitrile with hexahydro-1,3,5-triacrylyltriazine and their modification with organic amines, in particular diethylamine, as well as a study of the physicochemical characteristics and sorption properties of the obtained ion exchangers. The result of the study was the synthesis of granular ion exchangers with the necessary physicochemical properties based on acrylonitrile and divinylbenzene, N,N´-methylene-bis-acrylamide and hexahydro-1,3,5-triacrylyltriazine, the kinetics of this process was studied. The synthesized copolymers were modified with diethylamine, the physicochemical and ion-exchange properties of the obtained polymers were studied. It has been shown that acrylonitrile, its copolymers coated with divinylbenzene, N,N´-methylene-bis-acrylamide and hexahydro-1,3,5-triacrylyltriazine, as well as granular ion exchangers based on them, can be obtained. For the first time, copolymers of acrylonitrile and hexahydro-1,3,5-triacrylyltriazine with the necessary physicochemical characteristics were synthesized and, on their basis, conditions for obtaining weak anion-exchange resins on a complex basis were developed. The synthesized anion exchangers have complexing properties and can be used in the hydrometallurgy of non-ferrous and heavy metals, purification of waste water from toxic ions, separation and concentration of metal ions.

International audience; In this work, polymerizations of styrene (St) in the presence of divinylbenzene (DVB) as a crosslinking agent and sodium 4-vinylbenzenesulfonate (VBS) have been performed in Pickering emulsions, using silica nanoparticles (SNps) as stabilizing agents and ammonium persulfate as a hydrophilic initiator. In oil-in-water Pickering emulsions with alkaline continuous phase (pH = 9) at 1, 2, and 3 wt% DVB (relative to St), polydisperse spheroid copolymer submicronic nanoparticles were obtained. Comparatively, polymerizations performed in Pickering emulsions with acidic continuous phase (pH = 5) allowed preparing St-co-DVB microspheres with core–shell structures at 1 wt% DVB and St-co-DVB hybrid monoliths with bi-continuous morphologies at 2 and 3 wt% DVB. It is noteworthy that this work reports Pickering emulsion polymerization as a new strategy for preparing hybrid percolated scaffolds with bi-continuous porosity. The proposed mechanisms originated by pH, DVB, and VBS and the drastic impact caused on the final morphology obtained, either hybrid particles or monoliths, are discussed herein.

A study on the headspace volatile organic compounds (VOCs) profile of native populations of Sideritis romana L. and Sidertis montana L., Lamiaceae, from Croatia is reported herein, to elucidate the phytochemical composition of taxa from this plant genus, well-known for traditional use in countries of the Mediterranean and the Balkan region. Headspace solid-phase microextraction (HS-SPME), using divinylbenzene/carboxene/polydimethylsiloxane (DVB/CAR/PDMS) or polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber, coupled with gas chromatography-mass spectrometry (GC-MS) was applied to analyze the dried aerial parts of six native populations in total. Furthermore, principal component analysis (PCA) was conducted on the volatile constituents with an average relative percentage ≥1.0% in at least one of the samples. Clear separation between the two species was obtained using both fiber types. The VOCs profile for all investigated populations was characterized by sesquiterpene hydrocarbons, followed by monoterpene hydrocarbons, except for one population of S. romana, in which monoterpene hydrocarbons predominated. To our knowledge, this is the first report on the VOCs composition of natural populations of S. romana and S. montana from Croatia as well as the first reported HS-SPME/GC-MS analysis of S. romana and S. montana worldwide.

Due to its unique properties, raspberry-like colloidal particles (RCPs) have been widely used in various fields. However, a facile, scalable and robust approach of producing raspberry-like polymeric particles remains an ongoing challenge. Herein, raspberry-like poly(styrene-co-divinylbenzene) (PSD) polymeric particles were fabricated by one-step dispersion polymerization in the solvent mixture of ethanol and toluene. The morphologies of obtained polymeric particles could be easily tuned from spherical to raspberry-like structure by changing the composition of the solvent mixtures. A rational mechanism for the formation of raspberry-like polymeric particles was also proposed according to the morphological evolution under different copolymerization conditions. With the assitance of the immonilized PVP layer, the raspberry-like PSD colloidal particles can be further functionalized by depositing Ag nanoparticles on the particle surface. The antibacterial activity of raspberry-like PSD/Ag composite particles against E. coli was up to 99.99%. In addition, raspberry-like PSD/Ag composites can be further utilized to construct antibacterial superhydrophobic surface and liquid marbles.

