Types Of Monomers Research Articles

Dehydrogenation of Diethylene Glycol to Para-Dioxanone over Cu/SiO2 Catalyst: Effect of Structural and Surface Properties

Para-dioxanone, a typical monomer for high-performance biomedical polymers, is generally obtained from the catalytic dehydrogenation of diethylene glycol. In this work, Cu/SiO2 catalysts were prepared by two different methods and applied in diethylene glycol dehydrogenation. The effects of catalyst properties on the performance of para-dioxanone production were systematically explored by combined techniques. The results showed that the high specific surface area and regular pore structure of the catalyst promoted and stabilized the high dispersion of the copper species with an abundant Cu-Si interface, thereby providing numerous reactive sites. The appropriate Cu0/Cu+ ratio in the active components produced efficient synergy, which was responsible for the excellent dehydrogenation performance. In addition, the low surface acid density (0.532 μmol/m2) of the catalyst greatly reduced the occurrence of diethylene glycol dehydration, thus improving para-dioxanone selectivity over 90% with promising stability.

The effect of amphiphilic monomer on the interaction between amphiphilic polyacrylamide and crude oil on the solid surface

Hydrophobically modified polyacrylamide (HMPAM) is one of most used amphiphilic polymers for polymer flooding in oilfield. The interaction between HMPAM and crude oil is key to the oil displacement efficiency of HMPAM. However, due to the lack of experimental research method, there is little research on this aspect. In this work, HMPAMs containing different types of amphiphilic monomers were prepared, their interactions with crude oil were studied by dual polarization interferometry (DPI) for the first time, and their adsorption conformations on the surface of crude oil were discussed. The DPI results directly shown that the influence of amphiphilic monomer type on the interaction strength was as follows: nonionic type > cationic type ≈ anionic type. This order was consistent with the adsorption capacity of amphiphilic monomer on the surface of crude oil, indicating that the interaction strength between HMPAM and crude oil mainly depended on the type of amphiphilic monomers. In addition, the DPI results indirectly shown that the effect of amphiphilic monomer type on the HMPAM molecular coiled conformation on the surface of crude oil was also determined by the adsorption capacity of amphiphilic monomer. The research results of this paper can provide useful information for the amphiphilic monomer selection from the perspective of improving oil displacement efficiency of HMPAM.

Hydroxide Conducting Naphthalene-Containing Polymers and Membranes Via Polyhydroxyalkylations

Anion exchange membranes (AEMs) are critical components of alkaline membrane water electrolyzers and fuel cells that are under development today [1,2]. Consequently, there is a strong demand for highly conductive and alkali-stable AEMs. In this context, polyhydroxyalkylation has emerged as one of the most efficient synthetic pathways to chemically resistant polymer backbones for AEMs. In these Friedel-Crafts type polycondensations, an electron-rich aromatic compound reacts with an activated ketone or aldehyde to produce an aryl-ether-free polymer. The desired quaternary ammonium cations are then usually introduced through a Menshutkin reaction [3,4].In the current work, we have employed naphthalene-based compounds as monomers in polyhydroxyalkylations to prepare a series of high-molecular weight poly(naphthalene alkylene)s with various naphthalene contents. These polymers were then quaternized and cast into AEMs. Here, we will discuss the influence of the naphthalene monomer type and content on AEM properties such as solubility, water uptake, ion conductivity, ionic clustering, thermal and alkaline stability, and also the prospects of using these AEMs in electrochemical systems.

Threshold of Surface Initiator Concentration for Polymer Brush Growth by Surface-Initiated Atom Transfer Radical Polymerization.

