本研究中，我們以水熱法合成出結晶大小為 5 nm 的立方晶氧化鋯粒子，並 以羧酸進行氧化鋯的表面改質，使其可以穩定的分散在非極性溶劑下。接者與磺 化聚碳酸酯(SPC)混摻，製作出具有高折射率又可以以熱壓成型之透明光學材料。 我們先進行磺化反應來製作出不同磺化程度的聚碳酸酯(PC)，並與表面改質過的 氧化鋯在溶劑中混摻。經過表面改質的奈米結晶氧化鋯在二氯甲烷下只能形成白 色的懸浮液。但磺化聚碳酸酯(SPC)可以有效的螯合上奈米氧化鋯，故添加 SPC 混摻後可以形成穩定的透明分散液。因此判斷 SPC 分子鏈上的-SO 3 基團取代了 氧化鋯表面的羧酸，使其可穩定分散於二氯甲烷下。接著用乙醇洗去替換下的羧 酸並除去溶劑後，即可用鑄造成型和熱壓成型的方法來製造高穿透度的氧化鋯/ 聚碳酸酯奈米複合材料。此法不同於文獻中利用磷酸酯作界面劑將氧化鋯混入 SPC。我們最後熱壓成品厚度~100 µm，折射率可達到~1.67，無機含量可到達 60wt%。 我們以粉末 X-ray 繞射儀和拉曼光譜儀來鑑定氧化鋯的結晶大小與其結晶 相。以動態雷射粒徑儀觀察表面改質的氧化鋯在非極性溶劑下的粒徑大小分布。 以熱重損失儀和差示掃描量測儀檢驗奈米複合材料熱穩定性。傅立葉紅外光譜儀 分析聚合物與無機奈米材料混合前後之差別。最後以可見光光譜儀和阿貝折射儀 來測量其光學性質。 研究中發現 SPC 的磺化程度雖然不會影響折射率，但是在熱壓成型時卻會 使奈米複合材料黃化，導致穿透度下降。且其磺化程度也會影響與氧化鋯的相容 性。假若想要混入較多奈米氧化鋯，就必須提高 SPC 的磺化程度，但同時也就 降低了耐熱性，而無法以熱壓成型。;In this study, we developed a high refractive index thermoplastic zirconia/polycarbonate nanocomposite useful in preparing optical components via injection molding. We have employed our alkaline hydrothermal method to synthesize cubic zirconia nanoparticles having 5 nm grain size. The surface of these zirconia nanoparticles was further modified with a carboxylic acid to form a stable dispersion in a nonpolar solvent. Sulfonated polycarbonate (SPC), produced by the sulfonation reaction of polycarbonate, was chosen as the coupling agent to make the zirconia compatible with the polycarbonate (PC) matrix. The carboxylic acid chelated zirconia nanocrystals formed a stable suspension in dichloromethane. Upon the adding of SPC, the carboxylic acid ligand was replaced by the SO 3 group of the SPC and the nanocrystals became transparently dispersible in the solvent. This approach is different from the use of PEAH as capping agent reported in the literature. The SPC capped zirconia obtained, after removing the carboxylic acid and solvent, could be cast or hot- pressed into a transparent piece about 100 µm thick. The maximum zirconia loading achieved was about 60wt%, leading to an index of 1.67 for the composite. We used the XRD and Raman spectroscopy to analysis the grain size and crystal phase of the zirconia nanoparticle, and the DLS to check the particle size distribution in nonpolar solvents. The Fourier transform infrared (FTIR) spectrometer was employed to investigate the chemical structure of the nanocomposite. The thermal stability of nanocomposite was studied by the thermogravimetric analysis and differential scanning calorimetry. The optical properties of nanocomposite were investigated by the UV-spectrum and Abbe refractometer. Our study showed that the degree of sulfonated influences the compatibility between zirconia and PC. More zirconia nanoparticles must be added to increase the refractive index of a nanocomposite, which requires a higher degree of sulfonation. However, excessive sulfonation decreases the thermal stability of the SPC, leading to yellowing upon thermal treatment during the hot press process. Therefore, there is an optimal degree of sulfonation that gives a balance between the thermal processability and refractive index.
