The nature of the binding of high-molecular weight aminoammonium and quaternary ammonium salts with the amorphous silica surface

The adsorption of high-molecular weight aminoammonium salt (C10H21)2N(CH2)2N(C10H21)3I and quaternary ammonium salts with different structure of hydrophilic and hydrophobic areas: (CH3)(C10H21)2N(CH2)2N(C10H21)3I2, (C10H21)3N(CH2)6N(C10H21)3I2 and (C2H5)4NBr on amorphous silica (SG) has been investigated. The surface hydrate coating parameters of modified SG have been studied by the 1H NMR spectroscopy technique applied to the frozen suspensions. The data obtained were used for identification of the nature of the modifying agent binding with SG surface. It was shown that beside dipole–dipole intramolecular dispersive interaction plays an essential role in high-molecular weight salts immobilization on SG surface. The binding of aminoammonium salt with the surface is also a result of hydrogen bound complexes formation between ternary amine nitrogen of salt and surface hydroxyl group.