Magnetic Molecularly Imprinted Polymer Particles Synthesized by Suspension Polymerization in Silicone Oil

Summary: Magnetic nanoparticles have been prepared by a co‐precipitation method and modified with methacryloxypropyltrimethoxysilane. Magnetic molecularly imprinted polymer particles have been prepared by suspension polymerization in silicone oil. The particles possess a high affinity to the template molecules and are rapidly separated under a magnetic field.

SEM photograph of magnetic MIP particles.     

悬浮聚合法制备磁性分子印迹聚合物微球

以苯胺和二甲基苯胺为模板分子、甲基丙烯酸(MAA)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,采用悬浮聚合法制备了磁性分子印迹聚合物微球(MMIPMs)。结果表明,改性Fe3O4微粒在MMIPMs中分散较好,MMIPMs在水性介质中对模板分子的选择吸附性较差,但在有机介质中有较好的选择吸附性。     

反相悬浮聚合法合成超强吸水剂

以两性高分子作悬浮稳定剂，用反相悬浮聚合法合成了聚（丙烯酸盐－丙烯酰胺）类超强吸水剂．研究了交联剂、稳定剂、引发剂等用量、中和程度、单体组成及链转移剂等聚合条件对吸水剂吸水性能的影响．得到了吸蒸馏水１０５０ｍＬ／ｇ及吸０．９％ＮａＣｌ溶液８６ｍＬ／ｇ的超强吸水剂．此外，还比较了含不同反离子的聚丙烯酸类吸水剂的吸水性能     

Molecularly Imprinted Nanospheres by Nonaqueous Emulsion Polymerization

The preparation of nanosized, molecularly imprinted polymer particles by nonaqueous emulsion polymerization is presented. Monodisperse cross‐linked polymer nanospheres with a diameter of around 100 nm were synthesized using a standard monomer mixture of methacrylic acid and ethylene dimethacrylate, containing (±)‐propranolol as a template. The rebinding efficiency of the resulting particles was determined by batch rebinding tests and isothermal titration calorimetry (ITC). The results indicate that the proposed imprinting process under nonaqueous conditions lead to particles with an enhanced capacity of template rebinding compared to both nonimprinted ones and to particles obtained by more conventional emulsion polymerization in water.

     

反相悬浮聚合法制备硫氰酸根阴离子印迹微球及其离子识别性质

利用反相悬浮聚合法, 成功制备了微米级硫氰酸根(SCN^-)阴离子印迹微球。 以溶有分散剂Span-60的环已烷为分散介质, 以溶有模板阴离子SCN^-、阳离子单体丙烯酰氧乙基三甲基氯化铵(DAC)及交联剂N, N'-亚甲基双丙烯酰胺(MBA)的水溶液为分散相, 构成反相悬浮聚合体系, 在水相液滴中使DAC发生交联聚合, 成功制备了粒径约为200 μm的离子印迹微球(IIPMs)。 以同为一价阴离子的NO₃^-和I^-为对比离子, 深入考察研究了该离子印迹微球的离子识别与结合特性。 研究结果表明, 凭借强静电相互作用, 在水相液滴中, 阳离子单体DAC与模板阴离子SCN^-紧密相结合, 故在DAC交联聚合的同时, 实现了阴离子SCN^-的印迹。 所制备的阴离子印迹微球IIPMs对模板阴离子SCN^-具有很高的结合能力(结合容量为3.3 mmol/g(192 mg/g))和特异的识别选择性。 该印迹微球可选择性地识别与结合离子混合溶液中的SCN^-离子, 相对于NO₃^-和I^-阴离子, IIPMs对SCN^-阴离子的选择性系数分别为3.24和6.78。 该印迹微球还具有优良的重复使用性能。     

以两性高分子作反相悬浮稳定剂合成吸水剂

以聚（甲基丙烯酸十二酯－丙烯酸）两性共聚物为稳定剂，用反相悬浮聚合法合成了丙烯酸／丙烯酰胺／甲基丙烯酸羟乙酯三元共聚型超强吸水剂：吸蒸馏水1150mL.g^-1，吸0．9％NaCl溶液91mL.g^-1，研究了稳定剂结构及用量，单体组成，交联剂，链转移剂，中和程度等聚合条件及吸水剂性能的影响，实验表明甲基丙烯酸十二酯－丙烯酸共聚物是一种很好的反相悬浮稳定剂。     

