Surface and bulk porosity mapping of polymer membranes using infrared spectroscopy

• Published in: Journal of membrane science Vol. 452; pp. 152 - 156
• Main Authors: Kiefer, Johannes, Rasul, Nadia H., Ghosh, Pranay K., von Lieres, Eric
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.02.2014; Elsevier
• Subjects: Applied sciences; ATR spectroscopy; Attenuation; Chemistry; Colloidal state and disperse state; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; FTIR spectroscopy; General and physical chemistry; Infrared; Infrared radiation; Infrared spectroscopy; Mapping; Membrane characterization; Membranes; Polymer industry, paints, wood; Porosity; Porous materials; Porous membranes; Spectroscopy; Technology of polymers; ATR spectroscopy; Membrane characterization; Porous membranes; FTIR spectroscopy; Characterization; Infrared spectrometry; Polymeric membrane; Porous membrane; Porosity
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2013.10.022

The porosity is a key characteristic parameter and significantly influences the behavior of a membrane in a given application. This work demonstrates the use of infrared (IR) spectroscopy for mapping the porosity of polymer membranes. Conventional transmission IR spectroscopy is employed to assess the bulk porosity across the entire thickness of a polyethersulfone (PES) membrane, while attenuated total reflection IR (ATR-IR) provides information about the porosity of a thin layer at the membrane surface. The results indicate that the bulk porosity of the studied membrane is rather homogeneous while the surface porosity is characterized by systematic local deviations from its mean value up to about 30%. IR spectroscopy turns out to be a suitable and straightforward method to characterize the porosity distribution of membranes. [Display omitted] •Transmission IR spectroscopy allows bulk porosity of polymer membranes to be measured.•ATR IR spectroscopy facilitates surface porosity measurements of polymer membranes.•Surface porosity shows systematic distribution while bulk porosity appears homogeneous.