Vinylbenzyl Chloride Research Articles

Highly conductive and uniform PEDOT on poly(acrylic acid-vinylbenzyl chloride) functionalized surfaces

This study demonstrates increasing the uniformity and conductivity of poly(3,4-ethylene dioxythiophene) (PEDOT) thin films synthesized by vapor phase polymerization (VPP) through the utilization of a thin interfacial prime layer on the substrate surface. The prime layer, which is a copolymer of acrylic acid (AA) and vinylbenzyl chloride (VBC), was coated on the substrate surface using initiated chemical vapor deposition (iCVD) method. FTIR and XPS were used to analyze the structure of as-deposited films. The use of P(AA-VBC) copolymer as a prime layer allowed uniform and complete coverage of the oxidant solution on the substrate surface due to the hydrophilic nature of the AA constituent. During the VPP, the existence of the chlorine ions originating from the VBC constituent allowed in-situ doping of the as-deposited polymer, which contributes to the increased uniformity and the conductivity. The experimental studies were carried out to show the increase in uniformity, conductivity and adherence of the as-deposited PEDOT film in the presence of the prime layer. There was nearly a 4-fold increase in the conductivity of as-deposited PEDOT in the presence of the prime layer, with measured conductivity uniformity as high as 96% over a 5×5 cm2 glass surface.

Chitosan-based anion exchange membranes for fuel cell application: Enhanced hydration & durability to dry-wet cycling

Herein, a new type of anion exchange membranes (AEMs) based on chitosan (CS) and poly(4-vinylbenzyl chloride) (PVB) polymers is reported. Depending on whether the PVB side chains are mono-cationic (quaternized PVB, QPVB) or di-cationic (di-quaternized PVB, DQPVB), the AEMs are denoted as QPVB@CS and DQPVB@CS, respectively. Due to the lateral aggregation of chitosan chains assisted by hydrogen bonds, the in-plane expansion is limited (1.4–11.5 % at 80 °C), resulting in excellent mechanical properties of AEMs (dry tensile strength of 55.2–81.0 MPa). And after 10 dry-wet cycles, the AEMs maintain their appearance and show improved mechanical properties. Due to high through-plane swelling degree, AEMs effectively retaining water (water uptake of 272.5–501.5 % at 80 °C) in the AEMs. DQPVB@CS AEMs, with their higher ion content, exhibit superior ionic conductivity (74.2–116.5 mS cm−1 at 80 °C) compared to QPVB@CS (27.7–44.3 mS cm−1 at 80 °C) and achieve a peak power density of 729.6 mW cm−2 in an anion exchange membrane fuel cell (AEMFC), versus 128.1 mW cm−2 for QPVB@CS-2. To the best of our knowledge, the AEMs developed in this study represent the first example of AEMs prepared from chitosan gel membranes, achieving anisotropic swelling degree, high water uptake, and excellent dry-wet cycling resistance without the need for additional chemical cross-linking.

Dynamic Surface Properties of Copolymers of Styrene and Hydrophobized 4-Vinylbenzyl Chloride at an Air–Water Interface

Dynamic Surface Properties of Copolymers of Styrene and Hydrophobized 4-Vinylbenzyl Chloride at an Air–Water Interface

Zinc Phthalocyanine Core-First Star Polymers Through Nitroxide Mediated Polymerization and Nitroxide Exchange Reaction.

Nitroxide-mediated polymerization (NMP) and nitroxide exchange reaction (NER) are very efficient methodologies that require only suitable alkoxyamine derivatives and create different polymeric architectures in a controlled manner. Herein, the synthesis of star polymers containing TEMPO-substituted symmetric zinc phthalocyanine (ZnPc) is presented via NMP and NER. Moreover, linear polymer formation is conducted in a single arm on TEMPO-substituted asymmetric ZnPc to elucidate the properties of star polymers. All linear and star polymers are characterized by FT-IR, UV-vis, fluorescence, GPC, NMR, and EPR techniques. The results show that the proposed reactions are capable of forming controlled star-shaped polymers. The increasing arm number (from a single to four arms) results in variable dispersity values (Đ) (1.2-3) due to different arm lengths, especially in NMP. However, this difficulty has been overcome via NER, and star polymers have been successfully synthesized with relatively low molecular weight (30 K > 10 K) and low dispersity (1.2-1.9). The results clearly indicate that while styrene and 4-vinyl benzyl chloride monomers are introduced to the structure equally, star polymers with phthalocyanine can be synthesized in a controlled manner, and their quarternized derivatives have the potential to be effective as photoactive agents in photodynamic therapy.

