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The molecularly imprinted polymers (MIPs) were prepared by using the non-covalent approach. In the polymerization process, xylenol orange was used as a template (T), acrylic acid as a functional monomer (M), divinylbenzene as a cross-linker (CL) and 2,2’-azobisisobutyronitrile (AIBN) as an initiator and microemulsion as a solvent. The synthesized polymers were characterized by using FTIR and SEM micrograph. The batch binding analysis was used to evaluate the rebinding efficiency of imprinted polymers. The highest rebinding efficiency was obtained from the MIP-R2 (0.1:0.6:2, T:M:CL). The selected MIP-R2 was used for the removal of xylenol orange from the water sample and have shown removal efficiency of about 80%.

In this work, the synthesis, characterization and in vitro antibacterial activity of two novel compounds with aminophosphinic acid groups have been investigated. Both α-propylaminophosphinic acid grafted on styrene-6.7%divinylbenzene copolymer (AmPhinicPr) and α-benzylaminophosphinic acid grafted on styrene-6.7%divinylbenzene copolymer (AmPhinicBz) were obtained by a one-pot Kabachnik–Fields polymer-analog reaction. They were characterized using FT-IR spectroscopy, EDX and TG/DTA, to establish the degree of functionalization with pendant α-aminophosphinic acid groups. They exhibited remarkable efficiency in antibacterial tests. The bioactive aminophosphinic groups have an antibacterial effect against Staphylococcus aureus (S.aureus), Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Bacillus cereus (B. cereus). We have evaluated the applicability of the Weibull model to describe inactivation of microbial cells at our samples.

The synergistic effect of divinylbenzene and triallyl cyanurate on the properties and structure of the thermoplastic vulcanizate prepared from a blend of polypropylene and hydrogenated styrene–butadiene–styrene triblock copolymer by vulcanization under dynamic conditions with 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane was revealed. The synergism consists in the enhancement of the strength, increase in the relative elongation, and decrease in the compression set to a greater extent then when using divinylbenzene or triallyl cyanurate separately. The synergism is caused by the increased gel fraction content and vulcanization network thickness, with preservation of the higher molecular mass of the polypropylene matrix.

Volatile flavor components are critical to edible oils and influence consumption choice. Meanwhile, volatile organic compounds (VOCs) in edible oils are also potential biomarkers to detect adulterated products. However, VOCs are usually complex, unstable, and easily influenced by oil processing and even analysis conditions. Here, we report headspace solid-phase microextraction for comprehensive two-dimensional gas chromatography mass spectrometric analysis of VOCs in edible oils as being optimized and validated using central composite design (CCD). The results indicated that the optimal extraction conditions are as follows: SPE column of divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), equilibration time of 10.3 min, and extraction time of 19.6 min at 120 °C. This method could analyze edible oils to identify characteristic flavor components. As a result, 25 VOC tags were identified and used to characterize soybean oils. Chemometric methods were used to discriminate the authentic sesame oils from those adulterated with soybean oil. The results indicated that this method is an effective approach to measure VOCs in edible oils; such measurements can report counterfeit products.

Optimised extraction methods are required to better understand the impact of volatile compounds on the physical and organoleptic attributes of baked confectionary products (cakes, etc.). This is especially relevant with an increased focus on the reformulation of such products to aid in the reduction of diet-related chronic diseases. Headspace solid-phase microextraction (HS-SPME) has become one of the most widely used extraction techniques for volatile profiling of foods and beverages, mainly because it is very automatable, has a high sample throughput, is solvent-free and multiple fibre phases are available to target a wide range of volatile organic compounds. This study used response surface methodology to optimise HS-SPME parameters for the extraction of volatiles in baked confectionary products. After HS-SPME fibre selection, a central composite design was used to evaluate the effect of incubation time, extraction time and extraction temperature on 18 selected volatile compounds, representative of key volatiles in baked confectionary products, using a sponge cake crumb as the matrix. The most suitable fibre was the divinylbenzene/carboxen/polydimethylsiloxane. The results demonstrated that the final reduced models significantly (p

Polystyrene crosslinked microspheres were prepared by soap-free emulsion polymerization using styrene (St) and divinylbenzene (DVB) as monomers; then, the microporous structure was knitted by the Friedel-Crafts alkylation reaction, and the Au nanoparticles (AuNPs) were loaded into the pores through thermal reduction, to obtain AuNPs/hyper-crosslinked microporous polymer composite microspheres. SEM and particle-size test results show that the microspheres show good monodispersity. The micropore analysis indicates that the specific surface area and the pore volume of the microporous polymer microspheres decrease with increasing DVB content, and when the DVB content is 0.1%, the specific surface area reaches a maximum of 1 174.6 m2/g. After loading AuNPs, the specific surface area and the amount of micropores of the composite microspheres decrease obviously. The results of XRD and XPS analyses suggest that HAuCl4 is reduced to AuNPs. The composite microspheres show a good catalytic performance for the reduction catalyst of 4-nitrophenol.

