Study of the Effect of Nonselective Organic Solvent Nature on the Self-Organization of Amphiphilic Block Copolymers of D,L-Lactide and Ethylene Oxide in Aqueous Solution

Abstract

The self-organization of biocompatible amphiphilic block copolymers of D,L-lactide and ethylene oxide with various hydrophobic poly(D,L-lactide) block length in aqueous media has been investigated. It has been shown that the nature of nonselective organic solvent has a considerable effect on the size, size polydispersity, and morphology of micelles of a block copolymer with a long poly(D,L-lactide) block. To elucidate the dependence of properties of block copolymer micelles on the common organic solvent type (acetone, tetrahydrofuran, N,N-dimethylformamide, and acetonitrile) various parameters of the used solvents have been estimated, and correlation between the Flory–Huggins coefficient and the surface tension between the hydrophobic block and the nonselective organic solvent and the parameters of micellar structures has been found.