Glycol Dimethacrylate Cross-linker Research Articles

Well‐defined poly(methyl methacrylate) hybrid titanium dioxide via miniemulsion polymerization: Design and evaluation of methylene blue dye degradation and antibacterial

AbstractA poly(methyl methacrylate)/TiO2 (PMMA/TiO2) hybrid was synthesized in the presence of triethylene glycol dimethacrylate as a crosslinking agent. Different types of TiO2 rutile, anatase, and P25 were employed in this study, and the morphology, crystalline structure, particle size, thermal properties, photocatalytic activity, and antibacterial activity were investigated. The results show that the particle size of the PMMA/TiO2 hybrids was in the range of 73.3 nm to 210.0 nm. The morphology of the PMMA/TiO2 hybrid was spherical with a narrow particle size distribution. The thermal properties of the PMMA/TiO2 hybrid were analyzed using differential scanning calorimetry. The glass transition temperature of the PMMA/TiO2 was higher than that of pristine PMMA. The photocatalytic properties were investigated by monitoring the color changes of methylene blue (MB). It was found that the MB degradation for the PMMA hybrid anatase TiO2 (PMMA/aTiO2) reached 80%, which was similar to that for the PMMA hybrid P25TiO2 at 83% in 60 min. The minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of the PMMA/TiO2 hybrids were estimated. The MIC of PMMA hybrid anatase TiO2 was 9.65 mg mL−1 (P. aeruginosa) and 19.33 mg mL−1 (S. aureus) which can inhibit the bacteria. The MBC results of the PMMA/aTiO2 were 19.33 mg mL−1 for both P. aeruginosa and S. aureus.Highlights TiO2 nanoparticle encapsulation with poly(methyl methacrylate) via mini‐emulsion polymerization. Encapsulated particles exhibit excellent photocatalytic properties. Triethylene glycol dimethacrylate (TEGDMA) crosslinking ensures stability, enhances photocatalytic property. The influence of TEGDMA on the hybrid was discussed.

Development and Fabrication of a Molecularly Imprinted Polymer-Based Electroanalytical Sensor for the Determination of Acyclovir.

Acyclovir (ACV), a synthetic nucleoside derivative of purine, is one of the most potent antiviral medications recommended in the specific management of varicella-zoster and herpes simplex viruses. The molecularly imprinted polymer (MIP) was utilized to create an effective and specific electrochemical sensor using a straightforward photopolymerization process to determine ACV. The polymeric thin coating was developed using the template molecule ACV, a functional monomer acrylamide, a basic monomer 2-hydroxyethyl methacrylate, a cross-linker ethylene glycol dimethacrylate, and a photoinitiator 2-hydroxy-2-methyl propiophenone on the exterior of the glassy carbon electrode (GCE). Scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry were employed for the purpose of characterizing the constructed sensor (AM-ACV@MIP/GCE). Differential pulse voltammetry and a 5 mM ferrocyanide/ferricyanide ([Fe(CN)6]3-/4-) redox reagent were used to detect the ACV binding to the specific cavities on MIP. The study involves density functional theory (DFT) calculations, which were conducted to investigate template-functional monomer interactions thoroughly, calculate template-functional monomer interaction energies, and determine the optimal template/functional monomer ratio. DFT calculations were performed using Becke's three-parameter hybrid functional with the Lee-Yang-Parr correlation functional (B3LYP) method and 6-31G(d,p) basis set. The sensor exhibits linear performance throughout the concentration region 1 × 10-11 to 1 × 10-10 M, and the limit of detection and limit of quantification were 7.15 × 10-13 M and 2.38 × 10-12 M, respectively. For the electrochemical study of ACV, the sensor demonstrated high accuracy, precision, robustness, and a short detection time. Furthermore, the developed electrochemical sensor exhibited exceptional recovery in tablet dosage form and commercial human blood samples, with recoveries of 99.40 and 100.44%, respectively. The findings showed that the AM-ACV@MIP/GCE sensor would effectively be used to directly assess pharmaceuticals from actual specimens and would particularly detect ACV compared to structurally similar pharmaceutical compounds.

