磁性荧光聚合物载药微球的制备

采用反相微乳液法合成氨基功能化的CdTe-Fe_3O_4/SiO_2磁性荧光复合纳米粒子,通过去甲斑蝥酸钠(SNCID)的羧基与氨基化的CdTe-Fe_3O_4/SiO_2磁性荧光复合纳米粒子孔道表面的羟基形成氢键,制成磁性荧光聚合物载药微球。采用荧光分光光度计(FS)、扫描电镜(SEM)、紫外-可见分光光度计(UV-Vis)、傅里叶红外光谱仪(FT-IR)等方法对该聚合物载药微球的理化性质进行表征分析。结果显示磁性荧光聚合物载药微球为球状,具有良好的分散性和光致发光能力等优点,其载药量和包封率分别为21.49%和69.84%。磁性荧光复合纳米粒子可作为具有荧光性质的药物载体。     

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%.     

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。     

P(St-co-MAA)-Fe_3O_4@SiO_2 pH磁性微球的制备与性能研究

首先制备Fe_3O_4磁性纳米粒子,然后接上SiO_2层,最后通过共聚的方法制备磁性聚合物微球,并探索其对蛋白质的吸附关系。实验结果表明制备的Fe_3O_4与Fe_3O_4复合微球磁性均很强,而且复合微球对蛋白质的吸附能力很强。     

悬浮聚合法制备可降解磁性聚丙交酯微球

为了制备以纳米Fe3O4复合聚丙交酯得到聚合物微球,采用丙交酯和纳米级Fe3O4粉为基体,通过悬浮聚合制备可降解磁性聚丙交酯微球,并对其性能进行分析.实验表明通过悬浮聚合方法,合成了聚合物微球.该微球通过红外光谱、电镜、熔点测定等方法表征,确定该产物为目标产物,其粒径为30～50μm,熔点为67C,分子量为12825....     

纳米磁性高分子复合微球的制备及在分离工程中的应用

在总结国内外有关磁性高分子微球研究成果基础上，介绍纳米磁性高分子复合微球的制备方法，重点阐述核-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分离工程中的应用情况，并对磁性高分子微球的未来研究方向进行展望。     

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。     

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。     

纳米聚合物微球的封堵性及驱油性能

聚合物纳米微球因其对水、温度和矿化度具有良好抵抗力以及较低的使用成本而受到更多关注,作为一项新型调驱技术,可大幅提高油田采油效率。为了更好地认识聚合物纳米微球的驱油效果,开展了聚合物纳米微球的封堵及驱油研究。进行了微通道驱替实验,透过滤膜实验,通过激光粒度仪分析了溶胀后微球的尺寸变化,通过透射电镜观察了微球乳液,并研究了空气中微球乳液与干粉的表面张力。结果显示,在50和100 nm微球的微通道实验中都观察到了微米级别的团聚物,扩大了水分散体系的波及体积,2种纳米聚合物微球都会出现一定程度的团聚行为,具有溶胀性能,还发现了微球和乳化剂、油滴之间的缠结现象。微球乳液中含有的表面活性剂使其表面张力降低,从而提高了驱油效率。对纳米微球的封堵性能和驱油性能进行了研究,对揭示纳米微球的驱油机理和产品的可持续发展与创新具有显著意义。     

亲水性高分子磁性微球的合成和应用研究

对近年来国内外有关亲水性高分子磁性微球的研究成果和发展现状进行了综述,具体讨论了包埋法、单体聚合法及原位法等常用的合成制备方法及其优缺点,指出反相(微)乳液聚合是制备亲水性聚合物微球的有效方法。分析了亲水性高分子磁性微球在酶固定化和实现靶向给药等方面的应用及存在的问题,对磁性微球的发展前景进行了展望。     

Preparation and evaluation of magnetic imprinted polymers for 2,4,6‐trinitrotoluene by surface imprinting

