The degradation behaviour of nanoscale materials is a key determinant of their potential human and environmental toxicity, and can be chemical or electrochemical in nature. In addition, the environmental transformation of materials released from consumer products determines their end-point eco-toxicity. These processes are a challenge to study as they require high resolution– but statistically meaningful analysis. More generally the stability of nanomaterials is of importance for device lifetime. We are developing tools to study such reactions for a range of relevant materials (e.g. ZnO, Ag, CoCr, CeO₂, CNTs).

The development of nanoprobe X-ray systems at synchrotron sources is providing new insights into the behaviour of materials-environment interactions at nanoscale resolution. In this paper we will discuss our recent work on in-situ observation of deposition, localized dissolution and environmental transformation of nanoscale systems: providing both spatial and spectral information. In situ observation of local super-saturation, dealloying and nanoparticle chemical transformation all demonstrate the capabilities and opportunities for this technique. In addition, we will discuss the correlative use of ex-situ electron microscopy and assembly-averaged in-situ studies to develop holistic understanding of these systems.