Due to deteriorating air quality, air pollution has become one of the most serious environmental issue especially in urban localities. Therefore, in the current study we have focused on a new route for the efficient capture of CO2 and PM2.5 from the automobile exhaust smoke of light motor vehicle with the aid of amino functionalised high internal phase emulsion (HIPE) polymeric monolith. The Poly (Styrene-co-methyl methacrylate) monolith (PSM) was synthesised by copolymerising styrene with methyl methacrylate and cross linked with divinylbenzene. The –NH2 functionalization of the synthesised PSM monolith was carried out with ethylenediamine. The amino functionalised porous hydrophobic monolith (APSM) comprising of voids (cavity spaces) and pores (tiny openings) in the range of 3.0–7.4 µm and 1.1–2.4 µm respectively exhibited excellent thermal stability up to 323 °C. Capturing efficiency of the porous monolith filter for CO2 and PM2.5 was found to be 73% and 77.2% respectively. The filter also demonstrated outstanding dust loading capacity with a reduced pressure drop. Good resistance and quality factor value proved the viability of the membrane to act as an air filter. Regeneration capacity of the filter was also studied to demonstrate the effective filtration on continuous usage.

A one-step carbonization strategy without KOH activation has been developed to fabricate N-doped porous carbon with a large specific surface area of 1520 m2 g−1, a relatively high nitrogen content of 6.13 wt%, abundant active sites, partial graphitization, and high conductivity. This exploration is based on poly(styrene/divinylbenzene) (p(St/DVB) foam prepared by high internal phase emulsion (HIPE) and with the loading of urea as the nitrogen source. The carbonization process was subsequently carried out at 800 °C to achieve the synthesis of N-doped porous carbon. The electrochemical properties of N-doped porous carbon were evaluated in 0.5 M H2SO4 and 1 M KOH aqueous electrolytes, respectively. In acidic medium, the obtained sample exhibits a high specific capacitance of 276 F g−1 at 1 A g−1 in the potential range of 0–1 V and 70.2% capacitance retention at 20 A g−1. Quite high stability with only 2.2% capacitance loss is confirmed through a 10,000-GCD-cycle at 10 A g−1. In contrast, in a base electrolyte, the N-doped porous carbon also shows excellent energy storage performance with a specific capacitance of 268 F g−1 at 1 A g−1 in the potential range of – 1 to 0 V along with capacitance retention of 67.2% at 20 A g−1. After 10,000 cycles tested at 10 A g–1, our sample still maintains 94.4% retention of initial capacitance. It is convinced that the microstructures result in excellent electrochemical performance.

In this work, experimental and mathematical substantiation of the possibility of using the new RCTU-4 hydrophobic catalyst [0.9 mass % Pt/styrene and divinylbenzene (SDVB)] in the separation of pro...

It is believed that porous heterogeneous materials with excellent properties are promising candidates for efficient fixation of diluted and waste CO2. Herein, a family of mesoporous porous ionic copolymers (PIPs) was designed and prepared from the copolymerization of divinylbenzene (DVB) with vinyl-functionalized ionic liquids monomers through free radical copolymerization process. It was demonstrated that the heterogeneous PIP poly(divinylbenzene-1-allyl-tetramethylguanidinium bromide) PDVB-[AlTMG]Br-0.2 showed excellent activities in facile cycloaddition of CO2 into cyclic carbonates without using any external co-catalysts or metal additives. The results of characterizations and quantum mechanical calculations further showed that the specic hierarchical meso-macroporous structure of PDVB-[AlTMG]Br-0.2 offered the strongest binding interaction with SO and besides had a relatively good CO2 affinity, which results to the best cataltic activity for cycloaddition of CO2. Moreover, PDVB-[AlTMG]Br-0.2 exhibited high activities and good reusability in cycloaddition of 15 % diluted CO2 with various epoxides. It is believed that our work would have a great potential in energy-effective fixation of industrial combustion CO2 into high-value organic carbonates.