Leveraging an innovative process integration using highly acid-immune blend membranes for enhanced acid recovery and selective salt separation

We investigate the efficiency and advantage of the integrated diffusion dialysis-electrodialysis (DD-ED) system over the DD process for acid recovery with highly acidic wastewater. The investigation uses various acid (HCl/H2SO4) /salt mixtures encompassing iron, copper and aluminium salts (FeCl2, CuCl2, AlCl3, and FeSO4) as simulated feed. The membrane is prepared using blend mixture of polyvinylidene fluoride (PVDF) and polymethyl methacrylate-co-poly chloromethyl styrene copolymer (PMMA-co-PCMSt) solution by non-solvent induced phase inversion on a nonwoven fabric followed by treatment with different tertiary amines. Representative AEM-Q3 membrane prepared by the post modification of blend membrane with a mixture of N, N, N’, N’- tetramethyl diamino hexane (TMDAH) and trimethyl amine (TMA) (1: 1 w/w %) exhibited the best-balanced performance. The membrane recovered a 84.2% AR (%) of acid with 96.28% purity (%) at a flux (JH+) of 7.08 × 10-4 mol cm-2 h-1 from 3 M HCl and 0.2M FeCl2 mixture making it suitable for further studies. A comprehensive comparative study drawn between the DD and integrated DD-ED showed that there was a 2.3 fold increment in acid recovery for the integrated process over the DD process (for the HCl-FeCl2 system). The membranes have also shown good monovalent (Cl-) and bivalent (SO42-) anion selectivity of 7.8. However, the selectivity was further improved to 12.28 by modification of AEM-Q3 membrane, which is double side cast (referred as AEM-Q3/b). The synthetic strategy of the membrane is easy and scalable and has potential for both acid recovery and selective salt separation by ED process.

Changing the Linking Functionality in a Triblock Co-Polymer for Electrolyzer or Fuel Cell Membrane or Ionomer for Chemical Stability Improvements and Potentially Other Consequences.

We have developed a versatile scalable triblock polymer system for anion exchange membrane (AEM) based electrochemical energy conversion devices. This system is uniquely suited to solving both the membrane and ionomer challenges for the commercialization of AEM water electrolysis or fuel cells. Using our advanced fundamental understanding of AEMs based on our work which began in 2010, we can design systems from first principles to match the needs of the device. A triblock ABA polymer is readily fabricated that has both chemical and mechanical stability. The synthesis of these systems is robust, high yield and amenable to high volume production. It utilizes a novel dual chain transfer agent to mediate the chain-transfer ring-opening metathesis polymerization (ROMP) of cyclooctene (COE) or the polymerization of isoprene (IP) to give the hydrophobic B block of the polymer. This is followed by the reversible addition-fragmentation chain transfer radial polymerization of chloromethylstyrene (CMS). The polyCMS (pCMS) blocks are then quaternized with an amine to give the cationic hydrophilic A block. Before quaternization the B block is hydrogenated to give either semi-crystalline polyethylene (pE) or amorphous polymethylbutylene (pMB) from pCOE and pIP respectively. The obvious achilles heal in this system from a chemical durability standpoint is the linking ether functionality between the hydrophobic and hydrophilic blocks. The material we have synthesized to date have exceptional chemical and mechanical stability. It performs very well in ex-situ testing with KOH solutions and in device testing we have demonstrated >500 h at 50°C in water electrolysis in 5 cm2 cells in 1M carbonate electrolyte at 0.5 A cm-2. We attribute the chemical stability to the fact that we post quaternize the membrane to give methylpipiridinium cations and we assume that this reaction does not fully penetrate down the hydrophilic chain. This leaves a hydrophobic un-quaternized region close to the hydrophobic block that does not allow access to the ether linkage by the hydrated hydroxide anion. Recently a new approach to the telehelic mid block pCOE has been reported that has no ether linkages and allows the hydrophobic outer blocks to be linked by a methylene linker. This gives use an opportunity to directly contrast the chemical stability of two identical triblock co-polymers one with an ether linkage and one with a methylene linkage between blocks. In this presentation we will show the results from ex-situ chemical stability test one at low temperatures and higher hydroxide concentration and one at higher temperature and lower hydroxide concentration. There are many examples in polymer electrolyte chemistry where a simple change leads to unintended consequences. The geometry of the ether linkage versus the methylene linkage will change the way that the polymer chains will organize and entangle in ways that are not currently predictable. To probe the mechanical, chemical and morphological difference between these two polymers we will fully characterize and contrast both polymers physical chemical properties including water uptake, ionic conductivity, DSC, TGA, tensile strength and morphology through SAXS, WAXS and HRTEM. Data for the two polymer membranes will also be contrasted and compared in small laboratory 5 cm2 single cells for both electrolysis in dilute carbonate and H2/O2 fuel cells using conventional catalysts.