A series of four 1,4-divinylbenzene linked truxene moieties with different substituents were synthesized by Horner-Wadsworth-Emmons reaction. Their structures were characterized using NMR spectroscopy and HRMS spectrometry. The photophysical properties of these molecules in solvents of different polarity were investigated by UV–vis absorption and fluorescence spectroscopy. These results show that these compounds have strong one-photon absorption bands in the near ultraviolet region displaying relatively high fluorescence quantum yields and large Stokes' shifts. In addition, these compounds possess good solid-state fluorescence, high two-photon absorption cross-section and high thermal stability.

Cement industries are the second-largest anthropogenic carbon dioxide (CO2) emitter, have gained substantial research attention to capture CO2 and minimize environmental issues. Also, the recovered carbon dioxide (CO2) can be reutilized for several applications. The adsorptive capture of CO2 appears promising as compared to absorption, membrane separations, and cryogenic distillation because it allows easy CO2 recovery. This work demonstrates the adsorptive capture of carbon dioxide on amine-functionalized styrene-divinylbenzene copolymer. Both batch and continuous adsorption data of CO2 are presented at different temperatures. The equilibrium uptake of CO2 over the polymeric adsorbent showed 2.4 mole/kg capacity at 25⁰C and near ambient pressure, which decreased by 16% with a ten-degree rise in the operating temperature. The equilibrium adsorption data are modeled with Langmuir, Nitta, Toth, Dubinin-Radushkevich, and SIPS isotherm equations to characterize the CO2-polymer adsorption system and estimate the heat of adsorption, entropy, and Gibbs free energy for CO2 adsorption. The Toth isotherm gave the best fit of the experimental data suggesting monolayer adsorption of CO2 on energetically different sites of the adsorbent. The diffusivity of CO2 within the adsorbent’s interstitial space is determined as 2 – 9 ×10-11 m2/sec, indicating intraparticle mass transfer limitations for large-scale operations. The continuous adsorption/desorption studies of CO2 in mixtures with nitrogen were characterized via breakthrough curves. The desorption studies showed 92% – 94% recovery of CO2 in batch and continuous experiments at 56⁰C. A theoretical model for continuous adsorption of CO2 is also developed and validated with the experimental data. The current work could be promising for CO2 capture in the cement industry.

A headspace-solid phase microextraction - gas chromatography-flame ionisation detector (HS-SPME-GC/FID) method was developed for the simultaneous determination of furan, 2-methylfuran and 2-furaldehyde in thermally processed Mopane worms, corn, and peanuts. The optimal HS-SPME conditions with polydimethylsiloxane/carboxen/divinylbenzene (PDMS/CAR/DVB) fiber were 30 °C, 40 min and 600 rpm stirring speed. The recoveries, detection and quantification limits for the analytes in food samples were 67–106%, 0.54–3.5 µg kg−1, and 1.8–12 µg kg−1, respectively. These results showed that the developed method was accurate, reproducible, and sensitive for the determination of furan, 2-methylfuran and 2-furaldehyde in complex food matrices with limited interference from other components. The optimised analytical method was applied for monitoring the presence of the furanic compounds in heat-processed South African foods. Although 2-furaldehyde was not detected in food samples, the maximum concentrations of 24 and 95 µg kg−1 were found for furan and 2-methylfuran, respectively.

Amine-functionalized porous adsorbent is one kind of important materials in carbon dioxide capture due to its stability and efficiency. In this study, a copolymer (polyHIPE) with interconnected macropore networks, hierarchical porous structure and abundant branched amino groups was prepared by high internal phase emulsion (HIPE) strategy via copolymerization of styrene (St), divinylbenzene (DVB), tetraethyl orthosilicate (TEOS), and triethoxyvinylsilane (VTEO), and then a novel amine-functionalized CO2 adsorbent was synthesized by in situ ring-opening grafting copolymerization of aziridine with the polyHIPE. The structure, morphology, and physicochemical properties of the polyHIPEs were characterized by FTIR, TEM, TGA, and SEM. The key roles of VTEO and TEOS in introducing active hydroxyl groups onto the surface of the inert polymer was evaluated, which was essential to improve the hydrophilicity of the polyHIPE and to provide reactive sites to combine with amine agents. The contact angle of the polyHIPE while copolymerized with TEOS and VTEO significantly was decreased from 144° to 72°. In order to further increase the specific surface area of the polyHIPEs, post crosslinking of polyHIPEs was implemented through a Friedel–Crafts reaction. The specific surface area of post-crosslinked polyHIPE could reach 513 m2/g, which was proven to be effective to enhance its CO2 adsorption capacity. Finally, the abundant branched amino sites via aziridine grafting and high surface area greatly enhanced CO2 adsorption capacity of the amino-modified polyHIPEs. The adsorption capacity of 2.40 and 3.25 mmol CO2/g could be achieved under dry and humid conditions in 0.1 atm partial pressure of CO2, respectively.

