芘为荧光探针研究SDS/H_2O二元体系的热相变

PHASE TRANSITION OF SODIUM DODECYL SULFATEWATER SYSTEM: PROBING BY PYRENE FLUORESCENCE

以芘作为荧光探针,对十二烷基硫酸钠(SDS)40g%的水溶液在-20℃～30℃温区的相变进行了研究。该二元体系的主要相变是凝聚胶-液晶的转变,测定其相变温度为20℃。自由水形成的冰层在0℃融化,由此导致在化冰前后体系呈现出不同的凝聚胶相。在-17℃退火处理,体系出现了新的凝聚胶相。以上出现的各相均可由I_E/I_M值清楚地表征,从而首次证实了这种探针方法为一种成功的膜模拟体系相变的研究手段。

The phase transition of 400% sodium dodecyl sulfate (SDS)/water system has been studied by employing pyrene as a fluorescent probe in the temperature range of -20 ℃—+30℃. The binary system mainly undergoes coagel-liquid crystal phase transition at about 20℃. Free water layer melts at 0℃, below and above that different coagel phases were found. Anoval coagel phase was brought forth after annealing at -17℃ for 12 hours. All these phases have been fairly characterized by I_E/I_M. Structurual aspects of these phases are discussed concerning with the fluorescence information.