Polymerizable sol–gel synthesis of dark-visible light antibacterial magnetically-recoverable AgBr-loaded iron oxide/alumina nanocomposite

The demand for a facile approach for synthesizing multifunctional nanocomposites is increasingly vital across diverse applications. In this study, a polymerizable sol–gel synthesis has been reported to obtain nanocomposites of magnetic iron oxide deposited over alumina nanopowder. The synthesis is mediated by the deposition of a calculated amount of iron(III) methacrylate, along with ethylene glycol dimethacrylate crosslinker, over alumina nanopowder, followed by thermally-inducing free radical polymerization at 125 °C for 30 min. The powder thus obtained has been subjected to calcination at 400 °C for 150 min and the resultant nanocomposites were characterized using wide-angle x-ray scattering, attenuated total reflectance—Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, field-emission scanning electron microscopy, ultraviolet-diffuse reflectance spectroscopy, vibrating sample magnetometer and Brunauer–Emmett–Teller surface area measurements. The nanocomposites containing 15 and 20 wt% of iron oxide have been found to exhibit a saturation magnetization (M s) value ranging from 12 to 14 emu g−1. To the nanocomposite containing 20 wt% of iron oxide, 5 wt% of AgBr was loaded through thoroughly mixing a surfactant-based precursor, silver-tetraoctyl ammonium bromide (Ag-TOAB), followed by thermolysis. All the nanocomposites have been studied for their antibacterial activity against a representative gram-negative bacterium, Escherichia coli, under dark and visible light conditions. While a 3 mg ml−1 loading of the AgBr-loaded nanocomposite has exhibited complete clearance of the bacterial growth by 90 min in the dark, a similar activity has been observed in 60 min under light. The study has revealed the multifunctionality and high potential of the AgBr-loaded iron oxide/alumina nanocomposite as a promising dual-mode antibacterial and magnetically recoverable photocatalyst material.

Capturing Acidic CO2 Using Surface-Active Difunctional Core-Shell Composite Polymer Particles via an Aqueous Medium.

Multifunctional surface-active polymeric composites are attractive materials for the adsorption of various small molecules. Herein, dual-functionalized micron-sized surface-active composite polymer particles were prepared by a three-step process for CO2 adsorption. First, polystyrene (PS) seed particles were prepared via the dispersion polymerization of styrene. PS/P(MMA-AAm-EGDMA) composite polymer particles were then synthesized by aqueous seeded copolymerization of methyl methacrylate (MMA) and acrylamide (AAm) in the presence of an ethylene glycol dimethacrylate (EGDMA) cross-linker. Finally, the amide moieties of PS/P(MMA-AAm-EGDMA) composite particles were converted into an amine-functionalized composite by using the Hofmann degradation reaction. The presence of primary amine groups on the surface of aminated composite particles was confirmed by some conventional chemical routes, such as diazotization and Schiff's base formation reactions. The formation and functionality of the PS seed, PS/P(MMA-AAm-EGDMA), and aminated PS/P(MMA-AAm-EGDMA) composite polymer particles were confirmed by Fourier transform infrared (FTIR) spectra analyses. Scanning electron microscopy (SEM) analysis revealed spherical shape, size, and surface morphologies of the PS seed, reference composite, and aminated composites. The elemental surface compositions, surface porosity, pore volume, pore diameter, and surface area of both composite particles were evaluated by energy-dispersive X-ray (EDX) mapping, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses. Dynamic light scattering (DLS) and ζ-potential measurements confirmed the pH-dependent surface properties of the functionalized particles. The amount of the adsorbed anionic emulsifier, sodium dodecyl sulfate (SDS), on the surface of aminated PS/P(MMA-AAm-EGDMA) is higher at pH 4 than that at pH 10. A vice versa result was found in the case of cationic surfactant, hexadecyltrimethylammonium bromide (HTABr), adsorption. Synthesized aminated composite particles were used as an adsorbent for CO2 adsorption via bubbling CO2 in an aqueous medium. The changes in dispersion pH were monitored continuously during the adsorption of CO2 under various conditions. The amount of CO2 adsorption by aminated composite particles was found to be 209 mg/g, which is almost double that of reference composite particles.