Novel Anion Exchange Membrane Design Strategies Toward Improved Water Electrolysis Performance

Long-term energy storage is crucial for transitioning from fossil fuels to renewable energies due to the fluctuating energy generation of renewable energy sources such as solar or wind.[1,2] Water electrolysis could produce hydrogen from water and electricity from renewable energy resources, thus solving the energy storage problem.[3] Recent research aims to combine the advantages of alkaline water electrolysis (AWE) and the zero-gap architecture of proton exchange membrane water electrolysis (PEMWE). Limitations of this so-called AEMWE are the lower hydroxide conductivity compared to proton conductivity and, consequently, lower current densities. Furthermore, the chemical stability of AEMs still limits their technical applicability.[4–6] Sustainion®, a commercially available AEM, is a 4-vinylbenzyl chloride styrene copolymer quaternized with 1,2,4,5-tetramethylimidazole.[5,7] Sustainion® shows excellent performance in AEMWE and CO2 electrolysis.[7–9] However, on other polymer systems, it was found that the conductivity and alkaline stability could be increased if the cationic group is separated from the backbone by an alkyl spacer.[10–12] Furthermore, other cationic groups or polymer backbones also offer several advantages. In this study, we demonstrate some new membrane synthesis approaches aiming to enhance the performance of AEMs in electrochemical water-splitting devices. The demonstrated approaches involve attaching different side chains, which may vary in length or the presence of heteroatoms like oxygen. Furthermore, cationic groups like sterically protected imidazoliums are attached to these side chains to study their influence on long-term stability. Finally, our synthetic approaches comprise different membrane preparation strategies such as blending, crosslinking, or applying block-copolymers. The novel polymers are characterized by state-of-the-art methods of polymer chemistry and are further investigated regarding their applicability in AEMWE. Finally, their ionic conductivity, alkaline stability, ion exchange capacity, and the respective performance in AEMWE are investigated.[1] G. A. Lindquist, Q. Xu, S. Z. Oener, S. W. Boettcher, Joule 2020, 4, 2549.[2] A. Kiessling, J. C. Fornaciari, G. Anderson, X. Peng, A. Gerstmayr, M. Gerhardt, S. McKinney, A. Serov, A. Z. Weber, Y. S. Kim, B. Zulevi, N. Danilovic, J. Electrochem. Soc. 2022, 169, 24510.[3] N. Du, C. Roy, R. Peach, M. Turnbull, S. Thiele, C. Bock, Chemical reviews 2022, 122, 11830.[4] S. Gottesfeld, D. R. Dekel, M. Page, C. Bae, Y. Yan, P. Zelenay, Y. S. Kim, J. Power Sources 2018, 375, 170.[5] D. Henkensmeier, M. Najibah, C. Harms, J. Žitka, J. Hnát, K. Bouzek, J. Electrochem. Energy Convers. Storage 2021, 18.[6] N. Chen, Y. M. Lee, Prog. Polym. Sci. 2021, 113, 101345.[7] Z. Liu, S. D. Sajjad, Y. Gao, H. Yang, J. J. Kaczur, R. I. Masel, Int. J. Hydrog. Energy 2017, 42, 29661.[8] J. J. Kaczur, H. Yang, Z. Liu, S. D. Sajjad, R. I. Masel, Front. Chem. 2018, 6, 263.[9] R. I. Masel, Z. Liu, S. Sajjad, ECS Trans. 2016, 75, 1143.[10] H.-S. Dang, P. Jannasch, Macromolecules 2015, 48, 5742.[11] S. Miyanishi, T. Yamaguchi, Polym. Chem. 2020, 11, 3812.[12] S. P. Ertem, E. B. Coughlin, Macromol. Rapid Commun. 2022, 43, e2100610.