Although Huckel molecular orbital theory (HMO) has been generally outdated as a computational method for the energetics of organic molecules, there is still much we can learn from it. This paper explores two compounds, 1,4-divinylbenzene and 2-phenylbutadiene, which, according to Huckel theory, are isospectral, i.e., they have the same eigenvalues and orbital energy levels. However, by using a small, well-defined perturbation, we show it is mathematically possible to distinguish between these two compounds. We suggest that this is a general procedure for distinguishing isospectral pairs of molecules as opposed to the two species being identical.

Polymerized high internal phase emulsion (polyHIPE) monoliths have attracted much attention because of their ease of preparation, precise control of porous structure and useful properties. For many applications, such as chromatographic separation media, reactivity or absorptivity, post-modification of surface functional groups is required to achieve the desired functionality. However, for fluoro-polymers, it has been a challenge to fabricate high-performance foams with uniform porous structures using HIPE due to the lack of suitable surfactants to stabilize the fluorinated emulsions. In our work, we proposed a bottom-up approach where the same surfactant that stabilized the water droplets within the oil phase was used to control the solid foam surface chemistry. We employed reversible addition–fragmentation chain transfer living radical polymerization to synthesize amphiphilic-fluorinated macrosurfactant (mPEG5K-PHFBMA) to stabilize water-in-oil (W/O) HIPE. Using hexafluorobutyl methacrylate as the oil-phase monomer and divinylbenzene as the cross-linking agent, we achieved a one-pot preparation of polyHIPEs based upon poly(ethylene glycol) (PEG) with biocompatible pore surfaces and potential use in tissue engineering. The effects of amphiphilic macromolecular surfactant concentration, PHFBMA block length and initiator oil/water solubility on the emulsion droplet size, pore morphology, porous surface performance and mechanical properties were studied. The PEG modification on porous surface in the polyHIPE was also confirmed by a contact angle test and water uptake experiment. It was found that short-chain fluorinated materials demonstrated very little bioaccumulation potential and consequently better environmental safety attributes. The addition of PEG gave good biocompatibility, and the properties of these porous materials may have great potential in cell tissue engineering applications.

Controlled and straightforward functionalization are relevant strategies to obtain MoS2 platforms with defined functionality and improved processability. In this work, an efficient strategy for the functionalization of MoS2 using Reversible Addition Fragmentation Transfer (RAFT) polymerization is reported. The RAFT reagent was directly created on the surface of freshly exfoliated MoS2 and the obtained two-dimensional platform was used for the polymerization of styrene and acrylamide monomers. Various ratios of divinylbenzene were used to crosslink polystyrene brushes and create a polymeric coverage on the surface of MoS2. Furthermore, the polymerization of a mixture of styrene and acrylamide monomers using a MoS2-based RAFT agent resulted in two-dimensional platforms containing copolymer brushes. The structures of the synthesized two-dimensional materials were investigated using different spectroscopy and microscopy techniques as well as thermal and elemental analyses. This research provides an efficient method for the preparation of functional two-dimensional MoS2 nanostructures using RAFT polymerization in gram scale.

Magnetic polymeric nanocomposite particles were used as an adsorbent for the extraction of atrazine in soil and water samples. The authors combined magnetic dispersive solid-phase extraction (MD-SPE) and dispersive liquid–liquid microextraction (DLLME) coupled with a gas chromatography-nitrogen phosphor detection for the preconcentration and determination of the analyte. Magnetic nanocomposites of cross-linked poly(styrene/divinylbenzene) (Fe3O4@PS/DVB-MNPs) with the mean size of about 60 nm were prepared by a mini-emulsion polymerization technique. The parameters affecting the extraction efficiency including the amount of adsorbent, absorption and desorption times, the volume of the elution (disperser) and extraction solvents, pH and volume of the sample solution, and salt concentration were optimized by a response surface methodology. Acetone was selected as the eluent in MD-SPE and disperser solvent in DLLME, and chlorobenzene was used as the extraction solvent. Under the optimized conditions, the enrichment factor was 750 and extraction recovery was 53%. The response was linear in the range of 0.05–450 μg L−1 with a determination coefficient of 0.9988. The limit of detection was 0.01 μg L−1. The intra-day and inter-day precisions of the method were in the range of 2.8–5.2% and 4.6–7%, respectively. The relative recovery of the method was in the range of 81–103% for the real samples.

