有机硅微球的制备与折射率调控及其光散射性能的研究

发布时间：2018-09-13 10:50

【摘要】：LED照明节能、高效、体积小、长寿、环保等。同样亮度下,LED照明能耗仅为白炽灯照明的1/10,荧光灯照明的1/4。LED照明取代白炽灯及荧光灯照明优势明显。然而,LED发光强度高,光线较为集中,需要一个良好光扩散性能的灯罩使其光线发散均匀。因此,研究制备高性能的光散射材料并应用于大功率LED照明系统中,具有重要的实用价值。有机硅微球由于热稳定性好,尺寸稳定性佳,粒径和折射率可以通过化学反应来调控的特点,作为光扩散粒子应用于光扩散材料具有十分广阔的应用前景。本文以甲基三甲氧基硅烷(MTMS)、苯基三甲氧基硅烷(PTMS)为原料,采用水解-缩聚法成功制备了分散性优异的PMTMS和PPTMS有机硅微球。对反应体系中反应参数:如单体浓度、氨水用量、温度和搅拌速度等条件对微球形貌及粒径分布的影响进行了研究。采用扫描电子显微镜(SEM)、热重分析仪(TGA)、傅里叶变换红外光谱(FT-IR)等方法对微球进行表征。进一步,本文以MTMS和PTMS共聚制备了折射率从1.3851到1.5081可调的有机硅微球。并将得到的微球与环氧树脂E51及聚碳酸酯(PC)复合,制备了2mm厚的光扩散材料。所得结果如下:(1)影响微球形貌的主要因素是单体浓度和氨水浓度。随着反应体系中单体浓度的增加,微球的平均粒径逐渐增大,单体浓度较高时,微球容易发生团聚;氨水用量增加,催化反应速率较快,成核数增多,最终形成微球的平均粒径减小。当氨水浓度较低的情况下,硅氧烷单体水解不完全,缩聚程度不高,不易形成微球。当反应体系的pH为8～11时,能够得到分散性良好的有机硅微球。采用种子法研究了 PPTMS微球的生长过程,发现,硅氧烷在瞬间大量成核,接着核继续生长,向反应体系中补加单体后,并没有出现新核的形成。(2)对环氧树脂光扩散材料的透光率和雾度结果进行分析,得出:随着微球折射率的减小及掺杂浓度的增加,环氧树脂复合光扩散材料雾度增高,透光率降低。当采用微球粒径为1.05 μm,掺杂浓度为0.1 phr时,2 mm厚的光扩散片的透光率为83.6%,雾度为95.5%。(3)对PC光扩散材料的光扩散性能进行了研究,并对实验数据与理论模拟结果进行了对比分析,发现:当微球相对于PC的折射率为0.91～0.93时,有机硅微球与PC折射率匹配较好,能有效地解决透光率与雾度之间的矛盾,此时,能够制备出高透光率与高雾度的光扩散材料。当微球粒径为1.7 μm,折射率为1.458(相对折射率为0.92),填充浓度为0.4 phr时,厚度为2 mm的光扩射材料总透光率为87.9%,雾度为98.5%。
[Abstract]:LED lighting energy saving, high efficiency, small size, longevity, environmental protection and so on. Under the same brightness, the energy consumption of 1/4.LED lighting is only 1 / 10 of that of incandescent lighting, and the 1/4.LED lighting of fluorescent lighting has obvious advantages in replacing incandescent and fluorescent lighting. However, the light intensity of LED is high and the light is concentrated, so it needs a lampshade with good light diffusivity to spread the light evenly. Therefore, it is of great practical value to study the preparation of high performance light scattering materials and their application in high power LED lighting systems. Because of its good thermal stability and good dimensional stability, the size and refractive index of organosilicon microspheres can be controlled by chemical reaction. In this paper, PMTMS and PPTMS organosilicon microspheres with excellent dispersity were prepared by hydrolysis-condensation method from methyl trimethoxy silane (MTMS), phenyl trimethoxy silane (PTMS). The effects of reaction parameters, such as monomer concentration, amount of ammonia water, temperature and stirring speed, on the morphology and particle size distribution of microspheres were studied. The microspheres were characterized by scanning electron microscope (SEM) (SEM), thermogravimetric analyzer (TGA),) Fourier transform infrared spectroscopy (FT-IR). Furthermore, organosilicon microspheres with adjustable refractive index from 1.3851 to 1.5081 were prepared by MTMS and PTMS copolymerization. The obtained microspheres were compounded with epoxy resin E51 and polycarbonate (PC) to prepare 2mm thick photodiffusion materials. The results are as follows: (1) the main factors affecting the morphology of the microspheres are monomer concentration and ammonia concentration. With the increase of monomer concentration in the reaction system, the average particle size of the microspheres gradually increased. When the monomer concentration was higher, the microspheres were easy to agglomerate, and the amount of ammonia increased, the catalytic reaction rate was faster, and the nucleation number increased. The average particle size of the resulting microspheres was reduced. When the concentration of ammonia is low, the hydrolysis of siloxane monomer is not complete, the degree of condensation is not high, and it is not easy to form microspheres. When the pH of the reaction system is 8 ~ 11:00, the organosilicon microspheres with good dispersion can be obtained. The growth process of PPTMS microspheres was studied by means of seed method. It was found that the nucleation of siloxane was in a large quantity in the instant, then the nucleus continued to grow, and the monomer was added to the reaction system. (2) the results of light transmittance and haze of epoxy resin photodiffusion materials are analyzed. It is concluded that with the decrease of refractive index of epoxy resin and the increase of doping concentration, the fog of epoxy resin composite photodiffusion materials increases. The transmittance decreases. When the diameter of microspheres is 1.05 渭 m and the concentration of doping is 0.1 phr, the transmittance of the photodiffuser with 2 mm thickness is 83.6 and the fog is 95.55.3.The photodiffusion properties of PC photodiffusion materials are studied, and the experimental data and theoretical simulation results are compared and analyzed. It is found that when the refractive index of microspheres relative to PC is 0.91-0.93, the refractive index of organosilicon microspheres and PC is better matched, and the contradiction between transmittance and haze can be effectively solved. In this case, the optically diffused materials with high transmittance and high fog can be prepared. When the diameter of microspheres is 1.7 渭 m, the refractive index is 1.458 (relative refractive index is 0.92) and the filling concentration is 0.4 phr, the total transmittance of the diffused materials with thickness of 2 mm is 87.9 and the fog is 98.5.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O634.41

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