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.     

三硝基甲苯分子印迹微球的制备与应用

以三硝基甲苯（TNT）为模板分子,丙烯酰胺（AM）为功能单体,采用沉淀聚合法制备分子印迹聚合物MIP。通过紫外光谱法研究TNT和AM之间的相互作用,结果表明TNT与AM之间作用力较强,有助于形成结构稳定、亲和性强的聚合物;利用扫描电镜观测不同制备条件下印迹聚合物的表观形貌,发现乙腈用量为100mL,缓慢的搅拌速率下制备的聚合物形貌较优异;利用红外光谱分析聚合物的结构特征,验证印迹聚合物的制备与模板分子的洗脱;平衡吸附实验表明,MIP对TNT的吸附存在两种作用位点并且吸附量随TNT初始浓度增加而增加;动力学吸附实验发现印迹聚合物对TNT的吸附速率远大于非印迹聚合物;选择性吸附实验中,MIP对TNT表现出较好的特异吸附性能,而对于TNT的结构类似物DNT、RDX吸附能力较差。     

表面印迹聚合物的制备与吸附性能

以L-色氨酸作为模板分子,丙烯酰胺为功能单体,N,N'-亚甲基双丙烯酰胺为交联剂,通过在聚甲基丙烯酸甲酯多孔基质球表面复合印迹层,制备了L-色氨酸表面印迹聚合物微球(SMIPs),探索了不同比表面积基质球及添加丙烯腈对SMIPs吸附性能的影响,结果表明基质球比表面积为432.0m~2/g时,SMIPs对L-色氨酸的吸附量较高;当n(AN):n(L-trp):3:1时,SMIPs的综合吸附性能较好.     

莱克多巴胺分子印迹聚合物的制备及吸附性能研究

采用沉淀聚合法制备莱克多巴胺分子印迹聚合物,并通过平衡吸附实验和Scatchard分析,考察其对模板分子莱克多巴胺的吸附性能和识别能力。结果表明,所制备的分子印迹聚合物对莱克多巴胺具有良好的识别能力和吸附性。     

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     

Preparation and adsorption selectivity of rutin molecularly imprinted polymers

Molecularly imprinted polymer (MIP) for Rutin had been prepared through solution polymerization by redox initiation. The effects of monomers, crosslinker, initiators, polymerization time, and temperature on adsorption selectivity for Rutin were investigated and optimized. The structure and surface morphology of MIP were evaluated by Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The synthesized MIP under the optimal conditions showed a specific recognition of Rutin from the mixture of Rutin and Isorhamnetin. And the maximal separation degree of Rutin was 5.0. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

溶菌酶分子印迹聚乳酸微球的制备及吸附性能

以改性聚乳酸微球(MPLA)为载体,以γ-(2,3-环氧丙氧)丙基三甲氧基硅烷为功能单体,以四乙氧基硅烷为交联剂,采用溶胶凝胶方法制备了表面溶菌酶分子印迹改性聚乳酸微球(LZY-MIP-MPLA),采用红外、扫描电镜和粒径测定等方法对LZY-MIP-MPLA进行了表征,优化了制备条件。详细研究了LZY-MIP-MPLA对溶菌酶的吸附性能,考察了pH和NaCl对吸附性能的影响。结果显示,LZY-MIP-MPLA对溶菌酶的吸附能力明显大于非印迹改性聚乳酸微球(NIP-MPLA),达到吸附平衡的时间为200min左右。Scatchard方程的分析表明,印迹孔穴对模板分子的作用是不完全等价的,即存在两类不同的结合位点。LZY-MIP-MPLA对溶菌酶和牛血清白蛋白的分离因子为10.13,说明其对溶菌酶具有较好的选择吸附性能。     

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.     

硅胶表面罗红霉素分子印迹聚合物的制备及选择性吸附性能

以γ-氨丙基三甲氧基硅烷(AMPS)为硅胶表面改性剂,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,罗红霉素(ROX)为模板分子,制备得到罗红霉素分子印迹硅胶材料(ROX-MIP-PMAA/SiO₂),采用红外、扫描电镜和粒径测定等方法对其进行了表征.通过静态和动态吸附实验研究了ROX-MIP-PMAA/SiO₂对罗红霉素的吸附性能,并以红霉素为竞争底物,研究其选择吸附性能.结果显示,ROX-MIP-PMAA/SiO₂对罗红霉素的吸附能力明显大于非印迹硅胶(NIP-PMAA/SiO₂),其对罗红霉素和红霉素的分离因子为1.21,说明其对罗红霉素具有较好的选择吸附性能.     

