Preliminary Investigation on the Formation Mechanism of CCl4-Water-Cetyl Trimethyl Ammonium Bromide (CTAB) Gel
SUN Yan1, 2, CHEN Jing2, HE An-qi2, HUANG Kun2, 3*, YU Lei2，4, LIU Cui-ge1*, WEI Yong-ju1, ZHAI Yan-jun4, XU Yi-zhuang2*, WU Jin-guang2
1. College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050016, China 2. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China 3. Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 4. College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
Abstract：Gels are gaining extensive interest owing to their versatile applications in fields such as drug delivery, tissue engineering, cosmetics, templated materials and food industry. Surfactants have an ability to self-assemble into a variety of supramolecular aggregate structures and morphologies. Of particular interest in resent years are surfactant-based gels, one special class of materials due to surfactant assemblies resulting in viscoelastic solid-like rheological behaviors. Up to now, there is only limited understanding on the mechanism of gel formation, especially on the interaction among water, organic solvents and surfactant during thegel formation. In this study we prepare a Low-molecule-gel that is composed of cetyl trimethyl ammonium bromide (CTAB), water and carbon tetrachloride. Based on the experimental result of XRD and titration, the authors find that CTAB in gel are more than in saturated CTAB solution but CTAB is not solide in gel. CTAB is not solvented in CCl4. The solubility of CTAB in saturated CTAB solution is limited. So the authors suppose that CTAB is a synergistically solubilized by water and CCl4 in the gel. In addition, both NMR and FTIR spectroscopic results demonstrate that CTAB cations form a quasi-ordered structure in the gel.
[1] Terech P, Weiss R G. Chem. Rev., 1997, 97: 3133. [2] Bieser A M, Tiller J C. J. Phys. Chem. B, 2007, 111: 13180. [3] George M, Weiss R G. Acc. Chem. Res., 2006, 39: 489. [4] Lee K Y, Mooney D J. Chem. Rev., 2001, 101: 1869. [5] Tiller J C. Angew. Chem., Int. Ed. 2003, 42: 3072. [6] Vemula P K, John G. Chem. Commun., 2006，(21): 2218. [7] Hirst A R, Escuder B, Miravet J F, et al. Angew. Chem., Int. Ed., 2008, 47: 8002. [8] Sangeetha N M, Maitra U. Chem. Soc. Rev., 2005, 34: 821. [9] Trickett K, Eastoe J. Adv. Colloid. Interfac. Science, 2008, 144: 66. [10] Limin L, Grace T, Gary M, et al. Langmuir, 2008, 24(17): 9286. [11] WENG Shi-fu(翁诗甫). Fourier Transform Infrared Spectrometry(傅里叶变换红外光谱). Beijing: Chemical Industry Press(北京：化学工业出版社), 2005. [12] Snyder R G, MacPhail R A, Strauss H L. J. Am. Chem. Soc., 1980, 102: 3976.
