Explore the vast range of titles available.

Using Pentaerythritol tetra (3-mercapto propionate) as primary thiol and Pentaerythritol tetra (3-mercapto butylate) as secondary thiol, the effect of thiol structure on the properties of the thiol-ene system were investigated. The results show that for the triallyl isocyanurate system, the thiol structure had little effect on the glass transition temperature, but for the tri (1, 2-propylene glycol) diacrylate and divinylbenzene system, the secondary thiol systems showed a higher glass transition temperature. In terms of optical properties and anti-swelling, the primary thiol system showed better performance.

Background The presence of soluble lignin, furfural and hydroxymethylfurfural (HMF) in industrial pre-hydrolysis liquor (PHL) from the pulping process can inhibit its bioconversion into bioethanol and other biochemicals. Although various technologies have been developed to remove these inhibitors, certain amounts of sugars are also inevitably removed during the treatment process. Hence, polystyrene divinylbenzene (PS-DVB) resin was used as an adsorptive material to simultaneously remove fermentation inhibitors while retaining sugars with high yields to improve the fermentability of PHL after acid hydrolysis by enriching its xylose concentration. The fermentability of acid-hydrolyzed PHL (A-PHL) was evaluated by the bioconversion into ethanol and xylosic acid (XA) after treatment with PS-DVB resin. Results The results showed that the highest xylose concentration (101.1 g/L) in PHL could be obtained by acid hydrolysis at 100 °C for 80 min with 4% acid, while the concentration of fermentation inhibitors (furfural, HMF and lignin) in PHL could also be significantly improved during the acid-hydrolysis process. After treatment with PS-DVB resin, not only were 97% of lignin, 92% of furfural, and 97% of HMF removed from A-PHL, but also 96% of xylose was retained for subsequent fermentation. With resin treatment, the fermentability of A-PHL could be improved by 162–282% for ethanol production from A-PHL containing 30–50 g/L xylose and by 18–828% for XA production from A-PHL containing 90–150 g/L xylose. Conclusions These results confirmed that PS-DVB resin can remove inhibitors from PHL before producing value-added products by bioconversion. In addition, this work will ideally provide a concept for producing value-added chemicals from pre-hydrolysis liquor, which is regarded as the waste stream in the pulping process.

Reducing the ecological impact of dyes through wastewater discharge into the environment is a challenge that must be addressed in textile wastewater pollution prevention. Congo red (CR) dye is widely used in experimental studies for textile wastewater treatment due to its high organic loads used in its preparation. The degradation of organic dyes of the CR type was investigated using the photocatalytic activity of functionalized polymers. We have employed photodegradation procedures for both polymer-supported glycine groups (Code: AP2) and polymer-supported glycine-Zn(II) (Code: AP2-Zn(II)). A photocatalysis efficiency of 89.2% was achieved for glycine pendant groups grafted on styrene-6.7% divinylbenzene copolymer (AP2) and 95.4% for the AP2-Zn(II) sample by using an initial concentration of CR of 15 mg/L, a catalyst concentration of 1 g/L, and 240 min of photocatalysis. The findings provided here have shown that the two materials (AP2 and AP2-Zn(II)) may be effectively employed in the heterogeneous photocatalysis method to remove CR from water. From the perspective of the degradation mechanism of CR, the two photocatalysts act similarly.

Bimetallic nanoparticles (BNPs) have been used as a new line of defence against heavy metal contamination among several types of nanoparticles (NPs) due to their enhanced, synergistic activity. In this study, we investigated the adsorption behaviour of porous (styrene–divinylbenzene)/CuNi bimetallic nanocomposite (P(St-DVB)/CuNi BNC) in a continuous flow fixed-bed column and its ability to remove Pb (II), Cd (II), and Zn (II) ions from aqueous solutions. We examined how the initial metal concentration, flow rate, and bed height affected the adsorption characteristics. Experimental results confirmed that the adsorption capacity increased with increase in influent metal concentration and bed height and decreased with increase in flow rate. The breakthrough and the column kinetic parameters were successfully predicted with three mathematical models: Thomas, Yoon–Nelson, and Adams–Bohart models. Both Thomas and Yoon–Nelson models showed good agreement with the experimental results for all the operating conditions. Successful desorption of heavy metals from the P(St-DVB)/CuNi BNC was performed using 0.5 M NaOH solution, and it showed good reusability of the adsorbent during four adsorption–desorption cycles. The results show that P(St-DVB)/CuNi BNC are effective and low-cost adsorbents, and they can be used in real-time large-scale industrial water treatment processes for the removal of heavy metals.

