草酸根阴离子柱撑水滑石的合成及热稳定性研究

采用原位一步合成法和以硝酸根型水滑石为前驱体的水溶液中阴离子直接交换法合成了草酸根柱撑水滑石材料,用XRDI、R和DTA对合成的样品进行了组成和结构表征,在此基础上较为详细地研究了柱撑水滑石样品的热分解行为.研究表明:两种方法均能合成出柱撑水滑石材料,但相比之下,采用原位法合成制备的样品其结晶性和层有序性相对较好.DTA研究表明:Mg2Al系列样品具有比Zn2Al系列样品更高的对热稳定性,但有机阴离子引入水滑石层间,引起层柱材料的热稳定性略微降低,而不同方法合成的柱撑水滑石样品其热稳定性相差不大.图8,参14.

Synthesis and Thermal Stability of Oxalate-intercalated Hydrotalcites

Oxalate anions pillared layered double hydroxides(LDHs) were synthesized by in-situ synthetic method and direct ion-exchange reaction in aqueous solution using nitrate-containing LDH as precursors,and were characterized by XRD,IR and DTA.The thermal stabilities of synthesized samples were studied.Results show that the pillared products can be prepared using both methods,but the sample prepared by in situ synthetic method has higher crystallity and better layered structure than that of the sample prepared by direct anion exchange method.Results from DTA studies indicate that the thermal stabilities of the oxalate-intercalated Mg2Al-LDHs are higher than that of the Zn2Al-LDHs,and the thermal stabilities of the pillared products are slightly decreased with the NO3-ions replaced by the organo-anions.Less thermal stability differences are observed for the prepared samples via the two different methods.8figs.,14refs.