Tecniche Innovative ed eco-compatibili di esfoliazione di materiali bidimensionali e scale-up di processi produttivi di fabbricazione

The research project entitled “Innovative and environmentally friendly exfoliation techniques of two-dimensional materials and scale-up of manufacturing production processes” here reported, focuses on - production, microstructural characterization, and scale-up of a liquid phase exfoliation process of 2D Transition Metal Dichalcogenides (TMDs) and Metal Chalcogenides (MCs) materials; - Industrial exploitation of bidimensional exfoliated TMDs as anticorrosive coating of metal aluminum alloys and as mechanical reinforcement of photocuring resins; - Investigation of TMDs as new interfaces for gas sensing and photocatalytic applications. The first part of the research has been focused to the synthesis of 2D materials by topdown routes. Laboratory-scale experiments enabled to identify the critical parameters of the liquid phase exfoliation (LPE) method by comparing conventional toxic solvents vs. green and biodegradable ones. At competition of the first part, a scale-up of the liquid phase exfoliation process, comparing two industrial techniques referred as Microfluidization and Wet-jet milling was investigated and validated. The influence of main process parameters (pressure and number of cycles) was corelated with the quality of the exfoliate. Results shown better performances in term of the exfoliation yield utilizing the Wet-jet mill technique as respect to the Microfluidizer. The second part of the research project has been aimed to design a new method to produce inks based on light-curing epoxy resin added with reduced Graphene Oxide (rGO) to address the inconvenience of stereolithography (SLA) layering 3D prototypes. Additionally, focused on industrial application of replacing the hexavalent chromium bath (toxic and carcinogenic element by REACH regulation), it has been investigated the suitability of nanomaterials to prevent the corrosion of aluminium alloy. The third part of the research has been dedicated to investigate the environmental stability of TMDs/MCs in dry/wet air laboratory conditions, by exploiting new passivation strategies to protect the exfoliated nanoflakes from spontaneous degradation. Gas sensing mechanisms were elucidated by theory and practice. DFT theoretical calculations revealed humidity and different gases adsorption mechanisms over the sensor’s surface, whereas experiments confirmed the role of humid air (40% RH Background) upon sensor’s selectivity to different gases. A preliminary proof of concept of the photocatalytic activity of SnSe2 flakes dispersed via one-pot synthesis in mesoporous TiO2 films confirmed the photocatalytic activity of the SnSe2 flakes loaded TiO2 interface investigating the degradation of stearic acid and Rhodamine B at different light irradiation. Loading with SnSe2 flakes enhances the photoactivity of Titania film, topping 70% of degradation rate of stearic acid after 7.5 min and up to 90% Rhodamine B after 40 min with 6% loading of SnSe2.