单步溶胀聚合法制备单分散分子印迹聚合物微球

用无皂乳液聚合法制得的微米级聚苯乙烯微球为种球,以N-甲基天门冬氨酸(NMA)为模板分子,通过单步溶胀聚合法在水相中制备了单分散分子印迹聚合物微球(MIPMs)。研究了影响种球溶胀的因素,并对MIPMs的结构进行了表征。实验表明,单步溶胀聚合法能够制得粒径2~3μm、单分散性好的MIPMs,且具有较好的特异吸附性能。Scatchard分析表明,MIPMs在识别NMA过程中存在两类结合位点,计算得到高亲和力的结合位点的离解常数KD1和最大表观结合常数Bmax1分别为0.223 mmol/L和2.12μmol/g,低亲和力的结合位点的离解常数KD2和最大表观结合常数Bmax2分别为5.34 mmol/L和36.42μmol/g。     

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...     

单步溶胀聚合法制备单分散分子印迹聚合物微球

用无皂乳液聚合法制备了微米级粒径均匀的聚苯乙烯微球(PS).以制得的PS为种球,柚皮素为模板分子,通过单步溶胀聚合法制备了单分散分子印迹聚合物微球(MIPBs).研究了溶胀比及环己醇用量对MIPBs粒径及形态的影响,结果发现,采用粒径为1.50μm的PS作种球,且溶胀比控制在27～60时,可以制得粒径在4.5 μm～6.0 μ.m单分散的MIPBs;随着环己醇用量的增大,MIPBs球形更加规则、表面更加光滑.氮气吸附测量结果表明,制得的MIPBs是一种具有多孔结构、比表面积大的聚合物.Scatchard分析结果表明,在研究的浓度范围内,MIPBs存在一类等同的结合位点,其平衡离解常数Kd和最大表观吸附量Qmax分别为8.61 mmol·L-1和48.50μmol·g-1.制得的MIPBs对模板化合物柚皮素显示出较高的选择性,以槲皮素为竞争底物,其分离因子达1.96.     

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...     

二氯喹啉酸分子印迹聚合物微球的制备

采用改进的分散聚合方法制得的纳米级聚苯乙烯微球(PS)为种球,以二氯喹啉酸(quinclorac)为模板分子,通过单步溶胀聚合法在水相中制备了单分散分子印迹聚合物微球(MIPs)。通过红外光谱分析MIPs的结合位点;利用紫外光谱研究了MIPs的结合机理和识别特性;用扫描电镜观察了微球的形貌。结果表明,PS微球的粒径分布100～150nm,MIPs的粒径分布为200～300nm;Scatchard分析表明,MIPs在识别二氯喹啉酸过程中存在两类结合位点:高亲和性位点的解离常数KD1=0.0488mmol/L;低亲和性位点的解离常数KD2=0.423mmol/L。     

反相微乳液法制备磁性分子印迹聚合物微球

以二氯苯酚为模板分子、丙烯酰胺(AM)为功能单体、三羟甲基丙烷三丙烯酸酯(TRIM)为交联单体、Fe3O4为磁性组分,采用反相微乳液悬浮聚合法制备了磁性分子印迹聚合物微球(MMIPMs)。研究了吸附时间、温度、pH对吸附性能的影响,并考察了其重复利用性。结果表明,温度对二氯苯酚-MMIPMs吸附性能影响不大。底物溶液pH对MMIPMs的吸附性能有一定影响,吸附量随pH的升高而增大,当pH为7.0时,吸附量最大。MMIPMs具有良好的重复利用率。     

分子印迹聚合物微球制备研究

阐述了分子印迹技术基本原理,并使用牛血清白蛋白作为模板,通过反向悬浮法合成了聚丙烯酰胺(PAM)分子印迹微球,探讨了搅拌速度、单体浓度、分散剂浓度、引发剂添加速度、干燥方式对PAM微球形貌的影响,并通过紫外吸收法初步研究了PAM分子印迹微球对牛血清白蛋白的吸附性能.结果表明,通过反相悬浮法制备的PAM分子印迹微球对印迹分子具有一定的特异吸附性能.     

胆固醇分子印迹聚合微球的制备及其吸附性能

以胆固醇为模板分子、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂,在甲苯-乙腈(9:1, j)混合溶剂中沉淀聚合制备了分子印迹聚合物微球. 采用平衡结合法和Scatchard模型评价了该聚合微球的结合性,考察了其吸附行为. 结果表明,胆固醇分子印迹聚合微球中形成两类不同的结合位点,得到高亲和性结合位点的离解常数和最大表观吸附量分别为0.86 mmol/L和80.4 mmol/g,低亲和性结合位点解离常数和最大表观吸附量分别为0.39 mmol/L和61.6 mmol/g. 此方法合成的分子印迹微球对胆固醇有较好的结合性能,可用于胆固醇的分析检测.     