Preparation of molecularly imprinted polymer nanoparticles for selective adsorption of caffeine using dual-functionalized Ag2S quantum dots

Caffeine is the most abundant and widely consumed active medicinal compound, making it the most representative pollutant in the environment. This research involved synthesizing high-performance fluorescent HOOC-CC-functionalized Ag2S quantum dots (HOOC-QDs) measuring approximately 4.35 nm in size using the hydrothermal method. These QDs were then used to produce fluorescent molecularly imprinted polymer nanoparticles (MIP-Ag2S NPs) measuring 20.31 nm. The MIP-Ag2S NPs were created through a graft suspension copolymerization process involving methacrylic acid monomer, ethylene glycol dimethacrylate cross-linker, and caffeine template molecules. The polar carboxylic acid groups enhance the interaction with the template molecules, which is crucial for selectivity, and the -CC- groups aid in network formation. The MIP-Ag2S NPs emitted fluorescence at around 500 nm, which was significantly reduced after caffeine adsorption. The pH-sensitive MIP-Ag2S NPs had a maximum caffeine adsorption capacity of 488 mg/g at pH 6 and a maximum release of approximately 96% at pH 2.2. Additionally, repeated cycles of adsorption and desorption did not result in a significant loss of adsorption capacity. The HOOC-QDs can be used to prepare MIPs for extracting and recognizing pollutants and medicine in water and for controlled drug delivery systems.

Continuous generation of cross-linked polymer nanoparticles employing an ultrasonic microreactor

In this article, a new system employing an ultrasonic microreactor coupled with a tubular reactor is presented for the continuous generation of polymer nanoparticles. The continuous generation of cross-linked polymer nanoparticles utilizing the monomer butyl methacrylate and the cross-linker ethylene glycol dimethacrylate is demonstrated. Firstly, the miniemulsion polymerization of a monomer-in-water miniemulsion is studied in a batch system. Secondly, a coiled tubular reactor is employed for the continuous polymerization of the miniemulsion generated by an ultrasonic microreactor. Finally, the influence of monomer volume fraction and surfactant concentration on the synthesized polymer nanoparticles is studied. Polymer particles in a size range of 50–250 nm are synthesized and a high polymerization conversion is achieved utilizing the system demonstrated in this article.

Fabrication of molecularly imprinted electrochemical sensors for sensitive codeine detection

Codeine (COD) is a natural opiate alkaloid obtained from hashish or prepared by methylation from morphine, widely used as an analgesic, antitussive, and antidiarrheal drug. A sensitive and selective electrochemical sensor based on molecular imprinting polymer (MIP) was developed to detect COD in tablet form and biological fluid samples. The polymeric thin film on the glassy carbon electrode (GCE) surface was formed using template molecule COD, a functional monomer based on amino acid N-methacryloyl-L-tryptophan (MA-Trp), basic monomer 2-hydroxyethyl methacrylate (HEMA), cross-linker ethylene glycol dimethacrylate (EGDMA), and the pore-making sacrificial material zinc oxide (ZnO). The developed MIP-based electrochemical sensor (MA-Trp@MIP/GCE) was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) methods. The electrochemical properties of the sensor were examined using differential pulse voltammetry (DPV). Under optimum experimental conditions, the dynamic linear range of the developed sensor was calculated as 0.1–1.0 pM and the detection limit of 0.0150 pM. The current electrochemical sensor technique also demonstrated outstanding recovery in human urine, synthetic serum samples, and tablet form, with relatively high recoveries of 98.5%, 101.4%, and 101.5%, respectively. Moreover, the MA-Trp@MIP/GCE sensor exhibited good reproducibility, repeatability, stability, and fast response time for the electrochemical analysis of COD. The presented sensor successfully determined COD in tablet and biological fluid samples.

Preparation and characterization of high solid content acrylate latex pressure sensitive adhesives with difunctional cross-linker EGDMA

Cross-linked acrylate latex pressure sensitive adhesives (PSAs) were synthesized via unseeded semi-batch emulsion polymerization processes with butyl acrylate (BA), acrylic acid (AA), 2-hydroxyethyl acrylate (HEA) and difunctional cross-linker, ethylene glycol dimethacrylate (EGDMA). The influences of EGDMA on the comprehensive properties of the acrylate latex PSAs were investigated. The results indicated that both viscosity and particle size of the latexes were independent of the amount of EGDMA in the pre-emulsion feed when unseeded semi-batch emulsion polymerization process was employed. It was also found that water resistance of the latex PSA was improved with increasing EGDMA content, further confirmed by water contact angle measurements. DSC and TGA results showed that Tg of the copolymer was elevated, plus thermal stability was increased with introduction of EGDMA. Besides, with the increase of EGDMA content, the gel content of the polymer increased. Moreover, for the cross-linked adhesive film, the shear strength was improved greatly while at the sacrifice of loop tack and peel strength, when compared with the uncross-linked counterparts.

