Method of manufacturing composite material
The invention provides a light emitting apparatus including a projector color wheel and a light emitting diode (LED) device using a composite material, a method of manufacturing the composite material, and an optical film. The stability of the composite material has been greatly improved. Light emitting devices using the composite material have wide color gamut.
1. A method of manufacturing a composite material comprising:
preparing a mixture comprising a plurality of quantum dots and a non-polar solvent, wherein the quantum dots are dissolved in the non-polar solvent;
preparing a polar solvent and a surfactant;
mixing the mixture, the polar solvent and the surfactant to form an emulsion, wherein the emulsion comprises a plurality of dispersed phases and a continuous phase and the dispersed phases are dispersed in the continuous phase;
adding a catalyst and a silica precursor into the emulsion to form a plurality of composite materials in the dispersed phases respectively, wherein each of the composite materials comprises at least one quantum dot and a silica material encapsulating a surface of the at least one quantum dot.
2. The method according to claim 1 , wherein the emulsion is formed with reverse micelles where the dispersed phases comprise the polar solvent and the continuous phase comprises the non-polar solvent.
3. The method according to claim 1 , wherein the quantum dots with polar surfaces migrate from the continuous phase to the dispersed phases during mixing the mixture, the polar solvent and the surfactant, so as to form the emulsion.
4. The method according to claim 1 , wherein steps of adding the catalyst and the silica precursor into the emulsion to form the composite materials in the dispersed phases respectively comprise a hydrolysis, a condensation and a polymerization.
5. The method according to claim 1 , wherein the catalyst is a base comprising ammonia, ammonium fluoride, sodium hydroxide or a combination thereof.
6. The method according to claim 1 , wherein the silica precursor comprises tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), or a combination thereof.
7. The method according to claim 1 , wherein a weight ratio of the quantum dots to the silica precursor ranges from 1:1 to 1:200.
8. The method according to claim 1 , further comprising performing a centrifugation process and at least one cleaning process after forming the composite material.