Study of some properties of poly(N-vinyl imidazole) partially quaternized with n-butyl bromide aqueous solutions

This paper presents a study of the properties of aqueous solutions of poly(N-vinyl imidazole) quaternized with n-butyl bromide (PVIQ3). The influence of the temperature and polymer concentration on refractive index, electrical conductivity and surface tension was studied. The critical micelar concentration of PVIQ3 in aqueous solution was determined and correlated with the polymer solubility in water.All the PVIQ3 aqueous solutions properties were compared with those of poly(N-vinyl imidazole) (PNVI) and the influence of the quaternization process on the polymer properties was evidenced.     

Synthesis of Quaternized poly(4-Vinyl Pyridine) and the Study of its Ion Exchange Property

Lightly cross-linked poly(4-vinyl pyridine) has been synthesized from 4-vinyl pyridine and a small amount of ethylene glycol dimethacrylate (EGDMA) in aqueous medium through micelle technique. The polymer is then quaternized with 1,4-dibromobutane to develop an anion exchange resin with high selectivity and ion exchange capacity at a wide range of pH and temperature. The material exhibits high ion exchange capacity and reverse anion selectivity order compared to commercially available anion exchanger. A method has been designed to separate chromate and sulfate using the synthesized material.     

New N-vinylamide-based polymers for the preconcetration of nitrophenols from aqueous media

New cross-linked copolymer with molecular imprints of 4-nitrophenol have been synthesized by the radical polymerization of cyclic N-vinyl amides and ethylene glycol dimethacrylate. Sorption characteristics of the obtained polymers depend on the nature of the functional monomer, ratio of components in the prepolymerization mixture, pH of solution, and temperature. It has been established that N-vinylpyrrolidone-based copolymers provide higher selectivity of 4-nitrophenol extraction than N-vinylcaprolactam-based products.     

A neutral, water-soluble olefin metathesis catalyst based on an N-heterocyclic carbene ligand

A water-soluble ruthenium-based olefin metathesis catalyst supported by a poly(ethylene glycol) conjugated N-heterocyclic carbene ligand is reported. The catalyst displays greater activity in aqueous ring-opening metathesis polymerization (ROMP) reactions than previously reported water-soluble metathesis catalysts.     

Synthesis and metal binding behavior of hydroxamic acid resins from poly(ethyl acrylate) crosslinked with divinylbenzene and hydrophilic crosslinking agent

Porous poly(hydroxamic acid) chelating resin was prepared by the reaction with poly(ethyl acrylate) crosslinked with divinylbenzene and hydrophilic crosslinking agent, and hydroxylamine. The hydrophilic crosslinking agents and diluent used in this article were ethylene glycol dimethacrylate or butanediol dimethacrylate, and 2,2,4-trimethyl pentane, respectively. The characterization of this type chelating resin was carried out by IR spectroscopy, density measurement, and scanning electron microscopy. Various metal binding properties such as extraction, kinetics, and selectivity were investigated with atomic absorption spectrometer and inductively coupled plasma spectrometer. Poly(hydroxamic acid) resins crosslinked with mixed crosslinking agents showed better metal extraction properties and faster adsorption rate than those crosslinked with divinylbenzene alone. And alkali treatment enhances the binding rate for metal ions because of the formation of other chelating ligands or micropores. © 1995 John Wiley & Sons, Inc.     

Development of a solid‐phase microextraction fiber coated with poly(methacrylic acid‐ethylene glycol dimethacrylate) and its application for the determination of chlorophenols in water coupled with GC

