摘要
以Mg0 .67Al0 .3 3 (OH) 2 (CO3 ) 0 .165·0 .62H2 OLDHs为前体 ,以水为分散介质 ,由离子交换法组装了硼酸根插层LDHs ,并用XRD ,FT IR ,TG DTA ,ICP ,11BMASNMR等手段对样品进行了分析和表征 .结果表明 ,通过控制离子交换时的pH ,可使硼酸根取代Mg Al CO3 LDHs前体层间的CO2 -3 ,且可控制离子交换程度及客体的取向 ,从而控制插层结构 .对硼酸根插层LDHs的结构进行研究发现 ,控制pH =4.5 ,层间阴离子主要是一硼酸根和离子平面与LDHs层板平行的三硼酸根 ,出于结构稳定的需要 ,CO2 -3 不能完全被置换 ;控制pH =3 .5 。
Borate pillared layered double hydroxides (LDHs) have been prepared by an ion-exchange method with Mg0.67Al0.33(OH)(2)(CO3)(0.165).0.62H(2)O being the precursor. The samples were analyzed by XRD, FT-IR, TG-DTA, ICP and B-11 MAS NMR. The results showed that by controlling the pH of the Ion-exchange medium, borate ions can substitute carbonate ions in the interlayeres. Furthermore, the extent of ion exchange and the nature of the vip ions can be used to control the structure of the products. When the pH of the reaction mixture is 4.5, the interlayer anions are mainly monoborate anions and triborate anions with the plane of the latter being parallel to the layers of the LDHs. Under these conditions carbonate anions are not completely replaced. When the pH value is 3.5, monoborate anions and triborate anions with the plane of the latter being perpendicular to the layers are mainly present in the interlayer galleries.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2004年第13期1205-1210,J001,共7页
Acta Chimica Sinica
基金
国家自然科学基金重点 (No.90 30 60 1 2 )资助项目
