Vinylbenzyl Chloride-divinylbenzene Research Articles

Silver(I) recovery on thiomorpholine - modified functional polymer

The functional polymer containing heterocyclic ligands was synthesized by microwave modification of a crosslinked poly(vinylbenzyl chloride–divinylbenzene) matrix with thiomorpholine. The modification yield was 89.3%. The sorbent was used to recover Ag(I) from the synthetic and real chloride solutions. The maximum sorption capacity of Ag(I) was approximately 180 mg Ag/g. The sorption kinetic data were well-fitted to the pseudo-first-order kinetic model. The degree of silver desorption was approximately 50.0% using a 1.0% potassium cyanide solution in a 0.50% hydrogen peroxide solution. The resin retained its capacity toward Ag(I) in five consecutive sorption/desorption cycles. The thiomorpholine modified resin was highly selective toward Ag(I) in relation to Cu(II), Pb(II), Co(II), Ni(II), and Zn(II) from the real chloride leaching solution.

Novel Polymer Sorbents with Imprinted Task-Specific Ionic Liquids for Metal Removal.

In this paper, the potential of novel polymer sorbents with the imprinted IL-functional group for the removal of Cu(II), Cd(II), and Zn(II) from aqueous solutions was investigated by batch mode. The sorbents were fabricated by direct reaction of the prepared polymer matrix (poly(vinylbenzyl chloride-divinylbenzene), VBC, and poly(vinylbenzyl bromide-divinylbenzene), VBBr) with 1-(3- or 4-pyridyl)undecan-1-one and oxime of 1-(3- or 4-pyridyl)undecan-1-one. The Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy (Raman), Thermogravimetric Analysis (TG), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM) techniques were used to show functionality and stability of the sorbents. The materials were also characterized by contact-angle goniometry, X-rayphotoelectron spectroscopy (XPS), and Zeta potential analysis. The removal of Cd(II), Cu(II), and Zn(II) was monitored and optimized under the influence of several operational controlling conditions and factors such as pH, shaking time, temperature, initial metal ions concentration, and counter-ions at the functional group. The results obtained confirmed the very high potential of the sorbents; however, the properties depend on the structure of the functional group. The tested sorbents showed fast kinetics, significant capacity at 25 °C (84 mg/g for the Zn(II) sorption with VBC-Ox4.10, 63 mg/g for the Cd(II) sorption with VBBr-Ox3.10, and 69 mg/g for the Cu(II) sorption with VBC-K3.10), and temperature dependence (even 100% increase in capacity values at 45 °C). The selected sorbent can be regenerated without a significant decrease in the metal removal efficiency.

Novel ionic liquid-modified polymers for highly effective adsorption of heavy metals ions

Two novel efficient and selective sorbents were proposed for the Cd(II), Zn(II) and Cu(II) removal from aqueous solutions. The porous organic poly(vinylbenzyl chloride-divinylbenzene) copolymer modified by means of quaternization with 1-(4-pyridyl)undecan-1-one and 1-(4-pyridyl)ethan-1-one were found to be highly effective in removal of Cu(II), Zn(II), and toxic Cd(II) from aqueous solutions. The efficiency of the process depended on the functionalised agent structure, as well as temperature, metal ions concentration and pH of the aqueous solutions. Moreover, adsorption isotherms and kinetics were studied to understand the mechanism of the synthesized sorbent. The thermodynamics studies showed that the removals of mentioned ions onto novel sorbents was facilitated at higher temperature. The maximum adsorption capacities of Cd(II), Cu(II) and Zn(II), were 67.5, 105.4, and 99.9 mg/g of the ionic liquid-modified polymer sorbents, respectively. Moreover, the studied sorbent can be regenerated without significant adsorption capacities loss.

Preparation and properties of amorphous TiO2 modified anion exchange membrane by impregnation-hydrolysis method

Amorphous TiO2 was introduced into the anion exchange membrane (AEM) derived from vinylbenzyl chloride-divinylbenzene copolymers. The structures and morphologies were characterized by FT-IR, XRD and SEM. The properties such as ion exchange capacity, hydroxide conductivity, swelling ratio and water uptake were calculated, and the fuel cell performance was tested and compared. The results showed that the hydrophilic/hydrophobic phase separation of the AEM was improved, the water uptake of the AEM also increased from 22.5% to 40.6% and the hydroxide conductivity increased from 35 mS/cm to 43 mS/cm at 30 °C in deionized water, and the fuel cell performance was greatly enhanced under unsaturated humidification conditions.

