Surfactants, polymers and their nanoparticles for personal care applications

A "touch me not" plant folding up rapidly upon being attacked or microbes depositing on teeth or ocean vessels even under hostile conditions are examples in nature that provide inspiration for developing new classes of personal care release or deposition systems. In this paper, development of such systems based on polymer/surfactant colloid chemistry is explored for achieving transport and release of cosmetic and pharmaceutical molecules at desired rates at desired sites. The successful development of products depends upon understanding and utilizing key interactions among surfactants, polymers and hybrid polymers that are relevant to personal care products. Thus, the absorbed layers or tethers on the particulates can be manipulated for desired dispersion of actives or depositions on substrate under any and all conditions. New hybrid polymers and nanogels have been synthesized for tuning up nanodomains that can extract and deliver at will cosmetics/drugs/toxins by perturbing pH, temperature or ionic strength of the system. Particularly, hydrophobically modified polymers have features of both polymers and surfactants and due to the associative nature of the hydrophobic groups, such polymers can form intramolecular nanodomains for performing carrier functions. Nanogels developed recently include that of polyacrylamide, poly(acrylic acid) and starch nanogels modified for extraction and subsequent slow release of fragrances and overdosed toxic drugs. Binding and release processes were investigated using surface plasmon resonance and fluorescence spectroscopies, powerful techniques for monitoring short term and long term changes.