| Rhodamine 6G (abbreviated to Rh6G)is a typical laser dyes. Due to its excellent luminescent properties, Rh6G has shown more and more broad application in various dye lasers field. However, the traditional liquid dye lasers with a large number of organic solvents for matri caused various problems such as larger equipment, expensive operation cost and environmental pollution. In order to overcome these problems, the organic dyes have encapsulated in a solid substrate of the certain rigidity and mechanical strength. And it has been an important research in the field of dye lasers. If we can realize a effective regulation of the doping concentration of dye, their polarity and the microscopic environment of solid substrate, there is no doubt greatly reduce fluorescence quenching of the dye molecule and improve the optical stability of the dye.For now, organic polymer materials encapsulating dyes, such as organic polymer glass, have its poor thermal stability making its applicable field restricted. The commonly solid inorganic materials, like sol-gel materials, porous glass and zeolite, is limited application because of its dense phase, disorder channel structure and aperture size. In recent years, mesoporous molecular sieve materials, due to its orderly organization and ordered uniform pore structures, provides a effective confined spaces for dye molecules. Mesoporous molecular sieve materials encapsulated various dyes,have been potential application prospect, but most of them were still the powder materials. They were not conducive to further operations and more difficult to design device.For this reason, this paper has used transparent mesoporous gel monolith obtained by the research team. This work is a systematic study on the preparation of controlling the integrity and transparency of the mesoporous silica gel monolith doped dye. The results were as follows:1、After systemiclly screening, normal propyl alcohol were ideal cosolvent for Rh6G encapsulated mesoporous gel in many organic solvents. It not only has good solubility for Rh6G, but also guarantees the integrity of the whole mesoporous transparent gel doped Rh6G2、On this basis, using nonionic surfactant P123s F127 and Brij56 as template, direct doping method, we realized pure mesoporous silica transparent gel monolith doping Rh6G in the Rh6G/Si molar ratio 1 × 10-5～1 × 10-2.We systematically studied the changes of the dye concentration and template agent concentration on the influence law of material optical properties. There is the comparative study on the optical properties of no template silica doped Rh6G The results show that the presence of template agent can significantly improve the effective doping concentration range of Rh6G The biggest concentration of the dye doping mesoporous gel can reach 1×10-3 (Rh6G/Si mole ratio), in the traditional silica gel only 5×10-4 (Rh6G/Si mole ratio), higher concentration leading to the generation of fluorescence quenching. At the same time, under the same concentration of the dye, the fluorescence intensity of mesoporous gel can be up to 2-4 times of the traditional silica gel. This can explain the existence of the mesoporous structure and template agent can significantly improve dye fluorescence properties, we found that with the increase of the concentration of the template agent, dye luminous intensity tends to increase and blue shift in the fixed concentration of dye. It shows that high concentration of template agent is advantageous to the better dispersion of dye molecules, and hence improves the luminescence properties of the dye and the optical stability of the materials. In addition, due to the three kinds of template agent with the differences in structure and performance, that can lead to the difference of mesoporous gel materials, such as pore structure, pore size and pore wall thickness and the optical properties. Usually larger pore size and high specific surface area will be more conducive to a high encapsulated concentration of the dye.In the study of the three types of template agent, mesoporous gel using PI23 as template, can be obtained best fluorescence effect after encapsulating Rh6G3、 This work will further study that mesoporous silica gel containing Al encapsulated Rh6G by P123, F127, and Brij56 as template agent. It preliminary study on the performance of optical materials in the Rh6G/Si mole ratio=1×10-3and molar ratio Si/Al=5-80 range. The results showed that fluorescence intensity of the dye increased and had a blue shift with the increase metal Al content. It shows that the existence of the skeleton Al benefit the dispersion and stability of the dye in the mesoporous aluminumsilicate gel and more strengthen fluorescence properties of materials. When the Si/Al molar ratio is less than 10, the fluorescence intensity of the material decreases gradually with the increase of Al content in the gel. This may be caused with the formation of the skeleton of Al atoms. Though the template agent structure changes causing the similar change of the optical performance, the fluorescence intensity of the material with P123 as template agent decreases in the Si/Al started after less than 40.The reason is not clear.According to the results of the research, on the one hand, This work show that the preparation technology of transparent mesoporous silica and mesoporous aluminumsilicate gel has universality and expansibility. It offers a possibility of wider range of transparent mesoporous material doped dye. Due to the relatively mild synthesis system, it will also help to encapsulated various bioactive molecules in the mesoporous transparent gel that has important significance in the preparation of new composite functional materials. On the other hand, the favorable optical properties of the mesoporous gel doped Rh6G, will also be made possible for mesoporous molecular sieve from the material to the devices in a potential industrial application. |
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