The First Part Preparation Of Y₂O₃, TiO₂ Hollow Spheres And Their Composite Hollow Spheres By Templating Against Polymer Latex Directly

Inorganic hollow sphere is studied widely because of its hollow structure and potential application. Many inorganic hollow spheres are prepared by various methods, in which the method used frequently is templating against polymer latex directly. The mostly used polymer latex template is polystyrene latex. Presently, the fonnation mechanism of polymer latex/inorganic core-shell spheres is studied elementarily and there are no reports about using theory for guiding experiment. Few reports still about batch production of inorganic hollow spheres by templating against polymer latex and the preparation of composite hollow spheres have appeared so far.In our previous work, anionic poly(styrene-acrylic acid) (PSA-A) with a lot of COO- groups covering on its surface was prepared using Poly(C9-acrylic acid) (P(C₉-AA)) as emulsifier and it was used as template for preparing CdS, ZrO₂ hollow spheres and Ag/TiO₂, CdS/TiO₂ composite hollow spheres.In this dissertation, firstly, cationic Poly (styrene-acrylic acid) (PSA-C) latex with quaternary ammonium salt covering on its surface is prepared using Poly (C₉-methylic propylene acryl oxygen ethylic three methyl ammonium chloride) (P(C₉-DMC)) as emulsifier. TiO₂, Y₂O₃ hollow spheres and their composite hollow spheres are prepared by templating against PSA-C latex and PSA-A latex directly. The experiment conditions of core-shell spheres formation are studied and the optimum conditions are obtained. The experimental samples are characterized by SEM, TEM, TG-DTE and XRD.Secondly, ζ potentials of polymer latex, inorganic hydrolysis and core-shell spheres are investigated and the formation processes (formation mechanism) of PSA-A/inorganic hydrolysis and PSA-C/inorganic hydrolysis core-shell spheres are speculated. We conclude that pH changing velocity is crucial for the smooth core-shell formation. The optimum formation conditions for smooth core-shell are...