种子溶胀悬浮聚合法制备分子印迹聚合物微球的研究进展

分子印迹聚合物微球是一种具有特异性识别性能的新型高分子材料.种子溶胀悬浮聚合法所制备的印迹聚合物微球可应用于极性环境中,能够满足诸如酶模拟等实际应用环境的要求.本文综述了几种不同的制备分子印迹聚合物微球的种子溶胀悬浮聚合法,并对其研究方向做了展望.     

Molecularly imprinted polymer microspheres prepared via the two-step swelling polymerization for the separation of lincomycin

A molecularly imprinted polymer (MIP) was synthesized via a two-step swelling polymerization method for the purification of lincomycin. Polystyrene microspheres were prepared by the dispersion-polymerization process and used as the substrate. Methacrylic acid was used as the functional monomer, whereas ethylene glycol dimethacrylate was the cross-linker. The MIP was structurally characterized and examined for its separation performance at different conditions (temperature, solvents, etc.). It was found that the MIP possesses the good sphericity, porosity, monodispersity, and a high adsorption capacity of (180 μmol/g) in chloroform solution. Comparison studies showed that the MIP presents a higher capacity than the NIP (non-imprinted polymer) in chloroform solution and a much higher capacity in the practical lincomycin fermentation solution extracts, confirming the underlining mechanisms of the MIP. Scatchard plot revealed two adsorption mechanisms on the MIP, whereas the isotherm is better described by Freundlich equation. The adsorption/elution kinetics demonstrated that the MIP possesses good elution/regeneration capabilities with the elution ratio > 93%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47938.     

反相悬浮法制备磁性高分子微球的研究

本文采用反相悬浮法,通过聚乙二醇的缩醛化反应,制备了具有灵敏磁响应性、表面富含羟基的微米级的磁性高分子微球。主要探讨了反应时间、聚乙烯醇浓度、搅拌速度、戊二醛(GA)用量及磁流体用量的变化对磁性高分子微球制备及性质的影响,用红外(FTIR)、激光粒径分析仪、扫描电子显微镜(SEM)、振动样品磁强计(VSM)进行表征。结果表明,所制备磁球表面羟基含量高,分散性好,磁含量高,具有超顺磁性。     

单步种子溶胀法与二步种子溶胀法制备氯霉素分子印迹聚合物微球的比较

以聚苯乙烯乳液为种球、氯霉素为模板分子、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂,采用单步种子溶胀法与二步种子溶胀法制备了单分散氯霉素分子印迹聚合物微球,用光学显微镜和扫描电镜对微球的形貌进行了表征,并用静态吸附实验考察了微球的吸附识别性能,结果表明,二步种子溶胀法制备的微球分散性、吸附识别性能最佳,平均粒径...     

Molecularly imprinted polymer beads prepared by pickering emulsion polymerization for steroid recognition

Pickering emulsion polymerization was used to synthesize molecularly imprinted polymer beads for the selective recognition of 17‐β‐estradiol under aqueous conditions. Scanning electron microscopy analysis indicated that the imprinted polymer beads had a small diameter with a narrow size distribution (18.9 ± 2.3 μm). The reduction in particle size achieved in this study was attributed to the altered polarity of the stabilizing nanoparticles used in the Pickering emulsion. The imprinted polymer beads could be used directly in water and showed a high binding affinity for the template molecule, 17‐β‐estradiol, and its structural analogs. These water‐compatible polymer beads could be used as affinity adsorbents for the extraction and analysis of low‐abundance steroid compounds in aqueous samples. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39606.     

Molecular selectivity of tyrosine-imprinted polymers prepared by seed swelling and suspension polymerization

Tyrosine-imprinted microspheres have been prepared in an aqueous system by seed swelling and suspension polymerization, using trimethylolpropane trimethacrylate (TRIM), acrylamide (AM) as well as methacrylic acid (MAA), linear polystyrene and toluene as crosslinker, functional monomers, seeds and porogens, respectively. The size distribution proved to be greatly influenced by the ratio of water:TRIM (W/T) and the concentration of dispersant. When W/T was 46:1 (v/v), 4.6% (by mass) of poly(vinyl alcohol) (PVA) was used as dispersant, the molar ratios of tyrosine, MAA, AM and TRIM were 1:8:8:17, the polymer beads had the better size monodispersity, and the average size was 135 µm, while the sizes of the pores on the beads surfaces ranged from 1.25 µm to 9.0 µm. The adsorption behaviour and molecular selectivity of the beads were analysed using liquid chromatography; the results showed that the adsorption behaviour of the beads followed the rule of Langmuir, and the value of saturated absorption was 0.197 mmol g⁻¹. The tyrosine-imprinted polymers exhibited an inherent selectivity for tyrosine; when phenylalanine was used as the competing molecule the separation factor α was up to 1.91. However, the control polymers did not have this special molecule-selection capability, and the relative separation factor β was about 1.82 compared with the imprinted polymers. © 2002 Society of Chemical Industry     