The surface modification of various materials by grafting functional molecules has attracted much attention from fundamental research to practical applications because of its ability to impart various physical and chemical properties to the surfaces. One promising approach is the use of polymer brushes synthesized by atom transfer radical polymerization (ATRP) from surface-tethered initiators (SIs). In this study, for the purpose of controlling the grafting amounts/densities of polymer brushes, we developed a facile method to precisely regulate SI concentrations of SI layers (SILs) by serial dilution based on a sol-gel method. By simply mixing organosilanes terminated with and without an initiator group ((p-chloromethyl) phenyltrimethoxysilane (CMPTMS) and phenyltrimethoxysilane (PTMS), respectively) with tetraethoxysilane (TEOS), SI concentrations of SILs could be arbitrarily tuned precisely by varying dilution factors of (CMPTMS + PTMS)/CMPTMS (DFs, 1-107). The resulting SILs prepared at different DFs were highly smooth and transparent. X-ray photoelectron spectroscopy (XPS) also confirmed that the SIs were homogeneously distributed at the topmost surface of the SILs and their concentrations were proven to be accurately and precisely controlled from high to extremely low, comparable to theoretical values. Subsequent SI-ATRP in air ("paint-on" SI-ATRP) of two different types of monomers (hydrophobic/nonionic (2,3,4,5,6-pentafluorostyrene) and hydrophilic/ionic (sodium 4-styrenesulfonate)) demonstrated that polymer brushes with different grafting amounts/densities were successfully grafted only from SILs with DFs of 1-104 (theoretical SI concentrations: 3.9 × 10-4 ∼ 3.5 units/nm2), while at DFs of 105 and above (theoretical SI concentrations: <3.9 × 10-5 units/nm2), no sign of polymer brush growth was confirmed by thickness, XPS, and water contact angle data. Therefore, we are the first to gather evidence that the approximate threshold of SI concentration required for "paint-on" SI-ATRP might be on the order of 10-4 ∼ 10-5 units/nm2.

Eco-Conscious Approach to Thermoresponsive Star-Comb and Mikto-Arm Polymers via Enzymatically Assisted Atom Transfer Radical Polymerization Followed by Ring-Opening Polymerization.

This study explores the synthesis, characterization, and application of a heterofunctional initiator derived from 2-hydroxypropyl cyclodextrin (HP-β-CD), having eight bromoester groups and thirteen hydroxyl groups allowing the synthesis of mikto-arm star-shaped polymers. The bromoesterification of HP-β-CD was achieved using α-bromoisobutyryl bromide as the acylation reagent, modifying the cyclodextrin (CD) molecule as confirmed by electrospray ionization mass spectrometry (ESI-MS), nuclear magnetic resonance (NMR), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy analysis, and differential scanning calorimetry (DSC) thermograms. The initiator's effectiveness was further demonstrated by obtaining star-comb and mikto-arm polymers via an enzymatically assisted atom transfer radical polymerization (ATRP) method and subsequent ring-opening polymerization (ROP). The ATR polymerization quality and control depended on the type of monomer and was optimized by the way of introducing the initiator into the reaction mixture. In the case of ATRP, high conversion rates for poly(ethylene oxide) methyl ether methacrylate (OEOMA), with molecular weights (Mn) of 500 g/mol and 300 g/mol, were achieved. The molecular weight distribution of the obtained polymers remained in the range of 1.23-1.75. The obtained star-comb polymers were characterized by different arm lengths. Unreacted hydroxyl groups in the core of exemplary star-comb polymers were utilized in the ROP of ε-caprolactone (CL) to obtain a hydrophilic mikto-arm polymer. Cloud point temperature (TCP) values of the synthesized polymers increased with arm length, indicating the polymers' reduced hydrophobicity and enhanced solvation by water. Atomic force microscopy (AFM) analysis revealed the ability of the star-comb polymers to create fractals. The study elucidates advancements in the synthesis and utilization of hydrophilic sugar-based initiators for enzymatically assisted ATRP in an aqueous solution for obtaining complex star-comb polymers in a controlled manner.

