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以亚甲基蓝为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂.采用沉淀聚合法制备了亚甲基蓝分子印迹聚合物微球(MIP)。用扫描电镜表征了MIP的形貌,结果显示制备的MIP的粒径为1~3μm,粒径较为均匀。考察了MIP对亚甲基蓝的吸附性能,结果表明其吸附动力学过程可以用假二级吸附速率方程来描述,MIP对亚甲基蓝的最大吸附量为27.1mg/g,吸附效果较好,可以用于染料废水中亚甲基蓝的分离富集。 相似文献
34.
Daniel Antuña-Jiménez M. Carmen Blanco-LópezArturo J. Miranda-Ordieres María Jesús Lobo-Castañón 《Polymer》2014
Stable and easily-handled synthetic materials mimicking natural enzymes activity would find important biotechnological applications. This article describes the synthesis and characterization of magnetic molecularly imprinted catalytic polymers that exhibit peroxidase-like activity towards 5-hydroxyindole-3-acetic acid (5-HIAA) oxidation. This multifunctional material is obtained from highly crystalline magnetite nuclei coated with a silica layer to protect the iron nucleus from oxidation and to provide anchoring for hydroxyl surface groups. After acrylic functionalization via sol–gel process, a molecularly imprinted polymer with hemin as catalytic center and 5-HIAA as template has been successfully attached to the structure. The resulting hybrid composite is magnetically separable and possesses excellent catalytic ability for the selective oxidation of the indoleamine metabolite tumor marker, showing Michaelis–Menten kinetics with this molecule but not towards other structural analogs. Therefore, it can be considered an artificial peroxidase enzyme. 相似文献
35.
The last decade has seen a growing interest in hybrid electrically conducting nanocomposites. This article aims to provide a detailed overview of the present status of research in carbon nanotube–polyaniline (CNT/PANI) composites, from processing to structural and property evaluations. CNT/PANI are synthesized by electrochemical and chemical processing. When chemical methods are used, the main challenge is to obtain processable CNT/PANI in the emeraldine salt (ES) form composites. Stable dispersions of ES–CNT in organic media are prepared using the post doping method, inverse emulsion polymerization, or ex situ polymerizations. On the contrary, stable water dispersions of CNT/ES are prepared using hydrophilization of a preformed CNT/ES composite, direct synthesis of micelle–CNT hybrid templates, interfacial polymerization, covalent functionalization of CNT with a water soluble polymer, or using electrostatic interactions between two oppositely charged ES and CNT aqueous colloids. Moreover, the strategies for the synthesis of ternary CNT/PANI composites incorporating noble metal nanoparticles, metal oxide, or graphene sheets are also presented and analyzed in depth. Finally, we give a review of potential applications, including chemical sensors, capacitors, fuel cells and electronic devices. 相似文献
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A novel hierarchically imprinted cross-linked poly(acrylamide-co-ethylene glycol dimethacrylate) using a double-imprinting approach for the Cu2+ selective separation from aqueous medium was prepared. In the imprinting process, both Cu2+ ions and surfactant micelles (cetyltrimethylammonium bromide – CTAB) were employed as templates. The hierarchically imprinted organic polymer named (IIP-CTAB), single-imprinted (IIP-no CTAB) and non-imprinted (NIP-CTAB and NIP-no CTAB) polymers were characterized by SEM, FTIR, TG, elemental analysis and textural data from BET (Brunauer–Emmett–Teller) and BJH (Barrett–Joyner–Halenda). Compared to these materials, IIP-CTAB showed higher selectivity, specific surface area and adsorption capacity toward Cu2+ ions. Good selectivity for Cu2+ was obtained for the Cu2+/Cd2+, Cu2+/Zn2+ and Cu2+/Co2+ systems when IIP-CTAB was compared to the single-imprinted (IIP-no CTAB) and non double-imprinted polymer (NIP-CTAB), thereby confirming the improvement in the polymer selectivity due to double-imprinting effect. For adsorption kinetic data, the best fit was provided with the pseudo-second-order model for the four materials, thereby indicating the chemical nature of the Cu2+ adsorption process. Cu2+ adsorption under equilibrium was found to follow dual-site Langmuir–Freundlich model isotherm, thus suggesting the existence of adsorption sites with low and high binding energy on the adsorbent surface. From column experiments 600 adsorption–desorption cycles using 1.8 mol L−1 HNO3 as eluent confirmed the great recoverability of adsorbent. The synthesis approach here investigated has been found to be very attractive for the designing of organic ion imprinted polymer and can be expanded to the other polymers to improve performance of ion imprinted polymers in the field of solid phase extraction. 相似文献
38.