槲皮素和不同功能单体的分子印迹识别性能研究

以槲皮素为模板分子,采用紫外光谱法分析模板分子和甲基丙烯酸、甲基丙烯酸甲酯、丙烯酰胺和4-乙烯基吡啶等4种不同功能单体分别在二甲基亚砜和乙酸乙酯中的相互作用。结果表明,槲皮素和4-乙烯基吡啶在DMSO中有较强的相互作用,配位比1∶3,结合常数9.14×10~5。采用微波辐射加热悬浮聚合法,以4-乙烯基吡啶为功能单体,制备了槲皮素分子印迹微球,粒径约为50~90μm,具有能够吸附目标物的疏松多孔结构。     

槲皮素和不同功能单体的分子印迹识别性能研究

以槲皮素为模板分子,采用紫外光谱法分析模板分子和甲基丙烯酸、甲基丙烯酸甲酯、丙烯酰胺和4-乙烯基吡啶等4种不同功能单体分别在二甲基亚砜和乙酸乙酯中的相互作用。结果表明,槲皮素和4-乙烯基吡啶在DMSO中有较强的相互作用,配位比1∶3,结合常数9.14×10⁵。采用微波辐射加热悬浮聚合法,以4-乙烯基吡啶为功能单体,制备了槲皮素分子印迹微球,粒径约为505。采用微波辐射加热悬浮聚合法,以4-乙烯基吡啶为功能单体,制备了槲皮素分子印迹微球,粒径约为50⁹0μm,具有能够吸附目标物的疏松多孔结构。     

乳液聚合法合成水杨酸分子印迹聚合物微球

以水杨酸为模板分子,乙二醇二甲基丙烯酸酯为交联剂,采用乳液聚合法制备了水杨酸分子印迹聚合物微球（SMIP）,采用紫外差示光谱分析了模板分子与功能单体的相互作用,以荧光分光光度计为检测手段,讨论了不同功能单体、模板分子与功能单体的摩尔比、交联剂用量、洗脱液类型等对SMIP吸附性能的影响,并进一步考察了SMIP的形貌和粒径分布。研究结果表明,以丙烯酰胺为功能单体合成的SMIP表现出较好的吸附性能,印迹因子可达1.61,而且微球呈单分散性,平均粒径约60 nm。     

Preparation of functional polymer microspheres by suspension copolymerization of diallyl phthalate with carboxylic monomers

A study was made of the suspension copolymerization of diallyl phthalate (DAP) and acrylic and methacrylic acid (AAc and MAc, respectively, which were charged after delay to the suspension of partially prepolymerized DAP) and the structure of resulting gel particles. In the copolymerization of DAP with AAc, the conversion of AAc leveled off despite an appreciable amount of AAc remaining in the aqueous phase, whereas in DAP–MAc copolymerization most MAc was polymerized in the particles. The particle structure depended significantly on the mode of comonomer charge. Earlier charge of the comonomer to the reaction system resulted in the formation of particles having comonomer unit-rich surface layer. This was interpreted in terms of phase separation through loosely crosslinked structure in the particles and supported by an adsorption test using a dye and the observation of surface structure of the particles. The timing of comonomer charge changed the amount of comonomer units in the surface layer from 0.06 to 0.60 mmole/g particle.     

对羟基苯甲酸分子印迹聚合物合成功能单体选择与分子识别性能

以对羟基苯甲酸（p -HB）为模板分子,从4-乙烯基吡啶（4-VP）、丙烯酰胺(AM)和甲基丙烯酸(MAA)3种具有代表性的单体中,选择最适宜制备p-HB分子印迹聚合物的功能单体。首先采用分子力学方法计算了p-HB与功能单体4-VP、AM和MAA的结合能,其强度顺序为：4-VP＞相似文献   

二步种子溶胀法制备氯霉素分子印迹聚合物微球及其识别性能

以聚苯乙烯乳液为种球、氯霉素为模板分子、甲基丙烯酸为功能单体、二甲基丙烯酸乙二醇酯为交联剂,采用二步种子溶胀法制备了单分散氯霉素分子印迹聚合物微球(MIPMs).通过扫描电镜(SEM),考察了溶胀比、搅拌速度、水油比、交联剂用量、分散荆用量等对MIPMs形态,粒径大小及粒径分布的影响.并用静态吸附实验考察了微球的吸附识...     

