Attenuated Total Reflectance Mode for Transport through Membranes

This chapter is an introductory tutorial to attenuated total reflectance (ATR) mode of Fourier-transform infrared spectroscopy and how it can be used to measure transport through polymer membranes. In addition to covering the experimental set-up and time-resolved data processing, it will present the fundamental equations for analyzing the data in order to obtain diffusion coefficients. The chapter will present several example systems in which FTIR-ATR has been used to determine transport, including water diffusion through polyelectrolytes for fuel cells and block copolymers for water purification as well as ion transport through polymer electrolytes for lithium batteries. Perspectives on future applications in which the technique could provide fundamental understanding will also be covered.