Superhydrophobic to Superhydrophylic Biomimetic Poly(3-Hydroxybutyrate) Surfaces Made by Phase Inversion

Biodegradable and biocompatible materials have gained increased attentions because of their applications in biomedicine and tissue engineering. Among them, poly(3-hydroxybutyrate) (PHB), a natural origin polymer, has been employed in biomedical applications as a suitable substitute of synthetic polymers for preparing scaffolds and other devices. In this context it is relevant to understand the interactions between the cells and PHB surfaces, which are governed by aspects such as surface topography and chemical composition. Both, surface topography and chemistry determine surface wettability. The aim of this work is to process PHB surfaces exhibiting extreme wettablility properties, ranging from superhydrophobic (surface contact angle higher than 150 degrees) to superhydrophilic (surface contact angle lower than 5 degrees). A simple phase inversion method was used to fabricate surperhydrophobic PHB surface. Chloroform was used as solvent, and a mixture of water and ethanol as the coagulation bath. The water contact angle was found to be 154.3 +/- 2.9 degrees. Furthermore the surface was treated by argon plasma for different times, permitting the control of wettability of the PHB surface from the superhydrophobic to superhydrophilic regime.