A solid‐phase microextraction (SPME) fiber coated with poly(methacrylic acid‐ethylene glycol dimethacrylate) coupled to GC with a micro electron‐capture detector was developed for the determination of four chlorphenols in water samples for the first time. A novel and simple method for the preparation of this novel SPME fiber was proposed by copolymerization of methacrylic acid and ethylene glycol dimethacrylate in an appropriate solvent using a glass capillary as a “mold”. The factors affecting the polymerization were optimized in detail. Furthermore, the extraction performance of the poly(methacrylic acid‐ethylene glycol dimethacrylate) fiber was evaluated. Moreover, experimental headspace‐SPME parameters, such as extraction temperature, extraction time, salt concentration, stirring speed, and pH, were optimized by orthogonal array experimental designs. Under the optimized conditions, the target analytes were linear in the range of 0.2–50 ng/mL, and the correlation coefficients were all greater than 0.99. RSD was less than 8.9%, and the detection limits were in the range of 0.1–10 ng/L. Four cholorphenols were detected from tap and lake water samples using the proposed method, with the recoveries of spiked natural water samples were ranged from 91.8 to 110.8, and 90.6 to 111.4% for tap and lake water samples, respectively.     

Fast preparation of photopolymerized poly(benzyl methacrylate-co-bisphenol A dimethacrylate) monoliths for capillary electrochromatography

A novel porous polymer monolith was prepared in situ in a fused-silica capillary using photoinitiated polymerization. Bisphenol A dimethacrylate (BPADMA) was selected as a crosslinker, copolymerized with benzyl methacrylate (BMA) in the presence of a binary porogenic solvent consisting of cyclohexanol and 1-decanol in ≤10 min. The resulting poly(BMA-co-BPADMA) monoliths exhibited good permeability and mechanical stability. Mixtures of alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs) or phenolic compounds were successfully separated by CEC. A similar monolith was also prepared with ethylene dimethacrylate (EDMA) as the crosslinker instead of BPADMA to compare the separation ability of the resulting monoliths. The results indicated that poly(BMA-co-BPADMA) monoliths have better selectivity for aromatic analytes and greater chromatographic stability in higher aqueous mobile phase.     

Assesment of dimethyl phthalate removal from aqueous phase using barium hexaferrite containing magnetic beads

The barium hexaferrite (BaFe(12)O(19)) containing magnetic poly (ethylene glycol dimethacrylate-vinyl pyridine; mag-poly [EGDMA-VP]) beads (average diameter=53-212 μm) were synthesized and characterized. Their use as an adsorbent in the removal of dimethyl phthalate (DMP) from an aqueous solution was investigated. The mag-poly (EGDMA-VP) beads were prepared by copolymerizing of 4-vinyl pyridine (VP) with ethylene glycol dimethacrylate (EGDMA). The mag-poly (EGDMA-VP) beads were characterized by N(2) adsorption/desorption isotherms (BET), vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), elemental analysis, scanning electron microscope (SEM), and swelling studies. At a fixed solid/solution ratio, the various factors affecting the adsorption of DMP from aqueous solutions such as pH, initial concentration, contact time, and temperature were analyzed. The maximum DMP adsorption capacity of the mag-poly (EGDMA-VP) beads was determined as 96.2 mg/g at pH 3.0, 25 °C. All the isotherm data can be fitted with both the Langmuir and the Dubinin-Radushkevich isotherm models. The pseudo-first-order, pseudo-second-order, Ritch-second-order, and intraparticle diffusion models were used to describe the adsorption kinetics. The thermodynamic parameters obtained indicated the exothermic nature of the adsorption. The DMP adsorption capacity did not change after 10 batch successive reactions, demonstrating the usefulness of the magnetic beads in applications.     

Preparation of thermo-responsive polymer brushes on hydrophilic polymeric beads by surface-initiated atom transfer radical polymerization for a highly resolutive separation of peptides

Poly(N-isopropylacrylamide-co-N-tert-butylacrylamide) [P(IPAAm-co-tBAAm)] brushes were prepared on poly(hydroxy methacrylate) (PHMA) [hydrolyzed poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)] beads having large pores by surface-initiated atom transfer radical polymerization (ATRP) and applied to the stationary phases of thermo-responsive chromatography. Optimized amount of copolymer brushes grafted PHMA beads were able to separate peptides and proteins with narrow peaks and a high resolution. The beads were found to have a specific surface area of 43.0 m²/g by nitrogen gas adsorption method. Copolymer brush of P(IPAAm-co-tBAAm) grafted PHMA beads improved the stationary phase of thermo-responsive chromatography for the all-aqueous separation of peptides and proteins.     

