摘要
以α-Al_(2)O_(3)为原料,环保无毒的海藻酸钠为凝胶体系,通过氯化钙溶液引入钙离子,利用凝胶-滴注及无压烧结的方法制备了Al_(2)O_(3)多孔陶瓷球,研究了固化时间及烧结温度对Al_(2)O_(3)多孔陶瓷球的气孔率、抗压强度及显微结构的影响规律。结果表明:固化时间延长,有利于钙离子迁移,与海藻酸钠发生反应,形成三维交联网状结构,使Al_(2)O_(3)粉原位固化形成陶瓷球坯。烧结温度升高,颗粒间的间隙孔减少,显微结构更加均匀,抗压强度升高。Al_(2)O_(3)多孔陶瓷球的气孔率约在47.7%~78.1%之间,抗压强度在1.2~36.0 MPa范围内。通过优化固化时间、烧结温度、Ca^(2+)浓度等工艺参数可调控多孔陶瓷球的气孔率、孔结构及抗压强度。利用工艺简单的凝胶-滴注法方便进行多孔陶瓷球的直径、球形度及性能的控制,在催化剂载体、吸附、分离提纯等领域将具有广泛的应用前景。
Porous alumina (Al_(2)O_(3)) beads were prepared via gel-dripping and pressureless sintering withα-Al_(2)O_(3)as a raw material,nontoxic sodium alginate as a gelation reagent,and the calcium ions were introduced in the preparation using a calcium chloride solution.The effects of coagulation time and sintering temperature on the porosity,compressive strength and microstructure of porous Al_(2)O_(3)beads were investigated.The results show that calcium ions can transfer and react readily with sodium alginate as the coagulation time increases.Alumina particles are solidified to form a bead green body by a three-dimensional network.The number of meso-pores decreases and the microstructure becomes well-distributed with increasing the sintering temperature.The porosity and compressive strength are 47.7%–78.1%and 1.2–36.0 MPa,respectively.The porosity,pore structure and compressive strength can be tailored by optimizing the coagulation time,sintering temperature and calcium ion concentration.The diameter,sphericity and property of porous alumina beads can be controlled through the simple gel-dripping method.The porous alumina beads can be used in many fields,such as catalyst support,adsorption,separation,purification,etc..
作者
何秀兰
杨禹
张兆芬
王士龙
金鑫鑫
HE Xiulan;YANG Yu;ZHANG Zhaofen;WANG Shilong;JIN Xinxin(School of Materials Science and Chemical Engineering,Harbin University of Science and Technology,Harbin 150040,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2022年第3期729-734,共6页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金项目(51602082)。