A novel approach for the synthesis of miktoarm copolymer stars with divinylbenzene cross-linked core, via anionic polymerization is reported. This synthetic route gives access to polymers, characterized by low dispersity values and improved structural homogeneity for both arm species. Specifically, miktoarm copolymer stars of AnBn type, with cross-linked divinylbenzene (DVB) core and arms of polystyrene (PS) and poly(ethylene oxide) (PEO), are synthesized via anionic polymerization and sequential monomer addition, employing high vacuum techniques. Analytically, the first step involves the synthesis of a triblock terpolymer PS-b-PDVB-b-PEO. Then, in the presence of a free radical initiator the pending vinyl groups of the middle DVB block cross-link intermolecularly, leading to the final miktoarm copolymer star. The novelty of the proposed synthetic route, lies in the potassium alkoxide co-initiator, which is responsible for the controlled polymerization of both DVB and EO in one pot, without the need for end group modification between the two steps. Concerning the final polymer, there are numerous benefits advancing from this synthetic protocol, such as the control of the molecular characteristics of both arms, as well as the easily confirmed structural integrity of the precursor triblock which is inherited to the resulting miktoarm star. For comparison reasons, another batch of (PS)(PEO) miktoarm copolymers was synthesized, following the “in-out” synthetic route. For this reason, styrene was polymerized using s-BuLi, which is used as macroinitiator for the polymerization/cross-linking of DVB, resulting PS star with DVB cross-linked core. With the addition of EO, in the presence of p4 t-Bu phosphazene base, PEO arms are polymerized, initiating from the core’s active cites outwards.

A new nanofiltration composite membrane poly (butyl acrylamide-co-divinylbenzene) (poly-TaDb) was synthesized via a facile photopolymerization on polyetherimide using the monomers of n-tert-butyl acrylamide and divinylbenzene, and evaluated the separation performance in organic solutions. The unique poly-TaDb toplayer has a feature of branch structure containing regularly distributed oxygen and nitrogen groups that work as the interacting sites with metal ions (Fe3+, Zn2+, and Cu2+), as reflected by the characterizations of ATR-FTIR, XPS, AFM, etc. Without the metal ion treatment, the optimal poly-TaDb membrane shows the permeance of 31, 17, 20.4 L m−2h−1 MPa−1 respectively for organic solutions of tetrahydrofuran (THF), methanol (MeOH) and acetonitrile (ACN), with the rejection rates higher than 90% toward EB dye (879.8 g.mol−1). After interacting with these metal ions, the obtained Fe-binding poly-TaDb membranes possess higher permeance, with the THF, MeOH, and ACN permeance enhanced respectively to 113, 35, and 24.2 L m−2h−1 MPa−1, meanwhile maintaining high dye rejection rate. While the Cu- and Zn-binding membranes show much higher permeance but lower dye rejection rate. Density functional theory (DFT) calculations disclose that the void size of the toplayer network increases in the order of: the pristine (11.40 A)

Micro-mesoporous active carbons containing copper ions have been prepared by the pyrolysis of crosslinked styrene/divinylbenzene ion exchange resin with the sulphonic functional groups -SO3H and with the sorbed copper cations. The differentiation of the copper content was obtained by modification with nitric acid of different concentrations (1 M−7 M). The structure of ACs has been studied using nitrogen adsorption–desorption, TG/DTA, cryoporometry DSC, XRD as well as ED-XRF analyses, FTIR and XPS spectroscopy. The selected samples have been tested in the photocatalytic degradation of Safranin T (ST) under visible irradiation. It has been established that pyrolysis results in formation of micro-mesoporous structure which is accessible to molecules of different reagents that favors the processes of adsorption and photocatalysis. The DSC studies proved that the interactions between the molecules exhibiting hydrophilic-hydrophobic character with the surface of ACs are particularly effective, pointing out to the accessibility of pores to the organic molecules with different functionalities. It was found that the presence of the complex mixture of crystal copper-containing phases makes them an effective photocatalyst for water cleaning.

