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1.
2-methylphenoxyacetic acid (2-MPA), 2-methyl-4-chlorophenxyacetic acid (MCPA) and 4-chlorophenoxyacetic acid (4-CPA) were imprinted to investigate the cross-selectivities of molecularly imprinted polymers (MIPs). The result indicates that 2-MPA, which is similar in shape, size and functionality with phenoxyacetic herbicides, are suitable to be used as a suitable template to prepare the MIPs for retaining phenoxyacetic herbicides. To study the ion-pair interactions between template molecules and functional monomer 4-vinylpiridine (4-VP), computational molecular modeling was employed. The data indicate that the cross-selectivities of MIPs for phenoxyacetic acid herbicides depend on the binding energies of complexes.  相似文献   

2.
利用分子印迹技术的特异性识别,采用本体热聚合,以酸碱相互作用为基本作用机理,分别以甲基丙烯酸二甲氨基乙酯(DMAEMA)、甲基丙烯酸二乙氨基乙酯(DEAM)、甲基丙烯酸-2-氨基乙基酯盐酸盐(AMA盐酸盐)、4-乙烯基吡啶(4-VP)和甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)和二乙烯基苯(DVB)为交联剂,偶氮二异丁腈(AIBN)为引发剂,乙腈为溶剂设计合成了三氯生(TCS)的分子印迹聚合物(MIPs)。吸附结果表明,其中DEAM是TCS的最佳功能单体,吸附率达到了78.5%,印迹因子达到了1.7,用DEAM作为功能单体合成的MIPs对TCS的选择性实验结果显示,对TCS的吸附容量明显高于其结构类似物,对TCS的吸附实验结果显示,5次回收后重复利用,吸附容量仅降低了5.1%,表明该MIPs可以重复使用多次。  相似文献   

3.
甲基对硫磷分子印迹聚合物制备中溶剂和功能单体的影响   总被引:1,自引:0,他引:1  
为了有效的分离富集水样中的有机磷农药,以甲基对硫磷为模板、二甲基丙烯酸乙二酯为交联剂,采用传统方法制备了甲基对硫磷分子印迹聚合物(MIPs).考察了三种溶剂和三种功能单体及其用量对MIPs吸附性能的影响.结果表明,以氯仿为溶剂制得的MIP特异性最强,溶剂用量对MIPs比表面积和溶胀比的影响显著.氯仿用量为35 mL时MIP性能最理想;~1H-NMR研究显示,4-乙烯基吡啶(4VP)与模板分子通过π-π堆积作用形成稳定的复合物,按4VP与模板分子摩尔比4:1制得的MIP特异性和亲和性较理想.测定了该MIP的吸附等温线,利用Langmuir等温式分析结果,得出其饱和吸附量为625.5 μmol·g~(-1),明显高于非印迹聚合物的饱和吸附量285.7 μmol·g~(-1).利用该MIP对模拟海水样品进行研究,结果显示,MIP对不同有机磷农药的吸附能力表现出一定的差异.通过进一步优化,提高MIPs的选择性,该材料有望用于水样中甲基对硫磷的分离富集和分析.  相似文献   

4.
Molecular imprinting polymers (MIPs) for artemisinin were prepared by using 3‐aminopropyltriethoxysilane and calix[4]arene bonded on silica particle surface as the functional monomers, tetraethoxysilicane as cross‐linker, and artemisinin as template. The MIPs were characterized by Fourier Transform Infrared Spectroscope and SEM. Their adsorption capacities were evaluated by static adsorption experiments. The MIPs showed high adsorption capacity and good selectivity for artemisinin. The maximum adsorption capacity of MIPs for artemisinin was 40.0 mg/g. The imprinting factor and the selective factor of the artemisinin‐imprinting polymers was 2.0 and 1.5, respectively. The imprinted film coating onto the silica surface showed a fast kinetics for recognizing and binding templates. Especially, mass transfer reaches the equilibrium within 3.5 h and the adsorption capacity of MIPs for artemisinin reached 120.0 mg/g in supercritical CO2 fluid. © 2011 American Institute of Chemical Engineers AIChE J, 2011  相似文献   

