外加电场气相法制备纳米无机氧化物
The Electrically Controlled Flame Synthesis of Oxide Nanop article
气相燃烧法纳米无机氧化物粉体特征一方面取决于前驱体的水解反应速度和粒子的成核生长动力学, 另一方面受到燃烧反应器内物料的流动混合、热质传递等多种过程因素的影响。电场控制气相燃烧法制备纳米 无机氧化物是在原有的基础上外加电场,使火焰的轴向高度降低、径向宽度增大,形成厚度相对均匀的火焰层, 火焰温度梯度也随之增大,抑制粒子表面的生长和粒子之间的烧结,获得“粒径分布较窄的粒子和结构相似的 聚集体”。
For precise control of the nanophase powder characteristics, electrically assisted hydrocarbon flames using electrodes have shown quite effective, either by ion or electron attachment, so the coagulation rate of the particles is reduced, as unipolarly charged particles repel each other. Charged particles are also attracted towards electrodes, thus lowering the local particle concentration and therefore the collision rate. The flame structure, height, and temperature are also altered by the electric field, which can significantly influence the particle residence time at high temperatures and therefore affect particle growth or sintering and crystallinity. It was shown that field generated by the electrodes across the flame decreases the particle residence time in the high temperature region of the flame.
气相燃烧法 / 电场控制 / 火焰 / 纳米粒子 / 聚集体
gas combustion / electrically controlled / flame / nanoparticle / aggregates
庄清平(1956-),男,福建泉州市人,福建泉州WPF有限公司高级工程师
/
〈 |
|
〉 |