%0 Journal Article
%T Effects of Acid-leaching and Thermal Oxidation on Surface Characteristics and Aqueous Dispersibility of Silicon Nitride Powders<br>酸洗和热氧化对氮化硅粉料表面特性与浆料流变性能的影响
%A DAI Jian-Qing
%A HUANG Yong
%A <br>代建清
%A 黄勇
%J 无机材料学报
%D 2008
%I Science Press
%X Influences of acid leaching and thermal oxidation on aqueous dispersibility were investigated for four types of commercial silicon nitride powders, in conjunction with their DRIFT spectra and soluble counter-ions. Three of the powders, referred to FD1, FD2 and M11, were produced by the direct nitridation of silicon powder with different pulverization processes, while the UBE powder was made by calcination of the silicon diimide precipitate. Particle surface groups and soluble counter-ions (especially high-valency counter-ions) are proved to be the crucial factors that determine the aqueous dispersibility of Si3N4 powders. The study indicates that the high-valency counter-ions are the crucial factor limiting the dispersibility of powder FD1, which can be eliminated by acid leaching. For powder FD2, the barrier to preparing highly concentrated suspension is the large number of hydrophobic Si-O-C-R groups on particle surfaces, and those groups can be removed by thermal oxidation. For powder M11, the high concentration of soluble NH4+ restricts the aqueous dispersibility of the as-received sample, which can be removed by thermal oxidation. For the as-received powder UBE, however, hydrophobic Si-O-Si surface groups limit the preparation of highly concentrated slurries. After particle surface modification, the four types of silicon nitride powders show excellent aqueous dispersibilities.
%K Si3N4 powder
%K dispersibility
%K acid-leaching
%K thermal oxidation<br>氮化硅粉料
%K 分散性
%K 酸洗
%K 热氧化
%K 酸洗
%K 热氧化处理
%K 氮化硅
%K 粉料
%K 表面特性
%K 浆料
%K 流变性能
%K 影响
%K Powders
%K Silicon
%K Nitride
%K Dispersibility
%K Aqueous
%K Surface
%K Characteristics
%K Oxidation
%K Thermal
%K 表面改性处理
%K 限制性因素
%K 表面基团
%K 憎水
%K 存在
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=84529CA2B2E519AC&jid=ABC0063016AF57E1C73EF43C8D2212BD&aid=CFB3DB44F390AEC0033835E2062E0CE4&yid=67289AFF6305E306&vid=EA389574707BDED3&iid=CA4FD0336C81A37A&sid=31611641D4BB139F&eid=C5F8B8CB20F1B3D8&journal_id=1000-324X&journal_name=无机材料学报&referenced_num=0&reference_num=24