Fielding Lee A, Armes Steven P, Staniland Paul, Sayer Robert, Tooley Ian
Dainton Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK.
Dainton Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, UK.
J Colloid Interface Sci. 2014 Jul 15;426:170-80. doi: 10.1016/j.jcis.2014.04.002. Epub 2014 Apr 12.
Four poly(2-vinylpyridine) latexes with intensity-average mean diameters ranging between 246 and 955nm were prepared by aqueous emulsion polymerisation. These latexes were characterised by transmission electron microscopy, field emission scanning electron microscopy, dynamic light scattering, aqueous electrophoresis, disc centrifuge photosedimentometry and thermogravimetry. The adsorption of rice grain-shaped nano-sized titania particles onto the surface of these latex particles from aqueous solution was investigated. It was found that the titania particles adsorb strongly at pH 10 and the optimal loading and packing density of titania was investigated for each latex. The resulting core-shell P2VP-titania nanocomposite particles were characterised in terms of their titania contents, surface coverages and colloidal stabilities. UV-Vis spectra were recorded for the titania nanoparticles, the original P2VP latexes and the poly(2-vinylpyridine)-titania nanocomposite particles. It was found that, for the larger nanocomposite particles, UV-Vis absorption was dominated by the latex core, whereas the smaller P2VP-titania nanocomposite particles exhibited UV attenuation to longer wavelengths compared to both the bare latex and the titania particles. The poly(2-vinylpyridine) cores were selectively removed by calcination of the nanocomposite particles and the resulting hollow titania structures were investigated by transmission electron microscopy.
通过水乳液聚合制备了四种强度平均平均直径在246至955nm之间的聚(2-乙烯基吡啶)胶乳。这些胶乳通过透射电子显微镜、场发射扫描电子显微镜、动态光散射、水性电泳、圆盘离心光沉降法和热重分析法进行表征。研究了水溶液中米粒状纳米二氧化钛颗粒在这些胶乳颗粒表面的吸附情况。发现在pH 10时二氧化钛颗粒强烈吸附,并针对每种胶乳研究了二氧化钛的最佳负载量和堆积密度。对所得的核壳P2VP-二氧化钛纳米复合颗粒的二氧化钛含量、表面覆盖率和胶体稳定性进行了表征。记录了二氧化钛纳米颗粒、原始P2VP胶乳和聚(2-乙烯基吡啶)-二氧化钛纳米复合颗粒的紫外-可见光谱。发现,对于较大的纳米复合颗粒,紫外-可见吸收以胶乳核为主,而较小的P2VP-二氧化钛纳米复合颗粒与裸胶乳和二氧化钛颗粒相比,在更长波长处表现出紫外衰减。通过对纳米复合颗粒进行煅烧选择性地去除聚(2-乙烯基吡啶)核,并通过透射电子显微镜研究所得的中空二氧化钛结构。