Rheological property and drying mechanism of thermoresponsive gelcasting of ZnO  

ZnO温度响应凝胶注模成型的流变性能和干燥机制（英文）

作　　者：王小锋[1] 王日初[1] 彭超群[1] 孙文燕[1] 孙月花 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第8期2789-2796,共8页中国有色金属学报（英文版）

基　　金：Project(51202296)supported by the National Natural Science Foundation of China;Project supported by the State Key Laboratory of Powder Metallurgy,Central South University,China

摘　　要：To solve the problem of drying gelcast green body, the thermoresponsive gel system which contains macromonomer graft chains was used in gelcasting of ZnO. The effects of the amount and length of graft chains macromonomer PIPAAm, the total amount of organic matters, and the solid loading on the rheological properties of suspensions were investigated, and the drying mechanism of gelcast green body was analyzed. The results show that ZnO suspensions with the gel system still display shear- thinning rheological behavior, but its viscosity increases with increasing the addition amount and relative molecular mass of PIPAAm graft chain, and the total organic matter content. The PIPAAm graft chains inhibit or even eliminate the formation of the ＂dense layer” on the surface of gelcast ZnO green bodies, and accelerate the drying of green bodies. The introduction of PIPAAm graft chains facilitates the shrinkage of the gelcast ZnO green bodies, which is a feasible method to increase the relative density of green bodies.为解决坯体干燥问题,将含大单体支链的温度响应凝胶体系应用于ZnO的凝胶注模成型,研究大单体支链PIPAAm的加入量与支链长度、总有机物含量和固相体积分数对悬浮液流变性能的影响,并分析坯体的干燥机理。研究表明:添加该凝胶体系的ZnO悬浮液仍表现为剪切变稀流变行为,但其黏度随着PIPAAm支链的加入量与相对分子质量以及总有机物含量的增加而升高。大单体支链的引入抑制甚至消除ZnO温度响应凝胶注模坯体表面"密实层"的形成,加快坯体干燥,促进坯体收缩。

关 键 词：ZNO ZNO GELCASTING thermoresponse rheological property drying mechanism N-ISOPROPYLACRYLAMIDE 

分 类 号：O614.241[理学—无机化学]