The influence of PEG macromonomers on the size and properties of thermosensitive aqueous microgels

We describe the preparation and thermal response of aqueous microgels based on poly(N-vinyl caprolactam) containing grafted poly(ethylene glycol) (PEG) chains. These microgels were synthesized by free radical copolymerization of vinyl caprolactam and acetoacetoxyethyl methacrylate in the presence of methoxy-capped poly(ethylene glycol)methacrylate macromonomers. We show that variation of the amount of PEG macromonomer or the length of the PEG chain provides effective control of the microgel diameter in the range 60–220 nm. The presence of the grafted PEG chains improves the colloidal stability of the microgels. The incorporation of the PEG macromonomers into microgel structure decreases the swelling degree and induces a shift of the volume phase transition to higher temperatures. This paper is dedicated to Professor Haruma Kawaguchi in honor of his many contributions to the field of polymer particle synthesis and applications.     

多壁碳纳米管表面熊果酸印迹聚合物的制备及固相萃取

以聚乙烯醇修饰的多壁碳纳米管(MWCNTs)为基材,熊果酸(UA)为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,采用表面印迹技术在碳纳米管表面合成对熊果酸具有良好选择性的分子印迹聚合物( MWCNTs-MIPs).讨论了不同摩尔比例的功能单体与模板分子合成印迹聚合物的效果,得出...     

Determination of Sudan dyes in chili pepper powder by online solid‐phase extraction with a butyl methacrylate monolithic column coupled to liquid chromatography with tandem mass spectrometry

A poly(butyl methacrylate‐co‐ethylene dimethacrylate) monolithic column was fabricated and used as a novel sorbent for online solid‐phase extraction coupled to liquid chromatography with tandem mass spectrometry for the simultaneous determination of Sudan I–IV in chili pepper powder. The prepared columns were characterized by scanning electron microscopy, nitrogen adsorption‐desorption, and pressure drop measurements. Online solid‐phase extraction was performed on the synthesized monolithic column using 10 mM ammonium acetate solution as the loading solution with the aid of an online cleanup chromatography system. The desorption of Sudan I–IV was achieved with acetonitrile as the eluting solution at the flow rate of 0.5 mL/min. The extracted analytes were subsequently eluted into a C₁₈ analytical column for chromatographic separation using a mixture of 10% acetonitrile/90% formic acid (0.5%) solution as the mobile phase. Under the optimized conditions, the developed method had linear range of 1.0–50 μg/kg, a detection limit of 0.3 μg/kg, and a quantification limit of 1.0 μg/kg for each analyte. The intraday and interday recoveries of Sudan I–IV in chili pepper powder samples ranged from 94.8 to 100.9% and 94.9 to 99.4%, respectively. The intraday and interday precision were between 3.37–7.01% and 5.01–7.68%, respectively.     

Immobilization of Inulinase on Concanavalin A-Attached Super Macroporous Cryogel for Production of High-Fructose Syrup

In this study, concanavalin A (Con A)-attached poly(ethylene glycol dimethacrylate) [poly(EGDMA)] cryogels were used for immobilization of Aspergillus niger inulinase. For this purposes, the monolithic cryogel column was prepared by radical cryocopolymerization of EGDMA as a monomer and N,N′-methylene bisacrylamide as a crosslinker. Then, Con A was attached by covalent binding onto amino-activated poly(EGDMA) cryogel via glutaraldehyde activation. Characterization of cryogels was performed by FTIR, EDX, and SEM studies. Poly(EGDMA) cryogels were highly porous and pore size was found to be approximately 50–100 μm. Con A-attached poly(EGDMA) cryogels was used in the adsorption of inulinase from aqueous solutions. Adsorption of inulinase on the Con A-attached poly(EGDMA) cryogel was performed in continuous system and the effects of pH, inulinase concentration, and flow rate on adsorption were investigated. The maximum amount of inulinase adsorption was calculated to be 27.85 mg/g cryogel at 1.0 mg/mL inulinase concentration and in acetate buffer at pH 4.0. Immobilized inulinase was effectively used in continuous preparation of high-fructose syrup. Inulin was converted to fructose in a continuous system and released fructose concentration was found to be 0.23 mg/mL at the end of 5 min of hydrolysis. High-fructose content of the syrup was demonstrated by thin layer chromatography.     

