The interaction of an azo compound with a surfactant and ion pair adsorption to solid phases

Author(s)

Ribeiro Gomes, Ana Carolina ^[1] ; Fernandes Cafer, Luciene Dias ^[1] ; Homem-de-Mello, Paula ^[1] ; Coutinho-Neto, Mauricio Domingues ^[1] ; Gaubeur, Ivanise ^[1]

Affiliation

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Santo Andre - Brazil

• Document type: Journal article
• Source: Journal of Colloid and Interface Science; v. 367, p. 370-377, FEB 1 2012.
• Web of Science Citations: 7

Abstract

The adsorption of SPADNS (trisodium salt of 2-(p-sulfophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid) onto resins XAD 2, XAD 7 and silica gel was studied in the presence and in the absence of the cationic surfactant CTAB (cetyl trimethylammonium bromide). At a ratio of 2.5 CTAB to 1 SPADNS, the surfactant caused a marked increase in SPADNS adsorption. The experimental results for adsorption versus time were applied on the basis of three kinetic models (pseudo-first-order Lagergren, pseudo-secondorder, and intraparticle diffusion). The interaction between CTAB and SPADNS was investigated using spectrophotometric, conductometric, and computational techniques. Theoretical results point to the formation of an ion pair between CTAB and SPADNS that influences the solution spectra, in agreement with conductometric and spectrophotometric data. (C) 2011 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 08/09545-1 - Immobilization of 1,8-dihydroxy-2-(4-sulfophenylazo)naphthalene-3,6-disulfonic acid trisodium (SPADNS) in diverse solid phases - assessment and use in the development of spectrophotometric method
• Grantee: Ivanise Gaubeur
• Support Opportunities: Regular Research Grants