Synergy effect for performance of anionic SDS/ADS mixtures with amphoteric and nonionic surfactants

Abstract

Detergency and surface active properties of mixed anionic surfactants with amphoteric and nonionic were investigated. Sodium dodecyl sulfate (SDS) and ammonium dodecyl sulfate(ADS) as anionic surfactants and cocamidopropyl betaine (CAPB) as an amphoteric surfactant were used. Nonionic surfactants, which are butyl glucoside (BG), octyl glucoside (OG), decyl glucoside(DG), lauryl dimethylamine oxide (AO) and saponin were also used. To study the synergy effects of mixed SDS/ADS anionic surfactant systems, amphoteric and nonionic surfactants were added into the mixed anionic surfactants. Investigated properties of surfactant mixtures were critical micelle concentration (CMC), surface tension (γ), wettability. In addition, based on these properties, detergency of each sample was examined. Surfactant mixtures are anionics (SDS/ADS), anionic/amphoteric/nonionic (SDS/ADS/CAPB/ saponin), and anionic/nonionic (SDS/ADS/BG/saponin, SDS/ADS/OG/saponin, SDS/ADS/ DG/saponin, and SDS/ADS/AO/saponin). With the addition of amphoteric and nonionic to mixed anionic surfactants, CMC and γ were decreased. Addition of CAPB, which is amphoteric, showed the best property at CMC and γ. Furthermore, as the chain length of hydrocarbon in alkyl glucosides was increased, the CMC and γ were enhanced. However, the wettability did not exactly match up with CMC and γ. The surfactant mixture, which contained DG, showed the best performance at wetting time. Detergency was measured at various temperatures (15 oC, 30 oC, 50 oC). The cleaning performance was enhanced by increasing washing temperature. Moreover, detergency was influenced by not only CMC and γ but also wettability. Although CMC and γ were not minimum at surfactant mixture that included DG, the best cleaning performance showed in that sample.