Aminopolycarboxy acids (APAs) are well known for their ultrastong affinity for heavy metals. Their monolayer, full-coverage, robust and one-step decoration of the surface of a macroporous adsorbent has not yet been realized. In the current work, we derived a cost-effective strategy to produce a porous adsorbent with the aid of a dendritic macrosurfactant. Branched polyethylenimine (PEI) was partly alkylated with glycidyl cetylether (C16) to form a dendritic polyamine macrosurfactant (PEI@C16, Mn ∼ 104). This macrosurfactant well stabilized a water-in-oil high internal phase emulsion (HIPE), while a macrosurfactant counterpart based on linear PEI did so poorly. Heating the HIPE system triggered a simultaneous transformation of the residual amines of PEI@C16 into APAs and of the oil phase (consisting of styrene, divinylbenzene and radical initiator) into an open-cellular solid matrix. The resulting open-cellular monolith showed a rather large specific surface area and very high affinity for various heavy metal ions in water. The adsorption of Pb(II) was indicated to follow a chemical and monolayer adsorption mechanism. The adsorbent showed good recyclability, due to the robustly anchored APAs.

This work describes the suitability of a polyethylene styrene–DVB based interpolymer cation exchange membrane for use in a highly alkaline redox flow battery (RFB) with a [Fe(TEA)OH]2−/[Fe(TEA)OH]− and Fe(CN)63−/Fe(CN)64− redox couple. The alkaline stability of the membrane for 1440 h was evaluated in 5 N NaOH containing a 200 mM Fe(CN)63−/Fe(CN)64− redox couple. It was assessed according to the changes in the electrochemical and physicochemical properties. The performance of the membrane was evaluated over 40 charge–discharge cycles at a current density of 5 mA cm−2 current in a designed RFB cell. The obtained average coulombic efficiency (CE) was 92%, energy efficiency (EE) was 75%, voltage efficiency (VE) was 82% and volumetric efficiency was 34%. Under identical experimental conditions, the values of CE, EE, and VE for Nafion®-112 were 99%, 75%, and 76%, respectively. These results indicate the suitability of the polyethylene styrene–DVB based interpolymer cation exchange membrane for use in an alkaline RFB.

We report polymerization-induced self-assembly via controlled cross-linking copolymerization to produce robust block copolymer micelles with spherical, elongated, and branched shapes. Reversible addition–fragmentation chain transfer (RAFT) copolymerization of styrene and divinylbenzene (DVB) or 1,2-bismaleimidoethane (BMI) as a cross-linker in the presence of a polylactide macro-chain transfer agent (PLA-CTA) was performed in acetonitrile, which is a non-solvent to polystyrene (PS). The addition of the cross-linker accelerates the copolymerization compared to styrene homopolymerization, which leads to the formation of block polymer micelles within a shorter time frame, followed by in situ inter-chain cross-linking. The micelles are virtually identical to the core cross-linked star polymer consisting of a cross-linked polystyrenic core surrounded by a PLA corona. Molecular weights up to more than 1000 kg mol−1 could be obtained with relatively narrow dispersity values (1.1–1.4). In the case of copolymerization with DVB, the micellar morphology changes from spherical to elongated and branched shapes with increasing conversion. The size and morphology of the micelles are retained in a good solvent to PS, suggesting that the in situ cross-linking effectively stabilizes the micellar core. BMI undergoes alternating copolymerization with styrene in the early stage of polymerization and yields spherical micelles exclusively, because the densely cross-linked core seems to prevent further morphological transition.

Pre-concentrators are used to improve the detection of analytes that are at low concentration, particularly in air. Polymeric materials are the basis for most pre-concentrators and a strategy to enhance the pre-concentration capability is to add moieties that enhance the polymer matrix–analyte interaction. In this study, the sorption capability of poly(dimethylsiloxane) (PDMS)-based pre-concentrator films towards nitro-based explosives was improved by incorporating a 1,4-divinylbenzene (DVB) derived component. It was found that the mode of DVB incorporation strongly influenced the structure and pre-concentration properties of the resulting film. Films formed from blends of PDMS and DVB (PDMS:DVB) were found to have similar sorption properties as PDMS. The copolymerised (PDMS-co-DVB) film was found to be comprised of voids and spheroidal features, which were retained even after thermal treatment. The copolymer film offered the greatest sorption and retention of analyte vapor, which we attribute to increased material surface area and π–π interactions between the DVB-derived units and the nitroaromatic analytes. The copolymerised film was able to increase the effective concentration of TNT vapor by 3 orders of magnitude relative to the headspace vapor concentration.

