Reaction of SDS with Ozone and OH Radicals in Aqueous Solution

Abstract

Ozone can be used as an antiseptic in cleaning systems. SDS (Sodium Dodecyl Sulfate) has proved to be a suitable surfactant in such systems. However, kinetic studies have showed that SDS reacts with ozone at high concentrations. In contrast, the natural decomposition of ozone to oxygen is retarded at low SDS concentrations. NMR spectroscopic analyses of SDS solutions being continuously treated with ozone and OH radicals, respectively, have been performed. ¹H-, ¹³C-, COSY-, HMBC- and HSQC-NMR spectra were recorded showing that small carboxyl acids were formed at exposure to ozone. Randomly positioned carbonyl groups were also found along the hydrocarbon chain. However, the largest product was caused by direct reaction of SDS with ozone. The predominant product most likely is a SDS-peroxide. ¹H –NMR spectra of the samples treated with OH radicals also show the formation of small carboxylic and carbonyl groups. However, there is no indication of oxidation of the sulphate group.

Keywords:

• Ozone
• Sodium Dodecyl Sulfate (SDS)
• Peroxide
• OH Radical
• Oxidation
• Scavenger

ACKNOWLEDGMENT

OTRE AB is acknowledged for financial support. David Stenman at Nuclear Chemistry, Royal Institute of Technology is acknowledged for his help with gamma radiation of the SDS solution. Gustav Sundqvist at Analytical Chemistry, Royal Institute of Technology is acknowledged for his help with the preliminary electrospray mass spectroscopy analysis.

Notes

Ekberg, K. In Pct Int. Appl.; (Otre Ab, Swed.). No Wo 2001018456, 2001.

Eriksson, M., Kloo, L., Östensson, R. “Bacteriological Study of an Aqueous SDS Solution with Ozone or SDS Peroxide,” submited 2007.

Kloo, L. and M. Eriksson, “Cleaning Compositions Containing Stabilized Ozone Solutions,” In U.S. Pat. Appl. Publ.; (Otre Ab, Swed.). US, 2003228988, 2003.