Performance characterization of water extracts of Camellia oleifera cake/ sodium N-lauroylsarcosinate foam detergent with high foamability

In this study, we hypothesized that an environment-friendly foam detergent with synergistic effects could be synthesized from saponins-rich water extracts (WE) of Camellia oleifera cake, sodium N-lauroylsarcosinate (SLS), citric acid (CA), and ethanol. The ratio of WE and SLS was optimized by comparing the foam properties and cleaning efficiency. The synergistic effect was elucidated by viscosity, surface tension, zeta potential, contact angle, and particle size. The effects of ethanol and CA on the foam properties and cleaning efficiency were also studied, and the potential mechanism was analyzed. The results showed that SLS-WE (3-1) with the strongest foamability had the highest cleaning efficiency (82.8%) for olive oil. This is related to the synergistic effects of surface activity between WE and SLS. The addition of WE improved the foam elasticity and yield stress of the mixture system, thus preventing secondary contamination. The addition of CA (0.1 wt%), ethanol (3.7 wt%), and CA/ethanol (0.1/3.7 wt%) improved the foamability with no negative effect on foam stability. The cleaning efficiency of foam detergent reached 93.7% under the mixture of CA and ethanol. The SLS-WE (3-1) system improved the oil imbibition of foam by reducing surface tension and bubble size. Moreover, the SLS-WE (3-1) foam had a strong wiping motion. Ethanol and citric acid increased cleaning efficiency by improving imbibition and wiping, respectively. The environmentally friendly foam detergent fabricated in this research exhibited high foamability, stability, and cleaning efficiency.