Novel conventional and chelating anion exchange resins with amino ligands for sorption of silver

ABSTRACT The polymeric resins containing diethylenetriamine, tetraethylenepentamine, 2-(diethylamino)ethanol, 1-methylimidazole, and 1,2-dimethylimidazole ligands have been synthesized from vinylbenzyl chloride-divinylbenzene copolymers and used in the removal of Ag(I) from chloride solution. The best Ag(I) sorption was reached in the case of 1-methylimidazole resin. Resins retain their capacity towards Ag(I) in five consecutive sorption/desorption cycles. The resins with imidazole ligands were highly selective for Ag(I) from synthetic chloride solution and they did not sorb chloride complexes of Cu(II). Additionally, the recovery of Ag(I) was tested from real chloride solution coming from leaching of the copper concentrate from Lubin Concentrator (KGHM Polska Miedź S.A.).

A Novel Polymeric Adsorbent Embedded with Phase Change Materials (PCMs) Microcapsules: Synthesis and Application.

The heat released during the industrial gas adsorption (e.g., volatile organic compounds (VOCs)) on adsorbents (e.g., activated carbon) would lead to the risks of fire and explosion in the adsorption column. Herein, a novel highly-porous Vinylbenzyl chloride-Divinylbenzene (VBC-DVB) polymeric adsorbent was synthesized with embedded microcapsules (Hypercrosslinked VBC-DVB Beads (HVPM)). These microcapsules have a polydivinylbenzene-phase change materials (DVB-PCMs) core-shell structure. Paraffin wax was used as PCM filling in the spherical capsule. This microcapsules-embedded polymeric adsorbent HVPM (Φ1.5–2.0 mm) is found to possess a high specific surface area (~665 m²/g) and micropore-dominant structure. It also has heat storage capability indicated by DSC (Differential Scanning Calorimetry) analysis (11.1 J/g heat of fusion between 35.0 and 48.2 °C) for the encapsulated paraffin wax. The lab adsorption tests proved the capabilities of HVPM in adsorbing VOCs (toluene, 0.21 g/g) and controlling the temperature inside the adsorption column during the dynamic adsorption process, in which the temperature rise was lowered by 62.5%, relatively.

New hybrid matrices for the synthesis of ion-exchange resins. The impact of the synthesis procedure on their porosity, functionalization and sorption of noble metals

ABSTRACTIn the search for new polymeric supports for the synthesis of ion-exchange resins, a new method has been assessed. A series of core-shell-type polymeric supports, based on the Amberlite XAD-4 adsorbent and vinylbenzyl chloride-divinylbenzene copolymer, has been obtained. The polymers, characterized by a diversified porous structure, were assessed by their functionalization into anion exchangers and their ability to remove Au(III), Pt(IV) and Pd(II).The efficiency of functionalization using ethylenediamine, as well as sorption capacity, was compared to the textural parameters of the initial supports, defining methods and techniques that will allow materials characterized by the most efficient usage of the vinylbenzyl chloride (VBC) monomer to be obtained.

Surface Properties of Hyper-Cross-Linked Polymeric Resins Using Inverse Gas Chromatography: Effect of Post-Cross-Linking Solvents

Two series of hyper-cross-linked polymeric resins (hyper-resins) were prepared via post-cross-linking of low-cross-linked macroporous poly(vinylbenzyl chloride-divinylbenzene) (poly(CDVB)) or poly(styrene-divinylbenzene) (poly(DVB)) swollen in the solution of 1,2-dichloroethane or nitrobenzene, respectively. Inverse gas chromatography was used to investigate the effect of post-cross-linking solvents on the surface chemistry of hyper-resins. The dispersive component of the surface free energy (γsd) and surface acid–base character of hyper-resins were estimated using the retention time of different nonpolar and polar probes at the infinite dilution region. Results showed that the values of γsd were basically identical for the hyper-resins prepared using the same precursor; the acidity and basicity constants KA and KD confirmed that the surface of four hyper-resins were Lewis amphoteric with predominantly basic character, but the strength of the surface acidic and basic sites of hyper-resins synthesized usin...