Homopolymerization of substituted styrenes and their copolymerization with carbon monoxide catalyzed by iminopyridine palladium catalyst

Homopolymerization of styrenic monomer featuring different functional group and their copolymerization with carbon monoxide were investigated by imine-pyridine palladium complex with the assistance of AgSbF6. Poly(4-vinylbenzyl chloride) and poly(4-N,N-dimethylaminostyrene) were produced probably according to coordination-insertion mechanism. In the presence of carbon monoxide, substituted styrenes except for the 4-N,N-dimethylaminostyrene were copolymerized with CO to yield polyketones by the same catalysts. Thus, polyketones featuring chloromethyl group, diphenylaminomethyl group and quaternary ammonium salt were produced for the first time by direct alternating copolymerization. DSC results disclosed that glass transition temperature of the resulting polyketones was significantly affected by the substituents. The Tg of polyketone featuring quaternary ammonium salt was 160 °C.

Semi-Interpenetrating High-Temperature Proton Exchange Membranes Based on Cross-Linked Poly(fluorenyl-terphenyl-piperidinium) and Poly(vinylbenzyl chloride-co-vinylbenzyl chloride) for Fuel Cells

Semi-Interpenetrating High-Temperature Proton Exchange Membranes Based on Cross-Linked Poly(fluorenyl-terphenyl-piperidinium) and Poly(vinylbenzyl chloride-<i>co</i>-vinylbenzyl chloride) for Fuel Cells

Amino-modified microporous hyper-crosslinked resins for heavy metal ions adsorption

In this work, a high surface area micro/mesoporous hyper-crosslinked resin based on vinylbenzyl chloride and divinylbenzene is synthesized through a solvent-free polymerization followed by Friedel-Crafts alkylation. The hyper-crosslinked resin is then functionalized with amino moieties and the effect of the functionalization on the adsorption of metal ions is evaluated. After a chemical-physical characterization of the hyper-crosslinked resins, equilibrium adsorption tests of Pb(II) and Cu(II) in water are performed. The plain and amino-modified hyper-crosslinked resins (HCLR and HCLR-NH2) exhibit specific surface area (SSA) of about 1800 m2/g and 800 m2/g, respectively. They both exhibit micro/mesoporous structure, and their pore size distribution is modified upon functionalization. The amino-functionalization, while reducing prevalently the mesoporosity of the resin, does not significantly affect the micropores. HCLR-NH2 displays higher efficiency in removing both metal ions from aqueous solution compared to the unmodified resin. HCLR-NH2 is able to capture up to about 70 % of Pb(II) and up to about 48 % of Cu(II) dissolved in water at 5 mg/L concentration while in the same tests, HCLR captures about 25 % of Pb(II) and 17 % of Cu(II). The resins adsorption mechanisms follow the Langmuir model, suggesting a specific and functional groups-related adsorption mechanism. Therefore, the major adsorption capacity of HCLR-NH2 is to be primary attributed to the grafted amino moieties, which establish chelating interactions with the metal cations. Overall, results assess the relevance of the micropores and the amino functionalization to capture Pb and Cu ions via adsorption.