The effect of Fe–Zn mole ratio (2:1) bimetallic nanoparticles supported by hydroxyethyl cellulose/graphene oxide for high-efficiency removal of doxycycline

In this research, Hydroxyethyl cellulose – graphene oxide HEC-GO and HEC-GO/Fe–Zn mole ratio (2:1) nanocomposite as adsorbents were fabricated by crosslinking ethylene glycol dimethacrylate (EGDMA) to study the thermodynamic, kinetic and isotherm of doxycycline antibiotic adsorption. The morphology and structure of the adsorbents were analyzed by Fourier transform infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (FE-SEM- EDX), and Transmission electron microscopy (TEM). The adsorption behavior of doxycycline (DOX) was studied with different parameters including doxycycline concentration, pH, the dose of adsorbent (HEC-GO and HEC-GO/Fe–Zn, mole ratio (2:1)), contact time, and temperature. The optimal conditions for the removal of DOX are pH = 3.0, contact time 100 min, and 20 min for HEC-GO and HEC-GO/Fe–Zn mole ratio (2:1). The removal percentage for HEC-GO and HEC-GO/Fe–Zn mole ratio (2:1) was 97% and 95.5%, respectively. Equilibrium adsorption isotherms such as the Langmuir, Freundlich, and Temkin models were analyzed according to the experimental data. Also, four adsorption kinetics were investigated for removing DOX. The Langmuir isotherm and pseudo-second-order kinetic models provided the best fit for experimental data for HEC-GO and HEC-GO/Fe–Zn mole ratio (2:1). Thermodynamic data showed that negative values of Gibbs free energy (ΔG°) and the negative value of enthalpy (ΔH°) of the adsorption process for adsorbents. It means that DOX removal was a spontaneous and exothermic reaction.

Fabrication and implementation of bimetallic Fe/Zn nanoparticles (mole ratio 1:1) loading on hydroxyethylcellulose – Graphene oxide for removal of tetracycline antibiotic from aqueous solution

Tetracycline (TC) as an antibiotic with high consumption causes the spread of contamination in an aqueous solution. In recent decades, antibiotics are the main cause of hindering the growth of microorganisms. Also, they are one of the important groups of pharmaceuticals with extensive usage in human and veterinary medicine. In the first work of its kind, we used a suitable adsorbent of biodegradable hydroxyethylcellulose (HEC) with graphene oxide (GO) by crosslinking ethylene glycol dimethacrylate (EGDMA) and the Fe/Zn with mole ratio 1:1 bimetallic nanoparticles with HEC-GO support. The materials were identified using FTIR, FE-SEM, EDX, TEM, and TG- DSC analyses. The factors affecting the adsorption process (contact time, initial concentration of TC, solution pH, adsorbent dosage, and reaction temperature) were evaluated in a series of batch systems. The adsorption data showed that the high adsorption capacity was obtained on the HEC-GO and HEC-GO/Fe–Zn (mole ratio 1:1) nanocomposites at pH 3. Also, the contact time as the main factor affecting the adsorption process by adsorbents was investigated and the best contact time was 100 and 20 min. The TC removal percentages of both adsorbents were 85% and 95% for HEC-GO and HEC-GO/Fe–Zn, respectively. The maximum adsorption capacity for TC was evaluated by the isotherm models. The experimental data fitted well with the Langmuir model. In addition, pseudo-first-order, pseudo-second-order, intraparticle diffusion, and the Elovich models were applied to kinetic data. The data indicated that TC adsorption on HEC-GO and HEC–GO/Fe–Zn (mole ratio 1:1) followed the pseudo-second-order kinetic model. The thermodynamic parameters implied that the adsorption process was spontaneous and exothermic. Nano-biocomposite (HEC-GO/Fe–Zn) can be used as an adsorbent to remove water pollutants.

Noncovalent Enzyme Nanogels via a Photocleavable Linkage.