The development of new solid-phase microextraction coatings has attracted more attention due to a limited number of commercially available fibers and their inherent shortcomings, such as low effectiveness when extracting polar compounds, poor selectivity, and possible swelling upon exposure to certain solvents. In recent years, an increased interest has developed in the synthesis of SPME fiber coatings based on metal-organic frameworks, which are promising due to their permanent porosity, large surface area, and high mechanical and thermal stability. The in situ solvothermal method was employed in developing a new MOF-199-based coating on an etched stainless-steel core. Optimal MOF-199 deposition on the core was achieved after 16 h reaction time using 96.5% (v/v) ethanol as a solvent. The extraction effectiveness of 25 volatile organic compounds from the air (at 150 and 15 μg/m3) was evaluated using the newly developed SPME fiber with 22 ± 3 μm thickness and compared with two commercially available fibers - 65 μm polydimethylsiloxane/divinylbenzene and 85 μm Carboxen/polydimethylsiloxane. In comparison with polydimethylsiloxane/divinylbenzene, the MOF-199-based fiber provided 1.3–82.3 times higher responses of 16 volatile organic compounds, as obtained using gas chromatography-mass spectrometry. The responses of five volatile organic compounds obtained using the MOF-199-based fiber were in the same range as those from Carboxen/polydimethylsiloxane fiber. The newly developed fiber exhibited a greater selectivity toward low molecular volatile organic compounds. The extraction effectiveness of the MOF-199-based fiber for nine volatile organic compounds ranged between 35 and 88%, with distribution constants in the range of 9.4 × 104 to 127 × 104.

A novel interpenetrating polymeric network (IPN) of sulfonated polyvinylidene fluoride (SPVDF), nano-alumina (Al2O3), and aniline-2-sulfonic (A2S) acid with crosslinker divinylbenzene (DVB) is employed as an ion-exchange membrane in single-chambered microbial fuel cells (MFCs). Results reveal that the increasing concentration of A2S (10, 20, and 30 wt%) enhances the relative hydrophilicity and other intrinsic properties of the membranes. A series of characterizations like water uptake, swelling ratio, ion-exchange, proton conductivity, and tensile testing, affirms the enhanced attributes of the casted membranes. The increasing concentration of crosslinker DVB (> 1.4 wt%) constricts the internal spacing of the membrane that, in turn, hinders the transverse ionic conduction within the highly crosslinked, AS30 membrane. A maximum power and current density of 450.36 ± 23mW m-2 and 1734 ± 87mA m-2 was found in AS20 fitted MFC with around 89% of chemical oxygen demand (COD) removal in 30 days of operation. Incorporation of A2S and Al2O3 in SPVDF moiety demonstrates an approximate increment of 36% and 7% higher MFC performance over n-SPVDF and highly crosslinked AS30 membrane. The relative effect of these novel IPN membranes has been highlighted here as cost-efficient separator in MFCs for green electricity production, employing mixed firmicutes as biocatalyst.

Processable microporous organic polymers (MOPs) attract incomparable research interests becuase their vairous types such as monoliths and membranes are for practical application. Most of processable MOPs usually need the harsh conditions such as the use of expensive metal catalysts, specialized stereospecific monomers etc., which restrict the sustainable and real applications of processable MOPs. Therefore, the economical mass production of processable MOPs remains a formidable challenge. Herein, we report that a novel strategy for constructing processable hypercrosslinked polymers (HCPs) need two steps synthesis of pre-crosslinking and deep-crosslinking using divinylbenzene (DVB) as self-crosslinking monomer under the catalysis of a small amount of FeCl3 . The resulting HCPs monoliths possess high BET surface area of 1033-1056 m2 g-1 with hierarchical porosity, and show excellent mechanical strength up to 65 MPa. It is, to the best of our knowledge, the first report of using aromatic vinyl monomers as self-crosslinking monomers to generate HCPs monoliths with high surface area, yielding no by-products and high mechanical strength. This article is protected by copyright. All rights reserved.

