Production of porous poly(ε-caprolactone)/silica hybrid membranes with patterned surface pores

This paper reports a novel way of synthesizing porous poly(ε- caprolactone) (PCL)/silica hybrid membranes with a patterned surface pores by casting a mixture containing a PCL solution and sol-gel derived silica sol at room temperature. When the initial TEOS content in relation to the PCL content in the mixture was ≥ 20 vol.%, a highly porous structure containing patterned surface pores, ∼ 40-70 μm in size, was formed successfully. The silica phase was hybridized uniformly with the PCL polymer without any noticeable phase separation, as confirmed by energy dispersive X-ray spectroscopy (EDS). The porosity increased from 4.5 to 39.2 vol.% with increasing initial TEOS content from 0 to 40 vol.%. However, the hybrid membranes prepared at an initial TEOS content of ≥ 20 vol.% showed a reasonably high tensile strength and elastic modulus, ranging from 7.6 to 5.0 MPa and 79 to 51 MPa, respectively.