悬浮聚合法制备罗丹明B磁性分子印迹微球及其性能

以罗丹明B（RhB）为模板分子,采用悬浮聚合法制备了罗丹明B磁性印迹微球（M-MIPs）,对其进行了结构表征,并与本体聚合的印迹材料进行了对比。 结果表明,2种聚合物中的Fe3O4均呈现良好的晶形。 悬浮法制得的M-MIPs呈球形,粒径在50 μm左右,其饱和磁化强度(5.406 emu/g)比本体法制得的M-MIP（1.772 emu/g）更大,有利于快速磁性分离。 悬浮法所得M-MIPs的吸附量是本体法所得M-MIPs吸附量的近1.8倍,且在吸附速率、选择性、重复使用性能等方面,均明显优于后者。 2种材料均符合Langmuir吸附模型;悬浮法所得M-MIPs对RhB的吸附过程更符合二级动力学方程,而本体法所得M-MIPs较符合一级动力学方程。 悬浮法制得的M-MIPs更适合于RhB的识别、富集与分析应用。     

Molecularly Imprinted Photonic Polymers as Sensing Elements for the Creation of Cross‐Reactive Sensor Arrays

By combining molecular imprinting and colloidal crystal templating, molecularly imprinted inverse‐opal photonic polymers (MIPPs) acting as sensing elements have been exploited to create sensor arrays for the first time. With this new strategy, abundant sensing elements with differential sensing abilities were easily accessible. Because of the unique hierarchical porous structure integrated in each sensing element, high sensitivity and selectivity, fast response and self‐reporting (label‐free) detection could be simultaneously achieved. All these fascinating features indicate that MIPPs are ideal sensing elements for creating sensor arrays. By integrating the individual sensing elements on a substrate, the formed array chip delivers better portability and high‐throughput capability. As a demonstration, six kinds of contaminants were selected as analytes. The detection and discrimination of these analytes and even their mixtures in a wide range of concentrations, particularly trace amounts of analyte against a high background of other components, could be achieved, indicating the powerful capability of MIPPs‐based sensor array for sensing. These results suggest that the described strategy opens a new route for sensor array creation and should find important applications in a wide range of areas.     

The Synthesis of Magnetic Lysozyme‐Imprinted Polymers by Means of Distillation–Precipitation Polymerization for Selective Protein Enrichment

A protein imprinting approach for the synthesis of core–shell structure nanoparticles with a magnetic core and molecularly imprinted polymer (MIP) shell was developed using a simple distillation–precipitation polymerization method. In this work, Fe₃O₄ magnetic nanoparticles were first synthesized through a solvothermal method and then were conveniently surface‐modified with 3‐(methacryloyloxy)propyltrimethoxylsilane as anchor molecules to donate vinyl groups. Next a high‐density MIP shell was coated onto the surface of the magnetic nanoparticles by the copolymerization of functional monomer acrylamide (AAm), cross‐linking agent N,N′‐methylenebisacrylamide (MBA), the initiator azodiisobutyronitrile (AIBN), and protein in acetonitrile heated at reflux. The morphology, adsorption, and recognition properties of the magnetic molecularly imprinted nanoparticles were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and rebinding experiments. The resulting MIP showed a high adsorption capacity (104.8 mg g^?1) and specific recognition (imprinting factor=7.6) to lysozyme (Lyz). The as‐prepared Fe₃O₄@Lyz‐MIP nanoparticles with a mean diameter of 320 nm were coated with an MIP shell that was 20 nm thick, which enabled Fe₃O₄@Lyz‐MIP to easily reach adsorption equilibrium. The high magnetization saturation (40.35 emu g^?1) endows the materials with the convenience of magnetic separation under an external magnetic field and allows them to be subsequently reused. Furthermore, Fe₃O₄@Lyz‐MIP could selectively extract a target protein from real egg‐white samples under an external magnetic field.     

