1H NMR Study on Pre-micellization of Quaternary Ammonium Gemini Surfactants

Autor:	Xiaohong Cui, Yan Jiang, Hong Chen, Maili Liu, Shizhen Mao, Ping-Ya Luo, You-Ru Du
Rok vydání:	2008
Předmět:	Self-diffusion Aqueous solution Chemical shift Analytical chemistry Surfaces and Interfaces Condensed Matter Physics Micelle Oligomer chemistry.chemical_compound Pulmonary surfactant chemistry Electrochemistry Proton NMR General Materials Science Ammonium Spectroscopy
Zdroj:	Langmuir. 24:3118-3121
ISSN:	1520-5827 0743-7463
Popis:	Two quaternary ammonium Gemini surfactant series, 12-s-12, ([C(12)H(25)N+ (CH(3))(2)](2)(CH(2))(s).(2)Br(-)) and 14-s-14 ([C(14)H(29)N(+)(CH(3))(2)](2)(CH(2))(s).(2)Br(-)), where s = 2, 3, and 4, have been studied by the use of (1)H NMR in aqueous solution at concentrations below their critical micelle concentrations (CMC) at 25 degrees C. The appearance of a second set of peaks for the 14-s-14 series and the changes in chemical shifts, line widths, and line shapes of the 12-s-12 series with increasing concentration below the CMC are interpreted as evidence for the formation of premicelle aggregates (oligomers) that appear at approximately one-half their CMC values. Self-diffusion coefficients (D) and transverse relaxation times (T(2)) have also been detected and support the results obtained by (1)H NMR.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d975a3601103d68abc699f698b80f74f https://doi.org/10.1021/la703346p Zobrazit plný text záznamu