Effect of salts on synthesis of mesoporous materials with mixed cationic and anionic surfactants as templates

• Published in: Colloid journal of the Russian Academy of Sciences Vol. 78; no. 5; pp. 690 - 697
• Main Authors: Teng, Hong-ni, Shen, Teng, Hou, Yi-xiao, Chen, Yong, Kou, Xiao-yan, Wang, Xiu-yun, Hai, Man
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.09.2016; Springer Nature B.V
• Subjects: Chemistry; Chemistry and Materials Science; Liquid crystals; Polymer Sciences; Silicon dioxide; Size distribution; Specific surface; Surface area; Surfaces and Interfaces; Surfactants; Thin Films
• ISSN: 1061-933X; 1608-3067
• DOI: 10.1134/S1061933X16050203

Mesoporous silica materials were synthesized using tetraеthoxysilane as precursor and liquid crystals formed in aqueous mixtures of cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) as templates, without and with the addition of NaBr or Na 2 SO 4 . For this purpose, the formation of liquid crystals as a function of the ratio of CTAB and SDS under different conditions was studied. It was found that liquid crystals formed in the mixed system of CTAB and SDS at certain mixing ratios are well-structured templates for the synthesis of mesoporous silicas. The synthesized silica materials were characterized by transmission electron microscope and nitrogen adsorption/desorption analysis. The pore size of mesoporous silicas could be controlled between 3 to 6 nm by simply changing the concentration of NaBr in solution. The mesoporous silicas exhibited lamellar structure and the order of structural arrangement was promoted with addition of NaBr. However, addition of Na 2 SO 4 led to ink-bottle type pores of mesoporous silica with a narrow pore size distribution of around 2 nm and a higher specific surface area of 610 m 2 g –1 .