Combined effects of solar radiation and high vacuum on the properties of graphene/polysiloxane nanocomposites in simulated space environment

Polymer–matrix composites (PMCs) filled with graphene nanoplatelets (GNP) are ultralightweight combined with the ability to perform a wide range of functions. These materials are interesting for many applications in space environments, including the monitoring of degradation caused by radiation exposure. Recently, the growing interest in outer space exploration, by both unmanned probes and manned space vehicles, has encouraged research to make great strides to facilitate missions, with one goal being to monitor and limit the impact of highly damaging radiation. With this perspective, we investigate the effects of simulated space conditions on the physico-chemical, morphological, and mechanical properties of elastomeric PMCs made from a polydimethylsiloxane (PDMS) matrix embedding pristine GNP or a hybrid graphene/DNA filler with high sensitivity to ionising radiation. An analysis of the PMC stability, outgassing, and surface modification is reported for samples exposed to solar radiation under high vacuum (HV, 10−6 mbar). The experimental results highlight the mechanical stability of the PMCs with DNA-modified GNP under solar radiation exposure, whereas the surface morphology is highly affected. On the contrary, the surface properties of PMCs with pristine GNP do not vary significantly under simulated space conditions.