双分子膜上染料的吸附性质及对膜结构的影响

Adsorption, Aggregation of Dye Anions on the Surface of Aqueous Vesicle Bilayer and their Influence on Membrane Structure

系统地研究了染料甲基橙（MO）和达旦黄（TY）则在含席夫碱基囊泡双分子膜阳离子表面上的吸附和聚集，以及由此产生的对膜聚集结构的影响.染料的吸附和聚集可经电子吸收光谱和因吸附产生的沉淀证实，并且MO的聚集结构为H-聚集，TY的聚集结构为J-聚集.改变pH的研究表明MO在变色pH值以下因形成阳离子而解聚，TY在酸性条件下亦因离子化程度减弱和部分质子化而使聚集被削弱，但在碱性条件下其聚集产生更大的红移.温度变化的结果显示染料的聚集因囊泡聚集态的改变而逐步解聚.示差扫描量热（DSC）和差减的吸收光谱得出染料的吸附和聚集减弱了囊泡双分子膜的聚集相互作用并导致相变温度降低.

Adsorption, aggregation and membrane structure of dye anions such as methyl orange(MO) and titan yellow(TY) on the cationic surface of vesicle bilayers containing schiff base were studied systen1etically. The adsorption and aggregation wcre revealed through the wavelength shift of absorption 1l1axinmm and precipitation produced in bianery mirture. Blue shift and red shift showed that the aggregate structure was H-aggregate for MO and J-aggregation for TY respectively. pH dependences of dyes in mixture systems indicatcd that the MO aggregates formed at high pH would be destroyed under low pH, which resulted from the cationic structure formation. TY aggregates were also disaggregated in considerable scale at low pH because of partial protonation, bnt strong red shitt occurred at high pH. With temperature mcreasing, the aggregation of (lyes would gradmally he disintegrated following tlle change states of vesicle bilayer from gel to liquid crystal and finally to molecular dnspersion.Differential Scann Scanning Calormetery(DSC) showed tllat the adsorption of dyes an action to decreasc the phase transition temperature of vesicle and tlle differntial spectra confirmed that the aggregate interaction of vesicle bilayer was weakened.