Research Analyze UV Irradiated Graphene-Based Nanocomposites

Researchers from University of Salerno found that graphene nanoplatelets added in an epoxy-based free-standing film decrease mechanical damages caused by UV irradiation

Increasing need to extend the service life of bulk and coating polymeric materials can reduce the supply of resources. Carbon nanostructured forms can guard polymeric materials against potential hazards that are related to common use of polymeric materials. Carbon nanotubes and graphene-based nanoparticles can increase physical and chemical properties of the resulting nanocomposites. Now, a team of researchers from University of Salerno developed commercial epoxy-based films that can be used as coatings to protect surfaces of different materials.

The team added graphene-based nanoparticles in the epoxy films at different weight percentages. The films unloaded and loaded with graphene-based nanoparticles were degraded under accelerated photo-oxidization with the help of UV-A radiation. This in turn reproduced the ultraviolet component of solar radiation at the earth surface. Films without graphene-based nanocomposites are ultra-sensitive to UV treatment. The team used scanning electron microscope to observe robust damages in the morphological feature of the film surface after the UV treatment. Moreover, the damages were evident in the mechanical performance of the samples. Images obtained from conventional atomic force microscopy of the Derjaguin-Muller-Toporov modulus maps of the sample demonstrated that the values of elastic modulus, which are related to the regions of the epoxy matrix are lower than those detected for the matrix of the sample before UV treatment.

The team also assessed the effects of graphene-based nanocomposites on the morphological and structural organization of the samples that were exposed to the degradation. Graphene nanoplatelets integrated in the epoxy-based films demonstrated a significant decrease in damages suffered in the morphological feature of the film surfaces. The loss of mechanical performance was also reduced. The research was funded by the European Union’s Horizon 2020 research and innovation program and published in the journal MDPI Materials on March 22, 2019.