Knowledge Bank

The reaction between sodium polymethacrylate(SPMA), containing fluorescent pyrene groups, covalently attached to the SPMA chains and N-dodecylpyridiniumchloride ($C12PyCl$) - the quencher of pyrene fluorescence has been studied. The reaction is accompanied by a decrease of fluorescence intensity in the reactive mixture which indicates on the formation of the ionic bonds between SPMA and $C12PyCl$. Water-soluble non-stoichiometric polymer-surfactant complex (PSC): SPMA-$C12PyCl$ is formed as a result of this reaction. Composition and structure of such PSC has been investigated by foton-correlation spectroscopy technique. Addition of anionic surfactant to such complexes results in sharp increase of fluorescence intensity in the reactive mixture due to the proceeding of the reaction: $PSC(SPMA-C12PyCl)+RNa⟵SPMA+(C12PyCl-RNa)\downarrow$ (1) where $R=AlkSO3,AlkSO4,AlkCOO;Alk=C8H17-C14H29$; It was shown by ultraviolet and fluorescence techniques that equilibrium constant of this reaction is determined by the length of aliphatic radical of anionic surfactant, chemical nature of its ionogenic group and concentration of low-molecular electrolyte. Kinetic data and the mechanism of reaction(1) are discussed.