种子溶胀悬浮聚合法制备香草醛分子印迹聚合物微球

以分散聚合法制备的聚苯乙烯微球为种子,采用单步溶胀悬浮聚合法,香草醛为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,在水相中成功制备了分子印迹聚合物微球,通过扫描电镜、静态吸附和高效液相色谱手段对其进行表征。结果表明,该微球对香草醛具有较高的吸附能力和良好的特异选择性,用于液相色谱固定相可将其与结构类似物阿魏酸快速基线分离。     

悬浮聚合法合成马拉硫磷分子印迹聚合物的吸附性能研究

基于分子印迹技术,采用悬浮聚合的方法,合成了马拉硫磷分子印迹聚合物。通过优化,确定最佳合成条件为:模板分子(马拉硫磷)∶功能单体(α-甲基丙烯酸)为1∶8,模板分子(马拉硫磷)∶交联剂(乙二醇二甲基丙烯酸酯)为1∶40,温度60℃,引发剂用量为1.0%。吸附性能测试结果表明,印迹聚合物对马拉硫磷的最大吸附量为4.62μg/mg,而非印迹聚合物对马拉硫磷的最大吸附量为2.21μg/mg;通过选择性实验得到印迹聚合物对灭线磷、甲拌磷、特丁硫磷、乐果、马拉硫磷、克线磷的吸附量分别为3.87、3.75、3.57、4.00、4.44、3.61μg/mg,而非印迹聚合物的吸附量分别为1.42、1.37、1.30、1.43、1.12、1.23μg/mg。     

Semi‐Covalent Surface Molecular Imprinting of Polymers by One‐Stage Mini‐emulsion Polymerization: Glucopyranoside as a Model Analyte

This paper describes a new type of surface imprinting technique that combines the advantages of both the semi‐covalent approach and one‐stage miniemulsion polymerization. This process has been successfully applied for the preparation of glucose surface‐imprinted nanoparticles. The selective artificial receptors for glucopyranoside were fully characterized by IR, TEM and BET analyses, and their molecular recognition abilities by binding experiments carried out in batch processes. The molecular affinity and selectivity of the glucose molecularly imprinted polymers were accurately quantified. These characteristics are essential for verification of the efficiency of the developed surface imprinting process. The imprinting effect was clearly demonstrated using the batch rebinding method. We have found that the glucose imprinted polymers produced using the optimized one‐stage mini‐emulsion exhibited quite fast kinetics of binding and equilibration with glucopyranoside templates, compared to polymers prepared by bulk polymerization technique, as well as extremely low levels of unspecific bindings. We also demonstrated that glucose molecular imprinted polymer (MIP) exhibited very good selectivity for its original template compared to other glycopyranoside derivatives, such as galactose. Finally, the extraction of the binding properties from isotherms of binding by fitting to the bi‐Langmuir and Freundlich models allowed the determination of the affinity constant distribution of the binding sites. This imprinting protocol allowed the determination of an affinity constant (K_D), involving exclusively H‐bonding interactions, for the glucose MIP ( P2C ) with the best template 1 , in CH₃CN as the solvent system.

     

反相悬浮聚合分散剂的合成及性能

聚丙烯酸（钠）的吸水速度快,吸水量大,通常在有机介质环己烷、戊烷、（甲基）环戊烷中进行反相乳液聚合法生产,但一般只能获得颗粒细小的粉末状树脂,在介质中沉降速度慢,工程上易起粉尘危害．吸水树脂颗粒细小也影响树脂性能［１］,采用反相悬浮聚合法合成聚丙烯酸...     

Synthesis of Molecularly Imprinted Polymer Particles by Suspension Polymerization in Silicon Oil

Molecular imprinting is a method to prepare polymers with recognition site of desired and predetermined selectivity1. Molecularly imprinted polymers (MIP) are prepared by copolymerizing functional and cross-linking monomers in the presence of a molecular …     

Phosphate‐Loaded Hydrogel Nanoparticles for Sepsis Prevention Prepared via Inverse Miniemulsion Polymerization

