静电凝聚法制备苯乙烯-丙烯酸共聚物/氧化铈核壳纳米复合材料

Fabrication of Poly(styrene-co-acrylic acid)/Cerium Oxide Core-Shell Nano-composite by Electrostatic Conjugation Method

致力于苯乙烯-丙烯酸共聚物（P（St-co-AA））微球/氧化铈核壳纳米结构的制备,以无皂乳液聚合制备的P（St-co-AA）微球为负电组成,水热法合成的氧化铈纳米粉体为正电组成,设计了静电凝聚法复合工艺,对复合工艺条件进行了初步的探索。结果表明：采用无皂乳液聚合制备的P（St-co-AA）微球呈正球形,颗粒尺寸均一,尺寸在160~390nm范围内可控;以CTAB为表面活性剂,采用水热法在100℃条件下成功制得了颗粒尺寸在10~20nm的氧化铈纳米粉体。在水溶液体系中,在静电凝聚作用下,所制备氧化铈在P（St-co-AA）微球表面紧密堆积,形成了P（St-co-AA）/氧化铈核壳结构。可通过调节P（St-co-AA）微球的尺寸与负电性以及复合过程中pH值来调控所得核壳结构形貌。正负颗粒电性的匹配是构筑核壳结构的关键,一味地增加颗粒表面正电性或负电性对于实现调控复合过程形成纳米核壳结构并非有利。当苯乙烯与丙烯酸单体比例为10∶1时所得P（St-co-AA）微球在pH 2.0~3.0下所得核壳结构形貌均一,分散性较好。

Poly（styrene-co-acrylic acid）（P（St-co-AA））/cerium oxide core-shell nano-composites were successfully fabricated by an electrostatic conjugation method by using P（St-co-AA）microspheres as the negative potential blocks and cerium oxide nano powders as the positive potential blocks.The influences of the processing conditions on the formation and morphologies of the as-fabricated nano-composites were investigated.The results indicated that the P（St-co-AA）microspheres fabricated by soap-free emulsion polymerization were characterized of mono-dispersed spheres with particle sizes ranging from 160 nm to 390 nm.Cerium oxide nanopowders with particle sizes from 10 nm to 20 nm were synthesized by hydrothermal method.In the aqueous solution,P（St-co-AA）/cerium oxide core-shell nano-composites with dense shell layers were constructed.The key factor to control the morphologies of the obtained core-shell structures was the match of surface electric potentials between the positive and negative blocks.The optimal conditions were at St/AA of 10∶1and pH value from 2.0to 3.0.