Scintillation and structural properties of copolymers and mixtures of styrene, 9-vinylcarbazole and 4-vinylbenzyl chloride based plastic scintillators

The research team has developed new plastic scintillators in the form of microspheres, called PSm, by combining styrene, 9-vinylcarbazole (VK), and 4-vinylbenzyl chloride (VBC). The primary objective of this study was to explore the feasibility of incorporating the fluorescent solute (VK) into the polymer structure to prevent its leaching out when PSm are utilized in liquid flow through detection systems or organic solvents. The secondary aim was to examine the impact of adding the chlorine functional group to the scintillation polymer, with the intention of replacing it with an extractant in the future to create covalently linked PSresins.The findings of the study reveal that the homopolymer of polyvinylcarbazole (PVK) performs poorly while used as a unitary scintillator system for plastic scintillation measurements. However, the incorporation of monomers in the form of copolymers with styrene has a more significant impact on scintillation properties compared to the mixture of homopolymers. In the case of 9-vinylcarbazole (VK), its presence at a weight proportion of 10% leads to an increase in scintillation efficiencies, although it is still inferior to the classical PS. Conversely, the situation is different for 4-vinylbenzyl chloride (VBC), where the chlorine in the copolymer results in higher quenching, and the polymer is also less resistant to organic solvents due to the formation of short polymer chains. For VBC, the mixture of polymers yields better results and enables the production of covalently linked PSresins.

Impact of LaZnFe2O4 supported NiWO4@D400-MMT@CMS/MMA nanocomposites as a catalytic system in remediation of dyes from wastewater

Herein, a novel nanocomposite based on lanthanum zinc ferrite and nickel tungstate was created by incorporation between (MMT-jeffamine-400) nanoparticles (NPs), chloromethyl styrene as a binder and polymethyl methacrylate monomer using solution polymerization. The as-designed nanocomposites were employed to confiscate xylenol orange “X.O” as an acidic dye and rhodamine B “RhB” as “an amphoteric dye” from colored wastewater. The impact of several parameters such as solution pH, initial dye concentration, the effect of time, and the effect of temperature was explored. The consequences indicated that the pure organoclay had negligible adsorption while that composed of organoclay with PMMA@CMS-polymer incorporated with LaZnFe2O4@NiWO4 particles detached more than 90% for xylenol orange (XO) and 93% for “rhodamine B” molecules. Electrostatic interactions are the predominant factor in the adsorption of cationic and amphoteric adsorbates, as proven by zeta-potential measurement. Additionally, the adsorbent may be regenerate and utilized up to five times with good adsorption capabilities by adding sodium hydroxide. As a result, the removal can be effectively accomplished using the nanocomposite as an adsorbent. The actual and theoretical adsorption capacity values for both dyes at all doses were closely matched, which supported the adsorption kinetics data that fit the pseudo-first order rate model well. The adsorption data’s correlation values (0.995 for XO and 0.98 for RhB) indicated that both dyes’ Langmuir adsorption would perform well. Furthermore, the adsorption of XO and RhB dyes on the adsorbent is confirmed to be a viable reaction by the negative values of ΔGo. The enhanced adsorbent material for the removal of amphoteric and anionic dyes from waste water is the synthesized LaZnFe2O4 supported NiWO4@D400-MMT@CMS/MMA nanocomposites, which exhibits a reusability affinity of up to five cycles.

