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 amphotericand nonionic were investigated. Sodium dodecyl sulfate (SDS) and ammonium dodecyl sulfate(ADS) as anionic surfactants and cocamidopropyl betaine (CAPB) as an amphoteric surfactant wereused. 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 effectsof mixed SDS/ADS anionic surfactant systems, amphoteric and nonionic surfactants were addedinto the mixed anionic surfactants. Investigated properties of surfactant mixtures were criticalmicelle concentration (CMC), surface tension (γ), wettability. In addition, based on theseproperties, 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 theaddition 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 wereenhanced. However, the wettability did not exactly match up with CMC and γ. The surfactantmixture, which contained DG, showed the best performance at wetting time. Detergency wasmeasured at various temperatures (15 oC, 30 oC, 50 oC). The cleaning performance was enhancedby increasing washing temperature. Moreover, detergency was influenced by not only CMC and γbut also wettability. Although CMC and γ were not minimum at surfactant mixture that includedDG, the best cleaning performance showed in that sample.