@article {Lin201241,
	title = {Interaction between crystal violet and anionic surfactants at silica/water interface using evanescent wave-cavity ring-down absorption spectroscopy},
	journal = {Journal of Colloid and Interface Science},
	volume = {379},
	number = {1},
	year = {2012},
	note = {<p>cited By 4</p>
},
	pages = {41-47},
	abstract = {<p>Evanescent wave-cavity ring-down spectroscopy (EW-CRDS) is employed to characterize micellization of anionic surfactants and the related capability of removing cationic substance off the silica surface. Crystal violet (CV +) cationic dye is used as a molecular probe to effectively determine critical hemimicelle concentration (HMC) of surfactants on the surface. The HMC results are 1{\texttimes}10 -2, 4{\texttimes}10 -3, 8{\texttimes}10 -4, and 2.5{\texttimes}10 -4mol/L for sodium sulfate salts with a carbon-chain length of C-10, C-12, C-14, and C-16, respectively. A stronger hydrophobic interaction results in a less concentration required to undergo micellization. The HMC values on the surface are about half of those in solution. When NaCl solution is added, the electrolyte helps reduce the electrostatic repulsion between the anionic sulfate heads to facilitate the surfactant aggregation, and thus, the subsequent HMC is reduced. Furthermore, the probable phase change for dye-surfactant interactions on the surface at the concentration below HMC is observed, and the desorption rates of CV + are measured as a function of concentration and carbon-chain length of surfactants above HMC. Given each surfactant concentration at its respective HMC, the corresponding desorption rates are along the order of C-12\&lt;C-14\&lt;C-16\&lt;-C-10. The trend may be realized by two competing factors of hemimicelle size and number density. The consequences help with understanding how to apply surfactant in the chromatographic separation. {\textcopyright} 2012 Elsevier Inc.</p>
},
	keywords = {Absorption spectroscopy, ADSORPTION, Anionic surfactants, aqueous solution, Article, Biophysics, carbon, Carbon-chain length, Cationic dyes, Chain length, Chromatographic separations, concentration (parameters), Crystal violet, DESORPTION, Desorption rate, Dye-surfactant interaction, Dyes, electric conductivity, Electromagnetic wave reflection, Electrostatic repulsion, EW-CRDS, Hydrophobic interactions, hydrophobicity, Interfacial adsorption, Liquid chromatography, Micellization, molecular interaction, Molecular Probes, NaCl solution, Number density, Phase Change, priority journal, Ringdown spectroscopy, Silica, Silica surface, silicon dioxide, Sodium chloride, SPECTROSCOPY, Surface active agents, Surfactant, Surfactant aggregation, Surfactant concentrations, water},
	doi = {10.1016/j.jcis.2012.04.041},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861948384\&doi=10.1016\%2fj.jcis.2012.04.041\&partnerID=40\&md5=92ed762990e7749d0421ee55e5bc94a4},
	author = {M.-C. Lin and Lin, K.-C.}
}
