摘要
用Model-4200型恒温滴定量热系统,研究了非离子表面活性剂(Triton X-114,Triton X-100,Triton X-102,Triton X-405)和β-环状糊精的包结的热力学性质,结果表明:对所有体系,均形成1:1的包结物,△H°和△S°值均为负值,形成包结物的过程是焓有利而熵不利的过程,而且-△H°和-△S°值随非离子表面活性剂环氧乙烷(EO)链长的增加而减少.另外,非离子表面活性剂环氧乙烷(EO)链越长,包结物稳定常数越小.
The association of a series of Triton X surfactants which have ethylene oxide( EO) chains of different length with β- cyclodextrin was studied by means of isothermal titration calorimetry (ITC) at 298. 15K. For these type inclusion complexes, the results agreed well with a 1:1 association model. Apparent values for the association constants, and changes in the standard molar Gibbs' energies, enthalpies, entropies, were derived for the association process. The results indicate that the association of surfactants with β - cyclodextrin are strongly enthalpy driven with unfavorable entropy changes. The results also demonstrated that the shorter EO chain of Triton X series surfactant, the greater the association constant with β - cyclodextrin.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2000年第1期127-130,共4页
Acta Chimica Sinica
关键词
微量热法
非离子
表面活性剂
β环状糊精
包结物
isothermal titration calorimetry, Triton X series surfactants, β - cyclodextrin, association constant