5.
In this work, we initiated to study new synthetic conditions to obtain uniformly sized molecularly imprinted polymers (MIPs) in the micrometer to nanometer range, using carbamazepine (CBZ) as a model template. The MIPs were successfully prepared by precipitation polymerization using methacrylic acid (MAA) and methyl methacrylate (MMA) as functional monomers at different mole ratios. The effect of MAA-to-MMA mole ratios on the morphology, binding, recognition, and release behaviors of the final particles were studied, and the adjusting possibility of these properties was also obtained. The produced polymers were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry, and their morphology was precisely examined by scanning electron microscopy and photon correlation spectroscopy. We obtained very uniform imprinted nanospheres and microspheres with diameter in the range of 120 nm to 1.74 μm under various conditions. Among the MIP nanospheres and microspheres prepared, the MIPs using MAA-to-MMA mole ratio of 1 : 2 showed nanospheres with the lower polydispersity index (0.004) and the highest selectivity factor (10.4), which is defined as the binding ratio of CBZ and oxcarbazepine as template analog. Results from binding experiments proved that MIPs exhibit specific affinity to CBZ in contrast to control polymers, and this performance was affected by pH and concentration of the loading solution. Moreover, release experiments showed the controlled release of CBZ in long-time period. The 50% of loaded CBZ was released from the imprinted nanospheres within the first 30 h, whereas another 50% was released in the following 160 h. The release kinetics of CBZ from the MIPs highly affected with the properties of particles. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

6.
以b-环糊精(β-CD)、2-羟丙基-β-环糊精(HP-β-CD)和4-乙烯吡啶(4-VP)为功能单体,以氟比洛芬为模板分子,以环氧氯丙烷和乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合法制备分子印迹聚合物(MIPs),对氟比洛芬与功能单体的相互作用和MIPs的结构进行了表征,比较了3种MIPs对氟比洛芬的吸附性能. 结果表明,β-CD, HP-β-CD和4-VP与氟比洛芬之间以较强的相互作用形成复合物,通过交联、聚合形成聚合物,以HP-β-CD作功能单体所得聚合物印迹效果最佳,具有较强的特异性吸附能力,印迹因子和特异性吸附率分别为1.79和38.92%,分子印迹机制是β-CD的锥筒包结作用和羟丙基的亲和作用形成印迹空穴.  相似文献   

7.
《分离科学与技术》2012,47(3):404-412
In this paper the development and evaluation of a molecularly imprinted polymer (MIP) for ethopabate is described. Ethopabate (ETP), 4-acetamido-2-ethoxybenzoic acid methyl ester, is one of the antibiotics which is used as coccidiostat in poultry feeds. In the present study, two widely used functional monomers, methacrylic acid (MAA) and 4-vinylpyridine (4-VP) were compared theoretically and experimentally as the candidates for MIP preparation. Hyperchem software was employed to estimate binding energies between ETP and functional monomers and batch rebinding experiments were performed to study the binding characteristics of the polymers. The results showed that MAA is a better functional monomer to prepare MIP. UV/Vis and NMR spectroscopy were used as two common tools to study the interactions between ETP and MAA in the pre-polymerization mixture. Liquid chromatography experiments showed that the prepared MIP has recognition capability toward ETP in comparison with other structurally related compounds. The ETP-imprinted polymer was further applied for selective solid phase extraction (SPE) of ETP from a chicken tissue sample. The extraction yield of ETP was found to be quantitative (87 ± 3%) and the LOD and LOQ based on 3 and 10 times of the noise of HPLC profile were 0.05 and 0.32 ng ml?1, respectively. It was confirmed that the binding ability of the prepared MIP for ETP was essentially sufficient in the presence of other compounds coexisting in tissue sample. Therefore, as a selective and efficient solid phase material, ETP-imprinted polymer has a high potential application in the analysis of residues of this antibiotic in chicken tissue samples.  相似文献   

