在AIN粉末表面涂覆油酸和8-羟基喹啉，有效地提高了AIN的耐水性．该粉末在40℃温水中至少稳定70h;但随水温升高稳定性变差，在60～80℃的水中发生水解反应．反应动力学呈扩散控制和固相表面化学反应控制两个阶段，均为一级反应，活化能分别为125kJ／mol和114kJ／moL产生上述现象的原因归于有机膜吸附在AIN表面，增加了水分子向AIN表面扩散的阻力，从而提高了AIN的耐水性．但这种吸附是物理吸附，水温升高时，在高动能水分子作用下解吸，导致AIN迅速与水反应．上述观点由TG－DTA、XRD和IR分析所证实．
The resistance to hydrolysis of aluminium nitride (AlN) powder was improved by coating oleic acid (OA) and 8-hydroxyquinodline (HQ) on the surface of AlN particles.
The treated powders did not react with water at 40℃ when soaked for up to 70h at a constant pH, whereas at the same conditions the untreated AlN reacted with water
after 2～10h soaking. However, with an increase of temperature (60～80℃),the hydrolysis of the coated powder took place quickly. The hydrolysis kinetics of AlN
powder with OA and HQ films was divided into two steps, diffusion control stage and chemical reaction control stage, both of which were first order reactions with activation
energies about 125kJ/mol and 114kJ/mol respectively. The observed behavior was interpreted by the hydrophobic films as a diffusion barried between water and AlN surface, which
was responsible for the improvement of the hydrolysis resistance. The hydrolysis of the coated AlN powders at high temperature was attributed to an interfacial physical
bonding that was easily broken down by errosion of water. This explanation was supported by TG--DTA, XRD and IR examination.
参考文献
| [1] | Sheppard L M. Am. Ceram. Soc. Bull., 1990, 69 (11): 1801--1812 2 张宗涛. 电子元件与材料, 1996, 15 (5): 49--52 3 Egashira M, Shimizu Y, Takatsuki S. J. Mater. Sci. Lett., 1991, 10: 994--996 4 Bowen Paul, Highfield James G. J. Am. Ceram. Soc., 1990, 73 (3): 724--728 |
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