摘要
研究了烧结法制备的六钛酸钾晶须(PTW) 中的水溶钾. 实验发现: 水溶钾并不是来自PTW晶体的溶解; 水溶钾溶出很缓慢; 悬浮液pH值随水溶钾含量增加而升高. 根据实验现象, 从PTW生长机理分析认为PTW表面纳米缝隙中存在的微量K2O导致水溶钾的产生. 将烧结法制备的PTW在pH=4 5 的溶液中浸泡8 h以上或者超声波清洗, 可以获得水溶钾含量少于0 1‰(质量), 且满足复合材料使用要求的PTW. 硅烷偶联剂(A186) 改性PTW不影响水溶钾析出, 而无机包裹(SiO2) PTW水溶钾析出减少.
Water soluble potassium ions in potassium hexatitanate whiskers (PTW) of calcination synthesis were investigated. Experiments showed that the dissolved potassium ions were stripped slowly and not derived from the crystal structure of PTW. With the increase of the concentration of potassium ions the pH value of PTW suspension increased. The analysis based on the experimental results and growth mechanism of PTW showed that there should be trace K2O between nano-structure gaps on the surfaces of PTW. Thus the trace K2O between nano-structure gaps led to water soluble potassium ions in PTW. Moreover, potassium ions could be reduced effectively by soaking PTW in dilute acid solution for 8 h or ultrasonic cleaning, and the PTW fit for composites were obtained. The coating of shell (SiO2) on PTW might hinder dissolution of water soluble potassium ions, but the modification of silanes (A186) on PTW had no influence on the dissolution.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2005年第5期937-941,共5页
CIESC Journal
基金
国家杰出青年科学基金项目(29925616)
国家自然科学重点基金项目 ( 20236010 )
国家自然科学基金项目(20246002)
国家高技术研究发展计划项目(2003AA333010)~~
关键词
烧结法
水溶钾
六钛酸钾晶须
酸洗
超声波清洗
Calcination
Chemical modification
Dissolution
Nanostructured materials
Potassium
Synthesis (chemical)
Ultrasonic cleaning