Kinetic Modeling of Transesterification of Triacetin Using Synthesized Ion Exchange Resin (SIERs)

Strong anion exchange resins with QN+OH-, have the potential to be developed and employed as heterogeneous catalyst for transesterification, as they are chemically stable to leaching of the functional group. Nine different SIERs (SIER1-9) with QN + OH were prepared by suspension polymerization of vinylbenzyl chloridedivinylbenzene (VBC-DVB) copolymers in the presence of n-heptane (pore-forming agent). The amine group was successfully grafted into the polymeric resin beads through functionalization with trimethylamine. These SIERs are then used as a catalyst for the transesterification of triacetin with methanol. A set of differential equations that represents the Langmuir-Hinshelwood-HougenWatson (LHHW) and Eley-Rideal (ER) models for the transesterification reaction were developed. These kinetic models of LHHW and ER were fitted to the experimental data. Overall, the synthesized ion exchange resin-catalyzed reaction were welldescribed by the Eley-Rideal model compared to LHHW models, with sum of square error (SSE) of 0.742 and 0.996, respectively.

Highly efficient phase transfer catalyst supported on Janus composite particles: Synthesis, characterization, and applications

Abstract

Ion-exchange polyHIPE type membrane for removing nitrate ions: Preparation, characterization, kinetics and adsorption studies

Highly open cellular porous vinylbenzyl chloride/divinylbenzene (VBC/DVB) polyHIPE solid foam was synthesized via polymerization of a high internal phase emulsion (HIPE). In addition, the emulsion foam was reinforced using various amounts of an organically modified montmorillonite, i.e. Cloisite30B (C30B). Scanning electron microscope (SEM) micrographs showed a typical open-cell polyHIPE structure for all the reinforced polyHIPE foams. The incorporation of only 1wt% C30B decreased the mean cell diameter and intercellular pore size and increased the compressive mechanical properties of the copolymer foam. The amination of the neat and reinforced polyHIPE foams using an aqueous trimethylamine (TMA) solution resulted in amino-functionalized polyHIPE type membrane with nitrate anion exchange capability. The ion exchange capacity (IEC) of the resulting membranes was measured by titration procedure. The effect of the amine concentration and C30B level on the IEC of the membranes was investigated. Increasing the amination level enhanced the IEC to maximum value of 1.57mequiv./g dry membrane. On the other hand, the increase of C30B up to 1wt% increased the IEC value to 1.78mequiv./g dry membrane while further increase, 3wt%, decreased the IEC value even lower than that of the neat membrane. The prepared anion exchange polyHIPE membranes were used to remove nitrate ions from low-concentration aqueous solutions. The kinetic and thermodynamic adsorptions of nitrate ions on the membrane from the aqueous solutions were investigated. The sorption results also showed that the existence of competitive chloride and sulfate ions decreased the membrane performance for removing nitrate ions. Nevertheless, using another tertiary amine agent with bigger alkyl chain size, triethylamine (TEA), improved the selectivity of nitrate sorption to some extent in competition with the other existing interfering anions.

Incorporation of multi-walled carbon nanotubes in microspheres used as anion exchange resin via suspension polymerization

Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for preparation of anion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene–divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. These resulting anion-exchange polymers were characterized by a variety of techniques such as analytical titrations, transform infrared spectroscopy and thermal gravimetric analysis. Testing of these copolymers for breakthrough was performed. The results indicate that these anion exchangers have a meaningful increase in thermal stability over commercial anionic exchange beads. Resins containing MWCNTs achieved anion exchange capacity value of 323.6 meq/100 g over than that of copolymer resins and that useful in water desalination or treatment.

Scalable synthesis of TiO2–Ag Janus composite particles

Janus particles possess heterogeneous surface chemistries which can potentially enhance their interfacial activity and be exploited as useful catalysis agent. It is challenging to control the geometry of the Janus particles and to produce Janus particles in large quantities. In this report, we use a general approach of emulsion swelling assisted protrusion to synthesize the Janus composite particles of titania – poly (vinylbenzyl chloride-divinylbenzene) (TiO2-poly (VBC–DVB)). The size of the lobe of poly (VBC–DVB) is tunable. After a series of reactions, including Kornblum oxidation reaction and Tollens’ reaction, the target product of TiO2–Ag Janus composite particles is obtained.