Enzyme nanogels (ENGs) offer a convenient method to protect therapeutic proteins from in vivo stressors. Current methodologies to prepare ENGs rely on either covalent modification of surface residues or the noncovalent assembly of monomers at the protein surface. In this study, we report a new method for the preparation of noncovalent ENGs that utilizes a heterobifunctional, photocleavable monomer as a hybrid approach. Initial covalent modification with this monomer established a polymerizable handle at the protein surface, followed by radical polymerization with poly(ethylene glycol) methacrylate monomer and ethylene glycol dimethacrylate crosslinker in solution. Final photoirradiation cleaved the linkage between the polymer and protein to afford the noncovalent ENGs. The enzyme phenylalanine ammonia lyase (PAL) was utilized as a model protein yielding well-defined nanogels 80 nm in size by dynamic light scattering (DLS) and 76 nm by atomic force microscopy. The stability of PAL after exposure to trypsin or low pH was assessed and was found to be more stable in the noncovalent nanogel compared to PAL alone. This approach may be useful for the stabilization of active enzymes.

Fluorinated reversed micelles by polymerization-induced self-assembly with main-chain-type semifluorinated alternating copolymer

In this work, based on the semifluorinated macro-RAFT (reversible addition-fragmentation chain transfer) agent and polymerization-induced self-assembly (PISA) strategy, we established a mild and facile method to prepare reversed micelles up to 40 wt% of solid content with main-chain-type semifluorinated alternating copolymer as shell and hydrophilic polymer as core for the first time. The fluorinated macro-RAFT agent was synthesized by combination of step transfer-addition & radical-termination (START) polymerization and post-modification method. The reversed micelles were generated by the PISA of N,N-dimethacrylamide (DMA) in the presence of the fluorinated macro-RAFT agent in the non-polar solvent toluene at 70 °C, and fluorinated reversed micelles can be fixed in the presence of crosslinker ethyleneglycol dimethacrylate (EGDMA). This strategy will facilitate to open a new way in designing novel functional synthetic fluorinated nanomaterials.

Suspended Multifunctional Nanocellulose as Additive for Mortars.

Cellulose derivatives have found significant applications in composite materials, mainly because of the increased mechanical performance they ensure. When added to cement-based materials, either in the form of nanocrystals, nanofibrils or micro/nanofibers, cellulose acts on the mixture with fresh and hardened properties, affecting rheology, shrinkage, hydration, and the resulting mechanical properties, microstructure, and durability. Commercial cotton wool was selected as starting material to produce multifunctional nanocelluloses to test as additives for mortars. Cotton wool was oxidized to oxidized nanocellulose (ONC), a charged nanocellulose capable of electrostatic interaction, merging cellulose and nanoparticles properties. Oxidized nanocellulose (ONC) was further functionalized by a radical-based mechanism with glycidyl methacrylate (GMA) and with a mixture of GMA and the crosslinking agent ethylene glycol dimethacrylate (EGDMA) affording ONC-GMA and ONC-GMA-EGDMA, both multifunctional-charged nanocellulose merging cellulose and bound acrylates properties. In this work, only ONC was found to be properly suitable for suspension and addition to a commercial mortar to assess the variation in mechanical properties and water-mortar interactions as a consequence of the modified microstructure obtained. The addition of oxidized nanocellulose caused an alteration of mortar porosity, with a decreased percentage of porosity and pore size distribution shifted towards smaller pores, with a consequent increase in compressive resistance, decrease in water absorption coefficient, and increased percentage of micropores present in the material, indicating a potential improvement in mortar durability.

Polyaspartic acid, 2-acrylamido-2-Methyl propane sulfonic acid and sodium alginate based biocompatible stimuli responsive polymer gel for controlled release of GHK-Cu peptide for wound healing.

Stimuli responsive polymer based on Polyaspartic acid, 2-Acrylamido-2-methylpropane sulfonic acid and sodium alginate (NaAlg) were synthesized using two cross-linkers Ethylene glycol dimethacrylate (EGDMA) and TMPTA (Trimethylolpropane triacrylate). The polymers were standardized and optimized to obtain a polymer with maximum swelling in distilled water, saline, glucose and solutions of varying pH. The synthesized polymer swelled well in distilled water, glucose solution and acidic- alkaline medium. The biocompatibility of the polymer was evaluated for blood compatibility and protein adsorption. The polymer with maximum swelling property was used for peptide release studies. The polymer was further used to study the peptide encapsulation and release efficiency of the polymeric material which was confirmed by FTIR, Scanning Emission Microscope and EDX. The encapsulation efficiency of the polymer for encapsulating (glycyl-l-histidyl-l-lysine-copper) GHK-Cu was observed to be 55.26% and peptide release of 51.84% was observed for Ethylene glycol dimethacrylate based polymer after 24h whereas for Trimethylolpropane triacrylate based polymer the encapsulation efficiency was observed to be 49.6% and release was 39.01%. The EGDMA based polymer was further examined under in vivo studies in order to evaluate the efficiency of the synthesized polymer. The in vivo studies include wound closure, histopathological analysis, biochemical and toxicity assay. The material has shown promising results for both in vivo and in vitro studies.