Based on the electron-transfer mechanism between the template and quantum dots (QDs), an optical sensor was structured. It is a phenol sensor, which has the room-temperature phosphorescence (RTP) property of Mn-doped ZnS QDs and high selectivity of molecular imprinted polymers (MIPs). On the surface of the silane modified Mn-doped ZnS QDs, the phenol sensor was prepared by double cross-linker precipitation polymerization in the absence of any stabilizer and additive. Double cross-linkers, divinylbenzene (DVB) and ethyleneglycol dimethacrylate (EGDMA), make a great contribution to the imprinted polymerization with hydrogen-bonding interaction. Then, as a result of the functional monomer, methacrylic acid (MAA), a carboxylic acid was grafted onto the surface of ZnS QDs:Mn@MIPs. Under optimal conditions, the phenol determination experiment had a linear range of 5.0 to 55 μmol L−1 with a correlation coefficient of 0.9984, and a high imprinting factor (IF) of 3.43. In addition, the prepared ZnS QDs:Mn@MIPs were successfully used to detect phenol in real water samples. Therefore, this work provided a highly selective and sensitive RTP probe for phenol determination.

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).

High-refractive-index sulfur-rich polymers with significantly improved thermal properties are prepared using divinylbenzene (DVB) as a comonomer in a modified, low-temperature inverse vulcanization with elemental sulfur. Differential scanning calorimetry and Fourier transform infrared studies reveal that under the modified inverse vulcanization conditions, homopolymerized DVB segments form, leading to high glass-transition temperatures (

The present study describes the thermal properties of a series of porous microspheres synthesised from the dimethacrylate derivative of m-xylene, i.e. (4,6-dimethyl-1,3-phenylene)dimethylene bis(2-methylprop-2-enoate) and divinylbenzene via an aqueous suspension polymerisation in the presence of toluene and decan-1-ol as porogenic diluents. Various molar ratios of monomers were applied in the syntheses (1:4, 1:1, 4:1). The TG/DSC/FTIR analyses were performed in inert (helium) and oxidative (synthetic air) atmospheres. They revealed that the properties of the copolymeric microspheres were dependent on both their chemical composition and the testing atmosphere. The microspheres were stable up to 229–296 °C (in helium) and 302–308 °C (in synthetic air), as determined on the basis of the temperature of 1% mass loss. However, the most thermally stable were those synthesised at the molar ratio of the dimethacrylate derivative of m-xylene to divinylbenzene equal to 1:4. In helium, the copolymeric beads decomposed in one, two or three stages, whereas in synthetic air in two ones. The basic decomposition volatiles were carbon monoxide, carbon dioxide and organic carbonyl products, including esters, carboxylic acids and aldehydes as well as unsaturated and aromatic compounds.

In this study, the synthesis of divinyl benzene (DVB) cross-linked styrene (Sty)/butyl acrylate (BA)/acrylic acid (AAc) copolymer (SAC) latex particles via the semibatch seeded emulsion polymerization of poly(Sty/BA/AAc) seeds and Sty/BA/AAc or Sty/BA/AAc/DVB monomers was investigated. The structures and morphologies of SAC latex particles were explained by means of DSC, TG/DTG, SEM, 1H-NMR, FTIR, MFFT, and DLS techniques. Optimization studies showed that while the mass ratio of BA in the latex was 68, the glass transition temperature (Tg) value became − 19.8 °C, and when the mass ratio of BA decreased to 30, the Tg value increased to 31.5 °C. The glass transition characteristics of SAC latex were affected by the addition of DVB. The Tg for 0, 0.5, 1.0, 1.5, and 2.0 wt.% DVB/SAC latex particles is 7.5, 8.1, 22.8, 23.4, and 24.5 °C, respectively. The presence of DVB moiety in the SAC latex particles caused the increased thermal stability. The degradation step of the acrylate ester became more dominant with the increasing amount of DVB in the latex. The average particle size and polydispersity index values revealed that the DVB cross-linked SAC latex particles have satisfactory stability and good dispersibility.

The possibility of creating monolithic plates containing functional groups capable of performing therole of MALDI matrices is shown, and the first results on desorption / ionization of compounds with massesof the order of 400 Da are demonstrated. Monolithic plates were prepared based on (co)polymers of glycidylmethacrylate and ethylene glycol dimethacrylate with the content of the first from 0 to 29% and styrene anddivinylbenzene with the content of styrene from 0 to 35%. The best results were obtained for TLC plates withglycidyl methacrylate content from 19 to 29% and with a styrene content of 5 to 20%. It is noted that the absence of a monofunctional monomer in the polymerization mixture resulted in the suppression of analyteionization and the impossibility of using such TLC plates in the MALDI-MS mode. Another factor affecting the possibility of desorption / ionization of compounds is the quality of the surface. The presence of roughness,uneven surface dramatically affect the ability to work in the mode of MALDI-MS, and the monoliths,containing less than 19% of the GMA, were mechanically fragile, and manipulation with them easily led tosurface damage. Similar results were obtained for monolithic sorbents based on (co)polymers of styrene anddivinylbenzene with styrene percentage lower than 10%. In order to obtain information on the surface relief,monolithic layers were prepared on glass substrates (18 × 18 mm, 0.13–0.17 mm thick) with various contentsof monofunctional monomers and using various porogens and were studied by scanning electron microscopy.According to the height distribution histograms, it was found that for a sample of St-DVB copolymer containing 30% styrene and 10% divinylbenzene in the initial polymerization mixture (undecanol-toluene solvent 52: 8) the highest density corresponded to an average roughness value of 150 nm, whereas for sample composition (14% GMA + 26% DMEG, 60% cyclohexanol), the highest density corresponded to an average roughness value of 50-60 nm. The proposed method for obtaining MALDI-MS-TLC spectra eliminates one of the most labor-intensive stages of the process associated with the preparation and application of theMALDI matrix on a TLC plate