Synthesis and Characterization of a Few Amino-Functionalized Copolymeric Resins and Their Environmental Applications

The synthetic copolymeric resins acrylonitrile/divinylbenzene/vinylbenzyl chloride (AN/DVB/VBC), styrene/divinylbenzene/vinylbenzyl chloride (ST/DVB/VBC), and vinylbenzyl chloride/divinylbenzene (VBC/DVB) have been prepared by suspension polymerization. These polymeric matrixes were aminated with ethylenediamine (ED) and then protonated to increase their selectivity toward Cr(VI). The experiments were carried out in batch mode to optimize various influencing parameters, namely, contact time, pH, other interfering co-ions, and temperature. The chromium removal capacity (CRC) of AN/DVB/VBC–ED resin was found to be higher than those of the other prepared copolymers. The mechanism of chromium removal was governed by electrostatic-adsorption-coupled reduction and complexation. The polymeric resins and chromium-sorbed resins were characterized by FTIR, SEM–EDAX, BET, elemental analysis, and EPR studies. The adsorption data were fitted with Freundlich and Langmuir isotherms. The calculated values of thermodynami...

Environmentally friendly synthesis of alkaline anion exchange membrane for fuel cells via a solvent-free strategy

In this study, we described a solvent-free strategy for alkaline anion exchange membranes synthesis by in situ polymerization. Different from the available membrane synthesis by direct polymerization and post-polymerization modification, the non-solvent strategy demonstrated here was performed by dissolving brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) in monomers mixture of vinylbenzyl chloride (VBC) and divinylbenzene (DVB) and then in situ polymerization to incorporate BPPO into the network of poly(VBC–DVB). After quaternization, a translucent, flexible and robust anion exchange membrane was obtained. The membrane morphology was confirmed by SEM-EDXA images. Factors such as quaternizing conditions and components of the casting solution were fully investigated. The optimized membranes exhibited favorable water uptakes (ranging from 19.9% to 29.3%) and hydrated hydroxyl conductivities (ranging from 0.017 to 0.028Scm−1) at room temperature, which allows its application in alkaline anion exchange membrane fuel cells (AAEMFCs). Moreover, this solvent-free strategy is not limited to the above BPPO/VBC/DVB system. It can be applied to other compatible systems of (aromatic) polymers and (aromatic) monomers as long as homogeneous cast solution of the monomers and polymers can be formed. Thus this research will provide a versatile environmentally friendly route to prepare anion exchange membranes with tailored properties for alkaline fuel cells.

Synthesis and Properties of Anion Exchangers Derived from Chloromethyl Styrene Codivinylbenzene and Their Use in Water Treatment

Amination of vinylbenzyl chloride-divinylbenzene (VBC-DVB) copolymers is an effective method for preparation of ion-exchange resins. Conventionally, the starting polymer is produced by chloromethylation of a styrene-divinylbenzene copolymer that utilizes chloromethyl methyl ether, a known carcinogen. An alterative approach is to copolymerize vinylbenzyl chloride with divinylbenzene to generate the necessary VBC-DVB. This method provides precise control over the density of the ion-exchange groups. The regiochemistry of the vinylbenzyl chloride methods was realized using solvent-ion exchange groups. In this investigation, an improved solvent system was found for the preparation of anion exchange resins by the vinylbenzyl chloride route. The effectiveness of amination of the intermediate VBC-DVB polymers with a variety of trimethylamine reagents was investigated, and ethanolic trimethylamine produced the highest degree of amination. These resulting ion-exchange polymers were characterized by a variety of techniques such as analytical titrations, nitrogen analysis, Fourier transform infrared spectroscopy and thermal gravimetric analysis. Testing of these copolymers for breakthrough was performed. The results indicate that these anion exchangers have a meaningful increase in thermal stability over commercial anionic exchange beads.

The Uptake of Gold(I) from Ammonia Leaching Solution by Imidazole Containing Polymeric Resins

The polymeric resins containing guanylthiourea, 1-methylimidazole, 2-mercapto-1-methylimidazole ligands have been synthesized from vinylbenzyl chloride-divinylbenzene copolymers and used in the removal of Au(I) from ammonium buffer and ammoniacal thiosulphate solutions. The best gold sorption from ammonium buffer that contains 100 g/dm3 NH3 · H2O and 5 g/dm3 (NH4)2SO4, is reached in the case of 1-methylimidazole resin (2) (27.9 mg/g) and all three resins do not have a measurable sorption of copper(II) ammine complexes. The resins display a higher affinity towards gold(I) from ammoniacal thiosulphate solutions than from the ammonium buffer solution. The XPS analysis of gold loaded resins suggests the presence of gold at Au(I) oxidation state, most likely in the form of ionic pair Au(NH3)2 +OH− or neutral complex AuNH3OH and as highly-dispersed metallic gold. The degree of gold desorption is about 50% using 1% potassium cyanide solution in 0.3% hydrogen peroxide solution. Resins retain their capacity towards gold in five consecutive sorption/desorption cycles.