Characterization and Performance Evaluation of Digital Light Processing 3D Printed Functional Anion Exchange Membranes in Electrodialysis

With the rapid development of 3D printing technologies, more attention has been focused on using 3D printing for the fabrication of membranes. This study investigated the application of digital light processing (DLP) 3D printing combined with quaternization processes to develop dense anion exchange membranes (AEMs) for electrodialysis (ED) separation of Cl− and SO42− ions. It was discovered that at optimal curing times of 40 min, the membrane pore density was significantly enhanced and the surface roughness was reduced, and this resulted in an elevation of desalination rates (97.5–98.7%) and concentration rates (165.8–174.1%) of the ED process. Furthermore, increasing the number of printed layers improved the membranes’ overall polymerization and performance, with double-layer printing showing superior ion flux. This study also highlights the impact of the polyethylene glycol diacrylate (PEGDA) molecular weight on membrane efficacy, where PEGDA-700 outperformed PEGDA-400 in ion transport capabilities and desalination efficiency. Additionally, higher 4-vinylbenzyl chloride (VBC) content improved the quaternary ammonium group concentration and membrane conductivity, and hence elevated the ED performance. Under optimized conditions, DLP 3D printed membranes demonstrated exceptional selectivity of 24.0 for Cl−/SO42− and a selective purity of 81.4%. With a current density of 400 A/m2, the current efficiency and energy consumption were in the range of 82.4% to 99.7%, and 17.2 to 25.4 kW‧h‧kg−1, respectively, showcasing the potential of advanced manufacturing techniques in creating efficient and functional ion exchange membranes.

Photoactivatable poly(2-oxazoline)s enable antifouling hydrogel membrane coatings

In recent years, hydrophilic poly(2-oxazoline)s have been examined as an alternative polymer to poly(ethylene glycol) (PEG) with added stability and chemical versatility. They show excellent anti-fouling properties and, like PEG, are of interest in many fields where bio-inertness or anti-adhesiveness are important such as for medical devices, tissue engineering, biosensors, or drug delivery carriers. Surprisingly few studies have utilized this polymer class for the preparation of anti-fouling membranes. Here we describe a new termination reaction of the living cationic ring-opening polymerization of 2-oxazolines in which a benzophenone group is introduced as a photoactivatable terminal head group of poly(2-oxazoline)s. Using 4-vinylbenzyl chloride as initiator, heterotelechelic poly(2-methyl-2-oxazoline) (PMOXA) macromonomers were synthesized and copolymerized with hydroxyl-functional PMOXA macromonomers to yield photoactivatable PMOXA-based prepolymer bottle brushes. Likewise, star-PMOXAs were synthesized by using a trifunctional initiator. Photoactivatable PMOXA prepolymers allowed us to readily form anti-fouling hydrogels by a simple and versatile CH-insertion cross-linking (CHic) process. Hydrogels were applied to poly(ether sulfone) ultrafiltration membranes as pore coating and the pure water permeance (PWP) was investigated as a function of hydrogel architecture and cross-link density. Anti-fouling hydrogel pore-coated membranes having PWPs on the order of hundred kg·m−2·h−1·bar−1 were obtained.

Covalently crosslinked poly(biphenyl dimethylamino benzene) membranes for high temperature proton exchange membrane fuel cells

The electrolyte membrane plays a pivotal role in high temperature proton exchange membrane fuel cells (HT-PEMFCs). Herein, we develops a new triarylmethane-backboned polymer, poly (biphenyl dimethylamino benzene) (PBDAB), synthesized through a facile one-step Friedel-Crafts reaction using biphenyl and 4-(dimethylamino) benzaldehyde as monomers. The presence of tertiary amine groups in PBDAB facilitates strong interactions with phosphoric acid (PA) molecules. To enhance the membrane's dimensional and mechanical stabilities, covalent crosslinking is performed via the Menshutkin reaction between the tertiary amine groups in PBDAB and chloromethyl groups in various crosslinkers. In order to study the influence of crosslinker chemical structure on the properties of PBDAB-based membranes, five different crosslinkers are employed, including small-molecule types such as 1,2-bis(2-chloroethoxy) ethane (BCE) and 1,4-bis(chloromethyl) benzene (BCB), siloxane type 3-chloropropyl (trimethoxy) silane (CTS), polymer types such as poly (vinylbenzyl chloride) (PVBC) and polyepichlorohydrin (PECH). Results reveal that the flexible and ether containing polymer crosslinker of PECH crosslinked membrane, denoted as CL-y%PECH, exhibits superior overall performance. When doped in an 85 wt% PA solution, the CL-5%PECH membrane achieves a PA uptake of 201%, resulting in an anhydrous proton conductivity of 0.064 S cm−1 at 180 °C and a mechanical strength of 7.2 MPa at room temperature. Using H2 and O2 as fed gases without humidification and backpressure, a single cell with abovementioned membrane attains a peak power density of 302 mW cm−2 at 160 °C. This work offers a kind of promising PBDAB based membranes for HT-PEMFC applications.