Highly improved adsorption selectivity of L-phenylalanine imprinted polymeric submicron/nanoscale beads prepared by modified suspension polymerization

Molecularly imprinted polymer (MIP) submicron/nanoscale beads selective for L-Phenylalanine (L-Phe) and D-Phe as well as non-imprinted beads were prepared by modified suspension polymerization involving agitation of the reaction mixture at high rotation speed under safe radical conditions. The effects of pH, template and concentration of racemate solution on the performance of the phenylalanine (Phe) imprinted polymeric submicron/nanoscale beads were studied. L-Phe-imprinted submicron/nanoscale beads prepared for the first time by modified suspension polymerization showed enhanced adsorption capacity and selectivity over those of D-Phe imprinted and non-imprinted beads. Maximum adsorption capacity, 0.35 mg/g, and selectivity, 1.62, of L-Phe imprinted submicron/nanoscale beads were higher than the adsorption capacities, 0.30 and 0.19mg/g, and selectivities, 1.59 and 1.02, of D-Phe imprinted and nonimprinted submicron/nanoscale beads, respectively. FE-SEM analyses revealed that L- and D-Phe imprinted beads were larger (100 nm–1.5 μm) than non-imprinted nanobeads (100–800 nm). ¹³C CP-MAS NMR spectroscopy helped in correlating the bead sizes and the extent of reaction during polymerization. Similarly, FT-IR study was used for evaluation of structural characteristics of the prepared Phe-imprinted and non-imprinted beads. The preparation of Phe-imprinted submicron/nanoscale beads with improved adsorption and separation properties and the study of effect of template on the size and performance of the prepared beads are suitable from both economical and research point of view in MIP field.     

Preparation of molecularly imprinted polymer microspheres via reversible addition-fragmentation chain transfer precipitation polymerization

The first combined use of reversible addition-fragmentation chain transfer (RAFT) polymerization and precipitation polymerization in the molecular imprinting field is described. The new polymerization technique, namely RAFT precipitation polymerization (RAFTPP), provides MIP microspheres with obvious molecular imprinting effects towards the template, fast template binding process and an appreciable selectivity over structurally related compounds, while only irregular MIP aggregates were obtained via traditional radical precipitation polymerization (TRPP) under similar reaction conditions. The MIP microspheres prepared via RAFTPP have proven to show improved binding capacity, larger binding constant and apparent maximum number for high-affinity sites, and significantly higher high-affinity binding site density in comparison with the MIP prepared via TRPP.     

Synthesis of molecularly imprinted polymer by suspension polymerization for selective extraction of p-hydroxybenzoic acid from water

Molecularly imprinted polymer (MIP) for selective extraction of p-hydroxybenzoic acid (p-HB) was synthesized by suspension polymerization using p-HB as template, 4-vinyl pyridine as functional monomer and ethylene glycol dimethacrylate as crosslinker. As characterized by scanning electron microscopy, the MIP particles are spherical, with size ranging from 1 to 8 μm. Compared with the non-imprinted polymer (NIP), the MIP shows higher binding capacity toward p-HB: maximum binding capacity for p-HB being 8.07 μmol g⁻¹ over MIP and 3.88 μmol g⁻¹ over NIP. The adsorption of p-HB on MIP follows the Freundlich model and displays pseudo-second-order kinetics. The results of selective and competitive binding experiments confirm that the molecularly imprinted sites have excellent recognition ability toward p-HB. The results reveal that the MIP is a promising adsorbent for selective extraction of p-HB from water samples. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46984.     