Dynamic sorption of nitrophenols from aqueous solutions by polymers based on N-Vinylpyrrolidone

Sorption properties of a polymer based on N-vinylpyrrolidone and ethylene glycol dimethacrylate were studied for the example of sorption of nitrophenols from aqueous solutions under dynamic conditions. The conditions providing a 180–480-fold concentration in dynamic sorption and desorption of nitrophenols from aqueous solution were substantiated.     

Preparation and application of novel zwitterionic monolithic column for hydrophilic interaction chromatography

A novel zwitterionic hydrophilic porous monolithic stationary phase was prepared based on the thermal‐initiated copolymerization of N,N‐dimethyl‐N‐(3‐methacryl‐amidopropyl)‐N‐(3‐(sulfopropyl)ammonium betaine and ethylene glycol dimethacrylate. A typical hydrophilic separation mechanism was observed at a highly organic mobile phase (ACN >60%) on this optimized zwitterionic hydrophilic interaction chromatography (HILIC) monolithic stationary phase. Good permeability, stability, and column efficiency were observed on the final monolithic column. Additionally, a weak electrostatic interaction for charged analytes was confirmed in analysis of six benzoic acids by studying the influence of mobile phase pH and salt concentration on their retention behaviors on the obtained zwitterionic HILIC monolithic column. The optimized zwitterionic HILIC monolith exhibited good selectivity for a range of polar test analytes.     

Adsorption of cinnabarinic acid from culture fluid with magnetic microbeads

In this study, antimicrobial pigment cinnabarinic acid (CA) was produced from Pycnoporus cinnabarinus in laboratory‐scale batch cultures. Magnetic poly(ethylene glycol dimethacrylate‐N‐methacryloyl‐l‐tryptophan methyl ester) [m‐poly(EGDMA‐MATrp)] beads (average diameter = 53–103 µm) were synthesized by copolymerizing of N‐methacryloyl‐l‐tryptophan methyl ester (MATrp) with ethylene glycol dimethacrylate (EGDMA) in the presence of magnetite (Fe₃O₄) and used for the adsorption of CA. The m‐poly(EGDMA‐MATrp) beads were characterized by N₂ adsorption/desorption isotherms (Brunauer Emmet Teller), X‐ray photoelecron spectroscopy, scanning electron microscopy, infrared spectroscopy, thermal gravimetric analysis, electron spin resonance and swelling studies. The efficiency of m‐poly(EGDMA‐MATrp) beads for separation of CA from culture fluid was evaluated. The effects of pH, initial concentration, contact time and temperature on adsorption were analyzed. The maximum CA adsorption capacity of the m‐poly(EGDMA‐MATrp) beads was 272.9 mg g⁻¹ at pH 7.0, 25 °C. All the isotherm data can be fitted with the Langmuir, Freundlich and Dubinin–Radushkevich isotherm models. The adsorption process obeyed pseudo‐second‐order kinetic model. Thermodynamic parameters ΔH = 5.056 kJ mol⁻¹, ΔS = 52.44 J K⁻¹ mol⁻¹ and ΔG = −9.424 kJ mol−¹ to ‐11.27 kJ mol−¹ with the rise in temperature from 4 to 40 °C indicated that the adsorption process was endothermic and spontaneous. Copyright © 2015 John Wiley & Sons, Ltd.     

Novel functionalized poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) microspheres for the solid‐phase extraction of glycopeptides/glycoproteins

Novel 3‐aminophenylboronic acid functionalized poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) microspheres were prepared for the solid‐phase extraction of glycopeptides/glycoproteins. The adsorption efficiency, maximum adsorption capacity, and specific recognition of the microspheres to glycoprotein were investigated. The results indicated excellent adsorption of glycoproteins by the microspheres, which are attributed to the well‐defined boronic acid brushes on the microsphere surfaces. Furthermore, a solid‐phase extraction microcolumn filled with the microspheres was used to efficiently enrich glycopeptides from enzymatic hydrolysates from human serum samples. The mass spectrometry results demonstrated that the method is suitable for the separation and enrichment of glycopeptides/glycoproteins from complex biological samples.     

