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Qi Tao, Jianxi Zhu, R. Mark Wellard, Thor E. Bostrom, Ray L. Frost, Peng Yuan and Hongping He
J. Mater. Chem., 2011, 21, 10711-10719
DOI: 10.1039/C1JM10328H
Received 21 Jan 2011, Accepted 04 May 2011
First published on the web 22 Jun 2011
Abstract
A series of layered double hydroxides (LDHs) based composites were synthesized by using an induced hydrolysis silylation (IHS) method, surfactant precursor method, in situ coprecipitation method, and direct silylation method. Their structures, morphologies, bonding modes and thermal stabilities can be readily adjusted by changing the parameters during preparation and drying processing of the LDHs. The characterization results show that the direct silylation reaction cannot occur between the dried LDHs and 3-aminopropyltriethoxysilane (APS) in an ethanol medium. However, the condensation reaction can proceed with a heating process between the adsorbed APS and LDHs plates. While using wet state substrates with and without surfactant and ethanol as the solvent, the silylation process can be induced by the hydrolysis of APS on the surface of the LDHs plates. Surfactants improve the hydrophobicity of the LDHs during the process of nucleation and crystallization, resulting in fluffy shaped crystals; meanwhile, they occupy the surface –OH positions and leave less “free –OH” available for the silylation reaction, favoring the formation of silylated products with a higher population in the hydrolyzed bidentate (T2) and tridentate (T3) bonding forms. These bonding characteristics lead to spherical aggregates and tightly bonded particles. All silylated products show higher thermal stability than those of pristine LDHs.
相关链接1: 矿物表面结构和性能调控新进展
相关链接2: 广州地化所矿物表面结构和性能调控研究获新进展
英文摘要:http://doc.sciencenet.cn/DocInfo.aspx?id=3679
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