In this work, divinylbenzene selected as the cross-linking agent, a two-step one pot method based on the acylation reaction between maleic anhydride and chitosan had been developed to prepare a series of divinylbenzene cross-linked chitosan/maleic anhydride polymers (CS/MAH-DVB), which were used to remove cationic dye methylene blue (MB) from aqueous solutions. The synthesized polymers were characterized by FT-IR, XPS, SEM, TG and pH-drift methods. The adsorption parameters were discussed including pH, contact time, initial concentration of dye and temperature. The maximum adsorption capacities were 448 mg g−1, 482 mg g−1 and 503 mg g−1 respectively for three CS/MAH-DVB polymers with different molar ratios at 298 K, which were superior to other reported bio-based adsorbents. The adsorption process was found well to follow pseudo-second-order model and Sips isotherm. The adsorption mechanism was attributed to electrostatic interaction and π-π stacking interaction between MB and CS/MAH-DVB polymers. Furthermore, the CS/MAH-DVB polymers could easily be recycled by washing with acidic acetone, demonstrating excellent stability and favorable recyclability over five cycles. These results indicated the chitosan grafted maleic anhydride and further cross-linking using divinylbenzene could promote the adsorption performance of chitosan.

Fusel oil was used as a source of isoamyl alcohol in the synthesis of biolubricant by esterification with oleic acid catalyzed by different sources of lipase immobilized on poly(styrene/divinylbenzene) copolymer resin. In preliminary tests, Rhizopus oryzae lipase showed satisfactory performance, providing high molar conversion of the starting materials (>90% in 24 h of reaction), and was selected for subsequent experiments. The optimal conditions for isoamyl oleate production by immobilized R. oryzae lipase were 1:1.5 ratio of fusel oil to oleic acid and reaction temperature of 45°C. Continuous runs were carried out in a two-stage packed-bed reactor coupled to a water extraction column filled with molecular sieves. Each reactor stage was loaded with 2.6 g of immobilized lipase and then fed with fusel oil and oleic acid at a 1:1.5 molar ratio in the presence of isooctane. The performance of the proposed system was tested at a space time of 10.2 h, resulting in a mean ester productivity of 292.20 ± 18.46 µmol g−1 min−1 and biocatalyst half-life of 179.6 h. The properties of purified samples were in accordance with standard requirements for biolubricants.

In the present study, pores enriched high surface area of carbon electrode obtained from hypercross-linked polymer of poly(divinylbenzene-co-vinylbenzyl chloride) [P(DVB:VBC)] for supercapacitor application. First, hypercross-linking reaction was carried out in [P(DVB:VBC)] via. simple Friedel-Crafts alkylation method (HCP) followed by pyrolysis at 800 °C (HCP-800). The surface morphology of the synthesized HCP and HCP-800 materials was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) technique. HCP-800 showed a remarkable surface area of 1027 m2 g−1 with the abundance of micropores. In addition, the oxidation state of the porous carbon was assessed by x-ray photo electron spectroscopy (XPS). In a three-electrode and symmetric two-electrode configurations, electrodes exhibited a supreme specific capacitance of 272 and 145 F g−1 in aqueous electrolyte, respectively. Specific energy of 39.47 Wh kg−1 at specific power of 699.96 W kg−1 is yielded from the symmetric supercapacitor device (SSCD). Furthermore, SSCD retains more than 94% of its residual capacitance after 5000 GCD cycles at a current density of 5 A g−1 suggests a good cyclic stability.

Anion exchange membrane fuel cell (AEMFC) can be a viable technology to help combat global warming as they are clean energy conversion devices. Herein, a novel series of poly(olefin)-based anion exchange membranes (AEMs) comprising quaternary ammonium (QA) cations are designed and prepared successfully through ultraviolet cross-linking of olefin monomers, followed by an anion exchange reaction. Triallylmethyl ammonium iodine ([TAMA][I]) is synthesized and used both as a conductive group and a flexible cross-linker. Divinylbenzene (DVB) is used as a rigid cross-linker in the preparation of poly(olefin)-based membranes, and the poly(olefin)-based membranes exhibit robust alkaline stability because of their ether-free backbone. The content of rigid non-conductive DVB in poly(olefin)-based AEMs can be reduced by introducing [TAMA][I], leading to the improved conductivity and cell performance of the AEMs. The [PSAN]60-[TAMA][OH]40-1 membrane possesses a high conductivity of 51.30 mS cm−1 at 80 °C, which is higher than that of [PSAN]60-[TAMA][OH]40–4 (30.11 mS cm−1). The H2/O2 fuel cell assembled with [PSAN]60-[TAMA][OH]40–1 exhibit higher peak power density (266 mW cm−2, 60 °C) than the one assembled with [PSAN]60-[TAMA][OH]40–4 (83 mW cm−2). The results show that it is a facile, inexpensive, and commercially viable approach to the preparation of poly(olefin)-based AEMs.