The poor filtration properties of graphene oxide (GO) membrane limit its application in industry. Graphene oxide/polystyrene-divinylbenzene (PS-DVB) membranes were prepared by vacuum filtering layer-by-layer assembly method on a polyacrylonitrile (PAN) substrate membrane. The adsorption kinetics, adsorption isotherm and permeation performance of tetracycline (TC) and ciprofloxacin (CIP) in aqueous solution on the GO/PS-DVB/PAN membranes were investigated. The results revealed that the adsorption of two antibiotics fitted well with pseudo-second-order kinetics model and Langmuir isothermal adsorption model, with the maximum adsorption capacities of 22.79 and 46.69 mg g −1 for TC and CIP, respectively. The adsorption process was dominated by chemical adsorption. The results of membrane permeability showed that GO/PS-DVB/PAN membrane had high water flux, and the retention rate of antibiotics reached 100%. A high performance liquid chromatography method for determination of antibiotics was also established and the methodology was investigated. The GO/PS-DVB/PAN membrane has broad application prospect for removing antibiotics from water.

This article presents styrene–divinylbenzene copolymers that contain aminophosphinic acid groups, used to remove acetylsalicylic acid (AS). The chemically modified copolymers were obtained using phenylphosphinic acid and propylamine (AAP1), benzylamine (AAP2) and, respectively, butylamine (AAP3) by the “one-pot” Kabachnik–Fields synthesis. The obtained adsorbents were characterized by FT-IR spectroscopy, thermogravimetric analysis, SEM/EDX analysis and statistical modeling of the repetitive unit. The weight loss of the samples, when analyzed in a nitrogen atmosphere and at 800 °C, was the following: AAP1: 58.71%; AAP2: 59.52%; and for AAP3: 59.66%. The adsorption process at equilibrium was modeled by the Langmuir, Freundlich, Sips and Redlich–Peterson adsorption isotherms. The maximum adsorption capacity given by the Langmuir isotherm was influenced by the amine used in the synthesis of sorbent. The best results were obtained at 298 K, with a maximum adsorption capacity of 0.236 mmol/g (42.52 mg/g) on the copolymer AAP1. The adsorption process was fast, over 85% of the maximum adsorption capacity being achieved in the first 4 h. The adsorption of AS on the studied adsorbents is an exothermic and thermodynamically favorable process. Graphical abstract

The aim of this work was to the obtaining novel mixed-mode stationary phases with increased hydrophilicity and applying them in ion and hydrophilic interaction liquid chromatography. The resins were obtained by the sequential covalent attachment of branched polyethylenimine and polyelectrolytes synthesized from diepoxide and a secondary amine on the surface of epoxidized polystyrene–divinylbenzene. To increase the shielding degree of the polymer substrate, an additional polymerization of glycidol was carried out in the functional layer of the sorbent at an increased pH of the reaction medium. The synthesized phases possessed increased hydrophilicity compared to most resins based on a styrene–divinylbenzene copolymer with covalently attached layers. This was evidenced in the ion chromatography mode by a decrease in the relative retention of polarizable anions, weakly hydrated oxyhalides (up to a change in the elution order of the bromate), and haloacetic acids. In the hydrophilic interaction liquid chromatography mode, an increased hydrophilicity of the phases was confirmed by an increase in the retention factors of polar analytes, as well as by the reversal of the elution order of ascorbic and nicotinic acids as compared to the phases based on polystyrene–divinylbenzene presented in the literature. The low efficiency of the obtained stationary phases in the ion chromatography mode was noted, which is associated with slow mass transfer in the bulk polymer functional layer. The negative impact of the polymer layer on efficiency in hydrophilic interaction liquid chromatography is less pronounced due to the presumably smaller thickness of the part of the functional layer involved in this mode. The proposed method for the synthesis of resins ensures an increase in the efficiency, selectivity, and separation ability of sorbents in the hydrophilic interaction liquid chromatography mode as compared to phases based on a styrene–divinylbenzene copolymer described previously in the literature. The resulting highly hydrophilic resins makes it possible to separate a mixture of 9 nitrogenous bases and nucleosides in 18 min, 6 vitamins in 24 min, and 8 sugars in 11 min. Thus, the method of substrate hydrophilization proposed in this work is promising for improving the chromatographic characteristics of phases in the hydrophilic interaction liquid chromatography mode and can be used to create sorbents with increased selectivity and efficiency.