Poly(ionic liquid) materials tailored by carboxyl groups for the gas phase-conversion of epoxide and CO2 into cyclic carbonates

Carbon dioxide (CO2) is an important C1 resource, and the preparation of cyclocarbonate by catalyzing CO2 and epoxides is a nature-friendly route to utilize. In this study, polymer ionic liquid materials (PILMs) were prepared by copolymerizing the vinylimidazole-based ionic liquids (ILs) as monomer with carbonyl-rich copolymer monomer methyl methacrylate (MMA) and crosslinking agent ethylene glycol dimethacrylate (EGDMA), to enhance the affinity of PILMs for CO2 and PO. Then, epoxides and CO2 were converted to cyclic carbonates using PILMs by the gas-liquid reaction (GLR) and the gas phase-conversion progress (GCP). Amongst those polymer ionic liquid materials, the PILM containing carboxypropyl group (PILM-VCPImBr) exhibited the performance with the propylene carbonate (PC) yield of 96.7% (at 130 °C, 3 MPa CO2, reaction time 3 h) by GLR. And the yield of PC reached 94.2% (at 130 °C, 2 MPa CO2, reaction time 3 h) by GCP, which was the same as that of GLR. The excellent catalytic activity can be attributed to the fact that the PILMs fully dispersed the active sites and were rich in pores, which could effectively catalyze propylene oxide (PO) and CO2 to generate PC. Finally, 1H NMR spectra showed that VCPImBr and PO formed strong hydrogen bonds to participate the ring-opening process of epoxides, and a possible catalytic mechanism of H-bond synergistic effect was proposed. This article provides a novel strategy for designing both stable and nature-friendly catalysts in the CO2 transformation, and proposes a new method for cyclic carbonate conversion.

Designing Boron‐Based Single‐Ion Gel Polymer Electrolytes for Lithium Batteries by Photopolymerization

AbstractSingle‐ion lithium conducting polymer electrolytes based on delocalized borate groups are designed and synthesized by rapid UV‐photopolymerization. For this purpose, three different functional lithium boron sp3 anionic monomers, containing fluorinated, ethoxy, or a blend of both functionalities are synthesized. These monomers are photopolymerized in the presence of a poly(ethylene glycol) dimethacrylate crosslinker and tetraglyme as plasticizer. By this method, gel polymer electrolytes endowed with lithium single‐ion conduction are prepared (SIGPEs). The impact generated by the different functionalities of the borate groups and the addition of plasticizer on the electrochemical and ion conducting properties of the synthesized polymer electrolytes are analyzed in detail. These polymer electrolytes show high ionic conductivity (1.71 × 10−4 S cm−1 at 25 °C) and high lithium transference number values (up to 0.85). Finally, they are investigated as solid electrolytes in lithium metal symmetrical cells showing good performance (<0.85 V at ±0.2 mA cm−2 for 175 h).

Cobalt (II)-Mediated Molecularly Imprinted Polymer as a Monolithic Stationary Phase for Separation of Racemic Citronellal by Liquid Chromatography.

A metal-mediated molecularly imprinted polymer (MMIP) monolithic column was prepared as the stationary phase for high-performance liquid chromatography (HPLC) and applied to the enantiomeric separation of rac-citronellal. MMIP column was prepared through in situ copolymerizations with the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate/[BMIM][BF4] as the primary pore-forming agent and cobalt(II) acetate as the metal pivot. Interactions between polymer components in the synthesized monolith were assessed by FTIR to identify the functional groups. The monolith morphology was characterized with SEM, and the template removal was detected by UV Spectrophotometry at 253 nm. In this study, (R)-(+)-citronellal was used as a template, whereas 4-vinylpyridine (4-VP) was employed as the functional monomer with two monomer crosslinkers, trimethylolpropane trimethacrylate (TRIM), and ethylene glycol dimethacrylate (EDMA). The ternary mixture of porogenic solvent consisted of [BMIM][BF4], dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) with the applied ratio of 1 : 1:1 (v/v) and 10 : 1:5 (v/v) for the preparation of MMIP using TRIM and EDMA crosslinkers, respectively. Co(II) ion was added to the porogenic solvent before being mixed with the functional monomer and the crosslinker mixtures. Separating the rac-citronellal was achieved on the synthesized MMIP, showing better selectivity than the monolithic metal-mediated nonimprinted polymer (MNIP), nonimprinted polymer (NIP), and molecularly imprinted polymer (MIP).

