纳米磁性高分子复合微球的制备及在水检测中的应用

不同的纳米磁性高分子复合微球,因其结构不同,制备方法也各不相同。在总结国内外有关磁性高分子微球研究成果的基础上,介绍了纳米磁性高分子复合微球的制备方法,重点阐述了核-壳式结构和三明治式结构纳米磁性高分子复合微球制备的最新研究进展,概述了磁性高分子复合微球在检测水中微生物和有机物的应用。     

磁性高分子复合微球的研究进展

磁性高分子复合微球是粒径在纳米级至微米级,通过适当方法使有机高分子与无机磁性物质复合起来形成的具有一定磁性及特殊结构的微球。磁性高分子复合微球兼具高分子材料的功能特性和无机纳米粒子的磁响应性,可以在外加磁场作用下快速方便的分离。因此,磁性高分子微球作为一种新型的复合功能材料,在生物化学、靶向药物、化学工业、分离工程、水处理等诸多领域显示出了广泛的应用前景。本论文主要综述了磁性高分子复合微球的制备方法和应用领域,并对前景和存在的问题进行了分析和展望。     

高分子微纳米球为模板制备磁性空心微纳米球的方法

本发明公开了一种微纳米材料技术领域的高分子微纳米球为模板制备磁性空心微纳米球的方法,即以表面带有负电荷的高分子微纳米球为模板,通过在微纳米球表面原位反应生成以磁性纳米粒子为壳,模板粒子为核的磁性复合微球,之后也可以在此微球表面包裹一层SiO2。进一步通过烧灼去除模板来获得空心磁性微纳米球。本发明易行、高效、容易规模化,制备的磁性空心微纳米球粒径可控性很好、且磁性壳层的厚度或磁响应强弱也可以根据要求进行调节。     

磁性高分子复合微球去除重金属的研究进展

磁性高分子复合微球是近年来受到广泛关注的新型功能材料。本文介绍了磁性高分子复合微球的制备、特性、结构和组成。综述了磁性高分子复合微球及改性后的磁性高分子复合微球对水处理中重金属的去除研究,并对磁性高分子复合微球对重金属处理的研究进展做了总结与展望。     

微囊化载药高分子微球制备方法研究进展

本文综述了各种微囊化制备微球的方法和原理，并对微囊化微球技术的研究最新进展及其在纳米微球，磁性高分子微球、智能微球制备上的应用作了介绍。     

Fe_3O_4/SiO_2核壳结构复合纳米粒子的制备研究

首先通过共沉淀法、还原沉淀法和水热法制备Fe_3O_4纳米粒子,对其进行表面改性,防止粒子之间的团聚,然后采用溶胶-凝胶法,以Fe_3O_4纳米粒子为种子,在醇和水的混合体系中,碱性条件下催化正硅酸乙酯水解,生成物包覆在磁性纳米颗粒表面,制备小粒径核壳结构的二氧化硅磁性复合微球。利用X射线衍射仪对所制备的二氧化硅磁性复合微球的粒径和物相组成进行表征。实验结果表明二氧化硅磁性复合微球在室温下表现出良好的稳定性。     

新型悬浮聚合法制备多孔磁性高分子微球的研究

采用新型悬浮聚合法制备了平均粒径为4.06 μm的多孔磁性高分子微球.以硅烷偶联剂KH-570对羰基铁粉颗粒进行表面修饰,并经一步聚合得到多孔磁性高分子微球.SEM结果表明该微球表面由纳米级聚合物粒子层层粘合而成,粒子间孔径在几十到几百纳米之间不等.采用红外光谱及X射线衍射表征了多孔磁性高分子微球的化学成分和晶体结构.用热失重方法测得多孔磁性高分子微球中磁性物质的含量可达26.7%.     

羟基磁性微球的制备及表征

本研究以共沉淀法制备的Fe3O4为核,采用溶胶-凝胶法,使用正硅酸乙酯(TEOS),在Fe3O4表面包覆一层Si O2,进而用硅烷偶联剂3-(异丁烯酰氧)丙基三甲氧基硅烷对Fe3O4@Si O2复合微球进行表面改性,制得表面含有双键核壳结构的Fe3O4@Si O2复合磁性微球。采用乳液聚合法,将复合磁性微球与功能单体甲基丙烯酸羟乙酯(HEMA)共聚,得到表面带有羟基的高分子磁性微球。对所制备的复合磁性微球用傅里叶红外光谱(FT-IR)、扫描电镜(SEM)以及X射线衍射(XRD)进行表征,结果表明,成功制备出了单分散性良好的功能性高分子羟基磁性微球。     

