Critical Micelle Concentration Lab Report

Critical Micelle Concentration

The CMC (Critical Micelle Concentration) is the amount of a surfactant molecule in a bulk stage, beyond which aggregates of surface active agents, so-called micelles. The CMC is a significant distinctive property of surfactants for its application. Generally molecules have two different constituents with differing attraction for the solutes. The component of the molecule that has an empathy for polar solutes, like water, is assumed to be hydrophilic. The component of the molecule has empathy for non-polar solutes, like hydrocarbons, is assumed to be hydrophobic. And the same molecule with hydrophilic and hydrophobic moieties are known to be amphiphilic. Amphiphilic molecules demonstrate different conduct when act together with water. An amphiphilic molecule can dispose themself on the surface of aqueous phase so that the polar moiety interacts with the aqueous phase and the non-polar moiety is detained above the surface (in the air/ non-polar liquid) (Figure). Such compounds are known as ‘surface active agents’ or surfactants. Microbial cells (bacteria and yeast) are reported ubiquitously for producing these kind of surfactant in their ecological niche and known as

paracasei isolated from the Portuguese dairy industry was found to be 2.5 mg/ml with surface tension 41.8 mN/m (Gudina et al., 2010). Those surfactants can decrease the surface tension of water or PBS around 36-39 mN/m and even their cmc values ranges from 1.0-20 mg/mL. As compare to the chemical surfactant surface tension reduction and cmc values it has been very close to the surface tension reduce by the SDS (Sodium dodecyl sulfate) i.e. 37.0 mN/m and 1.8 mg/L respectively. Biosurfactant produced by the Lactobacillus spp. CV8LAC which inhibits the biofilm formation by human pathogen was found to be 106 µg/mL with a reduction in surface tension from 70.92 to 45.4 mN/m (Fracchia et al.,