本篇研究的目的為製備聚乙二醇/矽灰複合物作為固-液型態穩定轉換的相變化材料,並討論以不同分子量的聚乙二醇或是不同的填充環境下製成的相變化材料的熱性質及熱行為。接著，再經由原本應用於製藥工業的球晶技術將原本不規則狀的聚乙二醇/矽灰複合物製成球狀來改善其流動性。聚乙二醇/矽灰複合物是透過含浸法來製備的，將矽灰以不同的溶解度百分比的聚乙二醇水溶液進行填充。因聚乙二醇熔點及結晶點受其分子量大小影響，連帶影響了聚乙二醇/矽灰複合物應用在建築材料的摻料的選擇上，本篇選擇的聚乙二醇分子量大小為1000，並探討以分子量1000或4000製備的聚乙二醇/矽灰複合物的差異，在製備的條件上，壓力(真空與否)及溫度高低的影響都將在本研究討論。在常溫真空下製備的聚乙二醇/矽灰複合物擁有最高重量百分比67.5%的聚乙二醇，其熔點範圍為攝氏35-45度，結晶點約在攝氏10-20度。接著我們改變了製備過程中的壓力(真空與否)及溫度(攝氏5度、25度、60度)，並探討其熱性質及熱行為的改變，填充過程中，無論是否抽真空，皆沒有顯著影響，日後製成可在一般大氣下進行，節省啟動真空之能源;而溫度則顯著的影響了結晶度。 在球晶製程方面，以700轉的條件下所做出的複合團聚物之形狀可以明顯看出為球狀。因其範圍為1410-2000微米的顆粒有固定範圍尺寸且在所有尺寸顆粒上為相對多數，我們選擇此範圍粒徑作為代表來檢測卡爾係數及斷裂力測試，其卡爾係數為6.62±1.36，代表流動性高;而斷裂力為1.79±0.04牛頓，代表高強度。複合物球晶在不同的粒徑區間其特性都沒有太大的差異，在熱性質的表現上皆有不錯的均質性。 ;The aim of this research was to prepare a solid-liquid shape-stabilized phase change materials, polyethylene glycol/silica fume (PEG/SF) composite powders. Then, through the spherical crystallization technique which was derived from the area of pharmaceutical engineering to conglomerate the originally irregular PCM composite powders and turned them into spherical agglomerates to improve their flowability. In this research, the molecular weight 1000 of PEG was chosen as the PCM. Since the melting temperature and the crystallization temperature of PEG were affected by the molecular weight of PEG which also determined the application of PEG/SF composite powders. Therefore, thermal behaviors and thermal properties of PEG/SF composite powders with PEG1000 have compared the one with PEG4000. PEG1000 was embedded in SF to form the PEG1000(75)/SF composite powders with a PEG solid loading of 67.5 wt%. (The number 75 in the parentheses represented the 75% of solubility value of PEG1000 aqueous solution at 25℃ of 25 g/15 mL) The melting and crystallization temperature range of PEG1000(75)/SF composite powders were around 35-45℃ and 10-20℃ as determined by the 2nd temperature cycle of DSC after heating equilibrium with a heating rate and a cooling rate of 10℃/min, respectively. Next, the thermal behaviors and the thermal properties of PEG1000(75)/SF by adjusting the impregnation temperatures and pressures were also be studied. Whether the impregnation was under vacuum or not, did not change the actual PEG1000 loading and the phase change enthalpy too much. The crystallinity became higher when the impregnation temperature became higher and vice versa. The spherical agglomerates of PEG1000(75)/SF were made by the modified spherical agglomeration method. Under the agitation of 700 rpm, the shape of agglomerates appeared to be spherical. Since the 1410-2000 μm particles were the majority in the batch, they were for the Carr’s index and fracture force. The measurements of Carr’s index for the 1410-2000 μm sized agglomerates was 6.62±1.36, and the fracture force was 1.79±0.04 (N). In summary, similar thermal properties and good homogeneity were displayed by different sizes of spheres.
