Polymer membranes are at the core of a diverse set of technologies critical to our global health and security, ranging from energy production to water purification to carbon capture. These engineered membranes must maintain performance over many years and under harsh conditions, such as oxidizing chemical environments, thermal cycling, and mechanical loading. Although there are recognized methods for monitoring performance variations over time, changes in the mechanical properties of these types of polymer membranes have largely been ignored. Here, we propose a measurement approach based on a combination of wrinkling6 and cracking to characterize the stiffness, strength, and ductility of thin membrane materials. We then demonstrate this approach on a highly relevant model system comprised of the active layer of reverse osmosis membranes before and after chlorination, illustrating the ability to detect a ductile-to-brittle transition in these materials indicative of embrittlement, a behavior that impairs long-term durability and is detrimental to membrane performance. We believe that the proposed methodology is practical and applicable to a wide variety of thin-film materials and devices.
Citation: Nano Letters
Pub Type: Journals
membranes, thin films, polymers, wrinkling, cracking, mechanical properties