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    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

    • 摘要: 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。

       

      Abstract: 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-.

       

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