Effects of pH and temperature on the sorption of sodium dodecyl sulfate by cellulose acetate/polyaniline blend membranes

✍ Scribed by R. F. P. Pereira; D. A. Cerqueira; A. J. M. Valente; A. Y. Polishchuk; H. D. Burrows; V. M. M. Lobo

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 208 KB
• Volume: 111
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.29223

✦ Synopsis

Abstract

Cellulose acetate/polyaniline (PANi) blends show a selective response to the presence of sodium dodecyl sulfate (SDS). Such detection can be monitored by visible absorption spectroscopy. In this article, we show how this is dependent on the pH and temperature. At pH 2, the redshift of the maximum absorbance wavelength of blend films is essentially dependent on hydrochloric acid; however, at pH 3, this effect clearly decreases, and at pH values between 4 and 6, the alteration of the blend color depends only on SDS. The selective detection of SDS is faster with a higher percentage of PANi in the blend. At 25°C, the mechanism of sorption is essentially Fickian for short times, but this changes at higher temperatures, and at temperatures of 40°C and higher, the sorption kinetics show an initial time lag in which no visible response from the blend to SDS is detected. The response rate of blends to SDS detection increases with the temperature and PANi content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009