软骨藻酸分子印迹聚合物的制备及其固相萃取应用

以贝毒-软骨藻酸的结构类似物1,3,5-戊烷三羧酸为模板分子,4-乙烯基吡啶为功能单体,乙二醇二甲基双丙烯酸酯为交联剂,合成了对软骨藻酸具有较好选择性的分子印迹聚合物。经索氏提取去除模板分子后,在聚合物内部形成了与模板分子1,3,5-戊烷三羧酸以及结构类似物软骨藻酸尺寸、形状以及活性基团互补的结合位点。通过静态平衡结合实验研究了该聚合物的结合能力和选择性能,与化学组成相同的相应非印迹聚合物相比,1,3,5-戊烷三羧酸的分子印迹聚合物对软骨藻酸具有较高的吸附性能和选择性。用150mg印迹聚合物填充于1.0mL玻璃注射器制成的分子印迹固相萃取柱,采用离线模式,并结合高效液相色谱实现紫贻贝和海水中软骨藻酸的分离与检测。对于加标2mg/L的紫贻贝和海水样品,回收率分别达到(93.4±4.9)%和(89.7±3.2)%(n=3)。     

Radiation synthesis and characterization of poly(N,N-dimethylaminoethyl methacrylate-co-N-vinyl 2-pyrrolidone) hydrogels

In this study, radiation synthesis and characterization of swelling behavior and network structure of poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA), and poly(N,N-dimethylaminoethyl methacrylate-co-N-vinyl 2-pyrrolidone) (P(DMAEMA-co-VP)), hydrogels were investigated. PDMAEMA and P(DMAEMA-co-VP) hydrogels in the rod forms were prepared by irradiating the ternary mixtures of DMAEMA/VP/cross-linking agent, ethyleneglycol dimethacrylate (EGDMA), by gamma rays at ambient temperature. In composition ranges where the three components were completely miscible, water was also added to the ternary mixture to provide the formation of homogeneous polymerization and gelation. The influence of irradiation dose, comonomer, VP, and cross-linking agent, EGDMA, content on the total percentage gelation and monomer conversion were investigated. The effect of pH and temperature on the swelling behavior of hydrogels have also been examined. Hydrogels showed typical pH response and temperature responses, such as low-pH and low temperature swelling and high-pH and high temperature deswelling. Polymer-solvent interaction parameter (χ) and enthalpy and entropy changes appearing in the χ parameter for the P(DMAEMA-co-VP)-water system were determined by using Flory-Rehner theory of swelling equilibrium. The negative values for ΔH and ΔS indicate that prepared pure PDMAEMA and P(DMAEMA-co-VP) hydrogels have lower critical solution temperature (LCST) and Flory-Rehner theory of swelling equilibrium provides a satisfactory agreement to the experimental swelling data of the hydrogels.     

Dynamic deswelling studies of poly(N-vinyl-2-pyrrolidone/itaconic acid) hydrogels swollen in water and terbinafine hydrochloride solutions

Deswelling kinetics of water and terbinafine hydrochloride adsorbed poly(N-vinyl-2-pyrrolidone/itaconic acid) P(VP/IA) hydrogels were investigated. Hydrogels were prepared by irradiating the ternary mixture of VP/IA and cross-linking agent ethylene glycol dimethacrylate (EGDMA) in water by γ-rays at ambient temperature. Hydrogels swelled in pure water and terbinafine hydrochloride (TER-HCl) solutions at room temperature and deswelling or water loss were investigated between 4 and 45 °C temperature range and on human skin. The influence of IA content, % swelling, temperature and TER-HCl content on the water loss from gel matrix were investigated. Induction time for 80% water loss from hydrogel systems are found to increase from 9.6 to 21.2 h by increasing IA content in the gel system at 25 °C and decreased by 11 h with addition of TER-HCl in the gel system. Kinetic analyses had shown that the basic properties affecting the water loss behavior of these hydrogels are the IA and TER-HCl content and temperature of the medium.