Journal of Membrane Science, Vol.407, 128-135, 2012
Nanoscale characterization of synthetic polymeric porous membranes: Scrutinizing their stiffness, roughness, and chemical composition
Synthetic polymeric porous membranes (PPMs) have been widely used in several areas. Here, PPMs were scrutinized in a systematic approach over their mechanostructural features, chemical composition and filtration efficiency. Four types of PPMs (nitrocellulose, nylon, RIFE, and PVDF) were analyzed by single point force spectroscopy (FS), atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and energy-dispersive X-ray spectroscopy (EDS). PTFE membrane showed discrepancy between top and bottom parts related to FS parameters. The most irregular topography assessed by AFM was presented by nylon membrane showing out values for roughness parameters (Ra, Rz, and Rp) higher that all other membranes. Determination of filtration efficiency by spectrophotometric measurements did not allow us to visualize tendencies for incrustation of compounds. Nevertheless, AFM and SEM images of PPMs before and after filtration tests showed significant topographical differences. FTIR and EDS analyses also evidenced PPMs chemical and elemental composition, respectively. The use of these approaches focusing on nanometric aspects of each membrane can reveal new possibilities concerning their characterization and applications. It arises as an alternative tool for quality control evaluation, or search for support for biomolecules immobilization. (C) 2012 Elsevier B.V. All rights reserved.