8.
以D-对羟基苯甘氨酸(D-HPG)为模板分子,以丙烯酰胺(AM)和α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成了D-HPG分子印迹聚合物,并测定其对D-HPG的识别能力。静态吸附实验表明,以MAA为功能单体制备的分子印迹聚合物具有更强的分子识别能力,其饱和吸附量达43.9 μmol•g-1,印迹因子α为3.6。分子力学计算表明,MAA与D-HPG形成复合物的结合能较大,且MAA在乙醇和水中的溶剂化能较小,因此与AM比较,MAA和模板分子D-HPG在乙醇和水中能形成更加稳定的复合物。紫外光谱分析表明,MAA与D-HPG之间的结合力比AM与D-HPG之间的结合力要强,与分子力学计算以及静态吸附实验得到的结果相一致。  相似文献   

9.
The objective of this study was to identify a kind of molecular imprinting polymer (MIP) which was suitable for recognizing naringin (NG) in aqueous medium. Based on two crosslinkers (hexamethylene diisocyanate and epichlorohydrin) and two polymerization methods (solution polymerization and emulsion polymerization), four non‐covalent naringin‐β‐cyclodextrine (NG‐β‐CD) imprinted polymers were prepared by using β‐CD as a functional monomer and NG as a template molecule. The binding property and selectivity were evaluated by equilibrium binding experiments. These demonstrated that all the sites in the MIPs show good selective binding ability for NG from naringin dihydrochalcone, a structurally similar molecule. Of the four MIPs, rod‐like 3# MIP which was prepared by emulsion polymerization using hexamethylene diisocyanate as crosslinker exhibited the highest selectivity, its imprinting factor α being 1.53. Scatchard analysis of 3# MIP suggests that there are two classes of binding sites during the MIP's recognition of NG. Additionally, the 3# MIP could be used at least five times without any loss in sorption capacity. Copyright © 2011 Society of Chemical Industry  相似文献   

10.
董文国  闫明  张敏莲  刘铮  李艳梅 《化工学报》2005,56(11):2131-2136
采用密度泛函方法计算功能单体与印迹分子的结合能,以与目标分子结合能最大的单体分子来合成分子印迹聚合物.为此,以茶碱为印迹分子,氯仿为溶剂,首先计算了茶碱与甲基丙烯酸、丙烯酰胺和三氟甲基丙烯酸的结合能,其强度顺序为:三氟甲基丙烯酸 > 甲基丙烯酸 > 丙烯酰胺.然后以茶碱为印迹分子、氯仿为溶剂、二甲基丙烯酸乙二醇酯为交联剂,分别采用上述3种单体合成分子印迹聚合物并测定了其分子识别能力,实验结果和量子化学计算结果具有一致性.最后,采用1H NMR考察了茶碱和上述3种单体之间的氢键作用,揭示出二者相互作用的内在机制.研究结果表明量子计算方法可以应用于合成分子印迹聚合物时单体的选择.  相似文献   

11.
孙倩  杨明  盛鑫鑫  周魁 《化学世界》2012,53(10):606-609
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。  相似文献   

12.
Highly selective molecularly imprinted polymers (MIPs) having a phthalocyanine-based recognition centre as receptors for RNA nucleoside were prepared. In particular, a zinc phthalocyanine peripherally substituted with methacrylic groups was synthesized and utilized as functional monomer in combination with methacrylic acid (MAA) to form polymers with the aim to obtain MIPs having improved binding capacity and selectivity for nucleosides. Tri-O-acetyladenosine (TOAA) was utilized as model template in the preparation of the MIPs. The corresponding non metallated phthalocyanine was also prepared and used as functional monomer for the preparation of the MIPs in order to understand the role of the Zinc(II) ion in the binding capacity of the polymers towards the template molecule. The MIP prepared by using both the zinc phthalocyanine and MAA showed higher binding ability towards TOAA compared to the MIPs prepared using only MAA or its combination with the non metallated phthalocyanine. The results obtained suggest that the nucleoside is specifically bound to the polymer through multi-point interactions involving both the coordination of the nucleoside to the metal of the phthalocyanine and hydrogen bonding/electrostatic interactions with MAA and the modifiers linked to the phthalocyanines. As for the selectivity, the MIPs exhibited relative high binding affinities for TOAA while they did not show any binding capacity for the other RNA nucleosides.  相似文献   

