Phase transition of silica in the TMB-P123-H2O-TEOS quadru-component system: a feasible route to different mesostructured materials

Chunling Xin; Ning Zhao; Haijuan Zhan; Fukui Xiao; Wei Wei; Yuhan Sun

doi:10.1016/j.jcis.2014.07.021

Phase transition of silica in the TMB-P123-H2O-TEOS quadru-component system: a feasible route to different mesostructured materials

J Colloid Interface Sci. 2014 Nov 1:433:176-182. doi: 10.1016/j.jcis.2014.07.021. Epub 2014 Jul 24.

Authors

Chunling Xin¹, Ning Zhao², Haijuan Zhan¹, Fukui Xiao³, Wei Wei⁴, Yuhan Sun⁵

Affiliations

¹ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China. Electronic address: zhaoning@sxicc.ac.cn.
³ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China.
⁴ Center for Greenhouse Gas and Environmental Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.
⁵ CAS Key Lab of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203, China.

PMID: 25128865
DOI: 10.1016/j.jcis.2014.07.021

Abstract

Various siliceous structures were obtained using a nonionic block copolymer (Pluronic P123) surfactant and trimethylbenzene (TMB) as a hydrophobic additive by hydrolysis and condensation of tetraethoxysilane (TEOS) in a sol-gel process. The resultant materials were characterized by small-angle X-ray diffraction (SAXRD), nitrogen adsorption analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results revealed the structure transformation from hexagonal structure (HEX) to multilamellar vesicles (MLVs) and then to mesocellular foams (MCFs) in the TMB-P123-H2O-TEOS quadru-component system. The morphology of the mesoporous silica was mainly controlled by the mass ratio of TMB/P123 resulted from the increasing volume of the hydrophobic chain of micelle of P123 that caused by more amount of TMB dissolved in the PPO segment of polymer. The fact that the occurrence of rod-like particles with curved ends and the coexistence of the MLVs and the HEX structure indicates that the MLVs are developed from the ends of HEX structures, rather than formed by a direct cooperative self-assembly mechanism. Further increasing of packing parameter of surfactant resulted from TMB addition transforms lamellar micelles to reversed micelles, leading to the formation of MCFs.

Keywords: Mesoporous materials; Multilamellar vesicles; Phase transition; Silica.