Fabrication of amphiphilic porous PDVB-PAA Janus nanoparticles: Formation mechanism, simultaneous loading and regulated release of hydrophobic and hydrophilic cargos

In this work, we reported the amphiphilic porous polydivinylbenzene-poly(acrylic acid) (PDVB-PAA) Janus nanoparticles (NPs) with a cross-linked hydrophobic porous PDVB framework and a cross-linked hydrophilic porous PAA bulge, which were converted from polystyrene/polydivinylbenzene-poly(tert-butyl acrylate) (PS/PDVB-PtBA) Janus NPs via hydrolysis in dichloromethane. Cl,Br-labeled PS/PDVB-PtBA Janus NPs were designed and synthesized to experimentally verify the formation mechanism of PS/PDVB-PtBA Janus NPs and PDVB-PAA Janus NPs for the first time by combined techniques of TEM, SEM with element mapping and FTIR measurements. By simply varying the feeding amount of crosslinking agent ethylene glycol dimethacrylate (EGDMA) during the polymerization step of tBA, the morphologies of resultant PS/PDVB-PtBA Janus NPs and corresponding PDVB-PAA Janus NPs could be well controlled. It was demonstrated that the obtained amphiphilic porous PDVB-PAA Janus NPs could be applied as carrier materials for simultaneously loading hydrophobic coumarin 153 and hydrophilic rhodamine 6G.

Elucidating doxycycline loading and release performance of imprinted hydrogels with different cross-linker concentrations: a computational and experimental study

Effective non-covalent molecular imprinting on a polymer depends on the extent of non-bonded interactions between the template and other molecules before polymerization. Here, we first determine functional monomers that can yield a doxycycline-imprinted hydrogel based on the hydrogen bond interactions at the prepolymerization step, revealed by molecular dynamics (MD) simulations, molecular docking, and simulated annealing methods. Then, acrylic acid (AA)-based doxycycline (DOX) imprinted (MIP) and non-imprinted (NIP) hydrogels are synthesized in cross-linker ethylene glycol dimethacrylate (EGDMA) ratios of 1.0, 1.5, 2.0, and 3.0 mol%. Here, molecularly imprinted polymer with 3.0 mol% EGDMA has the highest imprinting factor (1.58) and best controlled drug release performance. At this point, full-atom MD simulations of DOX–AA solutions at different EGDMA concentrations reveal that AA and EGDMA compete to interact with DOX. However, at 3.0 mol% EGDMA, AA attains numerous stable hydrogen bond interactions with the drug. This study demonstrates that the concentration of the cross-linker and functional monomer can be adjusted to increase the success of imprinting, where the interplay between these two parameters can be successfully revealed by MD simulations.Supplementary informationThe online version contains supplementary material available at 10.1007/s10965-021-02740-6.

Preparation and properties of aflatoxins imprinted polymer grafted onto the surface of mesoporous silica SBA-15 functionalized with double bonds.

Mesoporous silica Santa Barbara-15 was functionalized by methacryloxypropyl trimethoxysilane. Taking this as the carrier material, a new mesoporous silica surface imprinted polymer was synthesized by using the C=C bond, functional monomer α-methacrylic acid, and crosslinker ethylene glycol dimethacrylate, which was used to extract aflatoxin from grain efficiently. It is different from the preparation of surface imprinted polymers which is physically wrapping carrier materials with polymer layers. The chemical grafting method makes the coating of the polymer layer more controllable. A new method for selective separation, enrichment, and determination of trace aflatoxin in grain was established by using the polymers as the filter of the solid-phase extraction column and high-performance liquid chromatography. The linear range of the method was 0.5-100 μg/kg, R2 =0.9990-0.9993. The recovery of aflatoxin G2, G1, B2, and B1 was 98.9-119.7% and the relative standard deviation was 3.07-5.76%. By comparing the self-made column with the immunoaffinity column, it was found that the self-made column had better extraction performance for aflatoxins than the immunoaffinity column. It can be used for the analysis and detection of aflatoxins in cereal.