Nor Azah Yusof Nor Dyana Zakaria Nor Amirah Mohd Maamor Abdul Halim Abdullah Md. Jelas Haron 《International journal of molecular sciences》2013,14(2):3993-4004
Molecularly imprinted polymers (MIPs) were prepared by bulk polymerization in acetonitrile using 2,4-dinitrophenol, acrylamide, ethylene glycol dimethacrylate, and benzoyl peroxide, as the template, functional monomer, cross-linker, and initiator, respectively. The MIP membrane was prepared by hybridization of MIP particles with cellulose acetate (CA) and polystyrene (PS) after being ground and sieved. The prepared MIP membrane was characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters studied for the removal of 2,4-dinitrophenol included the effect of pH, sorption kinetics, and the selectivity of the MIP membrane. Maximum sorption of 2,4-nitrophenol by the fabricated CA membrane with MIP (CA-MIP) and the PS membrane with MIP (PS-MIP) was observed at pH 7.0 and pH 5.0, respectively. The sorption of 2,4-dinitrophenol by CA-MIP and PS-MIP followed a pseudo–second-order kinetic model. For a selectivity study, 2,4-dichlorophenol, 3-chlorophenol, and phenol were selected as potential interferences. The sorption capability of CA-MIP and PS-MIP towards 2,4-dinitrophenol was observed to be higher than that of 2,4-dichlorophenol, 3-chlorophenol, or phenol. 相似文献
39.
Stereoselective release behaviors of imprinted bead matrices 总被引:2,自引:0,他引:2
Suedee R Srichana T Chotivatesin R Martin GP 《Drug development and industrial pharmacy》2002,28(5):545-554
In this work, the stereoselective release behaviors of “low”-swelling molecularly imprinted polymer (MIP) bead matrices in pressed-coat tablet type were studied. Either R-propranolol selective MIP or S-propranolol selective MIP was combined with excipients and racemic propranolol and fabricated into the matrix. Subsequently, the release of different propranolol enantiomers from the matrices was examined. Also, the microscopic structure of the hydrated “low”-swelling MIP matrix was determined using a cryogenic scanning electron microscope in order to compare with that of the hydrated “high”-swelling MIP matrix. In vitro release profiles of the “low”-swelling matrices showed a difference in the release of enantiomers, in that the non-template isomer was released faster than the template isomer. However, in the last phase of dissolution this difference reduced and later reversed, resulting at last in the type of specificity being similar to that obtained previously with “high”-swelling MIP matrices.
n summary, MIP beads can be fashioned into matrices and incorporated into different formulations to regulate the resultant stereoselectivity. From the behaviors of stereoselective release observed in MIP matrices, we can conclude that the enantioselective-controlled delivery mechanism of MIPs via formulations depends on the relative affinity of the enantiomer for the template sites, as well as the nature of the polymer, such as hydrophobicity and swellability. 相似文献
n summary, MIP beads can be fashioned into matrices and incorporated into different formulations to regulate the resultant stereoselectivity. From the behaviors of stereoselective release observed in MIP matrices, we can conclude that the enantioselective-controlled delivery mechanism of MIPs via formulations depends on the relative affinity of the enantiomer for the template sites, as well as the nature of the polymer, such as hydrophobicity and swellability. 相似文献
40.
Djavanshir Djozan Tahmineh Baheri Mohamad Hossain Pournaghi Azar Mehrdad Mahkam 《Materials and Manufacturing Processes》2007,22(6):758-763
A monolithic copolymer of methacrylic acid-ethylene glycol dimathacrylate as a fiber with 2 cm length and 0.3 mm diameter, containing codeine (CO) template was prepared through thermal radical co-polymerization procedure. This fiber is a robust recognition material capable of mimicking natural systems, combined with solid-phase micro-extraction (SPME) and gas chromatography/mass spectrometry for the extraction of trace CO from various street-drug samples. Effective experimental parameters such as Methacrylic Acid (MAA), Ethylene glycol dimethacrylate (EDMA), and CO proportions, nature, and dimension of mold, copolymerization time and temperature were optimized. Experimental studies such as scanning electron microscopy (SEM) reveal that highly homogenate fiber was achieved that can preciously be used for the above mentioned goals. 相似文献