13.
Core–shell structural surface imprinting microspheres were prepared by a simple and effective method. This method combined reversible addition–fragmentation chain transfer (RAFT) with distillation precipitation polymerization RAFT reagent-containing microspheres on the surface. Tetramethylammonium asparagine ([N1111]Asn) ionic liquid or l-Asn, 4-vinylpyridine (4-VP), ethylene glycol dimethacrylate (EGDMA), and RAFT reagent-containing microspheres on the surface were used as template, functional monomer, cross-linker, and chain transfer agent (CTA), respectively. Two kinds of imprinted polymer were obtained, namely, AsnIL-MIPs and Asn-MIPs. The morphology and structure of the polymers were characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy. The binding and selective recognition properties of l-Asn and its analogs were investigated in aqueous solution. Compared with l-Asn as template molecule, AsnIL-MIPs showed faster binding speed and better selective recognition. The binding reached saturation after 1 h, and the selective recognition factor (α) reached 5.28 and 4.26 for the template against l-Asp and l-Arg, respectively. AsnIL-MIPs showed an improved binding rate, binding affinity, and significantly increased recognition.  相似文献   

14.
A novel compound, diethyl(3‐methylureido)(phenyl)methylphosphonate (DEP), possessing an organophosphate skeleton, was synthesized and used as a dummy template to prepare molecularly imprinted polymers (MIPs) for the recognition of organophosphate pesticide analogs. Computational modeling was used to study the primary intermolecular interactions in the prepolymerization mixture. It was found that the interaction force between DEP and the monomers was hydrogen bonding. A series of MIPs were synthesized with different monomers and were evaluated by adsorption experiments, which showed that methacrylic acid was used as an appropriate monomer and a molar ratio of DEP to MAA of 1 : 9 was optimal. Scatchard analysis showed that there might have been two types of binding sites in the MIPs. DEP and several pesticides were used in molecular recognition specificity tests of DEP–MIP, which exhibited better selectivity and reservation ability for organophosphate pesticides, such as methamidophos and orthene, possessing amino or imino groups and a smaller steric hindrance. On the basis of the use of a dummy molecule as template, the problem of template leakage could be avoided; this, thereby, improved the specificity of analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

15.
Goretti Díaz-Díaz 《Polymer》2011,52(12):2468-2473
A method for the rational design of molecularly imprinted polymers with catalytic activity (MICs) that mimic hemeproteins is described. Density Functional Theory calculations applied to the pre-polymerization adduct and to a possible reaction intermediate allow to choose the best functional monomer that builds up the active sites. This functional monomer should stabilize both relevant stages, the first one in an adequate porogenic solvent and the second one in the aqueous reaction medium. In this work, a MIC was synthesized to catalyze the oxidation of 2,4,6-trichlorophenol (TCP), the substrate and template molecule. A hemin molecule was used as the catalytic centre and four functional monomers and six solvents were tested. According to the theoretical predictions, methacrylamide and 4-vinylpyridine MIPs successfully mimic the recently discovered ability of Chloroperoxidase (CPO) to catalyze the oxidative dechlorination of TCP in batch analysis. They exhibit good catalytic properties and substrate selectivity.  相似文献   

