A waterborne polyurethane-based hybrid fluorescent silicon quantum dot

An amino-hydroxy-functionalized strongly fluorescent hybrid silicon quantum dots (znoSiQDs) were prepared by a green and simple method. Waterborne polyurethane-based hybrid fluorescent silicon Quantum dots (znoSiQDs-WPU) was prepared by a modified acetone method using znoSiQDs as chain extender. The structure and properties were also investigated by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), fluorescence spectroscopy (FL), and so on. ZnoSiQDs was successfully connected to the polyurethane backbone by covalent bonding. ZnoSiQDs-WPU can effectively shield UV in the range of 300-400 nm. Compared with WPU, the UV shielding range of znoSiQDs-WPU is significantly larger, attributed to the direct band gap transition Gamma -> Gamma. The fluorescence intensity of znoSiQDs-WPU was dramatically enhanced compared with that of znoSiQDs. Compared with znoSiQDs, the maximum emission peak of znoSiQDs-WPU is blue shifted at about 18 nm, which was related to the increased polarity of the imidazole chromophore. The luminous life of znoSiQDs-WPU is up to 6.58 ns. The thermal stability of znoSiQDs-WPU is improved by bonding znoSiQDs to the main chains of WPU. Furthermore, it is water as a solvent, especially suitable for safety, green, environment amity of materials.

Automated summary

An amino-hydroxy-functionalized strongly fluorescent hybrid silicon quantum dots (znoSiQDs) were prepared using a green and simple method. These znoSiQDs were then used as chain extenders to synthesize waterborne polyurethane-based hybrid fluorescent silicon quantum dots (znoSiQDs-WPU). The znoSiQDs-WPU exhibited enhanced fluorescence intensity, expanded UV shielding range, longer luminescent life, and improved thermal stability compared to znoSiQDs. The use of water as a solvent also makes znoSiQDs-WPU a safer and more environmentally friendly material option.