title: [Determination of critical micelle concentration of alkyl polyglucoside (APG) nonionic surfactant aqueous system by multi-peaks Gaussian fitting of visible absorption spectra line shape].
abstract: A multi-peaks Gaussian fitting on the line shape of visible spectra was used to determine the critical micelle concentration (CMC) of alkyl polyglucoside (APG) nonionic surfactant aqueous system such as octyl beta D mono-glucoside (C8 G1) and decyl beta D mono-glucoside (C10 G1). Visible electronic absorption spectra of a series of different concentration C8G1 or C10G1 with crystal violet (CV) used as a probe were measured respectively and characterized by the overlap of the principal peak with lambda(max) at 598-609 nm and a shoulder at 538-569 nm assigned to monomer and dimer CV respectively. A multi-peaks Gaussian fitting was used to interpret the spectra and give relative integrating absorbance (A2/A1) of two peaks, red-shift (deltalambda) and half-width. A sudden change occurred at CMC in the curves of the relative integrating absorbance (A2/A1), red-shift (deltalambda) and half-width (w1, w2) versus the C8G1 or C10G1 surfactant concentrations. Significantly the dependence of the CMC upon the half-width was ob-served for the first time and successfully used to determine CMC of nonionic surfactant such as APG.
authors.affiliation: Department of Chemistry, Guangzhou University, Guangzhou 510006, China. zjhbox190@sina.com
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Zhang
authors.forename: Kai-Qing
authors.initials: KQ
authors.lastname: Kong
authors.forename: Zheng-Ling
authors.initials: ZL
authors.lastname: He
authors.forename: Zi-Li
authors.initials: ZL
authors.lastname: Liu