Phosphate Esters as Dispersants for the Cathodic Electrophoretic Deposition of Alumina Suspensions
Phosphate Esters as Dispersants for the Cathodic Electrophoretic Deposition of Alumina Suspensions
复制标题
DOI：
10.1111/j.1551-2916.2008.02379.x
复制
发表时间：
2008-06
影响因子：
3.9
通讯作者：
T. Uchikoshi;Y. Sakka
中科院分区：
文献类型：
--
作者：
T. Uchikoshi;Y. Sakka
研究了具有三种不同烷氧基(乙基、丁基和丁氧乙基)的磷酸酯(PES)制备的氧化铝乙醇悬浮液的稳定性及其对电泳沉积特性的影响。通过测量不同实验条件下悬浮液的pH值、电导率、Zeta电位和沉积产率来表征颗粒的荷电机理。用丁氧乙酸磷酸酯制备的悬浮液的稳定性最高，尽管三种悬浮液的Zeta电位非常相似。这归因于烷氧基官能团的空间斥力。PES使氧化铝颗粒带正电，从而使阴极沉积得以发生。Zeta电位、沉积产率和坯体密度是PE加入量的函数。Zeta电位最高时获得了最高的生坯密度，但该PE量的沉积速率最低。PE的过量加入降低了镀层的Zeta电位和坯体密度，但增加了镀层与金属基材的结合力。添加过量的PE悬浮液可获得表面光滑的厚镀层。
The stability of alumina ethanol suspensions prepared with phosphate esters (PEs) having three different alkoxy functional groups (ethyl, butyl, and butoxyethyl) and the corresponding effects on the electrophoretic deposition characteristics were investigated. The mechanism of particle charging was characterized by measuring the suspension pH, conductivity, zeta-potential, and deposition yield under various experimental conditions. The highest stability was observed for the suspension prepared with the butoxyethyl acid phosphate though the zeta-potentials of the three suspensions were very similar. This was attributed to the steric repulsion of the alkoxy functional group. The PEs made the alumina particles positively charged which allowed the cathodic deposition to occur. The zeta-potential, deposition yield and green density were functions of the PE addition amount. The highest green density was obtained at the highest zeta-potential, however, the deposition rate for this PE amount was the lowest. The over-addition of PE caused decreases in the zeta potential and green density, but an increase in the adhesion of the deposit to a metal substrate. Thick deposits with smooth surfaces were obtained from the over-added PE suspension.