A safe and facile approach for the preparation of magnetic molecularly imprinted polymer nanospheres for 2,4,6‐trinitrotoluene (TNT) recognition is reported. The imprinted nanospheres were synthesized using TNT as the imprinting molecule, acrylamide as the functional monomer, N,N'‐methylenebisacrylamide as the crosslinker and magnetic particles as the support. The structure of the materials was identified via Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy and transmission electron microscopy. Static adsorbing experiments were carried out and Scatchard plot analysis showed that two kinds of receptor sites were formed in the imprinted materials. The adsorption equilibrium constant and the maximum adsorption capacity were evaluated. These results indicated that the imprinted nanospheres have higher adsorption capacity and selectivity for TNT than non‐imprinted polymer nanospheres with the same composition. © 2013 Society of Chemical Industry     

Preparation of gold nanoparticles on poly(methyl methacrylate) nanospheres with surface-grafted poly(allylamine)

A facile method for in situ anchoring of gold nanoparticles onto the surface of polymer nanospheres was successfully developed in this study. As polymer nanospheres, amphiphilic poly(methyl methacrylate) (PMMA)/poly(allylamine) (PAA) nanospheres were prepared by graft copolymerization of methyl methacrylate from PAA. The gold nanoparticles anchored were spherically symmetric and the average sizes were ∼12 nm for all samples. It was found that surface-grafted PAA effectively anchored and stabilized gold nanoparticles for a long period of time.     

Superparamagnetic latex synthesized by a new route of emulsifier‐free emulsion polymerization

The aim of this study was to design polymeric nanospheres containing magnetic nanoparticle which could display superparamagnetic behavior and thus find application in allied fields. First magnetite nanoparticles were synthesized with coprecipitation method and then their stable acidic dispersion was prepared without surfactant and dropped into the polymerization system during a certain time interval after the polymerization started. The effects of time at which the magnetic sol was added into polymerization system on latex size and stability, average molecular weight of polymer were examined in the case of two different monomer concentrations. Extensive characterization by transmission electron microscopy, dynamic light scattering, thermal gravimetric analysis and magnetic measurements shows that when the magnetic sol was dropped during earlier time of polymerization at stage 1, the latex size, average molecular weight of polymer, thermal stability of polymeric composite, and saturation magnetization reduced, whereas polydispersity of size and molecular weight increased because of the reaction between persulfate and naked surface of magnetite at the aqueous phase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Alternating Magnetic Field Controlled, Multifunctional Nano-Reservoirs: Intracellular Uptake and Improved Biocompatibility

Biocompatible magnetic nanoparticles hold great therapeutic potential, but conventional particles can be toxic. Here, we report the synthesis and alternating magnetic field dependent actuation of a remotely controllable, multifunctional nano-scale system and its marked biocompatibility with mammalian cells. Monodisperse, magnetic nanospheres based on thermo-sensitive polymer network poly(ethylene glycol) ethyl ether methacrylate-co-poly(ethylene glycol) methyl ether methacrylate were synthesized using free radical polymerization. Synthesized nanospheres have oscillating magnetic field induced thermo-reversible behavior; exhibiting desirable characteristics comparable to the widely used poly-N-isopropylacrylamide-based systems in shrinkage plus a broader volumetric transition range. Remote heating and model drug release were characterized for different field strengths. Nanospheres containing nanoparticles up to an iron concentration of 6 mM were readily taken up by neuron-like PC12 pheochromocytoma cells and had reduced toxicity compared to other surface modified magnetic nanocarriers. Furthermore, nanosphere exposure did not inhibit the extension of cellular processes (neurite outgrowth) even at high iron concentrations (6 mM), indicating minimal negative effects in cellular systems. Excellent intracellular uptake and enhanced biocompatibility coupled with the lack of deleterious effects on neurite outgrowth and prior Food and Drug Administration (FDA) approval of PEG-based carriers suggest increased therapeutic potential of this system for manipulating axon regeneration following nervous system injury.     

