Preparation And Characterization Of 8YSZ Electrolyte Powder With Nano Size In A Double Microemulsion Method Of Two Mixed Surfactants

A new microemulsion system was found in which cyclohexane was used as the oil phase and poly（oxyethylene）₅ nonyl phenol ether（NP-5）and poly（oxyethylene）₁₀0 octyl phenol ether（OP-10）were used as mixed nonionic surfactant.Two microemulsion systems were prepared,containing different ratio of cyclohexane and mixed nonionic surfactant and Zr（NO₃）₃/Y（NO₃）₃ aqueous solution of different cation concentration from 0.3M to 1.2M,and some concentration of ammonia solution as the water phase,respectively.Precursors of zirconium hydroxide and yttrium hydroxide were formed by reacting the two microemulsion systems at room temperature.8YSZ powders were then obtained by calcining the hydroxide precursors by temperature programming.The characterization of the obtained powders includes SEM,XRD,and TG-DSC.The results showed that this newly found microemulsion system could produce nano-sized near-spherical 8YSZ powders under 30nm in a high degree of dispersion.Between two kinds of different ratios of microemulsion ingredients,the microemulsion system in which cyclohexane:NP-5=9:1（volume ratio）produced nano powders of 25nm（particle size）,while cyclohexane:NP-5=8:2（volume ratio）produced nano powders of30nm（particle size）;orderly,crystallite dimension varied from around 12¹3nm to around 14¹8nm.Among all 8 groups,microemulsion system with cyclohexane:NP-5=9:1（volume ratio）,and Zr（NO₃）₃/Y（NO₃）₃ aqueous solution=1.2M produced powders of most concentrated particle size,which almost took on a normal distribution.Both high solution concentration and low solution concentration could lead to low degree of crystallinity,only a suitable solution concentration could lead to high degree of crystallinity:crystallinity of around 80%was formed by 0.3M and 1.2M solution,while crystallinity of 96⁹7%was formed by 0.6M and 0.9M solution.Although there was a relatively low degree of crystallinity formed by 0.9M solution,its degree of crystallinity still reached to 92%which was 10%more than groups of high and low solution concentration derived 8YSZ nano powder.What’s more,this article also analyzed the reason of above conclusion.And according to the analyses,other analogous research was also compared with what was done in this research.This study enriched the pool of microemulsion recipe.And firstly started longitudinal study of microemulsion method and at the same time combined different characterization in a way of mutually proved by each other,exploiting the research in mixed nonionic surfactant.