- 學位論文
離子溶液為模版製備之中孔洞二氧化矽氣凝膠(A-SiO2)之應用 1.以PAN/A-SiO2複合高分子電解質(CPEs)製備高電容量鋰電池 2.高效能A-SiO2防曬材料之製備和性質
Application of Mesoporous Silica Aerogel Prepared with Ionic Liquid Template 1.PAN/A-SiO2 CPEs for High Capacity Lithium Battery 2.High Efficiency Sunscreen Encapsulated Silica
摘要
摘要 1.以PAN/A-SiO2複合高分子電解質(CPEs)製備高電容量鋰電池 本論文主要探討中孔洞材料在複合高分子電解質中的影響及鋰電池之應用。因此在本研究中製備一系列以PAN (polyacrylonitrile) 為主體的複合高分子電解質，並探討中孔洞材料的添加對PAN高分子電解質的影響。由離子導電度測試的結果，得知本研究所製備的複合高分子電解質在添加3% Aerogel (A-SiO2)、3% MCM-41 ( M-SiO2)和4% Degussa SiO2 (D-SiO2)及F＝0.6 LiClO4組成下，30℃時之導電度分別可達6.0×10-4 S/cm、4.5×10-4 S/cm和2.3×10-4 S/cm，此導電度在固態高分子電解質中已達可應用範圍。經紅外線光譜儀（FT-IR）、固態核磁共振光譜（Solid-state NMR）等測試所製備之複合高分子電解質中各成分間作用力。此外，利用線性掃瞄伏安法(linear sweep voltammetry, LSV)和循環伏安法(cyclic voltammetry, CV)探討高分子電解質的電化學穩定性。由結果顯示，本研究所製備的高分子電解質有不錯的電化學穩定性與高氧化破壞電壓(4.5V vs. Li/Li+)，並且與鋰金屬之間有好的相容性。其中以A-SiO2所製備之固態高分子電解質，在0.5C/0.5C充放電條件下測試，經過20次循環測試後仍有100％的放電電容量，顯示具有不錯的充放電結果，預期將可進一步進行相關充放電條件測試，並應用在鋰高分子電池。 2. 高效能A-SiO2防曬材料之製備和性質 根據過去的研究指出，防曬化妝品中常用的有機防曬劑大都是光不穩定性的物質，經由紫外線照射後會產生對皮膚有害之物質，因此本次研究利用多孔性SiO2進行MCX或EHS防曬劑的包覆，並以離子熔液為模板進行in-situ方式進行sol-gel反應，以便得到SiO2-MCX或SiO2-EHS防曬劑。經由BET、FT-IR、TGA、NMR、UV/Vis及SPF測試儀的鑑定，結果證實反應過程確實成功地將MCX或EHS包覆於多孔性的SiO2中。所獲得之包覆性防曬劑SiO2-MCX及SiO2-EHS，其包覆量分別為60wt％和55wt％。經測試亦證實SiO2-MCX防曬乳液的防曬係數比未包覆的MCX的高出許多，即MCX因包覆於SiO2中其防曬效果明顯提高。
並列摘要
Abstract 1. PAN/A-SiO2 CPEs for High Capacity Lithium Battery The objective of this study is to investigate the effect of morphology of SiO2 filler on the PAN-based composite polymer electrolytes (CPE). Hence, a series of composite polymer electrolytes based on PAN were prepared and the effect of addition of the SiO2 fillers, including the mesoporous silica aerogel (A-SiO2)、mesoporous MCM-41 silica (M-SiO2) and a nonporous commercial silica (D-SiO2), on the composite polymer electrolytes was discussed. The best conductivities obtained at room temperature is 6.0×10-4 S/cm, 4.5×10-4 S/cm and 2.3×10-4 S/cm for the CPE with 3wt% A-SiO2, 3wt% M-SiO2 and 4wt% D-SiO2, respectively. The interactions among the components of the electrolytes were also analyzed by the results of FT-IR and solid state Li NMR spectra. Furthermore, the electrochemical stability of the composite polymer electrolytes was studied by linear sweep voltammetry and cyclic voltammetry analyses. The above results revealed that the as-prepared polymer electrolytes prepared have good electrochemical stability, high oxidation breakdown voltage (4.5V vs. Li/Li+) and good compatibility with the lithium metal electrode. The capacity of the cell fabricated with the composite polymer electrolyte based on PAN/LiClO4/A-SiO2 measured with 0.5C of charge-discharge rate is 121mAh/g. It was also found that after twenty times charges-discharges, the capacity of the cell still remained 100%. The result indicates that the composite electrolyte prepared is a potential candidate as a solid electrolyte for secondary lithium battery. 2. High Efficiency Sunscreen Encapsulated Silica In this study the sun-screening material, octyl methoxycinnamate (MCX) or Octyl salicylate (EHS), was encapsulated by a mesoporous silica aerogel to enhance the screening effect and stability to prevent skin damages caused by ultraviolet. The encapsulated SiO2-MCX was prepared by in-situ sol-gel polymerization of tetraethyl orthosilicate (TEOS) and MCX with an ionic liquid as the template as well as the solvent. The as-prepared SiO2-MCX was characterized by Brunauer–Emmett–Teller (BET), Fourier transformation infrared (FT-IR), thermo¬gravimetric analysis (TGA), s solid state 29Si NMR, UV-Visible Spectrophotometer, and SPF-290S analyzer. The results indicated that the SiO2-MCX and SiO2-EHS particles are mesoporous material with high surface area and pore volume and about 60wt％ of MCX and 55wt % of EHS was encapsulated in the mesopores of the SiO2 framework, respectivley. It was also found that the UV absorption value of the as-prepared SiO2-MCX and SPF of the as-prepared SiO2-MCX containing sun-screening lotion were much higher than that of the corresponding pure MCX material and lotion.