Hydrophilic interaction 10 μm I.D. porous layer open tubular columns for ultratrace glycan analysis by liquid chromatography–mass spectrometry

The sensitivity of glycan analysis using nano-liquid chromatography interfaced with electrospray ionization mass spectrometry (ESI–MS) increases with the decrease of the mobile phase flow rate, accompanied by reduced ion suppression. In this study, we describe the preparation and performance of high efficiency 10 μm I.D. amine-bonded poly(vinylbenzyl chloride-divinylbenzene) hydrophilic interaction (HILIC) porous layer open tubular (PLOT) columns operated at 20 nL/min for the separation and analysis of glycan mixtures. HILIC-PLOT columns with a uniform porous polymer layer were reproducibly prepared (∼4% RSD in retention time from column-to-column) via in situ polymerization, followed by one step modification with ethylenediamine. When coupled on-line with negative ESI–MS, low detection limits (0.3 fmol) for a 3-sialyl-tetrasaccharide were achieved using a 2.5 m × 10 μm I.D. HILIC-PLOT column. A dextran ladder standard was used to evaluate the performance of the column, and high efficiency separation was achieved with detection of the dextrans up to G22 from ∼50 fmol amounts injected. As an example of the high sensitivity of the column, MS 6 characterization of glycan structures was possible from the injection of 10 fmol of a neutral and sialylated glycan. As another example of high sensitivity LC–MS analysis of 3 ng of a PNGase F digest of ovalbumin allowed 28 N-linked glycans to be confidently identified from a single analysis. High quality MS/MS spectra for each ovalbumin glycan were acquired and manually interpreted for structure analysis. The HILIC-PLOT column is a very promising approach for LC–MS analysis of glycans at the ultratrace level.

Palladium and platinum binding on an imidazol containing resin

Platinum and palladium were efficiently recovered from HCl solutions (at concentrations as high as 1–2 M) using a vinylbenzyl chloride-divinylbenzene resin reacted with the sodium salt of diethylmalonate followed by reaction with 3-aminopropyl imidazol. Both palladium and platinum exhibit sorption capacities as high as 1 mmol metal g − 1 in 2 M HCl solutions (1.4–1.5 mmol metal g − 1 in 1 M HCl and 1.6–1.7 mmol metal g − 1 in 0.1 M HCl). The sorbent has a greater affinity for Pd at low HCl concentration, while Pt is preferred at higher HCl concentration, as shown by sorption performances in binary solutions. The sorption capacity is influenced by chloride concentration, while the presence of competitor ions (such as base metals) has little influence on binding performances: zinc shows the highest inhibiting effect (compared to copper and nickel). The sorption kinetics show that the agitation speed has a limited impact on sorption rate, while the kinetic rate decreases linearly with increasing metal concentration. Metals loaded on the resin can be recovered using 0.1 M thiourea solution as the eluent, with desorption efficiency exceeding 95% under selected experimental conditions. The recycling of the resin was effective for at least five sorption/desorption cycles.

Synthesis and characterization of polymeric resins with aliphatic and aromatic amino ligands and their sorption behavior towards gold from ammonium hydroxide solutions

The functional resins with amino ligands are synthesized by the modification of lightly crosslinked poly(vinylbenzyl chloride–divinylbenzene) matrix with the following amines: 1-methylpiperazine, ethylenediamine, dipropylamine, 1-methylimidazole, 2-mercapto-1-methylimidazole, 1,2-dimethylimidazole and 1-(3-aminopropyl) imidazole. Two methods of the modification reactions were employed, the first one is the traditional heating of the polymer with either neat amine or amine solution in an appropriate solvent, the second method is heating of the reaction mixture in a microwave reactor. The resultant resins show different degrees of modification depending on the applied method and contain 1.61–3.68 mmol of ligand/g. The 1-methylimidazole resin displays the highest affinity towards gold from ammonium buffer (100 g/dm 3 NH 3 · H 2O, 50 g/dm 3 (NH 4) 2SO 4). For this resin, the sorption is as high as 15.5 mg/g and log K d (distribution coefficient) value is 2.94. All resins are highly selective and they do not sorb copper amino complexes. These polymeric materials were characterized using nitrogen, sulfur and chlorine elemental analysis and FTIR spectroscopy.