Membranes for specific adsorption: immobilizing molecularly imprinted polymer microspheres using electrospun nanofibers

Molecularly imprinted polymer microspheres were immobilized within a polymer nanofiber membrane by electrospinning. Such membranes simplify the handling of functional microspheres and provide specific recognition capabilities for solid-phase extraction and filtration applications. In this study, microspheres were prepared by precipitation polymerization of methacrylic acid and divinylbenzene as a cross-linker with the target molecule (-)-cinchonidine and then, they were electrospun into a non-woven polyacrylonitrile nanofiber membrane. The composite membrane showed specific affinity for (-)-cinchonidine which was attributed to the functional microspheres as confirmed by Raman microscopy. The target molecule capturing capacity of the composite membrane was 5 mg/g or 25 mg/g immobilized functional microsphere. No difference in target affinity was observed between the immobilized microspheres and the free microspheres. These results reveal that electrospun composite membranes are a feasible approach to immobilizing functional microspheres.     

Preparation and characterization of magnetic poly(styrene–glycidyl methacrylate) microspheres for highly efficient protein adsorption by two‐stage dispersion polymerization

Micrometer‐sized superparamagnetic poly(styrene–glycidyl methacrylate)/Fe₃O₄ spheres were synthesized by two‐stage dispersion polymerization with modified hydrophobic Fe₃O₄ nanoparticles, styrene (St), and glycidyl methacrylate (GMA). The morphology and properties of the magnetic Fe₃O₄–P (St‐GMA) microspheres were examined by scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, and attenuated total reflectance. The average size of the obtained magnetic microspheres was 1.50 μm in diameter with a narrow size distribution, and the saturation magnetization of the magnetic microspheres was 8.23 emu/g. The magnetic Fe₃O₄–P (St‐GMA) microspheres with immobilized iminodiacetic acid–Cu²⁺ groups were used to investigate the adsorption capacity and selectivity of the model proteins, bovine hemoglobin (BHb) and bovine serum albumin (BSA). We found that the adsorption capacity of BHb was as high as 190.66 mg/g of microspheres, which was 3.20 times greater than that of BSA, which was only 59.64 mg/g of microspheres as determined by high‐performance liquid chromatography. With a rather low nonspecific adsorption, these microspheres have great potential for protein separation and purification applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43005.     

Surface molecularly imprinted polymer prepared by reverse atom transfer radical polymerization for selective adsorption indole

The preparation of indole molecularly imprinted polymers (indole‐MIPs) using 4‐vinylpyridine as functional monomer, silica gel as matrix were used to adsorb indole from fuel oil specifically. The reverse atom transfer radical polymerization (RATRP) technology was introduced to prepare the surface molecularly imprinted polymers, and the precipitation polymerization was adopted in the preparation process. The obtained indole‐MIPs were characterized by nitrogen adsorption, Fourier transform infrared spectrometry and scanning electron microscopy. The results show that indole‐MIPs were provided with the larger surface areas and more pores. The adsorption capacity of indole‐MIPs was 31.80 mg g^?1 at 298 K, and the adsorption equilibrium was reached in a short time. The adsorption process was spontaneous by thermodynamic analysis, and an appropriate decrease in temperature could enhance the adsorption capacity. The adsorption process obeyed pseudo‐second‐order kinetic model by kinetics analysis. The isotherm analysis results show that both Langmuir and Sips equations were suitable to experimental data. The selective adsorption and reusable performance of indole‐MIPs were favorable. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40473.     

Preparation and characterization of molecularly imprinted silica particles for selective adsorption of naphthalene

A new kind of molecularly imprinted adsorbent for naphthalene was prepared by a covalent/noncovalent hybrid strategy. The monomer-template compound was prepared by the reaction of 3-(triethoxysilyl)propyl isocyanate with β-naphthol to form a thermally cleavable urethane bond. The silica gel was prepared by means of the gelation of monomer-template compound with tetraethoxysilane in ethanol using sol–gel technology. The removal of the template by the cleavage of urethane bond at elevated temperature resulted in the generation of recognition sites which could rebind naphthalene through noncovalent interaction. Binding experiments demonstrated that the imprinted silica particles showed a very fast uptake profile for naphthalene and displayed highly selective recognizing ability for naphthalene over benzene and other PAHs such as anthracene, phenanthrene, pyrene, fluoranthene and triphenylene.     

