Preparation of an aqueous photoinitiator through supramolecular assembly oriented towards 3D printing hydrogel without VOC emission

The direct ink writing (DIW) technology is probably the most feasible method for 3D printing hydrogels. The collaborative development of photosensitive hydrogel and DIW printing equipment based on specific application goals is a continuous research hotspot. To avoid UV damage to the skin, the development of an aqueous photoinitiator that can be initiated under visible light is of great significance for 3D printing hydrogel technology. A surfactant with pi - pi stacking ability is selected, and the water-based photoinitiator (Aqu-PI) is formed by supramolecular assembly with TPO without VOC emission by solvents. The particle size of the Aqu-PI is around 15 nm, and the absorption peak of its UV-visible spectrum reaches the visible region. The photosensitive hydrogel is prepared by Aqu-PI and aqueous monomers including mono functional monomer (AM) and bifunctional monomer (MBA). Then the tackifier is added which makes the viscosity enhance into the photosensitive hydrogel, so hydrogels with better mechanical properties are obtained. Then the photosensitive hydrogel is photocured by a 405 nm LED laser on the extrusion device of DIW printer and forms the interpenetrating network (IPN) structure, thus a 3D printout hydrogel is obtained consistent with the shape of the digital design model.

Automated summary

Direct ink writing (DIW) technology is the most feasible method for 3D printing hydrogels. The collaborative development of photosensitive hydrogel and DIW printing equipment based on specific application goals is a continuous research hotspot. The development of an aqueous photoinitiator that can be initiated under visible light is of great significance for avoiding UV damage and improving hydrogel technology.