表面功能化磁性聚苯乙烯纳米微球的尺寸可控制备

考察了核壳式表面功能化磁性聚苯乙烯纳米微球的可控制备工艺。采用紫外可见吸收光谱、透射电子显微镜、原子力显微镜及在不同溶剂中的分散性实验,对表面羧基化的磁性聚苯乙烯纳米微球的结构与形态进行了表征。结果表明,改变外加晶核Fe2O3纳米颗粒数目,可有效实现磁性聚苯乙烯纳米微球的尺寸可控。     

细乳液聚合制备磁性复合微球研究进展

介绍了细乳液聚合的特点、细乳液聚合制备磁性复合微球的一般步骤;从制备影响因素角度,对近年来国内外细乳液聚合制备磁性复合微球的研究进行了综述。磁性复合微球主要采用正相细乳液聚合,影响微球制备的主要因素有乳化剂类型和用量、磁性纳米粒子表面修饰、超声分散、助稳定剂类型、交联剂引发剂和磁流体用量等。今后,细乳液聚合制备磁性复合微球的研究仍将关注提高复合微球性能(高磁响应性能、粒子大小可控且均匀、具有表面功能基团)及产率(磁性粒子包覆率)等方面。     

水基聚合物/无机纳米复合材料的研究与应用

介绍了无机纳米材料的结构特性,对用于制备聚合物/无机纳米复合材料的直接分散法,插层复合法、溶胶-凝胶（sol-gel）法等3种方法及聚合物/无机纳米复合材料的性能进行了综述,并介绍了聚合物基纳米复合材料的现状和发展趋势。     

Graphene nanoribbon: fundamental aspects in polymeric nanocomposite

This paper presents an overview of unique carbon nanostructure graphene nanoribbon (GNR). GNR is a thin elongated strip of sp²-bonded carbon atoms with a narrow width of ≤10 nm. The electronic, mechanical, thermal, chemical, and magnetic properties of GNR make it an attractive nanofiller in polymeric nanocomposite. Polyaniline, poly(methyl methacrylate), poly(vinylidene fluoride), poly(vinyl alcohol), polystyrene, polyethylene, epoxy, and polyamide have been explored with GNR so far. Despite of outstanding potential of polymer/GNR nanocomposite, not much research is found in this area. Few application areas of polymer/GNR nanocomposite discovered till now are related to sensor, supercapacitor, fuel cell, and electromagnetic interference shielding materials.     

New Role of Layered Silicates as Phase Transfer Catalyst for In Situ Polymerization of Poly(ethylenetetrasulfide) Nanocomposite

In this study, polyethylenetetrasulfide/montmorillonite nanocomposite (PETS/nanoclay) is synthesized from ethylene dichloride and sodium tetrasulfide monomers by in situ polymerization method. The effect of phase-transfer catalyst (PTC) on polymerization kinetics in addition to the structure of resulting PETS containing nanoclay is investigated. The results show that surface-modified montmorillonites by methyl tallow bis-2-hydroxyethyl quaternary ammonium chloride could properly act as PTC. Therefore, it is demonstrated that the addition of nanoclay as PTC reduces the reaction time and increases the polymerization rate during the production of final nanocomposite. The samples were characterized using Fourier transform infrared and Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), nuclear magnetic resonance spectroscopy besides energy-dispersive X-ray spectroscopy (EDS) combined with SEM (SEM–EDX). In addition, thermal behavior of nanocomposite was perused by differential scanning calorimetry and thermogravimetric analysis. XRD and AFM results show proper dispersion of clay in PETS matrix and SEM–EDX results demonstrate suitable distribution of clay in polymer matrix. PETS/nanoclay nanocomposite show a better thermal stability, and also higher glass transition and melt temperature compared to pure polysulfide polymer. The solubility of nanocomposite is also studied and results show that the solubility depends on solvent concentration in addition to reinforcement (nanoclay) deals.     

Efficient Dispersion of Magnetite Nanoparticles in the Polyurethane Matrix Through Solution Mixing and Investigation of the Nanocomposite Properties

Recent studies on inorganic/polymer nanocomposites have shown enhancements in thermal, mechanical, and chemical properties over the neat polymer without compromising density, toughness, and processibility. When nanoparticles are incorporated into the polymer matrix, significant enhancements in thermal and mechanical properties of the nanocomposite are observed. The present study is focused on the preparation and characterization of nanosize magnetite-reinforced PU composites, which induces magnetic properties to a specific thermoplastic polyurethane elastomer. The nanocomposites are prepared and the effects of magnetite content on thermal, mechanical, and magnetic properties of the nanocomposites are evaluated. Ultrasonication was used to disperse the nanoparticles and break up any large clumps and aggregates and followed by mechanical mixing. The magnetic nanocomposites were characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). Characterization of the magnetic nanocomposite by FT-IR showed a successful incorporation of magnetite nanoparticles into the polymeric matrix. TGA and magnetometry of the magnetic nanocomposites revealed the amount of magnetite that was incorporated into the polymeric phase. Finally, the corresponding magnetization behavior of the nanocomposites was studied.     

