Interaction of polysilicic acid with monolayers of substances containing quaternary ammonium groups

The action of polysilicic acid on monolayers of a quaternary ammonium salt and a phospholipid spread on substrates of various pH values was studied. The films of benzyl dimethyl hexadecyl ammonium chloride were considerably affected above pH 2. No interaction was observed, at any pH, between silicic acid and dipalmitoyl phosphatidyl serine.The results support the existence of ionic interactions between dissociated silanol groups and tetra-alkylammonium groups. The involvement of hydrogen bonds is ruled out.