New adsorbents based on silica and polystyrene–divinylbenzene (PS–DVB) for hydrophilic interaction liquid chromatography (HILIC) with eremomycin in functional layers were obtained. The chromatographic properties of the new adsorbents were assessed using the Tanaka test for hydrophilic stationary phases and by studying the retention of substances of various classes in HILIC, chiral, and reversed-phase chromatography modes. It was shown that the use of eremomycin to create functional layers leads to an increase in the hydrophilicity of the adsorbents on different types of substrates and ensures the shielding of their charge. Eleven nitrogenous bases, nucleosides with an efficiency of up to 25 000 tp/m, or seven vitamins with an efficiency of up to 40 000 tp/m can be separated on a modified sorbent based on aminopropyl silica, and three different HPLC modes can be implemented on the sorbent with eremomycin based on PS–DVB.

A simple and inexpensive method for the preparation of porous SiC microspheres is presented. Polysiloxane microspheres derived from polyhydromethylsiloxane (PHMS) cross-linked with divinylbenzene (DVB) were ceramized under conditions leading to the removal of oxygen from the material. The content of free carbon (Cf) in highly crystalline silicon carbide (SiC) particles can be controlled by using various proportions of DVB in the synthesis of the pre-ceramic material. The chemical structure of the ceramic microspheres was studied by elemental analysis for carbon and oxygen, 29Si MAS NMR, 13C MAS NMR, SEM/EDS, XRD and Raman spectroscopies, and their morphology by SEM, nitrogen adsorption and mercury intrusion porosimetries. The gaseous products of the thermal reduction processes formed during ceramization created a porous structure of the microspheres. In the SiC/Cf microspheres, meso/micro pores were formed, while in carbon-free SiC, microspheres macroporosity dominated.

Highlights Copolymer of divinylphenyl-acryloyl chloride copolymers (PDVB- co -PACl) is designed and synthesized to graft on the surface of aluminum nitride (AlN) to improve its hydrolysis resistance. AlN fillers functionalized by PDVB- co -PACl with the molecular weight of 5100 g mol -1 exhibits the highest hydrolysis resistance and the lowest interfacial thermal resistance. When the mass fraction of AlN@PDVB- co -PACl is 75 wt% and the grafting density of PDVB- co -PACl is 0.8 wt%, the λ for AlN@PDVB- co -PACl/PMHS composites is 1.14 W m -1  K -1 and maintains 99.1% after soaking in 90 °C deionized water for 80 h. A series of divinylphenyl-acryloyl chloride copolymers (PDVB- co -PACl) is synthesized via atom transfer radical polymerization employing tert-butyl acrylate and divinylbenzene as monomers. PDVB- co -PACl is utilized to graft on the surface of spherical aluminum nitride (AlN) to prepare functionalized AlN (AlN@PDVB- co -PACl). Polymethylhydrosiloxane (PMHS) is then used as the matrix to prepare thermally conductive AlN@PDVB- co -PACl/PMHS composites with AlN@PDVB- co -PACl as fillers through blending and curing. The grafting of PDVB- co -PACl synchronously enhances the hydrolysis resistance of AlN and its interfacial compatibility with PMHS matrix. When the molecular weight of PDVB- co -PACl is 5100 g mol −1 and the grafting density is 0.8 wt%, the composites containing 75 wt% of AlN@PDVB- co -PACl exhibit the optimal comprehensive performance. The thermal conductivity ( λ ) of the composite is 1.14 W m −1  K −1 , which enhances by 20% and 420% compared to the λ of simply physically blended AlN/PMHS composite and pure PMHS, respectively. Meanwhile, AlN@PDVB- co -PACl/PMHS composites display remarkable hydrothermal aging resistance by retaining 99.1% of its λ after soaking in 90 °C deionized water for 80 h, whereas the λ of the blended AlN/PMHS composites decreases sharply to 93.7%.