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

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.