层状化合物K_(0.81)Li_(0.27)Ti_(1.73)O_4的氢离子交换反应与胺剥层反应

采用固相法合成层状化合物K0.81Li0.27Ti1.73O4,考察不同原料配比、反应时间及反应温度等条件对其氢离子交换反应和有机胺插层剥层反应的影响.结果表明:在0.1～14mol/L的HNO3溶液中K0.81Li0.27Ti1.73O4均可以通过氢离子交换生成H1.08Ti1.73O4·H2O固体钛酸,若反应温度高,则产物容易转变成TiO2.合适的氢离子交换条件是:室温下浸泡4～7d,n(HNO3)∶n(KLiTiO)=10～20,c(HNO3)=1～10mol/L.在正丙胺(n-PA)和正丁胺溶液中H1.08Ti1.73O4·H2O均可以进行插层剥层反应.反应温度高和有机胺与H1.08Ti1.73O4·H2O的物质的量比过小都容易使生成物转变成TiO2相.理想的插层剥层反应条件为:120℃,反应1d,n(n-PA)∶n(HTiO)=20～100.

The H~+ -Exchange and Exfoliation Reactions of K_(0.81)Li_(0.27)Ti_(1.73)O_4

K_(0.81)Li_(0.27)Ti_(1.73)O_4 was synthesized by a solid state reaction. The conditions such as materials ratios,reaction time and reaction temperature,which are the main influencing factors of the H+ ionic exchange reaction and exfoliation of K_(0.81)Li_(0.27)Ti_(1.73)O_4 were studied. The results show that K_(0.81)Li_(0.27)Ti_(1.73)O_4 can be transformed into H_(1.08)Ti_(1.73)O_4·H_2O in a 0.1～14 mol/L HNO_3 solution by ionic exchange. If the reaction temperature is higher,the product is transformed into TiO_2. The optimum H+-exchange conditions are: the concentration of HNO_3 is 1～10 mol/L,n(HNO_3) : n(KLiTiO)=10～20,at room temperature for 4～7 d. H_(1.08)Ti_(1.73)O_4·H_2O can be exfoliated by both n-propylamine (n-PA) and n-butylamine. The exfoliation of H_(1.08)Ti_(1.73)O_4·H_2O is sensibly influenced by the reaction temperature and the ratio of H_(1.08)Ti_(1.73)O_4·H_2O and amine,i.e.,at a higher temperature and/or a smaller ratio of amine and H_(1.08)Ti_(1.73)O_4·H_2O,the product is TiO_2 rather than a layered compound. The optimum exfoliation (or intercalation) conditions are: n(n-PA) : n(HTiO)=20～100,at 120 ℃ for 1 d.