16.
Molecularly imprinted polymers (MIPs) were fabricated on glass slides with a “sandwich” technique giving ~20 μm thick films. Methanol/water as a solvent, and polyethyleneglycol and polyvinylacetate as solvent modifiers, were used to give a porous morphology, which was studied with scanning electron microscopy and gravimetric analysis. Various MIPs were synthesized through non-covalent imprinting with phenol as the template; itaconic acid, 4-vinylpyridine, and styrene as monomers; ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and pentaerythritol triacrylate (PETA) as cross-linkers. Binding and imprinting properties of the MIPs were evaluated based on phenol adsorption isotherms. Since phenol has only one weakly acidic hydroxyl group and lacks unique structural characteristics necessary for binding specificity, the preparation of selective MIPs was challenging. The recognition of phenol via hydrogen bonding is suppressed in water, while hydrophobic interactions, though promoted, are not specific enough for highly-selective phenol recognition. Nevertheless, the styrene-PETA MIP gave modest imprinting effects, which were higher at lower concentrations (Imprinting Factor (IF) = 1.16 at 0.5 mg·L−1). The isotherm was of a Freundlich type over 0.1–40 mg·L−1 and there was broad cross-reactivity towards other structurally similar phenols. This shows that phenol MIPs or simple adsorbents can be developed based on styrene for hydrophobic binding, and PETA to form a tighter, hydrophilic network.  相似文献   

17.
Molecularly imprinted polymers (MIPs) have been extensively used in chemical and biochemical related areas due to their high molecular recognition affinity and selectivity for the target molecule. On the other hand, supercritical polymerization is relatively novel technique, which can be applied in the polymerization without hazard organic solvent. This work introduces a supercritical fluid polymerization technique for preparation of MIP particles. The adsorption properties of prepared MIP particles are also investigated. The MIPs were prepared with methyl methacrylate (MMA) as a third monomer, methacrylic acid (MAA) as a functional monomer, templates (bisphenol A (BPA) and 2,4-dichlorophenoxyacetic acid (2,4-D)), methyl methacrylate (MMA) as a third vinyl monomer and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. Equilibrium binding experiments are conducted to evaluate the binding characteristics of MIPs and templates (BPA and 2,4-D). The Scatchard plot analysis demonstrates that two classes of binding sites are formed with the equilibrium dissociation constants. The adsorption ability of the MIPs was also evaluated by measuring the adsorbed amounts of a similar imprinted template structure, the selectivity factor (α), and the imprinting-induced promotion of binding (IPB).  相似文献   

18.
丁杨  苏立强 《化工时刊》2008,22(10):21-23
采用分子印迹技术,以2,2',4,4'-四羟基二苯甲酮为模板分子,2-乙烯基吡啶为功能单体,二甲基丙烯酸乙二醇酯为交联剂,偶氮二异丁氰为引发剂,在乙腈溶液中合成2,2',4,4'-四羟基二苯甲酮分子印迹聚合物。通过平衡吸附和液相色谱的方法分析了印迹聚合物的识别特性。研究结果表明,聚合物对印迹分子具有很好的亲和性和特定的选择性,用作液谱固定相可将其与结构类似物2,4-二羟基二苯甲酮、2-羟基-4-甲氧基二苯甲酮快速基线分离。  相似文献   

19.
人血红蛋白分子印迹聚合物的制备及分子识别性能   总被引:3,自引:1,他引:2  
以丙烯酰胺和甲基丙烯酸为功能单体制备得到了具有选择性识别能力的人血红蛋白分子印迹聚合物. 该印迹聚合物的分子识别特性来自聚合物的结合基团与印迹分子的功能基团之间的氢键和静电作用,以及印迹孔穴的空间几何选择性. 研究表明,聚合单体中甲基丙烯酸的含量会影响聚合物对血红蛋白的特异结合能力及分子印迹聚合物的吸附容量和洗脱性能.  相似文献   

20.
Diblock copolymer brushes of polystyrene and poly (4-vinylpyridine) (PS-b-P4-VP) were synthesized by sequential monomers addition to a monolayer of 3-methacryloxypropyltrimeth-oxysilane. The diblock brushes were characterized by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscope (AFM). The results suggested that the 3-methacryloxypropyltrimeth-oxysilane initiator layer grafted on the silicon surface and the PS-b-P4-VP chains were covalently anchored onto the Si/SiO2/3-MPS surface.  相似文献   

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