Local depletion of intestinal phosphate triggers changes in bacterial phenotypes that adversely affect the health of the host. This article describes a process for encapsulating phosphates in crosslinked poly(ethylene glycol) diacrylate (PEGDA) nanoparticles using inverse miniemulsion polymerization as a drug delivery approach for sustained release of phosphates to the intestinal epithelium. The effects of crosslinker, PEGDA co‐monomer, N‐vinyl pyrrolidone, (NVP) and surfactant concentrations on the nanoparticle size distribution, swelling ratio and monomer conversion are investigated. Increased surfactant and PEGDA concentrations result in smaller particle size and swelling ratio. A copolymerization model of crosslinking is used to predict conversion and gelation dynamics as a function of polymerization conditions. The model assumes that bulk polymerization can be used to approximate inverse miniemulsion polymerization with an aqueous‐phase initiator. The initiator efficiency is used as an adjustable parameter to simulate the conversion dynamics, thus accounting for radical confinement effects and interaction with emulsifier molecules.     

Nanoparticle‐Imprinted Polymers for Size‐Selective Recognition of Nanoparticles

Citrate‐stabilized gold nanoparticles 15 nm and 33 nm in diameter were transferred concomitantly with a monolayer of positively charged polyaniline by Langmuir–Blodgett transfer at pH 5 onto a conducting indium‐doped tin oxide (ITO) support. Films consisting of one to three layers of polyaniline with thicknesses of 1–3 nm were prepared and characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy. After electro‐oxidation of the Au nanoparticles in 0.1 M KCl, cavities were left behind in the film that could be analyzed by SEM. These cavities were able to recapture analyte nanoparticles from a solution of pH 10 and showed size‐exclusion properties. The amount of nanoparticles taken up by the cavities was conveniently analyzed by measuring the charge associated with the electro‐oxidation of these particles in 0.1 M KCl after the film had been rinsed with water. The size‐exclusion properties improved with the number of Langmuir–Blodgett layers transferred.     

氨基安替比林分子原位烙印柱的制备及其水中结合性质的研究

实验采用原位聚合法以甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁扉(AIBN)为引发剂,正十二醇和甲苯为致孔剂直接在液相色谱柱中制备了氨基安替比林分子烙印柱．讨论了模板分子及其类似物在有机相和水相中的色谱行为及作用机理．实验表明,在水相中烙印柱具有很强的保留性能,氨基安替比林的保留因子可达到94．41．结果认为离子作用和疏水作用是使得氨基安替比林及类似物具有很强的保留性的重要原因,为研究模板聚合物的结合特性,采用前流分析法分别测定了氨基安替比林、氨基比林和安替比林在烙印柱上的吸附等温线．实验表明,分子烙印聚合物对烙印分子表现了较高的选择性,这和通过比较各物质在分子烙印柱和空白柱上保留因子所获得的结果一致．     

Molecularly Imprinted Polymer Nanomaterials and Nanocomposites: Atom‐Transfer Radical Polymerization with Acidic Monomers

Molecularly imprinted polymers (MIPs) are artificial receptors which can be tailored to bind target molecules specifically. A new method, using photoinitiated atom‐transfer radical polymerization (ATRP) for their synthesis as monoliths, thin films and nanoparticles is described. The synthesis takes place at room temperature and is compatible with acidic monomers, two major limitations for the use of ATRP with MIPs. The method has been validated with MIPs specific for the drugs testosterone and S‐propranolol. This study considerably widens the range of functional monomers and thus molecular templates which can be used when MIPs are synthesized by ATRP, as well as the range of physical forms of these antibody mimics, in particular films and lithographic patterns, and their post‐functionalization from living chain‐ends.     

原位聚合法制备氨基安替比林分子烙印聚合物及分离特性的研究

以氨基安替比林为模板分子,采用原位聚合法制备了具有特定识别性能的棒状分子烙印聚合物。通过考察烙印分子的化学基团对分离的影响,以及离子作用和氢键作用在分离中的贡献,论证了分子烙印聚合物选择性专一的作用机理。结果表明,这种棒状聚合物对模板分子及其类似物有很好的分离能力。     

分子印迹聚合物微球的制备及应用研究进展

球形分子印迹聚合物具有制备简单、使用方便；分子识别效率高且便于功能设计等优点，近年来成为分子印迹技术领域研究的热点之一。对球形分子印迹聚合物微球的制备及其应用研究进展作了较为详细的介绍。