Properties of model E-glass fiber composites with varying matrix monomer ratios

ObjectiveTo evaluate properties of fiber-reinforced-composites (FRC) containing Bis-EMA/UDMA monomers but identical dispersed phase (60% wt BaSi glass power +10% wt E-glass fibre). MethodsA control (Group A), monomer mixture comprising 60% Bis-GMA, 30% TEGDMA, and 10% PMMA (typical FRC monomers) was used. The following monomer mass fractions were mixed: 50% bis-GMA plus 50% of different ratios of Bis-EMA+UDMA to produce consistent formulations (Groups B-E) of workable viscosities was also studied. Flexural strength (FS), fracture toughness (KIC), water sorption (SP), solubility (SL) and hygroscopic expansion (HE) were measured. FS and KIC specimens were stored for 1, 7 d, and 30 d in water at 37 °C. SP/SL specimens were water-immersed for 168d, weighed at intervals, then dried for 84 d at 37 °C. To analyze differences in FS, and KIC, a two-way ANOVA and Tukey post-hoc tests (α = 0.05) were conducted. For SP/SL, and HE, one-way ANOVA with subsequent Tukey post-hoc tests (α = 0.05) were utilized. ResultsFS and KIC for groups A, D, E decreased progressively after 1 d. Groups B and C (highest amounts of Bis-EMA) did not decrease significantly. The modified matrix composites performed significantly better than the control group for SP and HE. The control group outperformed the experimental composites only for SL with up to 250% higher SL for group E (6.9 μg/mm) but still below the maximum permissible threshold of 7.5 μg/mm. Significance: Experimentalcomposites with highest amounts of Bis-EMA showed improved hydrolytic stability and overall enhancement in several clinically-relevant properties. This makes them potential candidates for alternative matrices to a semi-interpenetrating network in fiber-reinforced composites.

Photopolymer-metal Composites Based on Metal Foil Deposition on Additive Manufactured Substrates: An Overview

Photopolymer materials are a type of polymer material that can undergo chemical reactions when exposed to light of a specific wavelength or intensity. Liquid photopolymers are used in applications such as 3D printing, where they are deposited layer by layer and cured by exposure to light. Solid photopolymers, also known as photoresists, are used in applications such as lithography and microfabrication, where they are applied as a thin film and selectively exposed to light to create a pattern. The properties of photopolymer materials, such as mechanical strength, thermal stability, and chemical resistance, can be tailored by adjusting the monomer type, photo initiator type, and processing parameters such as the exposure time and intensity. Overall, photopolymer materials are a versatile and widely used type of polymer material that can be tailored for specific applications through the choice of monomer, photo initiator, and processing parameters. Photopolymer-metal composites based on metal foil deposition on additive manufactured substrates are a technique for creating composite materials with a combination of metal and polymer properties. This approach involves the deposition of a thin layer of metal foil onto a 3D printed polymer substrate, which is then cured using photopolymerization to create a composite material with unique properties.

Shape matters: Effect of amphiphilic polymer topology on antibacterial activity and hemocompatibility

Understanding the intricate relationship between polymer architecture and biological activity is critical for advancing the development of antibacterial polymers. In this study, we systematically investigated the antibacterial properties and hemocompatibility of 27 different synthetic polymers prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. The antibacterial activities of these polymers were probed against two gram-negative bacteria, namely Pseudomonas aeruginosa PAO1 and Escherichia coli K12. Furthermore, the antibacterial efficacy and hemocompatibility of synthetic polymers were correlated with their polymer topology, encompassing linear (LPs), hyperbranched (HPs), and star polymers (SPs), characterized by varying hydrophobic compositions (20 %, 25 %, and 30 %). HPs were prepared using two types of crosslinking monomer (acrylate vs. acrylamide). The [crosslinker]:[RAFT agent] ratio in the synthesis of HPs greatly affect their hemocompatibility, while the type of crosslinker had a negligible impact. HPs showed a remarkable 2- to 4-fold enhancement in hemocompatibility compared to LPs at the same hydrophobic ratio. Interestingly, SPs with a low hydrophobic ratio, did not display toxicity towards red blood cells, while maintaining similar potent antibacterial activities as LPs and HPs. Overall, SPs exhibited superior bioactivity compared to HPs and LPs (SPs > HPs > LPs), demonstrating that the manipulation of polymer topology offers a promising avenue for enhancing the performance of synthetic antibacterial polymers.

