四甲基溴化铵及不同链长表面活性剂对甲基纤维素-邻甲氧基肉桂酸溶液凝胶化行为的影响

Effect of Tetramethyl Ammonium Bromide or Surfactants with Different Chain Length on Sol-Gel Transition of Methylcellulose-Ortho-Methoxycinnamic Acid Solution

测定了四甲基溴化铵以及表面活性剂十二烷基三甲基溴化铵(DTAB)、十四烷基三甲基溴化铵(TTAB)和十六烷基三甲基溴化铵(CTAB)对甲基纤维素(MC)-邻甲氧基肉桂酸钠盐(OMC-)体系的凝胶化行为的影响。结果表明:含DTAB、TTAB以及CTAB的MC-OMC-溶液的溶胶-凝胶转变温度不随表面活性剂质量分数的变化而变化,但是向MC-OMC-溶液中加入四甲基溴化铵,体系的溶胶-凝胶转变温度会显著下降。在含四甲基溴化铵或不同链长表面活性剂的MC-OMC-溶液中,TTAB等表面活性剂分子更倾向于在水溶液中形成球状胶束;四甲基溴化铵与OMC-有着较强的静电作用,会导致MC和OMC-形成的核-壳结构破裂。

The sol-gel transitions of methylcellulose（MC）-ortho methoxycinnamic acid sodium（OMC ） solution in the presence of tetramethyl ammonium bromide,dodecyl ammonium bromide （DTAB）, tetradecyl trimethyl ammonium bromide （TTAB） and cetyl trimethyl ammonium bromide （CTAB） were studied. Results showed that the sol-gel transition temperature of MC-OMC solution unchanged with the mass fraction of DTAB, TTAB and CTAB. However, when tetramethyl ammonium bromide was added to MC OMC solution, the sol gel transition temperature of the solution decreased significantly. In MC OMC solution containing tetramethyl ammonium bromide or different chain length surfactants, surfactants such as TTAB tended to form free hemispherical micelles. Strong electrostatic interaction between OMC and tetramethyl ammonium bromide would destroy the core-shell structure formed by MC and OMC .