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.     

焦性没食子酸分子印迹聚合物的制备与吸附特征研究

以焦性没食子酸为模板分子,丙烯酸为功能单体,甲醇为溶剂,研究了模板分子与功能单体的结合比例,表明焦性没食子酸和丙烯酸之间通过氢键形成1∶1型配合物。在模板分子与功能单体、交联剂物质的量的比为1∶4∶20的条件下,采用沉淀聚合法制备了焦性没食子酸分子印迹聚合物微球。静态吸附实验表明,可制备出吸附量大且特异性识别能力较高的分子印迹聚合物,对焦性没食子酸有较高的亲和性和选择性。采用恒温振荡平衡吸附法以及Scatchard分析研究了聚合物的吸附特征,结果表明焦性没食子酸分子印迹聚合物在水环境下存在2种吸附位点,最大表观吸附量分别为7.5516μg/mg和11.9225μg/mg,平衡离解常数分别为9.2720×10-3mmol/L和0.1892 mmol/L。     

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.     

邻苯二甲酸二辛酯印迹吸附树脂的制备及其吸附性能

以大孔吸附树脂D101为载体,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,邻苯二甲酸二辛酯(DOP)为模板分子,制备了DOP分子印迹吸附树脂(DOP-MIP-D101),采用红外和扫描电镜等方法对其进行了表征。研究了DOP-MIP-D101对DOP的静态等温吸附性能、吸附动力学以及选择性吸附性能。结果显示,DOP-MIP-D101对DOP的吸附能力明显大于非印迹树脂(NIP-D101),且具有较高的选择性,吸附行为符合Freundilich方程。DOP-MIP-D101对DOP的吸附达到平衡的时间为100min左右。     

没食子酸表面分子印迹材料的制备及其吸附性能

以凹凸棒为载体,没食子酸为模板剂,合成表面分子印迹聚合物,考察分子印迹聚合物对没食子酸的的吸附性能。结果表明,表面分子印迹聚合物对没食子酸具有高度选择性,吸附行为更符合多层吸附的Freundlich方程,吸附动力学为准一级动力学。重复使用5次,吸附效果没有明显下降。用此表面分子印迹聚合物从茶叶中提取出没食子酸,与纯品相似度为99.9%。     

A molecularly imprinted polymer for the efficient adsorption of morphine

Molecularly imprinted polymers (MIPs) were synthesized via the precipitation polymerization technology for the specific adsorption of morphine. A number of polymers (methacrylic acid, trifluoromethyl acrylic acid, and acrylamide) were studied, respectively, as the precursor monomers under various synthetic conditions (the imprinting (IP) ratio, cross-linking (CL) ratio, solvent ratio, reaction temperature, etc.). The MIP with optimal performance was derived using methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinker, and azobisisobutyronitrile (AIBN) as the initiator, with an IP ratio of 1:3 and a CL ratio of 5:1. This MIP presented a maximum morphine adsorption capacity of 38.24 mg/g (one of the highest capacities ever reported in the literature) at a bulk morphine concentration of ~230 ppm in acetonitrile solution. The adsorption capacity, selectivity, reusability, as well as the chemical and mechanical stabilities of the MIP were confirmed by the adsorption experiments, instrumental characterization, thermodynamic analysis, as well as the proposed mechanisms.     

Preparation of cinchonine molecularly imprinted photonic crystal film and its specific recognition and optical responsive properties

The cinchonine molecularly imprinted photonic polymer (MIPP) film was prepared by using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross linker, benzoyl peroxide and N,N‐dimethylaniline as initiation system by a combination of colloidal crystal template method and molecular imprinting technique. The structure and morphology of the polymer film were characterized by infrared spectra and scanning electronic microscope. The results exhibit that a highly ordered three‐dimensionally interconnected macroporous array with typical face‐centered cubic (fcc) structure was formed in the MIPP film. The binding experiments showed that the special, hierarchical porous structure enabled this polymer to possess rapid adsorption kinetics, improved binding capacity, and specificity to analytes. The Bragg diffractive measurements showed that the MIPP film has good specific responsiveness for the template molecules. The Bragg diffraction peaks shifted from 527 to 503 nm with the concentration of the cinchonine varying from 0 to 10^?3 mol/L, whereas there were no obvious peaks shifts for its structural analogues. This may be ascribed that the changes in the lattice constants and the average refractive indices of MIPP film caused by the special adsorption of template molecules toward recognition sites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43191.