Toward Camouflage Colors by Electrochemical Copolymerization

AbstractIn this paper, a new electrochromic copolymer containing 6,9‐bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)‐1,2,3,4‐tetrahydrophenazine (EBE) and 4‐(9‐benzyl‐9H‐carbazol‐3‐yl)‐7‐(thiophen‐2‐yl)benzo[c][1,2,5]thiadiazole (CBT) in the main chain was reported. The homopolymers, (Poly(EBE) and Poly(CBT)), were also prepared via electrochemical polymerization and their electrochemical, spectroelectrochemical and electrochromic properties were analyzed in order to compare their properties with those of copolymer (Poly(EBE‐co‐CBT)). The copolymer exhibited good switching property for military camouflage necessities with color change from hues of brown to green. Furthermore, it has been tried to analyze the effects of combination of two donor‐acceptor‐donor (DAD) type monomers with different symmetries on the copolymer properties.

Demulsification law of polyether demulsifier for W/O crude oil emulsion containing hydrophobically modified polyacrylamide in water

Hydrophobically modified polyacrylamide (HMPAM) is one of the commonly used polymers for polymer flooding. Because it is water soluble, there are many reports on the impact of HMPAM on the stability and treatment of produced water (it is O/W emulsion), but few reports on its influence on the demulsification of W/O crude oil emulsion. In this paper, firstly, three types of HMPAM containing cationic, anionic, and nonionic hydrophobic monomers (abbreviated as P(AM-AANa-N)Cn, P(AM-AANA-S)Cn, and P(AM-AANA-O)Cn, respectively) were synthesized; Then, demulsification experiments and interface behavior experiments (including dynamic interfacial tension, dilatational rheology and dynamic coalescence time measurement) were conducted to investigate the influence of HMPAM on the demulsification performance of a W/O heavy oil emulsion demulsifier D1. The demulsification results showed that HMPAM reduced the dehydration speed of D1, the type of hydrophobic monomer and the length of hydrophobic chain in HMPAM can affect the final water separated of D1. P(AM-AANa-S)Cn, P(AM-AANa-N)Cn with long hydrophobic chain, and P(AM-AANa-O)Cn with short hydrophobic chains had the negative effect on performance of D1. The results of dynamic interfacial tension experiments indirectly showed that HMPAM had the influence on the D1′s conformation and speed of rearrangement at the W/O interface during the water droplet coalescence process, thereby affecting the reduction of elastic modulus (G′) of W/O interface and the coalescence rate of water droplets. When there was HMPAM in water, the coalescence time of water droplets increased, resulting in the decrease of dehydration rate. At the meantime, HMPAM had an impact on the lg(G1′/Gdemulsifier′)/lgG1′, thereby affecting the final water separated of D1.

Preparation and performance study of organosilicon fluorine modified acrylate emulsion

In this study, a novel type of organosilicone fluoride modified acrylate emulsion was developed using the semi-continuous pre-emulsification method. The emulsion was synthesized by incorporating organic fluorine monomer and three types of organosilicone monomers. The effects of the organosilicon types, the amount of organosilicon and organofluorine on the performance of the emulsions were investigated. The structure of the organosilicon fluorine modified acrylate was characterized using infrared spectroscopy, and the properties of the emulsion and coating films were evaluated through thermal analysis, contact angle, and conventional tests. The results demonstrated that the optimal comprehensive performance of the organosilicon fluorine-modified acrylate emulsion was achieved when the reaction was conducted at 80 °C for 4 h with the MMA/BA ratio of 0.7:1. The addition amounts of A-171 silicone, organic fluorine, and electrolyte were determined to be 3, 1.25, and 0.25% of the total monomer, respectively. The contact angle of the emulsion coating reached 89° and the pencil hardness reached 6H. Furthermore, the thermal stability of the newly modified acrylate emulsion showed significant improvement, indicating its potential for broad applications.

