超顺磁性高分子微球的制备与表征

用化学共沉淀方法制备了Fe3O4纳米微粒,并用油酸(十八烯酸)和十二烷基苯磺酸钠为双层表面活性剂进行表面修饰,制备了稳定的水分散性纳米Fe3O4可聚合磁流体.在Fe3O4磁流体存在下,将苯乙烯与甲基丙烯酸通过乳液聚合方法制备了磁性高分子微球.透射电镜研究表明,Fe3O4微粒的平均粒径在10nm左右,乳液聚合形成的磁性高分子微球的粒径平均约为130nm;用超导量子干涉仪对微粒及高分子微球进行了磁性表征,结果表明,合成的Fe3O4纳米微粒以及磁性高分子微球均具有超顺磁性.同时,还用红外光谱及X射线衍射表征了磁性高分子微球的化学成分和晶体结构.用热失重方法测得磁性高分子微球中磁性物质的含量为23.6%.     

钇掺杂锆酸钡中空微球的发光性能

采用水热法合成了不同钇掺杂量的BaZrO3中空微球,并通过TEM,XRD和SEM等手段对样品进行了表征.结果表明,样品均为中空微球,钇掺杂进入BaZrO3晶格,产物均具有立方钙钛矿型结构.中空微球的粒径随钇掺杂量的增加由180 nm增大到300 nm.钇掺杂量小于3%时,可得到纯相.不同掺杂量的中空微球在410 nm光...     

Competitive adsorption of fibrinogen and albumin onto polymer microspheres having hydrophilic/hydrophobic heterogeneous surface structures

The competitive adsorption of bovine fibrinogen (BFb) and bovine serum albumin onto polymer microspheres from the mixture solution was examined under various protein-to-microsphere ratios using various homopolymer microspheres and poly(2-hydroxyethyl methacrylate)/polystyrene composite microspheres having heterogeneous surface structures consisting of both hydrophilic and hydrophobic parts. They were produced by emulsifier-free (seeded) emulsion polymerizations. The selective adsorption of BFb was not observed for the homopolymer microspheres, but observed for the composite polymer microspheres having optimum compositions.Part CXXXVIII on the series Studies on Suspension and Emulsion     

PREPARATION AND ADSORBABILITY OF DEXTRAN MICROSPHERES WITH UNIFORM DIAMETER

The method of preparing uniform dextran microspheres with a narrow diameter distribution was introduced and the adsorbability of these microspheres was evaluated. The microspheres were prepared in W/O microemulsion using 0.5% dextran solution as the aqueous phase and n-hexane as the oil phase. Characteristics of the prepared dextran microspheres were examined with laser light blocking technique, optical microscope and ultraviolet spectrometer. The results show that the prepared dextran microspheres have uniform morphology and narrow diameter distribution, nearly 92% of them having a diameter of 56.6μm. In vitro evaluation of adsorbability, wet dextran microspheres have good adsorption of 98.32mg/g of model drug methylene blue in 20.86mg/L methylene blue solution at 25℃, The adsorption of dried dextran microspheres under the same condition is 132.15mg/g, which is even higher. And the adsorbability of dextran microspheres has significant relationship with the concentration of methylene blue and temperature. The adsorbability is better at lower temperature and higher concentration of methylene blue.     

Rational Fabrication of Size Tunable SnO2 Hollow Microspheres

A designed solution route was developed to fabricate size tunable SnO₂ hollow microspheres based on the sol-gel theory. The hydrolysis of SnSO₄ released protons to form SnO₂ particulates and induced the decrease of pH value. To minimize the high surface energy, the SnO₂ particulates tended to assemble into large particles, the size of which was affected by the electrolyte concentration or pH value. Elevating SnSO₄ content aroused the decrease of the pH value that directed to the shrinkage of the aggregated particle size of SnO₂. Size tunable SnO₂ hollow microspheres were then rationally fabricated under solvothermal conditions via Ostwald ripening by simply adjusting the SnSO₄ concentration. The in situ pH decrease directed to the shrinkage of the particle size from 270 nm to 112 nm. The formation mechanism was confirmed and rationally elucidated by the time dependant morphology evolution. Charge-discharge tests revealed that the reduced particle size aroused an improved lithium ion battery performance.     

