高浓度纳米氢氧化铝(ATH)悬浮液制备的难点是黏度大导致传质困难。对碳分纳米ATH悬浮液进行了流变研究,得知它是黏度极高的时变性非牛顿流体,其黏度随质量分数增加显著增加,在质量分数达到12.9%后,黏度已对搅拌等过程有显著影响。用流变的方法筛选出对悬浮液有明显降黏作用的分散剂,其中一种聚电解质和一种阳离子分散剂相配伍可降黏一个数量级以上。在高浓度碳分反应中添加所筛选出的分散剂,成功制得板状形貌,单个的粒度0.2 μm╳0.05 μm(长╳厚)且分散性良好的纳米ATH,产率较未添加分散剂的有明显提高。
Abstract
Carbonation precipitation of nano-alumina trihydroxide (ATH) suspensions at high concentrations is problematical because of poor mass-transfer characteristics associated with the high viscosity of the mixtures. The ATH suspension obtained from such carbonation is a very sticky time-dependent non-Newtonian fluid and its viscosity increases rapidly with the content of ATH and becomes intractable when the content of ATH reaches 12.9%. A rheological method has been used to select dispersants which can decrease the viscosity of the ATH suspension. Addition of a polyelectrolyte plus a cationic surfactant was found to give a decrease of more than one order of magnitude in the viscosity of the suspension. Nano-ATH can thus be prepared from a concentrated precipitation mixture. The resulting ATH has nano-tabulate morphology with size 0.2 μm×0.05 μm (length×thickness) and is well dispersed.; furthermore the yield is also increased.
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 梁磊,郭奋. 碳分纳米氢氧化铝悬浮液的流变行为与纳米粒子团聚[J],北京化工大学学报,2006,33(2):48-52
[2] 艾照全、周奇龙、张洪涛. 高固含量聚合物乳液制备方法新进展[J],高分子通报,2004,3:43-47
[3] D.T. Beruto, A. Ferrari, F. Barberis, M. Giordani. Dispersions of micrometric powders of molybdenum and alumina in liquid paraffin: role of interfacial phenomena on bulk rheological properties. Journal of the European Ceramic Society 22 (2002) 2155–2164
[4] 王浚、高濂、孙静. Y-TZP悬浮液的界面吸附特性[J],无机材料学报,1999,14(5)757-762
[5] S. Baklouti, M. R. B. Romdhane, S. Boufi,, C. Pagnoux, T. Chartier, J.F. Baumard. Effect of copolymer dispersant structure on the properties of alumina suspensions. Journal of the European Ceramic Society 23 (2003) 905–911
[6] C.H. Schilling,C. Li, P. Tomasik, J.C. Kim. The rheology of alumina suspensions: influence of polysaccharides . Journal of the European Ceramic Society 22 (2002) 923–931
[7]王浚、孙静、高濂. 聚电解质分散剂对Y-TZP悬浮液性能的影响[J]. 无机材料学报,1999,14(2):233-238
[8]张松海、娄清香、毛国梁、吴韦. 阳离子聚电解质与阴离子表面活性剂大分子复合物的形成及其溶液流变性能[J],化学世界,2005,2:79-82
[9] 张清岑、刘小鹤、黄苏萍. 超分散剂分子结构设计的研究[J]. 矿产综合利用,2002,4:15-19
[10] 武照强、冯开才、刘振兴. 超分散剂[J]. 现代塑料加工应用,2001,13(5):45-49
[11] 李裕、刘有智、王燕萍. 液相中超细Al(OH)3粒子的生长团聚机理[J]. 化学研究与应用,2003,15(1):62-63
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}