Characterization and Development of a New Method for Determination Charge Density of 3-(Trimethoxysilyl)-propyldimethyloctadecyl Ammonium Chloride Coatings on Polyester Surfaces

Medical science benefits from models that predict antimicrobial activity, as well as the mechanism of antimicrobial agent activity effective in treatment of infectious diseases. A new method to determine the charge density of quaternary nitrogen in 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride on the surface of polyester (PET) fabric was developed using C.I. Direct Red 47. The properties K/S (color strength), charge density, antibacterial efficiency, hydrophilicity, and surface potentials were examined. The experimental charge density value of 1.33 x 10 ¹⁶ units/cm ² was close to the calculated value of 1.35 x 10 ¹⁶ units/cm ² for 0.05% load quat-silane assumed by the amount of quat applied. In addition, correlation between K/S values and charge density had a linear correlation coefficient close to unity.