An eco-friendly self-assembled catalyst preparation and study of tetracycline degradation: Performance, mechanism to application

Chloromethyl styrene resin can undergo specific chemical modifications and is an excellent adsorbent material for treating difficult-to-degrade substances in wastewater. In this study, chloromethyl styrene resin will be used as a carrier, and polystyrene chloromethyl resin (PS-Cl) was converted into PS-NH2 by amino modification. The self-assembly of cobalt-based metal–organic framework (CoMOF) was induced on the surface of PS-NH2 by using a novel preparation technique. The performance of the prepared PS-NH2@CoMOF self-assembled catalysts with core–shell-like structures in degrading the target pollutant, tetracycline (TC), was evaluated. The catalysts effectively induced rapid OH radical production from H2O2, had a degradation rate of as high as 88.3 % for 20 mg/L TC solution, and were highly stable and adaptable to aqueous environments. Free radicals and intermediates in the catalytic degradation process were detected by electron paramagnetic resonance and high-performance liquid chromatography mass spectrometry, and possible catalytic degradation pathways were analyzed. The catalytic dissociation behavior of H2O2 in the presence of different catalysts was studied in depth and compared with that of similar metal–organic framework materials through density-functional theory calculations. Results demonstrated the excellent performance of the PS-NH2@CoMOF catalysts. Finally, the catalysts' potential for use in practical engineering applications was evaluated with a flow column experimental model, and the results were more than satisfactory. Therefore, the use of the catalysts to degrade TC has great potential.

Effects of Structurally Different Tertiary Amines on the Properties of Quaternized Anionic Exchange Membranes Potentially Applicable for Water Electrolysis.

In this work, two structurally different monoamines (trimethylamine [TMA] and N-methylpiperidine [N-MPip]) are used for the amination of a g-VBC-15 graft copolymer, obtained by the functionalization of a mechanically robust, commercially available styrene-butadiene block copolymer (SB) with vinylbenzyl chloride (VBC) via solution free-radical polymerization. Results demonstrate that g-VBC-15-based membranes quaternized with TMA have superior electrochemical performance than N-MPip counterparts; while, the mechanical properties are good and only slightly inferior to those of N-MPip. Therefore, TMA is the selected monoamine to be alternatively mixed with two polyamines (tetramethyl-1,3-propanediamine [TMPDA] and N,N,N',N'',N''-pentamethyldiethylenetriamine [PMDETA]) into different proportions, in order to modulate the average functionality of the amination mixture in terms of number of amine functional groups available for the quaternization reaction of the membranes. g-VBC-15-based membranes derived therefrom are extensively characterized to assess their thermal, mechanical, and ex situ electrochemical properties. Results indicate that membranes quaternized with a TMA/PMDETA mixture (90:10 in mole) display the highest conductivity among all the investigated membranes aminated with polyamine-based mixtures. Moreover, they have comparable mechanical and electrochemical properties to those quaternized with TMA, while exhibiting a reduced water uptake.

Construction of porous chitosan-based organic/inorganic composite with synergistic antibacterial activity