An adequate and simple analytical method based on solid-phase microextraction (SPME) followed by gas chromatography–flame photometric detection (GC–FPD) for the determination of eleven organophosphorus pesticide residues (i.e., ethoprophos, sulfotep, diazinon, tolclofos-methyl, fenitrothion, chlorpyrifos, isofenphos, methidathion, ethion, triazophos, leptophos) in vegetables samples (cabbage, kale and mustard) was developed. Important parameters that influence the extraction efficiency (i.e., fibre type, extraction modes, extraction time, salt addition, desorption time and temperature) were systematically investigated. Four types of commercially available fibres (i.e., 50/30 μm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), 65 μm polydimethylsiloxane/divinylbenzene (PDMS/DVB), 100 μm polydimethylsiloxane (PDMS), and 85 μm polyacrylate (PA)) were evaluated. PA fibre exhibited the best performance and was used for the rest of the studies. The optimised extraction conditions were: extraction time, 30 min at room temperature; stirring speed, 1275 rpm; salt content, 10% NaCl; desorption time and temperature, 11 min at 260 °C; and no pH adjustment of the sample extract. The method was validated over the range 0.1–100 μg/L. Repeatabilities were satisfactory, ranging between 2.44% and 17.9% for all analytes. The limits of detection and quantitation ranged from 0.01 to 0.14 and 0.03 to 0.42 μg/L, respectively. The method was applied to twenty local vegetable (cabbage, kale and mustard) products. Chlorpyrifos (0.22–1.68 μg/kg) was the most detected pesticide in the tested samples. The obtained values are however lower than the Maximum Residue Limits (MRLs) as stipulated in the Food Act & Regulations of Malaysia. Keywords: Organophosphorus pesticide, Direct immersed-solid phase microextraction, Gas chromatography–flame photometric detector, Vegetables

A facile approach has been adopted for coating cross-linked polystyrene (PS) shells on the surface of Fe3O4 magnetic clusters using reflux-precipitation polymerization (RPP). Treating the PS shell with chlorosulfonic acid yields magnetic composite particles with acid functionality. By adjusting the amount and proportion of monomers (styrene and divinylbenzene), the obtained magnetic composite particle solid acid (MPM-5S) exhibits a saturation magnetization value of 18 emu/g, a specific surface area of 243 m2/g and an acid density of 2.113 mmol/g. The MPM-5S magnetic solid acid catalyst was evaluated for esterification of oleic acid with methanol to prepare biodiesel. Under mild conditions, the conversion of oleic acid reached 91%, which was much higher than the catalytic activity of Amberlyst-15 and close to the catalytic activity of concentrated H2SO4. The solid acid catalyst can be recovered by magnetic separation and reused three times maintaining over 95% of its initial catalytic activity. Additionally, the solid acid can be used to catalyze the dehydration of fructose to 5-hydroxymethylfurfural.

A reliable method using disposable pipette extraction (DPX) based on composite of pernigraniline and styrene–divinylbenzene (Sty–DVB) copolymer was applied to the analysis of dexamethasone in synovial fluid using high-performance liquid chromatography and ultraviolet (UV) detector (HPLC–UV). DPX variables, namely, number of draw/eject cycles for extraction or desorption, sample pH, volume, and desorption solvent, were optimized to establish the best sorption equilibrium and analysis time. The highest extraction efficiency value was obtained with 50 μL of synovial fluid mixed with 1950 μL of water, in five cycles of 300 μL of sampling, followed by liquid desorption of the drug with 300 μL of methanol in three cycles. The developed method demonstrated a linear response over the range from 10 to 100 ng/mL, with R2 = 0.993. The limit of quantification (LOQ) was 10 ng/mL. Based on the validation results, the proposed method can be a useful tool to detect dexamethasone levels in synovial fluid.

