A New Preparation Method of Inorganic Ultrafine Particles by Using Water-borne Associating Polymer

烷基改性聚乙烯醇（pva）被归类为水性缔合聚合物，其在水中缔合并形成缔合团簇。在这项研究中，疏水改性聚乙烯醇，其中十二烷基仅位于主链的一端，用于制备无机细颗粒，如氧化锆。制备细颗粒的基本方案是形成由烷基改性聚乙烯醇团簇和团簇中的疏水锆盐（醋酸锆）组成的复合团簇。为了形成这种复合簇，将烷基改性PVA水溶液与醋酸锆-乙酸溶液混合，并将混合物轻度搅拌数小时。在这种温和的搅拌过程中，醋酸锆有望进入PVA簇的内部。该混合物经过干燥和煅烧，以便从醋酸锆中形成氧化锆细颗粒。考察了制备条件对颗粒形貌和一次、二次颗粒直径的影响。通过疏水改性聚乙烯醇，得到了以氧化锆为一级结构的细颗粒。我们所期望的与观察到的不同之处是，使用对照聚合物（即普通PVA）也获得了细颗粒（初级结构），尽管颗粒的大小比使用疏水改性PVA制备的颗粒大。

Alkyl modified poly(vinyl alcohols) (PVAs) are classified as water-borne associating polymers which associate in water and form associating clusters. In this study, hydrophobically-modified polyvinyl alcohols, in which a dodecyl group is located only at one end of the backbone, were used for preparing inorganic fine particles such as zirconia. The basic scheme for preparing fine particles is formation of composite clusters which consist of the alkyl modified PVAs clusters and a hydrophobic zirconium salt (zirconium acetate) in the clusters. For forming such composite clusters, an alkyl modified PVA aqueous solution was mixed with a zirconium acetate-acetic acid solution, and the mixture was stirred mildly for several hours. During this mild stirring, zirconium acetate is expected to enter the inside of the PVA cluster. The mixture was dried and calcined in order to form zirconia fine particles from zirconium acetate. The effects of preparation conditions on the particles morphology and the diameters of primary and secondary particles were investigated.By applying hydrophobically-modified PVAs, zirconia fine particles as a primary structure were obtained. Difference between what we expected and what was observed is that fine particles (primary structure) were also obtained using the control polymer (i.e., an ordinary PVA), although the size of the particles was larger than that of the particles prepared using the hydrophobically-modified PVA.