Development of multiceramics compornent and monodispersed particle preparation by new emulsion method for practical precess

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This study was carried out for preperation and size control of sperical and monodispersed particles by hydrolysis reaction in acetnitril-n-octanol mixed solvent. To understand the solution condition before and after hydrolysis reaction we decided the solubility of Ti (OC_4H_9)_4. The solubility of Ti (OC_4H_9)_4 was decreased accompanied by the increase of acetnitril concentration. Above 60vol% of acetnitril concentration it becomam 0 and alcoxide were sedimented forming emulsion or solution under that condition. Stability of the emulsion was influenced by HPC concentration. There was critical and minumam HPC concentration for emulsion existing in stable condition.We came to abel to get monodispersed spherical particles by using homogeneous solution and emulsion method by the ultrasonic waves at the high acetnitril concentration, in which monodispersed particle could not synthesized before. Several parameters which influence the size of the particels were investigated. When composition of the mixed solvent was changed the size of the particles were changed between 0.5-6mum ([Ti (OC_4H_9)_4] =0.1mol/l, [H_2O] =0.5mol/l, [HPC]=0.2g/l). And when concentratio of HPC was changed the size of the particles were changed between 0.5-200mum ([Ti (OC_4H_9)_4] =0.1mol/l, [Acetonitril] =80vol%, [H_2O] =0.5mol/l, ). And at the same time in-situ observation of hydrolysis reaction in the particle of 100mum in diameter.Internal structure and thermal change of the particles about 10-100mum in diameter. The inside of the as-prepared particle was homogenious and packed thoroughly Sometimes hole was existed at the center of the particle. By thermal analyzes they were proved that the over 50wt% of organic materials were remained in the as-prepared particles in which the non-reacted alcoxid could by aging more long time. The shapes of the particles were maintained up to 900ﾟC.