Sol - Gel Preparation Of Tio <sub> Flaky Powder And Characterization Of 2 </ Sub>

This paper discussed a method for preparing flaky TiO₂.A resin lamina of ethylα-cyanoacrylate was first coated on the flat slide glass substrate as release layer.Then sol-gel-derived TiO₂ films were fabricated onto these glass substrates by dip coating method.After being dried,the coated substrates were immersed in acetone to dissolve the release layer and finally TiO₂ flakes were obtained after calcination.TiO₂ sols were prepared with Ti(OC₄H₉)₄ as precursor,HCl as catalyst and C₅H₅OH as solvent.The appearance,gel time and viscosity of sol,the morphology and gloss of the produced flakes were considered as scale standards for preparing TiO₂ sol.The material-feed way,the amount of H₂O,C₂H₅OH and HCl,the reaction temperature and other factors influencing the formation of sol and flakes were investigated.The optimal preparing condition was got as follows:pH=2,n[H₂O]:n[Ti(OC₄H₉)₄]= 5,n[C₂H₅OH]:n[Ti(OC₄H₉)₄]=9 and reaction temperature is 30℃.The properties of flaky TiO₂ were characterized by FTIR,TG-DTA, XRD,SEM and Particle Size Distribution Test.The XRD results indicated that the TiO₂ flakes treated at 400℃have the appearance of anatase phase, and completely transformed to rutile phase at 800℃,whereas have two types of anatase and rutile calcined at 600℃.The SEM photoes showed flaky TiO₂ were 10～60μm in size and about 1μm in thickness.The Adhesion,the Antiscratch properties were evaluated for the films.Better performance can be achieved when coated only one layer of film and calcined at 400℃.Furthermore,TiO₂ flakes doped with SiO₂ or ZrO₂ were prepared and studied similarly.In the system of TiO₂-SiO₂,it was found that SiO₂ doping can retard the transition of TiO₂ from anatase to rutile and the growth of TiO₂ crystalline size.In the system of TiO₂-ZrO₂,ZrO₂ doping can also retard the growth of TiO₂ crystalline size.It can improve the High-temperature Resistance and Thermal Stability of TiO₂,and the Antiscratch property of TiO₂ films can be greatly increased.