成膜条件对PZT超微粒/硬脂酸复合LB膜及PZT超薄膜的影响

用胶体化学的方法获得PZT溶胶,利用LB技术制备PZT超细陶瓷微粒/硬脂酸复合LB膜,热处理后得到PZT超薄膜.研究了PZT超微粒/硬脂酸复合LB膜的成膜条件,有效改善复合膜和超薄膜的性能:亚相浓度为0.01 μmol·mL~(-1)可以获得与硬脂酸有效复合的稀溶胶体系,滑障速度为6～8 mm·min-1可以获得紧密的复合单分子体系,转移膜压为30～35 mN·m~(-1)和pH值为7.0可以获得较理想的转移比,提拉速度为5～9 mm·min~(-1)有利于有序多层膜的制备.工艺条件中崩溃压和单分子面积的变化反映了硬脂酸分子和超微粒的有效作用.复合LB膜及PZT 超薄膜的AFM粒径分析结果表明,吸附于硬脂酸上的PZT超微粒子的平均半径为30.508 nm,经过焙烧得到的PZT超微粒子平均半径为30.412 nm.

Influences of Film Formation Conditions on PZT Superfine Particles/Stearic Acid Complex LB Films and PZT Ultrathin Films

The PZT sol system with stearic acid as carrier can be dispersed in subphase system and then forms the PZT ultrafine particles-stearic acid complex monolayer. Then by the LB technique to draw the composite LB film, the ultrathin PZT film can be achieved after heat treatment. The influences of formation parameters on the complex LB films and PZT ultrathin films are determined by the measurement of e-A curves. The dilute sol system can be gained effectively when the subphase concentration is 0.01 μmol·mL~(-1); the tight complex monomolecules system can be attained when the barrier speed is within 6 ～ 8 mm·min-1; the transfer ratio is near 1.0 when the surface pressure is within 30 ～ 35 mN·m~(-1) and pH value is 7.0; the 5 ～ 9 mm·min~(-1) lifting rate values can be favorable to the preparation of oriented multilayer films. The changes of the collapse pressures and single-molecule areas can reflect the interaction of stearic acid molecules with ultrafine particles. The AFM image observations show the decreased uniformity of PZT ultrafine particles with slightly aggregation. Particle size and roughness analysis by AFM images show that the PZT ultrafine particles absorbed and desorbted on stearic acid have an average radius of 30.508 nm(with roughness of 3.544) and 30.412 nm(with roughness of 3.395), respectively.