Synthesis of Li/Al layered double hydroxide-guest composites under mild acid conditions

Author： Yang Deng-Shiu Wang Ming-Kuang Wang Shan-Li

ISSN： 1471-8030

Source： Clay Minerals, Vol.39, Iss.2, 2004-06, pp. : 115-121

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Layered double hydroxides (LDHs) are known as 'anionic clays'. They comprise a class of material with positively charged octahedral double hydroxyl layers and exchangeable anions. The Li/Al LDH term includes a group of LDHs with Li/Al octahedral double hydroxyl layers. We have demonstrated a modifed method, using Li/Al LDH-OH (OH^¯ as interlayer anions) as the starting material, for preparing Li/Al LDH-X (X represents interlayer anions, including dioctyl sulphosuccinate (DOSS), dodecyl sulphate (DDS), mercaptoacetate (MA), EDTA, Tiron and dichromate) under mild acid conditions (pH in the range 4 to 5). However, in the case of acidsensitive anions, Fe(CN)₆^4¯, Li/Al LDH-Fe(CN)₆^4¯can be prepared by a two-step procedure using Li/Al LDH-DOSS or similar compounds as intermediates to react with acid-sensitive anions under mild alkaline conditions (pH ≈ 9).