Using Indentation to Quantify Transport Properties of Nanophase Segregated Polymer Membranes

Published

July 14, 2015

Author(s)

Eric Davis, Nichole Nadermann, Kirt A. Page, Christopher Stafford, Edwin Chan

Abstract

Heterogeneous, nanophase segregated polymers are ubiquitous in technologies such as fuel cells and batteries, water purification, and drug delivery, where the thickness of the polymer layer ranges from hundreds of microns to tens of nanometers. Correspondingly, there is a growing need for robust experimental platforms to measure transport and material properties of nanophase segregated polymers over a wide range of length scales. Herein, we propose the use of poroelastic relaxation indentation (PRI) to characterize network structure and water transport in heterogeneous polymer membranes with thicknesses ranging from bulk-like to tens of nanometers. As a first demonstration, we use measure the in-plane diffusion coefficient of water and the intrinsic permeability in a nanophase segregated ionomer, Nafion, the current state-of-the-art polymer for electrochemical devices. Furthermore, a picture of the transport structure experienced by water molecules during the diffusion process is presented through the use of pore network theory. We successfully apply this experimental platform to bulk Nafion membranes with thickness ≈ 200 μm, as well as a range of Nafion thin films with thicknesses from ≈ 55 nm to 1 μm. Results from this work highlight the unique ability of PRI, in combination with pore network theory, for characterizing transport and structure in nanophase segregated polymer membranes.

Citation

Advanced Materials

Volume

27

Issue

33

Pub Type

Journals

Keywords

Polymer thin films, membranes, poromechanics, indentation, polymer networks

Citation

Davis, E. , Nadermann, N. , Page, K. , Stafford, C. and Chan, E. (2015), Using Indentation to Quantify Transport Properties of Nanophase Segregated Polymer Membranes, Advanced Materials (Accessed September 8, 2024)