摘要或動機

界面活性劑因分子一端具極性基(polar group)而有導電性，本研究以市售之界面活性劑(PAOS洗碗精)從事其水溶液導電度探討，實驗顯示，PAOS水溶液之導電度隨溫度升高而增加，90°C之導電度約為常溫之三倍，純水之變化則極微。除溫度外，界面活性劑濃度亦影響導電度，濃度越高導電度越大，定溫(23°C)之導電度隨PAOS含量增加呈直線上升關係，PAOS含量每增2%導電度約增加1000μS，當含10%PAOS之水溶液中期導電度約增為4700μS。乳化效果對導電度亦有明顯之影響。在含PAOS 0.5~3%之水溶液中加入沙拉油，隨沙拉油加入量之增加其導電度均呈現下降現象。例如，在含有PAOS 3%之200克水溶液當中加入10克沙拉油時，其導電度約下降了15%。如果加入更多沙拉油，或者乳化攪拌過後之停滯時間過久，造成乳化平衡破壞，其導電度數據則較不規則。因此，我們可由溶液導電度之量測結果判定乳化效果，並可測定乳化攪拌之最佳條件。實驗除了以導電度探討其乳化效果外，並用顯微鏡同步觀測，以對結果做出更具說服力的解釋。將實驗數據以3D圖(立體圖)呈現以描述系統的連續變化狀態。再利用簡易的曲線回歸、斜率比較等，判定在定溫、一定攪拌條件下，清潔劑的較佳使用濃度。Surfactants have polar end groups at its molecular structure lead it with electrical conductivity in properties. This report discuss conductivity of a market purchasable surfactant named PAOS. Experiment results indicate conductivity of PAOS water solution increases with rising temperature. Triple in conductivity of this solution was found at 90°C than that of at room temperature. While the changes for pure water is very small. Except temperature influence, surfactant concentration also influence its conductivity. Generally, higher concentration gives higher electrical conductivity. At room temperature(23°C) a straight line relationship was observed between the solution concentration and the conductivity. For every increase 2% will led to increasing in conductivity for 1000 μS. When 10% PAOS in water solution is reached 4700 μS in conductivity was observed. Emulsification give obvious inference in conductivity. If cooking oil is added in 0.5~3% PAOS solution, conductivity will decrease with increasing oil added. For instance, when 10 grams of oil was added in 200 grams water solution that contain 3% PAOS, conductivity of this solution decreased for 15%. If more oil is added or setting time is too long after the solution is emulsified that destroy the emulsify balance. The conductivity of the system become irregular. In this way, it is possible to detect effect of emulsify through the measurement in its conductivity. Therefore most favorable condition in emulsification can be determined. In addition to using conductive measurement to determine effect of emulsification, microscopic technique also used trying to find even more convincible explanations. The data of different concentration experimented above can be presented on a 3D chart, we obtain several curves that can be differentially analyzed and estimated for a relatively ideal concentration, which will work more efficiently than others in the condition of the experiment.