A series of poly(ionic liquid)s-supported N-heterocyclic carbene silver complexes (Poly(NHC-Ag/IL)s), poly(ionic liquid)s (PILs) and poly(N-heterocyclic carbene silver complexes) (Poly(NHC-Ag)s) were prepared through radical co-polymerization of N-vinylimidazolium ionic liquids, NHC-Ag monomers and divinylbenzene, respectively. These polymers were applied to catalyze the cycloaddition reaction of carbon dioxide and epoxides without any co-catalyst. Poly(NHC-Ag/IL)s exhibited higher activities than the corresponding PILs and Poly(NHC-Ag)s, which was attributed to the synergistic effect of NHC-Ag and bromide. Furthermore, Poly(NHC-Ag/IL)s could be easily recycled five times without significant loss of catalytic activity. Multi-functional poly(ionic liquid)s-supported N-heterocyclic carbene silver complexes (Poly(NHC-Ag/IL)s) were synthesized by radical co-polymerization of N-vinylimidazolium ionic liquids, NHC-Ag monomers and DVB. Poly(NHC-Ag/IL)s exhibited high activities for cycloaddition reaction of carbon dioxide and epoxides due to their multi-functional groups including Lewis acidic silver and a bromine anion.

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.

Στην παρούσα διδακτορική διατριβή επιδιώκεται η σύνθεση και ο χαρακτηρισμός πολυμερικών νανοδομών ελεγχόμενης μορφολογίας, με την τεχνική του πολυμερισμού μέσω ελευθέρων ριζών (FRP) σε οργανωμένα υδατικά διαλύματα, καθώς και η διερεύνηση δυνητικών εφαρμογών των υλικών αυτών. Για το σκοπό αυτό, ο πολυμερισμός των υλικών πραγματοποιείται παρουσία οργανωμένων υπερμοριακών δομών, οι οποίες αναμένεται να λειτουργήσουν ως εκμαγεία (templates). Τα εκμαγεία αυτά οργανώνονται από κατάλληλες επιφανειοδραστικές ενώσεις μέσω υδρόφιλων/υδρόφοβων ή/και ηλεκτροστατικών αλληλεπιδράσεων σε υδατικό περιβάλλον. Οι κατηγορίες εκμαγείων που αξιοποιήθηκαν σε αυτή τη μελέτη είναι: οι δομές αυτοοργάνωσης των επιφανειοδραστικών ενώσεων σε φυλλώδη (Lamellar) ή σπογγώδη (sponge) φάση, η ανάπτυξη σκωληκοειδών μικκυλίων και η ικανότητα των επιφανειοδραστικών ενώσεων να δημιουργούν γαλακτώματα παρουσία κάποιας οργανικής φάσης.Τα μονομερή που επιλέχθηκαν για τον πολυμερισμό στο επιθυμητό εκμαγείο είναι το στυρόλιο (St), το 4-βινυλοβενζυλοχλωρίδιο (VBC), ο οξικός βινυλεστέρας (VAc) και το στυρενοσουλφονικό νάτριο (SSNa), ενώ οι επιφανειοδραστικές ενώσεις που χρησιμοποιήθηκαν για το σχηματισμό των εκμαγείων ήταν το δωδεκυλο θειικό νάτριο (SDS), το βρωμιούχο δεκαεξυλτριμεθυλαμμώνιο (CTAB) και ο πολυαιθυλενο-γλυκολ-δωδεκυλ-αιθυλαιθέρας (Brij-30). Για τη σταθεροποίηση της μορφολογίας, όλοι οι πολυμερισμοί πραγματοποιήθηκαν παρουσία του διασταυρωτή διβινυλοβενζόλιο (DVB). Μέσω ηλεκτρονικής μικροσκοπίας σάρωσης (SEM) ή/και διαπερατότητας (TEM) επιβεβαιώθηκε, η σύνθεση νανοσφαιρών (PSt), πλακόμορφων νανοδομών (PSt, PVAc και PVBC) και δικτύου νανοράβδων (PSt και PVBC). Η επιτυχία των συνθέσεων καθώς και η διατήρηση της μορφολογίας έπειτα από θερμική καταπόνηση ή χημικές τροποποιήσεις, όπως θα παρουσιαστούν στη συνέχεια, πιστοποιήθηκε με φασματοσκοπία υπερύθρου ATR-IR, θερμοσταθμική ανάλυση TGA και ηλεκτρονική μικροσκοπία σάρωσης SEM. Η ειδική επιφάνεια των δειγμάτων προσδιορίστηκε με τη μέθοδο Brunauer-Emmet-Teller (BET).Η αναζήτηση πρωτότυπων δυνητικών εφαρμογών των συντεθέντων υλικών αποτέλεσε το αντικείμενο ενασχόλησης των επόμενων σταδίων της παρούσας διδακτορικής διατριβής. Έτσι, διερευνήθηκε η εφαρμογή τους ως εν δυνάμει προσροφητές χρωστικών ουσιών από υδατικά απόβλητα ή προσροφητές μοριακού οξυγόνου από υδατικά συστήματα ή αέρα. Όσον αφορά την πρώτη εφαρμογή, αξιοποιήθηκαν τα δίκτυα νανοράβδων διασταυρωμένου PVBC τα οποία τροποποιήθηκαν κατάλληλα με φορτισμένες ομάδες ή φορτισμένα πολυμερή. Διαπιστώθηκε πως η προσροφητική ικανότητα των υλικών αυτών έναντι των αντίθετα φορτισμένων χρωστικών ουσιών Orange II και Methylene blue είναι σημαντική, 175mg/g – 500 mg/g και 160 mg/g για τις δύο χρωστικές αντίστοιχα.Η εναλλακτική λειτουργικότητα των νεοσυντεθέντων υλικών που μας απασχόλησε ήταν η προσρόφηση μοριακού οξυγόνου από υδατικά συστήματα ή αέρα. Για το σκοπό αυτό αξιοποιήθηκαν τόσο υδατοδιαλυτά πολυμερή όσο και σφαιρικά νανοσωματίδια PSt ή PVBC, στα οποία ενσωματώθηκε κατά τον πολυμερισμό η δραστική ομάδα της ανθρακινόνης (AQ), η οποία αντιδρά με το οξυγόνο έπειτα από κατάλληλη ενεργοποίηση με UV ακτινοβολία. Ανάλογα με την περίπτωση τα νέα υλικά μελετήθηκαν σε διαλύματα, διασπορές ή ενσωματωμένα σε πολυμερικές μήτρες. Διαπιστώθηκε πως έπειτα από κατάλληλη ενεργοποίηση με UV ακτινοβολία απομακρύνουν αποτελεσματικά το διαλυμένο οξυγόνο από υδατικά συστήματα, με τελική τιμή ~1ppm, ενώ λειτουργούν ικανοποιητικά για τη δέσμευση οξυγόνου του αέρα. Στην περίπτωση του υδατοδιαλυτού συμπολυμερούς, αυτή η λειτουργία συνοδεύεται με αλλαγές στα φάσματα απορρόφησης UV-vis αμέσως μετά την ακτινοβόληση με UV ακτινοβολία, ως ένδειξη σχηματισμού νέων ειδών AQ, καθώς και με σημαντική εκπομπή φωτός από τα φωτο-διεγερμένα είδη της.

