Comparative study of PVDF-HFP-curcumin porous structures produced by supercritical assisted processes

In this work, the comparison between PVDF-HFP porous structures loaded with 3% w/w curcumin (Cm), produced by supercritical assisted processes, was performed. In the case of membranes, different operative conditions (from 250 bar/35 °C to 150 bar/55 °C) and polymer concentrations (from 10 to 30% w/w) were tested. A cellular membranes morphology was observed and porosity values up to 89% were measured. Cm release was prolonged from 20 h to 26 h changing the PVDF-HFP membrane concentration from 20 to 30% w/w. PVDF-HFP-Cm aerogels were produced by supercritical drying, operating at 200 bar and 45 °C. A nanofibrous aerogels morphology was obtained with open and interconnected pores, reaching porosity values of 94%. The maximum Cm release was prolonged up to 44 h for 12% w/w PVDF-HFP aerogel. Kosmeyers-Peppas model produced a fair good representation of the Cm release experimental results for PVDF-HFP-Cm membranes and aerogels.