Production of multiresponsive thin films containing carbon dots

Carbon dots (CDs) are an emerging carbon nanosized species with high photoluminescence quantum yields. CDs were accidentally discovered in 2004 during the isolation and purification of single-walled carbon nanotubes synthesized by arc-discharge methods. Since their discovery, various synthesis methods employing various precursors have been developed, that fall into two broad classes: top-down and bottom-up approaches. Also, CDs based composite materials have been studied widely for applications in many fields. CDs are typically quasi-spherical nanoparticles with an amorphous to nanocrystalline structure, containing sp2/sp3 carbon, oxygen/nitrogen-based groups, and superficial chemical groups. Carbon dots have attracted a broad interest in several fields due to their unique combination of optical properties, exceptional biocompatibility, minimal toxicity, great aqueous solubility, cost-effectiveness, simple synthesis, easy functionalization. These characteristics have spread their use from bioimaging, biosensing, chemical sensing to nanomedicine, antibacterial therapy, and optoelectronic devices. This thesis work is focused on exploited high-fluorescence CDs as a component of a composite material to create multifunctional films. CDs were synthetized by ultrasonic-assisted method using Citric Acid (CA) and p-Phenylendiamine (p-DPA) as precursors. Different molar ratios of the precursors were used to find the right compromise between high photoluminescence and scalability. The film is obtained from pre-functionalised CDs, a photopolymerizable resin and a photoinitiator under UV light exposure. Both CDs and multifunctional films have been characterised with spectroscopic techniques, AFM, TGA, FTIR, DSC and swelling test. The films obtained could be used either to monitor interfaces for biomedical applications or to release active substances/CDs or a combination of the previous ones. In each case the main source of information is the variation of photoluminescence (PL) intensity throughout the film life cycle.