Self-healing materials can recover from physical and chemical damage autonomously or with the input of a simple stimulus. Similarly, self-cleaning materials can remove attached foulants with the application of a simple stimulus. Such “smart materials” are envisioned to improve safety, reduce process downtime, and extend the lifetime of materials before disposal. This presentation will delve into the design of these two categories of materials, focusing on their application in environmental contexts, such as membrane-based water treatment processes. The discussion will highlight the tradeoffs associated with the use of these materials in the context of environmental engineering.
Self-healing materials rely on one of two approaches: 1) embedding an encapsulated reactive healing agent that is exposed when the material is damaged and 2) using materials with reversible bonding that reform easily after breaking. The talk will discuss the importance of healing agent chemistry and reaction kinetics, how embedding microcapsules and capillary tubes within membranes impacts their performance, and if reversible secondary bonds are a viable approach to self-healing in aqueous environments. In situ fouling cleaning can be achieved using electrically conductive surfaces and electrochemical reactions that occur on these surfaces. Specific mechanisms include dispersal of attached biofilm via gas evolution reactions, electrostatic repulsion of bacteria and natural organic matter, as well as localized pH change to dissolve inorganic scalants. This talk will discuss the relationship between conductive surface coverage and fouling control.