2007-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/687199摘要：奈米尺寸效應近年來在各種跨領域研究都成為相當受重視的課題。由於奈米尺寸效應，許多材料在奈米尺度下所展現出來的物理特性與化學性質會與微米尺度及塊材極為不同。本計畫提議針對各種常見蒸發岩類礦物(如鈉硝石、石膏、硬石膏、無水芒硝、方解石與菱鎂礦)之熱分解反應進行奈米尺度與微米尺度下之反應機制與反應速率之探討與比較。預期在奈米尺度下之礦物熱分解反應會有不同的反應動力學特性與反應機制。本研究分為三部分進行，第一部分將以XRD與拉曼光譜對上述各種礦物之奈米及微米等級合成粉體做定性分析。第二部分將以熱重分析(TGA)和熱示差分析(DTA)以各種升溫速率對不同顆粒粒徑之上述各種類粉末樣本進行熱分析，以瞭解其熱分解過程之重量散失與吸放熱變化，並對分解殘餘物和過程中所釋出之氣體進行後續之分析處理。第三部分將採用本研究團隊所發展之主導曲線模型(MCM)來分析從不同顆粒粒徑之粉體樣本所得到之熱重分析和定性分析資料，建立數值曲線模型以瞭解其個別之反應機制、反應速率和反應視活化能。最後綜合前三部分所得之結果，對前述礦物之奈米尺度與微米尺度下反應動力學特性進行比較與探討。因為主導曲線模型是種全新的反應動力學分析利器，所以本計畫所獲得的數據都是以往得不到的，預期可以從全新的角度深入探討奈米尺寸效應對蒸發岩類礦物之熱分解反應動力學與反應機制之影響。<br> Abstract: Nano-size effect has become a very important subject in many interdisciplinary research fields. Under the influence of size effect, most materials show different physical and chemical properties in their nanocrystalline form. In this project, we propose a research on the decomposition kinetics and reaction mechanisms of common evaporite minerals (such as nitratine、gypsum、anhydrite、thenardite、calcite and magnesite) of various sizes. We believe that nanoparticles of evaporite minerals will show different decomposition kinetics and reaction mechanisms from bulk materials. This research consists of three parts: First, analyze the synthetic powders of evaporite minerals with XRD and Raman Spectrum to identify the mineral phases and compositions of sample powders. Second, conduct a series of thermal decomposition experiments with various grain-sizes of sample powders by TGA and DTA at various heating rates, in order to gather the weight loss and heat variation data during the decomposition process. After thermal decomposition experiments, the residual and the released gases of the process will be analyzed. Third, construct adequate numerical models of the thermal decomposition processes. A Master Curve Model (MCM) will be used to analyze the TGA data of sample powder with different grain sizes, and to derive the apparent activation energies of the reactions. Finally, based on the results from the above three parts, the reaction kinetics of evaporite minerals and the influence of size effect will be analyzed. The Master Curve Model is a new tool on the analysis of kinetic reactions; therefore all the kinetic data derived from this project will also be new and not possible to obtain until now.蒸發岩奈米尺寸效應熱分解動力學evaporitenano-size effectthermal decompositionkinetics