(534e) QCM-D Study of the Solvent-Polymer-Catalyst Particle Interface in Fuel-Cell Inks | AIChE

(534e) QCM-D Study of the Solvent-Polymer-Catalyst Particle Interface in Fuel-Cell Inks


Berlinger, S. A. - Presenter, University of California Berkeley
Radke, C., University of California-Berkeley
McCloskey, B., University of California, Berkeley
Weber, A., Lawrence Berkeley National Laboratory
Quartz-crystal microbalance with dissipation (QCM-D) is a widely-applicable tool capable of measuring mass uptake in liquid media. The Sauerbrey equation is routinely used to analyze QCM-D data. In many instances, however, the assumptions of the Sauerbrey equation (namely that there exists a thin, rigid, homogeneous adsorbed layer) are not met. This is particularly the case when studying polymer adsorption to a surface, primarily because mass change is due to both adsorbed polymer and trapped water. Furthermore, the dissipation signal is often affected by hydrodynamic complications as a result inhomogeneous film formation.1 Therefore, deconvolution of the data to isolate the contribution of adsorbed polymer is nontrivial. Herein, we explain the complexities of analyzing polymer adsorption data obtained with QCM-D by studying polymer adsorption to model surfaces, with application to fuel-cell inks.

Fuel-cell electrodes are made from inks that are mixtures of polymer and catalyst nanoparticles dispersed in a mixed solvent (typically water and alcohols). The polymer is a perfluorinated sulfonic acid polymer (PFSA), which has a Teflon backbone with sidechains that terminate in sulfonic-acid moieties. The duality between the strongly acidic sidechains and hydrophobic backbone of the polymer cause it to adopt unique conformations in solution, which are a strong function of the amount of water present in the ink.2-3 Understanding PFSA adsorption to the catalyst particle surface is critical for understanding ink (and electrode) structure and performance. In this study, we explore the polymer/particle interaction using QCM-D with model functionalized surfaces that can be related to the more complex catalyst-particle system. PFSAs of different ion-exchange capacities in a variety of solvents are investigated to understand how polymer adsorption and desorption behavior is affected by solvent quality. Results reveal that hydrophobic interactions are a major driving force for PFSA adsorption.


This study was mainly funded under the Fuel Cell Performance and Durability Consortium (FC-PAD) funded by the Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office, of the U.S. Department of Energy under contract number DE-AC02- 05CH11231. S.B. also acknowledges support from the National Science Foundation Graduate Research Fellowship under grant number DGE 1752814.


  1. Reviakine, I.; Johannsmann, D.; Richter, R. P., Analytical Chemistry 2011, 83 (23), 8838-8848.
  2. Welch, C.; Labouriau, A.; Hjelm, R.; Orler, B.; Johnston, C.; Kim, Y. S., ACS Macro. Lett. 2012, 1 (12), 1403-1407.
  3. Berlinger, S. A.; McCloskey, B. D.; Weber, A. Z., J. Phys. Chem. B. 2018.