Preparation of silica nanospheres and porous polymer membranes with controlled morphologies via nanophase separation

ABSTRACT: We successfully synthesized two different structures, silica nanospheres and porous polymer membranes, via nanophase separation between silica sol and polymer. Silica sol, which was in-situ polymerized from tetraorthosilicate, was used as a precursor. Subsequently, it was mixed with a polymer that was used as a matrix component. It was observed that nanophase separation occurred after the mixing of polymer with silica sol and subsequent evaporation of solvents, resulting in organizing various structures, from random network silica structures to silica spheres. In particular, silica nanospheres were produced by manipulating the mixing ratio of polymer to silica sol. The size of silica beads was gradually changed from micro- to nanoscale, depending on the polymer content. At the same time, porous polymer membranes were generated by removing the silica component with hydrofluoric acid. Furthermore, porous carbon membranes were produced by using carbon source polymer through the carbonization process.     

Comparison of the enthalpic relaxation of poly(lactide–co‐glycolide) 50:50 nanospheres and raw polymer

The phenomenon of enthalpic relaxation was evaluated for poly(lactide‐co‐glycolide) (PLGA, 50:50), in terms of storage of nanospheres for use as a controlled drug delivery system. Samples were stored for different times and temperatures below the glass transition temperature (T_g). Relaxation occurred at a significant rate up to 15 degrees below the T_g of 39.2°C. The effect of polymer morphology was considered by comparing the relaxation kinetics of the raw polymer with that of nanospheres formed using a novel technique. The nanospheres were shown to have a larger change in heat capacity at the glass transition and a longer average relaxation time than that of the raw polymer, and the relationship between these two parameters was discussed. For both the raw polymer and the nanospheres, relaxation was found to occur at a significant rate at room temperature. The storage of this system at subambient temperatures was therefore deemed important for maintaining the physicochemical properties of the system. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1868–1872, 2002     

Synthesis of Cibacron Blue F3GA‐coupled magnetic PMMA nanospheres and their use for protein affinity separation

BACKGROUND: New magnetic carrier separation technologies, capable of treating dilute solutions in large‐scale processes, even in the presence of biological debris, are necessary for the future development of biotechnology. Non‐porous magnetic carriers are more resistant to fouling, show better mass transfer and have lower non‐specific adsorption than porous carriers. Nanosized magnetic carriers have a surface area comparable to that of typical macroporous resins, and therefore their application has advantages. RESULTS: Magnetic poly(methyl methacrylate) (PMMA) nanospheres with an average diameter of 76 nm and narrow size distribution were prepared by a facile mini‐emulsion polymerization. After surface modification with poly(ethylene glycol), Cibacron Blue F3GA (CB) was coupled to the magnetic PMMA nanospheres to form dye ligand‐attached magnetic adsorbents for bovine serum albumin (BSA) adsorption. The CB‐coupled magnetic PMMA nanospheres showed very high adsorption capacity (121.98 mg g^?1) and little non‐specific adsorption for BSA. The adsorbed protein could be easily desorbed using high ionic strength solution. CONCLUSION: The CB‐coupled magnetic PMMA nanospheres showed a high BSA adsorption capacity, low non‐specific adsorption and fast adsorption kinetics in comparison with other dye‐affinity adsorbents. These characteristics indicate that these magnetic PMMA nanospheres have great potential for protein affinity separation and purification. Copyright © 2009 Society of Chemical Industry     

The preparation of multi-walled carbon nanotubes encapsulated by poly(3-acrylaminopropylsiloxane) with silica nanospheres on the polymer surface

A silica-polymer-carbon nanotube hybrid was prepared in which the nanotubes were encapsulated by poly(3-acrylaminopropylsiloxane) with silica nanospheres on the polymer surface. First, highly reactive poly(acryloyl chloride) (PAC) was grafted onto the nanotubes through the reaction of side acyl chloride groups with hydroxyl groups present on the surface of acid-oxidized nanotubes. Second, reacting 3-aminopropyltriethoxysilane with the grafted PAC through the reaction between amino and acyl chloride groups, siloxane-containing sub-grafts were introduced onto the primary PAC grafts. Third, silica nanospheres were covalently linked to the sub-grafts by condensation to form a nanotube-polymer-silica hybrid. Each intermediate structure was confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy (TEM). TEM observation revealed a nanostructure in which the nanotube was encapsulated with a polymer layer bearing silica nanospheres on its surface.