口腔修复材料-可见光固化复合树脂的制备与性能的研究

本论文分为两部分：1. 综述部分（第一章），介绍了可见光固化复合树脂的组成、分类、性能以及应用；评述了复合树脂的研究进展。2. 实验部分（第二章至第七章），包括以下几个方面的内容：无机填料的制备与硅烷化处理研究；树脂基质固化过程的研究；可见光固化复合树脂的制备及物理机械性能的评价；研究不同浸泡液对复合树脂吸水性、挠曲强度、弯曲弹性模量以及复合树脂单体洗出量的影响，并探讨了这些物理机械性能与复合树脂组成成分的关系。 无机填料能赋予复合树脂良好的物理机械性能。本论文通过烧结法和醇盐水解法分别制备了1 µm和0.75 μm的无机填料，利用醇盐水解法成功制备了纳米级二氧化硅，最终制得强度符合临床要求的复合树脂，为工业化生产提供了依据。 无机填料硅烷化处理效果的好坏对复合树脂的各种性能会产生很大影响，本论文对无机填料进行硅烷化处理，引入了比商品化产品更多的硅烷偶联剂，而且实验中硅烷化处理的8235玻璃粉表面既有化学包覆又有物理包覆的硅烷偶联剂。渗透实验表明3-甲基丙烯酰氧丙基三氯硅烷处理的无机填料表面疏水性比3-甲基丙烯酰氧丙基三甲氧基硅烷强。 膨胀单体可以用来减小甚至消除复合树脂聚合过程的体积收缩，论文第四章尝试用螺双内酯作为复合树脂的单体，提出了一种新型的先阳离子聚合后阴离子聚合的联合引发聚合过程。论文第五、六章用环氧化芳香族超支化聚合物制备了新型可见光固化复合树脂，研究结果表明：①环氧化芳香族超支化聚合物的加入，环氧树脂基复合树脂的挠曲强度和弯曲弹性模量增大；②收缩变小；③吸水量变大；④环氧树脂的转化率降低；⑤玻璃化转变温度降低。环氧化芳香族超支化聚合物能够增强增韧脂肪族环氧树脂，如果对其进行必要的改性，所得复合树脂有可能被应用到牙科修复中。 不同浸泡液对复合树脂的物理机械性能和生物相容性会产生不同的影响，论文第七章系统研究了不同浸泡液对复合树脂各种物理机械性能的影响。结果表明：① 三种浸泡液对复合树脂各种性能的影响随浸泡液种类的不同而不同，其中乙醇/水对复合树脂的影响最严重；②即使在同一浸泡液中，不同组成的复合树脂也有不同的物理机械性能。

Bonding quality of Yb : Y3Al5O12/Y3Al5O12 composite crystals

The Yb:Y3Al5O12/Y3Al5O12 (Yb:YAG/YAG) composite crystals were prepared by thermal bonding method with different technological parameters. The bonding interface of the composite crystals were observed by optical microscope, scanning electron microscope, and atom force microscope. The light scattering experiments for bonding interface of the composite crystals were measured by the laser and transmission spectra. All experiments show that high-quality Yb:YAG/YAG composite crystals without space transition layer and light scattering on the bonding interface can be obtained by thermal bonding method under appropriate technological parameters.

Wafer bonding technique used for the integration of cubic GaN/GaAs (001) with Si substrate

We successfully used the metal mediated-wafer bonding technique in transferring the as-grown cubic GaN LED structure of Si substrate. The absorbing GaAs substrate was removed by using the chemical solutions of NH4OH : H2O2=1 : 10. SEM and PL results show that wafer bonding technique could transfer the cubic GaN epilayers uniformly to Si without affecting the physical and optical properties of epilayers. XRD result shows that there appeared new peaks related to AgGa2 and Ni4N diffraction, indicating that the metals used as adhesive and protective layers interacted with the p-GaN layer during the long annealing process. It is just the reaction that ensures the reliability of the integration of GaN with metal and minor contact resistance on the interface.

PHOTOINDUCED CHANGES OF HYDROGEN-BONDING IN SEMIINSULATING IRON-DOPED INDIUM-PHOSPHIDE

After illumination with 1-1.3 eV photons during cooling-down, metastable PH modes are observed by IR absorption at 5 K in semi-insulating InP:Fe. They correlate with the photo-injection of holes, but not with a change of the charge state of the K-related centres present at equilibrium. They are explained by a change of the bonding of H, induced by hole trapping, from IR-inactive centres to PH-containing centres, stable only below 80 K. One metastable centre has well-defined geometrical parameters and the other one could be located in a region near from the interface with (Fe,P) precipitates.

Effect of immersion in various media on the sorption, solubility, elution of unreacted monomers, and flexural properties of two model dental composite compositions

Immersion in various media has different effect on the properties of dental composites, such as sorption, solubility, elution of unreacted monomers, flexural strength, and flexural elastic modulus. In the present work, the effect of immersion in various media and the relationship between the variation of these properties and the components of dental composite were investigated.

Metal printing with modified polymer bonding lithography

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