Abstract:
Recently, surfactant-based processes have been widely investigated for environmental application. In all of these applications, surfactant adsorption onto solid surfacetant-modified adsorbents, which oppose the economics of the system, I losses of surfactants from the adsorbent due to pH changes or dilution of surfactant concentration and desorption. The purpose of this research is to minimize the surfactant losses from alumina surface using polymerizable surfactants. Minimum surfactant losses can be achieved because the polymerized film, which comes from polymerization of polymerizable surfactants, acts as strong surfactant bilayer coated onto alumina surface. The specific objectives of this study are to investigate the surfactant adsorption both polymericable surfactants and non-polymerizable surfactant; the adsolubilization capacity for organic solutes of polar nature, styrene, and non-polar nature, ethylcyclohexane into admicelles; and the desorption of the surfactants from alumina surface. The results showed that as the number of EO groups of the surfactants increased, the area per molecule increased and the maximum adsorption decreased. The lowest maximum adsorption was obtained at the number of EO groups of 20 of Hitenol BC 20 corresponding to 0.08 mmole/g or 0.34 molecule/nm. This attributed to the most bulky head due to the highest number of EO groups. For adsolubilization capacity of organic solutes, increasing the number of EO groups of the surfactants decreased the adsolubilized styrene and increased the adsolubilized ethylcyclohexane. For the surfactant desorption study, the polymerization of polymerizable surfactants could enhance the stability of surfactants adsorbed onto alumina surface and reduce the desorption of the surfactants from alumina surface. These results provide the useful information of the surfactant systems for designing surface modification to enhance contaminant remediation and industrial scale applications.