Solid-state blending for the preparation of porous eco-friendly PCL membranes: Potential for filtration applications

Abstract

Cryomilling is a promising method for fabricating polymeric blend and composite powder raw materials for various subsequent manufacturing processes. In this study, biodegradable porous membranes were fabricated from poly (ε-caprolactone) (PCL) using the cryomilling/hot pressing/porogen leaching approach. Powder mixtures of six different model compositions were compounded by cryomilling; thereafter, films were fabricated by hot-pressing. Poly (ethylene-oxide) (PEO) and salt were utilized as eco-friendly porogens in these mixtures, which were dissolved in water to introduce porosity in the films. Wood sawdust (WSD) and alum were investigated as fillers potentially capable of manipulating the hydrophilicity, mechanical and antimicrobial properties of the membranes. The morphological, hydrophilicity, mechanical, and filtration efficiency properties were explored and compared to those of commercial laboratory microfiltration (MF) membranes. SEM analysis revealed dense membrane skins for all compositions, along with lamellar porous structures. Mean pore radius ranged from 0.15 to 0.21 μm, which is within the MF pore size range. Water contact angle measurements averaged 70° and decreased with the addition of WSD and alum, indicating increased hydrophilicity. Tensile test results showed a decrease in mechanical properties, with higher porosities and with the addition of WSD. Adding alum (≥10 wt%) resulted in embrittled membranes. Filtration performance was evaluated in terms of pure water flux and turbidity reduction for textile wastewater, and it compared favorably to commercial membranes. In conclusion, this study has successfully introduced a new facile and versatile membrane fabrication approach.

Establishment of Unique Cone Shapes and Universal Shape Parameters toward Predicting Fiber Diameter in Polymer Electrospinning

“…The primary goal of this work was to objectively establish common shape parameters across uniquely identified cone shapes in polymer electrospinning and correlate specific parameters with fiber diameter. PCL was chosen for investigation due to its wide use in diverse applications from filtration , to biomedical engineering. , Indeed, previous studies from our group have demonstrated the application potential of electrospun PCL fibers in drug release and phenotypic polarization in immune cells . In the current study, fluorinated alcohols TFE and HFIP were chosen for preparing PCL solutions due to their extensive use in the electrospinning of poly­(α-esters). , TFE and HFIP were chosen also due to intrinsic differences in their surface tension values (21.1 mN/m and 14.6 mN/m, respectively) that would be expected to likely result in differential cone shapes and curvatures.…”

“…The primary goal of this work was to objectively establish common shape parameters across uniquely identified cone shapes in polymer electrospinning and correlate specific parameters with fiber diameter. PCL was chosen for investigation due to its wide use in diverse applications from filtration 45,46 to biomedical engineering. 47,48 Indeed, previous studies from our group have demonstrated the application potential of electrospun PCL fibers in drug release 49 and phenotypic polarization in immune cells.…”