Optimization of polyalkylcyanoacrylate nanoparticle preparation: Influence of sulfur dioxide and pH on nanoparticle characteristics

Abstract

Simultaneous influence of pH and presence of sulfur dioxyde (SO 2) on nanoparticle preparation and characteristics have been investigated with poly(isohexylcyanoacrylate) and poly(isobutylcyanoacrylate). Turbidity, nanoparticle size, and molecular weights were followed to understand the exact role of each parameter tested. Results showed the extreme importance of SO 2 concentration on nanoparticle characteristics and confirmed its role as a polymerization inhibitor. We also demonstrated that, in certain circumstances, pH could compensate, in a limited way, for the effect of SO 2. In fact SO 2 was always shown to have such a strong effect on size and molecular weight that reproducible batches could be achieved only with SO 2-free monomers. Subsequent work on nanoparticle charges under similar conditions will help to gain a better understanding of SO 2 influence.