Open tubular CEC (OT-CEC) column with a very high separation efficiency was prepared for peptides separation. A pretreated silica-fused capillary was reacted with 3-(methacryloxy) propyltrimethoxysilane followed by vinylbenzyl chloride and divinylbenzene to produce first thin monolithic monolayer. The second copolymer layer was formed on thin monolithic monolayer of the capillary by reversible addition-fragmentation transfer polymerization of N-phenylacrylamide and styrene. The key parameters including buffer pH value and organic modifier were systematically evaluated to provide the optimal chromatographic condition. The resultant OT-CEC columns were validated by separating a synthetic mixture of peptides and cytochrome C tryptic digest in capillary electrochromatography. The number of theoretical plates as high as 2.4 million per column was achieved for synthetic mixture peptides. In addition, the fabricated OT-CEC column also resolved more than 18 high-efficiency digestion peptides from a mixture containing tryptic digest of cytochrome C. The column to column and inter- to intraday repeatabilities of OT-CEC column through RSD% were found better than 3.0%, exhibiting satisfactory stability and repeatability of the two-layer deposited OT-CEC column. The results reveal that the open tubular capillary column modified with two-layer copolymer shows the great prospect for the separation of proteins in capillary electrochromatography.

The preparation of nanofibers with finer diameters is of great importance to meet the needs of nanomaterials in fabricating nano-devices. The diameter of polydivinylbenzene nanofibers can be reduced from 200 nm to 20–50 nm by adding a very small amount of oleic acid-capped Fe3O4 nanoparticles during the polymerization of divinylbenzene. Through ultrasonic disruption and magnetic separation of the nanofiber composites, we can obtain purified ultrafine nanofibers without Fe3O4 nanoparticles. The ultrafine nanofibers have widespread potential applications in nanomaterials and nano-devices with smaller requirements.