Test measures key properties of polymer thin-films and membranes

Abstract

Scientists in the USA have developed a measurement technique based on what is referred to as wrinkling–cracking phenomena. They say it enables unambiguous measurements of three fundamental mechanical properties in nano-scale thin-film geometries to be taken, including elastic modulus, strength and fracture strain. The research has shown that in addition to polymer and metal thin-films, the method can be applied to the active nano-layers of a composite reverse osmosis membrane before and after chlorination, illustrating the ability to detect a ductile-to-brittle transition in these materials indicative of “embrittlement” – behaviour that impairs long-term durability and is detrimental to membrane performance.