文献类型：期刊文献

英文题名：Micellization of cationic gemini surfactant and its interaction with DNA in dilute brine

作者：He, Yunfei[1,2];Shang, Yazhuo[1,2];Shao, Shuang[3];Liu, Honglai[1,2];Hu, Ying[1,2]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Dept Chem, Shanghai 200237, Peoples R China;[3]Zhejiang Int Studies Univ, Dept Chem, Hangzhou 310012, Zhejiang, Peoples R China

年份：2011

卷号：358

期号：2

起止页码：513

外文期刊名：JOURNAL OF COLLOID AND INTERFACE SCIENCE

收录：;EI(收录号：20111713938715);WOS:【SCI-EXPANDED(收录号:WOS:000290188400028)】；

基金：This work is supported by the National Natural Science Foundation of China (Projects No. 20736002, 20706013), the creative team development project of Ministry of Education of China (No. IRT0721), the 111 Project of Ministry of Education of China (No.B08021) and the Fundamental Research Funds for the Central Universities. The authors thank Prof. Dominique Langevin and Dr. Eric Raspaud for fruitful discussions.

语种：英文

外文关键词：DNA; Cationic gemini surfactant; Micellization; Interaction

摘要：The micellization of cationic gemini surfactant trimethylene-1,3-bis (dodecyldimethylammonium bromide) (12-3-12.2Br) was investigated and critical micelle concentrations (CMC) and thermodynamic parameters were evaluated as functions of ionic strength and temperature. The micellization of 12-3-12.2Br is entropically driven and thermodynamically favored. Raising the temperature slightly increases the CMC, while increasing the ionic strength lowers the CMC. A multi-technique study of the 12-3-12.2Br/DNA interaction and its dependence on ionic strength, temperature and DNA concentration were presented. DNA with loose coil conformation, necklace-like structure, highly ordered toroidal aggregates and coexisting of large aggregates and small structures in DNA/12-3-12.2Br system were observed. Critical aggregation concentrations (CAC), interaction saturation concentrations (C-2), and associated thermodynamic parameters were determined. The screening effect of salt decreases the DNA/12-3-12.2Br electrostatic attraction, but favors the formation of free 12-3-12.2Br micelles or aggregates on the DNA chain. DNA acts as a separate phase contacting with the surfactant molecules and therefore CAC is independent of DNA concentration. Increasing DNA concentration postpones the appearance of free micelle in bulk phase, consequently increases the C-2. Finally an interaction mechanism between 12-3-12.2Br and DNA was proposed. Copyright (C) 2011 Elsevier Inc. All rights reserved.