FORMULATION DEVELOPMENT TO OBTAIN THIN FILM COATINGS ON SOLID SURFACES USING ADMICELLAR POLYMERIZATION

Abstract

Hydrophobic and hydrophilic properties are imparted on solid surfaces to enhance the properties of surfaces. From over a decade several methods have been employed to impart thin film coatings onto surfaces. Apart from different polymerization methods, admicellar polymerization process was implemented to impart enhanced properties to selected solid surfaces. Admicellar polymerization (AP), a surface analogue of emulsion polymerization was used to develop film coatings on surfaces. AP follows three basic steps. First step is adsorption of surfactant molecules on to surface. The second step is adsolubilization of monomer into adsorbed surfactant molecules on surface. The next step is to initiate reaction and once the polymer is formed, modified surfaces are rinsed for removal of excess surfactant. Development of a system for AP involves measurement of surfactant adsorption and adsolubilization or partitioning of monomer into adsorbed structures. Two-site adsolubilization model and binary adsolubilization models were used to calculate the size of surfactant aggregates over the surface of solids. High performance liquid chromatography (HPLC) analytical technique was used to obtain the adsorption and adsolubilization measurements. We have to modify the two-site adsolubilization model to fit for the surfaces we have used. Adsolublized monomers were polymerized to form thin film coatings on surfaces. The modified solid surfaces were analyzed using different analytical techniques SEM, EDS, TGA, BET, FTIR to confirm the polymer formation. Hydrophilic and hydrophobic properties are tested with respective test methods depending on what type of surface used.