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。     

分子印迹聚合物微球的制备

分别以甲胺磷、乙酰甲胺磷为印迹分子,α-甲基丙烯酸为功能单体,三羟甲基丙烷三丙烯酸酯为交联剂,悬浮聚合法制得甲胺磷、乙酰甲胺磷分子印迹微球。     

Preparation,characterization and adsorption performance of molecularly imprinted microspheres for erythromycin using suspension polymerization

BACKGROUND: There are few reports on erythromycin molecularly imprinted polymers (MIPs) used as HPLC stationary phase and solid phase extraction matrices. These imprinted polymers are prepared by bulk polymerization, which is tedious and time‐consuming, and they are irregular and possess poor reproducibility and low binding capacity. In this study, molecularly imprinted microspheres for erythromycin were prepared by aqueous suspension polymerization for the first time. RESULTS: Imprinted microspheres for erythromycin were prepared using suspension polymerization in which 1.5% PVA‐water solution is used as continuous phase, and chloroform solution containing erythromycin, methacrylic acid and crosslinker is used as disperse phase. The composition of disperse phase is optimized, and the optimum molar ratio of erythromycin to methacrylic acid was 1:5. Selectivity analysis revealed that the imprinted microspheres can specifically recognize erythromycin from its structure analogues. The binding mechanism between erythromycin and methacrylic acid was investigated by UV‐Vis spectrophotometry. Adsorption kinetics and the adsorption isotherm of the imprinted microspheres indicate that erythromycin can be adsorbed rapidly by the imprinted microspheres and the maximum theoretical static binding capacity is 128.6110 mg g^?1. The imprinted microspheres were used to extract erythromycin from a milk sample and a high recovery rate was obtained. CONCLUSION: Molecularly imprinted microspheres for erythromycin were uniform and possess high adsorption capacity and excellent selectivity. They are therefore a promising extraction and chromatographic media. Copyright © 2011 Society of Chemical Industry     

Tyrosine imprinted polymer beads with different functional monomers via seed swelling and suspension polymerization

Molecularly imprinted polymers (MIPs) in bead form were prepared by seed swelling and suspension polymerization with trimethylolpropane trimethacrylate (TRIM) as crosslinker and tyrosine as template. The appearance of the beads was found to be greatly influenced by the concentration of polyvinyl alcohol (PVA) used as dispersant and the ratio of water to TRIM (W/T) during polymerization. When W/T was 46:1 (V/V) and the concentration of PVA‐water solution was 4.6 (%m/m), the result was more desirable size distribution with fewer misshapen beads. A series of imprinted polymers with methacrylic acid (MAA), acrylamide (AM), 2‐vinylpyridine (VP) and 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS) as functional monomers (FM), respectively, were prepared, where the molar ratio of tyrosine, FM and TRIM was chosen as 1:16:17. The molecule adsorbing and selecting analysis of the polymers showed that although all the imprinted polymers adsorbed the templates following the rule of Langmuir and exhibited an obvious molecule selecting capability compared with their control polymers (CP), the adsorbing constant and the separating factor were much different when the functional monomers varied. AMPS worked better than the other FM in the present work with a higher value of asymptotic maximum solid phase concentration (0.282 mol/kg), adsorbing constant (198.81/mol), and a larger separating factor (1.93) when phenylalanine was used as the competitive molecule.     

Preparation and adsorption selectivity of deltamethrin molecularly imprinted polymers by two-step seed swelling method

Deltamethrin (DM) is one of the most efficient pyrethroid insecticides, which is widely applied to the control of insect pests in tea. In this work, efficient molecularly imprinted polymers (MIPs) were synthesized using DM as the template and acrylamide as the functional monomer, in conjunction with two-step seed swelling polymerization. Scanning electron microscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller surface area analysis confirmed the staggered pore structure and the presence of binding site in DM MIPs. The adsorption properties of the DM MIPs were also investigated based on assessing equilibrium adsorption as well as kinetic modeling and solid-phase extraction. Isothermal equilibrium adsorption experiments show that the adsorption behavior is consistent with the Freundlich and Halsey models, indicating heterogeneous multilayer specific adsorption. Fitting of the kinetic data demonstrates that chemical adsorption could be the rate-limiting step in DM extraction, which is consistent with a pseudo-second-order kinetic model. Using the imprinted polymers as solid-phase extraction filler, the DM recoveries from various teas were greater than 80% and exceeded those of the structural analogs cypermethrin, lambda-cyhalothrin, and bifenthrin. These results confirm that the MIPs exhibit specific adsorption of this analyte. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47415.     

Preparation and characterization of monodisperse molecularly imprinted polymer microspheres by precipitation polymerization for kaempferol

A new kind of molecularly imprinted polymer (MIP) microspheres for the selective extraction of kaempferol was prepared by precipitation polymerization using 4-vinylpridine (4-VP) and ethylene glycol dimethacrylate (EDMA) as functional monomer and cross-linker respectively. The synthesis conditions, such as ratios of 4-VP/EDMA and polymerization time were discussed in detail. Results showed that the 2% was the optimal concentration of co-monomers to obtain monodisperse MIP microspheres, the best ratio of 4-VP/EDMA was 1:2, and 24 h was considered as the proper polymerization time. Compared with the MIP agglomeration or coagulum particles, monodisperse MIP microspheres showed the better adsorption capacity: the saturated adsorption capacity of monodisperse MIP microspheres was 7.47 mg g^?1, the adsorption equilibrium could be obtained in 30 min. Finally, the adsorption performances of the optimal MIP microspheres were evaluated by kinetic adsorption, adsorption isotherm, and selective adsorption experiments, which indicated that the adsorption mechanism were chemical single layer adsorption and the separation factor was up to 3.91 by comparing with the structure similar compound (quercetin). The MIP microspheres exhibit prospects in the kaempferol efficient and selective separation.     

分子印迹膜的制备及应用进展

分子印迹膜是将分子印迹技术与膜分离技术相结合而制备的一种新型分离膜。因其具有高度的选择性和特异的分子识别能力,在手性物质分离、仿生传感及固相萃取等方面表现出良好的应用前景。介绍了分子印迹膜的发展、制备方法及应用等几个方面,并对其发展前景做出展望。     

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     

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.