温敏梳状嵌段共聚物对PS微球阻抗蛋白吸附作用的研究

采用可逆加成断裂链转移聚合(RAFT)方法和大分子单体技术,制备了温敏性聚N-异丙基丙烯酰胺(PNIPAM)-聚乙烯基吡咯烷酮(PVP)与PNIPAM-聚氧化乙烯(PEO)梳状嵌段共聚物,这些共聚物具有PVP或PEO支链.以溶菌酶为蛋白模型研究了所得共聚物对聚苯乙烯(PS)微球表面蛋白吸附的抑制作用.通过絮凝实验、激光散射法表观粒径测定、电泳迁移率测定及蛋白吸附量的定量数据比较了不同梳状结构的抗蛋白吸附效果.结果表明,预吸附梳状嵌段共聚物可有效阻抗蛋白吸附,亲水支链增加阻抗性能提高,即使环境温度高于PNIPAM的相转变温度也能阻抗蛋白吸附.透射电镜和共聚物胶体粒径测试表明,梳状嵌段共聚物阻抗蛋白吸附的机制是预吸附后PVP或PEO亲水支链在微球表面形成了阻隔层.通过PS微球的变温絮凝实验可评价预吸附聚合物的抗蛋白吸附性能,快速获得定性结果.     

NiO纳米片和多孔纳米片自组装的空心微球的无模板水热法制备与磁学性质

报道一种非常简单的制备NiO和Ni(OH)₂空心微球的无模板水热法, 即通过NiCl₂与氨水在140 ℃水热反应12 h, 制备了Ni(OH)₂纳米片自组装的空心微球, 经400 ℃热处理2 h得到了NiO空心微球. 采用X射线衍射仪、扫描电镜和透射电子显微镜对产物进行表征, 并在室温下测试了它的磁学性能, 结果表明, Ni(OH)₂空心微球的直径约为3～4 μm, 它是由尺寸1.1～1.3 μm左右的六方相结构的Ni(OH)₂纳米片组装而成; NiO空心微球是由立方相纳米片和多孔纳米片组装而成, 它具有弱的铁磁性, 其矫顽力为583 Oe, 剩余磁化强度为0.213 emu/g. 研究了氨在Ni(OH)₂纳米片的形成与组装过程中的作用, 提出了可能的生长机理.     

碳纳米管/活性炭复合微球的制备及其对VB12的吸附应用

采用反相乳液法制备碳纳米管/壳聚糖复合微球(CNTs/CTS), 并对其进一步炭化、活化制得碳纳米管/活性炭复合微球(CNTs/AC). 以此复合微球为吸附材料, 探索了其对中分子代表物质VB12的吸附. 研究结果表明, 碳纳米管含量70%(w)的复合微球经水蒸气适当活化后球形度好、吸附性能优异, 其对VB12的吸附量达23.59 mg·g-1, 分别是活性炭和大孔吸附树脂的5.4和2.7倍. 分析表明这是由于碳纳米管/活性炭复合微球具有发达的中孔结构.     

以PHBV-PLGA为载体的硫酸庆大霉素缓释微球

以生物可降解聚羟基丁酸酯和羟基戊酸酯的共聚物(PHBV)、乙交酯和丙交酯的无规共聚物(PLGA)两种高分子作为壁材,采用复乳溶剂挥发法,制备了包裹硫酸庆大霉素(GS)的载药微球。在扫描电镜下观察到所得微球表面呈多孔状,为球形或椭圆形,粒径在20~80μm。分析结果表明,包封率在60%以上,在体外16~20 d内药物全部释放,90 d微球体外降解50%左右。