Construction, molecular docking simulation and evaluation of electrochemical properties of polymeric nanospheres comprising novel synthesized monomer via green microemulsion polymerization

AbstractIn recent years, the invention of polymers have attracted attention due to their unique properties. (E)‐2‐cyano‐N‐cyclohexyl‐3‐(dimethyl amino) acrylamide (CHAA) is a new type of functional monomer created by the usage of 2‐cyano‐N‐cyclohexylacetamide (3) and dimethylformamide‐dimethylacetal (DMF‐DMA) utilized microwave energy as a green technology. In addition, polymers with significant nanosphere groups were obtained by polymerizing a new synthetic monomer (CHAA) with methyl methacrylate (MMA), dimethylaminoethyl methacrylate (DMAEMA) and acrylic acid (AA) using microemulsion polymerization technology. These polymer nanospheres were approved by different spectroscopic analyzes, such as FT‐IR, TEM, TGA, and H1NMR. New structurally defined poly (MMA/DMAEMA/AA/CHAA) nanospheres with an equivalent spherical diameter close to 50 nm and high thermal stability were obtained. In addition, these new polymer nanospheres exhibit good electrochemical performance and greater specific values compared to compound (CHAA) or poly (MMA/DMAEMA/AA). This is very important for the supercapacitor due to the fact that the voltammetry plots of these nanospheres display a well‐known hysteresis cycle. The newly synthesized polymer nanospheres exhibited antibacterial activity, which was confirmed by molecular docking simulations with different affinities. Also, the DFT investigation of the polymeric nanosphere was optimized utilizing B3LYP/6‐31(G) basis set and determination physical decribitors.

Imine-linkage covalent organic framework synthesis in deep eutectic solvent at ambient conditions

Covalent organic frameworks (COFs) are important porous materials with large surface areas and adjustable pore channels with the ability of being effective adsorbents. The solvothermal synthesis of COFs usually requires elevated temperature, closed systems under high pressure, and harmful organic solvents. In addition, different conditions are needed to produce different COFs depending in part on the type of monomers used, meaning there is no ‘one size fits all’ approach synthesis route for COFs. In this work, a green synthesis routine was proposed for a series of imine-linkage COFs by using deep eutectic solvent (DES) as the reaction media at room temperature and atmospheric pressure. The obtained COFs are equipped with a large surface area (∼1300 m2 g−1), mesopore structure, high degree of crystallization and were synthesized with high yield. In addition, the stability of the DES structure under different temperatures and the effect of adding acetic acid (AC) for the catalytic synthesis of the COFs was also verified for the first time. Finally, the proposed routine showed good reusability which can fabricate COFs with good crystallization after four times. The synthesized COFs also showed excellent adsorption performance for dye solutions with ultra-fast kinetics, achieving nearly 100 % dye removal within 3 min with an adsorption rate of 7.399 g mg−1 min−1. The proposed routine showed clear advantages of using DES as a reaction media which includes lower synthesis temperature and pressure (i.e. room temperature and atmospheric pressure), open-air vessels, eco-friendly solvents, and good reaction media reusability.

Thermoresponsive and Photocrosslinkable Poly(2-alkyl-2-oxazoline) Toolbox - Customizable Ultralow-Fouling Hydrogel Coatings for Blood Plasma Environments.

This study focuses on developing surface coatings with excellent antifouling properties, crucial for applications in the medical, biological, and technical fields, for materials and devices in direct contact with living tissues and bodily fluids such as blood. This approach combines thermoresponsive poly(2-alkyl-2-oxazoline)s, known for their inherent protein-repellent characteristics, with established antifouling motifs based on betaines. The polymer framework is constructed from various monomer types, including a novel benzophenone-modified 2-oxazoline for photocrosslinking and an azide-functionalized 2-oxazoline, allowing subsequent modification with alkyne-substituted antifouling motifs through copper(I)-catalyzed azide-alkyne cycloaddition. From these polymers surface-attached networks are created on benzophenone-modified gold substrates via photocrosslinking, resulting in hydrogel coatings with several micrometers thickness when swollen with aqueous media. Given that poly(2-alkyl-2-oxazoline)s can exhibit a lower critical solution temperature in water, their temperature-dependent solubility is compared to the swelling behavior of the surface-attached hydrogels upon thermal stimulation. The antifouling performance of these hydrogel coatings in contact with human blood plasma is further evaluated by surface plasmon resonance and optical waveguide spectroscopy. All surfaces demonstrate extremely low retention of blood plasma components, even with undiluted plasma. Notably, hydrogel layers with sulfobetaine moieties allow efficient penetration by plasma components, which can then be easily removed by rinsing with buffer.