Preparation and characterization of polystyrene/modified carbon black composite beads via in situ suspension polymerization

A facile and effective method was introduced into this article to modify carbon black (CB). Fourier‐transform infrared spectrum demonstrates the chemical structure of CB has obviously changed after surface modification. Compared with pure CB, the thermogravimetric analysis illustrates thermal behavior of modified CB (MCB) exhibits a well‐defined difference from CB. Besides, aggregation phenomenon existed in CB is weakened evidently after surface modification. A series of polystyrene (PS) composite beads in presence of MCB were synthesized via in situ suspension polymerization process. The effects of benzoyl peroxide dosage and MCB dosage on the polymerization time of PS composite beads were systematically researched. After modification, the inhibition effect of MCB on the polymerization of PS/MCB composite beads is obviously weakened. The dispersion of MCB in PS/MCB composite beads is greatly improved than that of CB in PS/CB composite beads. Moreover, PS/MCB beads have the better thermal stability than that of PS and PS/CB composite beads. POLYM. COMPOS., 34:1110–1118, 2013. © 2013 Society of Plastics Engineers     

Synthesis of molecularly imprinted polymers for amino Acid derivates by using different functional monomers

Fmoc-3-nitrotyrosine (Fmoc-3-NT) molecularly imprinted polymers (MIPs) were synthesized to understand the influence of several functional monomers on the efficiency of the molecular imprinting process. Acidic, neutral and basic functional monomers, such as acrylic acid (AA), methacrylic acid (MAA), methacrylamide (MAM), 2-vinylpyridine (2-VP), 4-vinylpyridine (4-VP), have been used to synthesize five different polymers. In this study, the MIPs were tested in batch experiments by UV-visible spectroscopy in order to evaluate their binding properties. The MIP prepared with 2-VP exhibited the highest binding affinity for Fmoc-3NT, for which Scatchard analysis the highest association constant (2.49 × 10(4) M(-1)) was obtained. Furthermore, titration experiments of Fmoc-3NT into acetonitrile solutions of 2-VP revealed a stronger bond to the template, such that a total interaction is observed. Non-imprinted polymers as control were prepared and showed no binding affinities for Fmoc-3NT. The results are indicative of the importance of ionic bonds formed between the -OH residues of the template molecule and the pyridinyl groups of the polymer matrix. In conclusion, 2-VP assists to create a cavity which allows better access to the analytes.     

Enhancing molecularly imprinted polymer binding properties via controlled/living radical polymerization and reaction analysis

Fractional double bond conversion and associated template binding parameters of molecularly imprinted polymers were explored in this study in relation to initiator type and concentration, crosslinking monomer length, temperature, and solvent concentration. Controlled/living polymerization techniques were used to synthesize recognitive poly(methacrylic acid-co-ethylene glycol dimethacrylate) (poly(MAA-co-EGDMA)) networks which resulted in a 63% increase in the number of binding sites at approximately equivalent average binding affinity while retaining selectivity of the target molecule, ethyladenine-9-acetate. This is hypothesized to be attributed to a decrease in kinetic chain length and/or a more narrow dispersity of kinetic chains which leads to increased structural homogeneity and increased stability and integrity of binding sites. Reaction analysis of a typical poly(MAA-co-EGDMA) molecularly imprinted network measured via differential scanning calorimetry revealed low double bond conversion (35 ± 2.3% at 0 °C to 54 ± 1.9% at 50 °C) which is due to severely constrained network formation; therefore, the final composition of imprinted polymers does not represent the initial formulation when using significant amounts of short bifunctional crosslinking monomer. Optimization of conventional photoinitiator was shown to lead to a small improvement in template selectivity at equivalent affinity and capacity. However, the use of controlled/living polymerization techniques within the field of imprinted polymers has the greatest potential to improve the structural homogeneity and drastically enhance the binding parameters. Polymerization reaction analysis and the use of controlled polymerization strategies will lead to a greater understanding of the imprinting mechanism, optimization of binding parameters, and an increase in the application potential of imprinted networks.     

沉淀聚合法制备咖啡因分子印迹聚合物微球

以咖啡因为印迹分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,采用沉淀聚合法在乙腈溶液中制备了针对咖啡因的分子印迹聚合物微球。对沉淀聚合中单体、引发剂、溶剂用量的比例关系进行探索,并利用平衡结合实验研究了聚合物对印迹分子的吸附性能,结果表明该印迹聚合物微球呈现出较好的结合能力。     

Preparation of molecularly imprinted polymers for vanillin via reversible addition‐fragmentation chain transfer suspension polymerization

Molecularly imprinted polymers (MIPs) for vanillin were synthesized by suspension polymerization using ethylene glycol dimethacrylate as cross‐linker and methacrylic acid as functional monomer, respectively. The analysis of scanning electron microscopy and equilibrium binding experiments indicated that the MIPs can selectively separate the target analytes. Reversible addition‐fragmentation chain‐transfer (RAFT) technique was used to synthesize MIPs using benzyl dithiobenzoate as RAFT agent. The results showed smaller particle size, higher molecular adsorption, and considerable binding specificity toward vanillin than those prepared by suspension polymerization. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013