Modification of polymer membranes by ion implantation

This paper presents an experimental study of the transport properties of ion implanted isotactic polypropylene (iPP) polymer membranes. The polymer samples have been irradiated with O⁷⁺, S⁹⁺ and F⁶⁺ ions having the energy 10 keV/q with fluence up to 10¹⁶ ions/cm². In this experiments the incident ions were produced by the ECR ion source. The transport properties (diffusive permeability), changes of the chemical structure and wettability of ion implanted membranes were investigated. The transport properties were studied by measurements of the solute concentration profiles. The changes of the chemical structure were investigated by the differential scanning calorimetry (DSC) thermograms and the atom force microscopy (AFM) images measurements. Finally, the wettability – by the contact-angles methods. The results of the AFM imaging show that ion implantation induce changes in surface topography of polypropylene samples. The degree of crystallinity of iPP foils is decreased by ion implantation. The hydrophilicity of the modified iPP is increased considerably in comparison to the unimplanted foils. Also the hysteresis in the contact-angle gives some indication about the surface roughness or composition. The behavior of the iPP membranes modified by ion implantation shows greater permeability for transported substance.