Preparation and characterization of stimuli-responsive composite microspheres

刺激响应型复合微球因其独特的优异性能在药物控释，酶固定等多领域具有广泛应用前景而逐渐受到人们的关注，本文主要对刺激响应型复合微球的制备方法做了适当的探究，并且对所得产品进行了表征和应用测试。 本文首先采用Fe3O4、N-异丙基丙烯酰胺(NIPAM)和丙烯酸(AA)制备了具有磁响应、温度响应和pH响应的多重响应复合微球。先用共沉淀法制备了Fe3O4磁性纳米颗粒，并用油酸对其改性。继而以改性后的Fe3O4为种子，制备Fe3O4@P(NIPAM-co-AA)磁性微球。研究结果表明在pH值为10的合成条件下，复合微球的分散性较好；采用疏水性引发剂可相对增加有机，无机相之间的亲和性。通过扫描电镜、红外...Recently, stimulate-response composite microspheres have been concerned widely because of its unique excellent performance in many fields such as controlled drug delivery and enzyme immobilization. In this thesis, the methods for preparation of stimulate-response composite microspheres were appropriate proposed. The as-prepared products were characterized and their applications were also carefull...学位：工程硕士院系专业：化学化工学院化学工程与生物工程系_化学工程学号：2062009115125

稀土改性的氧化镍基低温乙烷氧化脱氢催化剂活性氧物种的Raman光谱研究

利用共沉淀法制备了几种稀土金属氧化物改性的氧化镍催化剂 ,考察了其乙烷氧化脱氢 (ODE)制乙烯的催化性能 ,讨论了不同稀土金属氧化物掺杂浓度对催化剂催化性能的影响 ,利用Raman光谱技术初步表征反应在该类催化剂上的活性氧物种为Raman谱带出现在 1 0 60cm- 1 的表面双原子超氧物种O-2 ,该谱峰的大小与催化剂的ODE性能有很好的对应关系

Preparation and Characterization of P(NIPAM-co-AA)/Fe_3O_4 Composite Microspheres

通讯联系人: 刘庆林, 主要从事功能聚合物的研究, E-mail: qlliu@ xmu. edu. cn[中文文摘]采用Fe3O4、N-异丙基丙烯酰胺(NIPAM)和丙烯酸(AA)制备了具有磁敏、温敏和pH敏感的多重敏性复合微球。先使用共沉淀法制备Fe3O4磁性纳米颗粒,并用油酸对其改性。继而采用种子聚合法制备P(NIPAM-co-AA)磁性微球。研究表明,在pH值为10的合成条件下,复合微球的分散性较好。采用疏水性引发剂可相对增加有机、无机相之间的亲和性。通过扫描电镜(SEM)、红外光谱(FT-IR)、动态光散射(DLS)和超导量子干涉磁强计(SQUID)等对微球进行了结构与形态表征,结果证明,复合微球形貌统一,各组分之间聚合良好。复合微球的粒径约为249 nm,对温度、pH可作出预期的响应,饱和磁化强度为40 emu/g。[英文文摘]Mult-i sensit ive composite microspheres w ere fabricated using Fe3O4, N-isopropylacrylamide ( NIPAM) and acrylic acid ( AA) . The Fe3O4 nanoparticles w ere prepared by co-precipitation method and modified by oleic acid. Composite microspheres w ere then prepared by seed polymerization method. The results show that the microspheres have bet ter dispersion ability w hen react ion pH value is 10. The compat ibility betw een the organic phase and inorg anic phase could be enhanced using the hydrophobic initiator in this system. The product s w ere characterized by scanning elect ron microscope ( SEM) , Fourier Transform inf rared spectroscopy ( FT-IR) , dynamic light scat tering( DLS) and superconduct ing quantum interference device( SQUID) . It is found to be that the microspheres are uniformly dist ributed and the average diameter of composite microspheres is about 249 nm. The products have expected sensit ivity to the temperature and pH. T he saturated magnet ization of microspheres can reach 40 emu/ g .国家自然科学基金资助项目( 20976145, 21076170

Preparation of Cell-Embedded Colloidosomes in an Oil-in-Water Emulsion

National Nature Science Foundation of China [21376194, 21076170]; research fund for the Priority Areas of Development in Doctoral Program of Higher Education [20130121130006]Cell encapsulation by locking the interfacial microgels in a water-in-oil Pickering emulsion has currently been attracting intensive attention because of the biofriendly reaction condition. Various kinds of functional microgels can only stabilize an oil-in-water Pickering emulsion, and it is thus difficult to encapsulate cells in the emulsion where the cells are usually dispersed in the continuous phase. Herein, we introduce a facile method for preparing cell-embedded colloidosomes in an oil-in-water emulsion via polyelectrolyte complexation. Escherichia coli (E. coli) was chosen as a model cell and embedded in the thin shell of chitosan/poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AAc)) microcapsules. This is beneficial for expressing cell function because of the little resistance of mass exchange between the embedded cells and the external environment. Cells can be used in biocatalysis or biomedicine and our product will hold great promises to improve the performance in those fields. The synthesis route presents a platform to prepare cell-embedded microcapsules in an oil-in-water Pickering emulsion in a facile and biocompatible way. First, an emulsion stabilized by P(NIPAM-co-AAc) microgels was prepared. Then, the interfacial microgels in the emulsion were locked by chitosan to form colloidosomes. The mechanism of cell encapsulation in this system was studied via fluorescent labeling. The viability of E. coli after encapsulation is ca. 90%. Encapsulated E. coil is able to metabolize glucose from solution, and exhibits a slower rate than free E. coil. This demonstrates a diffusion constraint through the colloidosome shell

Facile preparation of homogeneous polyelectrolyte complex membranes for separation of methanol/methyl tert-butyl ether mixtures

National Nature Science Foundation of China [20976145, 21076170]; Nature Science Foundation of Fujian Province of China [2009J01040, 2010I0013]; research fund for the Doctoral Program of Higher Education [20090121110031]Facile preparation of homogeneous polyelectrolyte complex membranes (PECMs) based on sulfonated polyarylethersulfone with cardo (SPES-C) and polyethyleneimine (PEI) is reported in this work. The PECMs were characterized using Fourier transform infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and contact angle metering. The FTIR results confirmed the acid-base crosslinking between SPES-C and PEI. With increasing PEI content, both the hydrophilicity and the amorphous region of the PECMs increased. The effect of PEI content On the degree of swelling and separation performance of the PECMs was investigated. PECM-16 was found to have the optimum performance. A flux of 0.194 kg m(-2) h(-1) and a separation factor of 1860 at 40 degrees C were achieved in pervaporation of 15 wt methanol/methyl tert-butyl ether mixture. (c) 2013 Elsevier B.V. All rights reserve