Reactivity and Coaggregation of p-Nitrophenyl Esters with Polymer Micelles at Solid Surfaces

The polymer micelle, poly[(N-(n-dodecyl)-4-vinylpyridiniumco-N-ethyl-4-vinylpyridinium) bromide], PDE, containing 30% dodecyl groups has been found to promote the adhesion of lipophiles to various surfaces including quartz, polystyrene, and poly(methyl methacrylate) cuvette surfaces from aqueous solutions. The adsorption of PDE/ester coaggregates to the surfaces was studied by hydrolysis of p-nitrophenyl esters in aqueous PDE(30) solutions. The extent of reaction of p-nitrophenyl myristate, an ester with a linear acyl carbon chain length of 14, can be viewed as a probe to study the adhesion of the PDE/ester coaggregates to the cuvette surfaces. The difference between initial concentration of ester and concentration of hydrolysis product, p-nitrophenoxide ion, gives the concentration of unreacted ester in the aggregates or film adhering to the solid surface. Up to 40% of p-nitrophenyl myristate was found unreacted on the surface of quartz cuvettes after apparent completion of the reaction. No adhesion of the related caproate ester with a linear acyl carbon chain length of 6 was detected. Copyright 2000 Academic Press.