Transient Self‐Assembled Materials with Controllable Lifespan for Programmable Fluorescence

AbstractTransient structures play a wide range of vital roles in biological systems. Different from static structures that form the skeleton of bio‐tissues, transient structures only occur at certain spatial and temporal scales to undertake their duties in the life circle. Despite the significant progress in the field of artificial molecular self‐assembly studies, it still remains challenging to construct functional transient structures. Herein, the shaping of transient coordinating self‐assembled structures and their fluorescence is reported via host‐guest interaction that disfavors the assembly. The host‐guest interaction between the luminescent ligand and cyclodextrin drastically changes the kinetics of the coordinating self‐assembly, enabling the formation of transient structures. Different from the static equilibrium one with typical monomer emission in the UV region, the transient self‐assembly forms excimers, leading to visible emission. More intriguingly, the life cycle of the transient structures can be easily modulated by varying the host‐guest ratio, ligand‐metal ratio, as well as temperature. This makes it possible to create living patterns that mimic the growth of plants at different life stages. It is therefore envisioned that the creation of transient molecular self‐assembly will open a new paradigm in the field of molecular self‐assembly featuring advanced materials with dynamic functions.

Bioconversion of glycerol into polyhydroxyalkanoates through an atypical metabolism shift using Priestia megaterium during fermentation processes: A statistical analysis of carbon and nitrogen source concentrations

Polyhydroxyalkanoates (PHA) are bioplastics which are well known as intracellular energy storage compounds and are produced in a large number of prokaryotic species. These bio-based inclusions are biodegradable, biocompatible and environmental friendly. Industrial production of, short chain and medium chain length PHA, involves the use of microorganisms and their enzymes. Priestia megaterium previously known as Bacillus megaterium is a well-recognized bacterium for producing short chain length PHA. This study focuses to characterize this bacterium for the production of medium chain length PHA, and a novel blend of both types of monomers having enhanced properties and versatile applications. Statistical analyses and simulations were used to demonstrate that cell dry weight can be derived as a function of OD600 and PHA content. Optimization of growth conditions resulted in the maximum PHA production as: 0. 05 g. g-x. H−1, where the rate of PHA production was 0.28 g L−1. H−1 and PHA concentration was 4.94 g. L−1. This study also demonstrated FTIR to be a semi quantitative tool for PHA production. Moreover, conversion of scl-PHA to mcl-PHA with reference to time intermissions using GC-FID are shown.

Chlorinated benzothiadiazole-based donor-acceptor polymers with tunable optoelectronic performances

Chlorinated benzo[c][1,2,5]thiadiazole, a new analogue of benzo[c][1,2,5]thiadiazole (BT), exhibits strong electron-withdrawing ability nature, while also offering advantages of lower cost and easier accessibility compared to its fluorinated analogues. This inspires us to investigate donor-acceptor-type (D-A) conjugated polymers based on chlorinated BT. Therefore, in this work, three D-A-D type monomers (0Cl, 1Cl, and 2Cl) were successfully synthesized with BT and chlorinated BT as acceptor units and EDOT as donor units by Stille coupling reaction. Subsequently, the corresponding D-A polymers (P0Cl, P1Cl, and P2Cl) were obtained via electrochemical polymerization. The results show that the two chlorinated monomers have higher initial oxidation potentials of 1.08 V (1Cl) and 1.09 V (2Cl), which are significantly higher than their non-chlorinated analogue (0.72 V). The two chlorinated polymers demonstrate good redox activity but with relatively poor stability (only 65.7 % and 20.7 % electroactivity are preserved after 100 cycles). Due to the decreased effective conjugation length caused by the deviations from planarity, both absorption spectra of the chlorinated polymers were blue-shifted when compared with P0Cl, leading to an increase in the optical band gap (1.64–1.68 eV). Introducing the Cl atom substitution on the BT unit resulted in the improvement of both the switching time and coloration efficiency. Specifically, the monochlorinated polymer (P1Cl) showed light gray in the neutral state and obvious electrochromic properties in the near-infrared region (optical contrast: 24 %, coloration efficiency: 195.6 cm2 C−1, and quick response time: 0.4 s). This study further expands the selection of chlorinated BT-based acceptor units and the application prospect of D-A electrochromic polymers.

