ISSN:
1435-1536
Keywords:
Binding isotherms
;
ionic surfactants
;
human hair
;
thermodynamic parameReferences
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Binding isotherms of two types of ionic surfactants, CmH2m +1SO4Na (m = 8,10,12) and CnH2n + 1N+(CH3)3C1 (n=10, 12), to human hair in aqueous solutions were examined to clarify effects of hydrophobic and electrostatic interaction of ionic surfactants with hair. The binding isotherms of anionic surfactants showed cooperativity with discontinuously increasing shapes, while the binding isotherms of cationic surfactants showed a Langmuir-type, regardless of the difference of a hair condition. The calculated free energy change (— ΔG@#@) for binding, obtained from Klotz' plots, suggests that the binding processes are governed mainly by a hydrophobic interaction, and bound surfactants probably expose their alkyl chains to the aqueous phase, since no-ΔG was observed with the increase of m or n and values of enthalpy change(ΔH) were positive or zero.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01500756
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