Feedback mechanisms at inorganic–polyelectrolyte interfaces for applied materials

Abstract

Non-linear processes at the interface between inorganic and polymeric species mimic a wide variety of natural processes such as stimulus-responsive behavior, self-healing, actuation, transport and delivery, and pH buffering. There are plenty of models describing phenomena at solid–polymer and polymer–liquid interfaces, but they do not provide complete understanding of the occurring processes. The authors analyze here recent progress in fundamental aspects of programmable materials based on polyelectrolyte feedback mechanisms on inorganic surfaces of applied materials in (a) photochemistry (focus on semiconductor–polyelectrolyte interfaces), (b) electrochemistry and (c) self-adaptive materials. The functionalization of the inorganic surface with polyelectrolyte layers provides an opportunity to construct novel hybrid materials with improved characteristics in comparison with pristine inorganic analogues. The importance of the transition from traditional to system thinking is highlighted, as well as the hierarchical scale of the time of polyelectrolyte responses due to complex overlapping between the processes of ion diffusion, chain site diffusion and self-diffusion.