Enhanced Modification of Fast-Growing Wood: Application and Evaluation of Castor Oil-Based Unsaturated Polyester Resin.

A type of multifunctional maleic acid ester monomer (COEGMA) was synthesized using castor oil as raw material, and green wood-plastic composites were prepared by chemically impregnating and curing the monomer into wood. The structure of the synthesized products at various stages was determined by FT-IR spectroscopy, 1H NMR, and GPC, and the curing experimental conditions were optimized. The results show that the water absorption of wood-plastic composites treated with COEGMA is reduced from the original 167.3% to less than 20%. The compressive strength has increased from 35.7 to 86.1 MPa, and the thermal stability has also increased by 40 °C. This research provides promising prospects for the development of environmentally friendly wood-plastic composites, especially as fossil resources become scarce and environmental pollution becomes more severe.

Preparation of copolymer brush‐type restricted access microspheres with adjustable adsorption selectivity to variety of dyes

AbstractRestricted access materials (RAMs) with adjustable selectivity was developed for the removal and detection of residual dyes for the solve problems of dye contamination. In this work, using homemade poly(4‐vinylbenzyl chloride‐co‐divinylbenzene) (PVBC/DVB) microspheres as substrate and successive two‐step surface‐initiated atom transfer radical polymerization (SI‐ATRP) as synthesis method, the two types of monomers, sodium 4‐vinylbenzene sulfonate (Nass) and styrene (St) were first grafted for constructing mixed interactions of adsorption sites, and then the hydrophilic glycidyl methacrylate (GMA) was polymerized, following by hydrolysis to construct diol groups on the external PVBC/DVB as the restricted access sites. The developed PVBC/DVB@poly(St‐co‐Nass)@poly(GMA) of adsorption properties was investigated by six dyes including methylene blue (MB), basic fuchsin (BF), acid fuchsin (AF), neutral red (NR), methyl orange (MO), and Congo red (CR), the adsorption capacities of those dyes and the removal rate for the binary mixed dye solution both rely on the ratio of St/Nass, confirming the adjustable adsorption selectivity. When PVBC/DVB@poly(St‐co‐Nass)@poly(GMA) was packed as solid phase extraction adsorbent in couple with UV–vis spectrum, it was applied to the determination of MB and BF in the water, fish and shrimp, good linearity with satisfactory recoveries for MB and BF are obtained to show the favorable practicability.

2D Covalent Organic Frameworks with Kagome Lattice: Synthesis and Applications.

2D covalent organic frameworks with Kagome (kgm) topology are a promising class of crystalline frameworks that possess both triangular and hexagonal pores. These dual-pore structures enable kgm COFs to exhibit unique advantages in selective separation, mass transfer, and targeted drug release. However, the synthesis of 2D kgm COFs has been hindered by the reliance on empirical methods. This review systematically summarizes the conventional macrocycle-to-framework strategy, typical [4+2] co-polymerization synthetic strategy, and bifunctional molecules self-condensation approach for constructing 2D kgm COFs. Factors influencing the formation of kgm lattice are surveyed, such as monomer type, solvent polarity, substrate concentration, etc., and highlight the representative examples on targeted synthesis. Additionally, applications of 2D kgm COFs and relationships between structure and performances are summarized. Finally, key fundamental perspectives are proposed to accelerate the further development of this intriguing material.