The surface chemical structure of poly(β-hydroxybutyrate) microparticles produced by solvent evaporation process

Abstract

The surface chemistry of poly(β-hydroxybutyrate) particles produced by the solvent evaporation approach has been examined, before and after cleaning, by zetapotential measurements and static secondary ion mass spectrometry (SSIMS). The SSIMS analysis was able to detect the presence of the residual stabiliser (surfactant sodium dodecyl sulphate (SDS)) on the particle surface. The surface analysis showed that DS still predominates at the particle surface even after cleaning by dialysis and ultrafiltration methods. A significant reduction in DS surface content was seen after cleaning by gel permeation chromatography. The implications of these findings are discussed with reference to the particle production technique and the cleaning processes.