The addition of amphiphilic materials to a solvent in which they are clear is fundamentally different from adding materials that are not amphiphilic to the same solvent. Consider water as the solvent. Addition of a non-amphiphilic material like salt (NaCl) results in a clear solution that has the same concentration of sodium ion and chloride ion equally dissolved therein. Consider now an amphiphilic material like sodium lauryl sulfate (SLS). The addition results in a clear “solution” but this time the concentration throughout the solvent is not the same. This is because the C12 alkyl group that is contained therein is disrupting the hydrogen bonding between water molecules. The energetics of the system causes the SLS to saturate the air/water interface (lowering surface tension) and then to form agglomerates called micelles. The concentration at which micelles form is the “critical micelle concentration” (CMC). The phenomenon is shown in Figure 1. It is important to note that the water has a surface tension of around 72 dynes/cm before addition of the SLS, and 30 dynes/cm after the critical micelle concentration is reached. Surfactants based on hydrophobes, as well as oils having alkyl groups, have a surface tension in the 30 dynes/cm to 35 dynes/cm range. This results from the fact that this class of materials has predominately methylene groups (–CH2–) present in the molecule. Surfactants having silicone groups as the hydrophobe have lower surface tensions in the 20 dyne/cm2 range. This happens because silicone hydrophobes have predominately methyl groups (CH3–) present in the molecule. This observation is critical to the understanding of how silicone surfactants lower the surface tension in oil based systems. Figure 2 shows the CMC graph for PEG-8 dimethicone. Note the surface tension at the CMC is 20 dynes/cm.