Cr(III)‐containing Fe3O4/mercaptopropanoic acid‐poly(2‐hydroxyethyl acrylate) nanocomposite: Highly active magnetic catalyst for direct hydroxylation of benzene

In this study, polymer‐grafted magnetic nanoparticles containing chromium(III) ions incorporated onto Fe₃O₄/mercaptopropanoic acid‐poly(2‐hydroxyethyl acrylate) was prepared via a simple and in situ method. The obtained magnetic nanocomposite exhibited high catalytic activity and excellent selectivity in direct hydroxylation of benzene in the presence of hydrogen peroxide under solvent‐free condition. The magnetic catalyst could be also separated by an external magnet and reused seven times without any significant loss of activity/selectivity. Due to the Lewis acidity of the Fe³⁺ groups in the structure of magnetic nanoparticles, the high efficiency of this catalyst is possibly due to the synergetic effect of Cr³⁺ and Fe³⁺ groups in the structure of magnetic nanocomposite. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40383.     

聚丙烯/蒙脱土纳米复合材料的研究进展

对聚丙烯(PP)／蒙脱土(MMT)纳米复合材料的国内外研究进展进行综述,介绍了PP/MMT纳米复合材料的制备原理和制备方法。包括原位插层聚合法、聚合物溶液插层法、聚合物熔融插层法、溶胶一凝胶法,重点介绍了聚合物熔融插层法的研究进展。聚合物熔融插层法具有操作简单、无需处理过多溶剂的优点,避免了环境和能源问题,更易于工业化。最后对PP／MMT纳米复合材料的未来发展进行了展望。     

New Magnetic Polymer Nanocomposites on the Basis of Isotactic Polypropylene and Magnetite Nanoparticles for Adsorption of Ultrahigh Frequency Electromagnetic Waves

In this study, we report about the preparation of magnetic polymer nanocomposites on the basis of isotactic polypropylene and magnetite Fe₃O₄ nanoparticles. The structure and composition of polymer nanocomposite materials have been studied by scanning electron microscopy, atomic force microscopy, and X-ray dispersive analysis. The magnetic properties of polymer nanocomposites based on PP+Fe₃O₄have been investigated. It is found that not significant adhesion and agglomeration of nanoparticles occur, by increasing the nanoparticle content in polymer matrix up to 40%, and therefore they act as single-domain nanoparticles. The samples of nanocomposites based on PP+Fe₃O₄, with up to 40% content of Fe₃O₄, exhibit superparamagnetic properties. It was also found out that the magnetic polymer nanocomposite material based on PP+Fe₃O₄ is able to absorb ultrahigh frequency electromagnetic waves in the frequencies range from 0.1 to 30?GHz. The increase in Fe₃O₄ concentration from 5 to 40% at the 400?µm thicknesses of the films leads to an increase in absorption of electromagnetic waves of high frequency from 15 to 22.7%.     

尼龙6/粘土纳米复合材料的研究

综述尼龙6／粘土纳米复合材料的研究进展、各种制备方法、复合机理及其微观性能的表征。粘土足一种层状硅酸盐，以纳米尺寸分布在聚合物中能提高聚合物的各种性能，尼龙6和粘土无论是通过原位聚合法还是熔融法都能制得剥离态的尼龙6倦土纳米复合材料。     

Facile fabrication of nanocomposite microspheres with polymer cores and magnetic shells by Pickering suspension polymerization

Pickering suspension polymerization was used to prepare magnetic polymer microspheres that have polymer cores enveloped by shells of magnetic nanoparticles. Styrene was emulsified in an aqueous dispersion of Fe₃O₄ nanoparticles using a high shear. The resultant Pickering oil-in-water (o/w) emulsion stabilized solely by magnetic nanoparticles was easily polymerized at 70 °C without stirring. Fe₃O₄ nanoparticles act as effective stabilizers during polymerization and as building blocks for creating the organic–inorganic hybrid nanocomposite after polymerization. The fabricated magnetic nanocomposites were characterized by FTIR, XRD, TGA, DSC, GPC, XPS and SEM. The structures of the polymer core and the nanoparticle shell were analyzed. We investigated the effects on the products of the weight of Fe₃O₄ nanoparticles used to stabilize the original Pickering emulsions. Pickering suspension polymerization provides a new route for the synthesis of a variety of hybrid nanocomposite microspheres with supracolloidal structures.