NIR induced photopolymerization of acrylate-based composite containing upconversion particles as an internal miniaturized UV sources

Inventing a new light source for overcoming the disadvantages of conventional radiation curing technology is essential. Upconversion particles capable of emitting photon span from ultraviolet to NIR region of electromagnetic spectrum under excitation of NIR laser, could play the role of a light source within the formulation. Different amount of these upconversion particles were introduced to TMPTA monomer in order to survey their curing ability. The curing process was performed under various NIR laser intensities. The monomer to polymer conversion was studied using FT-IR and real-time FT-IR analysis. Increasing the filler content leads to better curing of the composite. Furthermore, the feasibility of curing TMPTMA containing camphorquinone as photoinitiator, by the blue upconversion emission was studied. Besides, the ability of these particles as UV and blue source cooperation in dual curing was observed. Increasing the photo-initiator and upconversion particles concentration resulted in higher double bond conversion. Increasing the laser intensity, by enhancing the upconversion emissions leads to better monomer to polymer conversion. The new source passed the inducing of dual curing process.