The increasing resistance of antibiotics and the global spread of pathogenic bacteria highlight the urgent need for novel antibacterial materials. In this study, a terpolymer (PVBA) with carboxyl (-COOH) and benzyl chloride (-C7H6Cl) groups was synthesized using acrylic acid (AA), butyl acrylate (BA), and 4-vinyl benzyl chloride (VBC) as monomers. The -C7H6Cl groups in the PVBA terpolymer was then reacted with N-N-dimethylhexadecane 1-amine (HAM) to prepare a more hydrophilic antibacterial (PVBA-N) terpolymer. Further, a synthetic/natural (PVBA-N/C) composite with quaternary ammonium (QA) groups was prepared by covalent crosslinking of the PVBA-N terpolymer and chitosan (CS). Finally, the AgCl-decorated PVBA-N/C (AgCl@PVBA-N/C) antibacterial composite was were constructed by anchoring silver chloride nanoparticles (AgClNPs) to the surface of the PVBA-N/C composite. Remarkably, the resulting AgCl@PVBA-N/C antibacterial composite had a porous network structure and exhibited favorable antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) based on both contact-typed and release-typed antibacterial modes, and low cytotoxicity against L929 cells. This research provides an effective strategy to combat the threat of bacterial resistance to human health relying on the advantage of the respective antibacterial mechanisms of various antibacterial ingredients.

Homogeneous-like photocatalysis: covalent immobilization of an iridium(III) complex onto polystyrene brushes grafted on SiO2 nanoparticles as a mass/charge transfer-enhanced platform.

Current heterogeneous photocatalysis faces the major bottlenecks of limited mass transfer, charge recombination and tedious immobilization of expensive photocatalysts. In this work, fac-Ir(ppy)3 is directly anchored at a low cost via covalent linkage to poly(4-vinyl benzyl chloride) (PVBC) brushes grafted on SiO2 nanoparticles (PVBC@SiO2 NPs) via Friedel-Crafts alkylation, affording PVBC@SiO2 NP-supported fac-Ir(ppy)3 with high luminous efficacies such as emission lifetime and quantum yield. In the reductive cross-coupling of benzaldehydes/acetophenones with 1,4-dicyanobenzene (1,4-DCB), the as-fabricated photocatalyst affords benzhydrols in the same yields as homogeneous fac-Ir(ppy)3, except for o-substituted benzaldehydes/acetophenones. In terms of the same yields as homogeneous fac-Ir(ppy)3, a new catalytic model, named homogeneous-like photocatalysis, is proposed. In this catalytic model, the open stretching of PVBC brushes in DMSO enables the anchored fac-Ir(ppy)3 to catalyse the reaction in a similar manner as homogeneous fac-Ir(ppy)3, effectively avoiding charge recombination and mass transfer limitation. Furthermore, no significant decrease in yield (<5%) is observed over eight catalytic cycles, due to the good chemical and mechanical stabilities of PVBC@SiO2 NP-supported fac-Ir(ppy)3. Overall, the immobilization of fac-Ir(ppy)3 onto the PVBC brushes grafted on SiO2 NPs provides a mass/charge transfer-enhanced platform for supported photocatalysts.

Preparation of dyed polymer microspheres by a physical-chemical dual-binding method and their application in lateral flow immunoassay.

Lateral flow immunoassay (LFIA) has shown great competitiveness in point-of-care testing due to its flexibility and simplicity. Dyed polymer microspheres are one of the most widely used marker particles for signal presentation as they are very convenient for visual interpretation, which is one of the most attractive features of LFIA. The color intensity, as the most critical factor, is directly related to the visual effect. In this work, a physical-chemical dual-binding strategy was proposed for the preparation of functionalized dyed microspheres. Bifunctional seed microspheres were synthesized by introducing 4-vinylbenzyl chloride (VBC) into the soap-free emulsion polymerization process, and the effective immobilization of dyes inside and on the surface of the polymer microspheres was achieved by covalent bonding and swelling methods. The microspheres were characterized by SEM, FT-IR spectroscopy and UV-vis spectroscopy. The results showed that the microspheres containing VBC were spherical with an average particle size of 300 nm. When the microspheres were prepared by adding 10 wt% VBC relative to the total monomer, the immobilization amount of 1-[[4-[(dimethylphenyl)azo]dimethyl phenyl]azo]-2-naphthol (Red-27) was increased to 180 mg g-1, which was 1.8 times that of the microspheres without VBC. The resulting nanomaterials were successfully used to establish a lateral flow immunoassay for the detection of COVID-19 virus N protein. The linear response concentration range was 2.64-87.84 COI, and the detection limit was 14.95 COI.