液滴滴落到物體上並隨時間向外擴展，最後因蒸發而回縮並消失，這種現象在日常生活中十分常見。而液滴擴展與蒸發行為可廣泛應用許多領域，像是噴墨打印、薄膜塗層及鑑識技術，這些領域中對於液滴蒸發後的沉積物分布結果有著不同的要求，而液滴在擴展及蒸發後會影響最終沉積物的分布範圍，故探討液滴的擴展及蒸發行為對於內部沉積物的控制具有重要意義。本研究以30 wt%甘油–正丙醇液滴為研究溶液，分析液滴於25、30、40及50°C的親水玻璃基板上的擴展與蒸發特性。利用高速攝影機、立體顯微鏡及紅外線熱像儀以量測液滴幾何外形變化及液滴表面的溫度分布，用以比較不同基板溫度下液滴動態行為。結果顯示，基板溫度提高會加速液滴擴展及蒸發行為，液滴最大擴展直徑隨溫度單調增加。且在液滴經慣性及黏性擴展後，會出現隨基板溫度上升而出現的再擴展現象。結果指出，高溫造成液滴的黏度及內部濃度變化，可能改變液滴內部的力平衡並影響擴展行為。;The phenomenon of a droplet contacting a surface， spreading outward over time， and eventually receding and disappearing due to evaporation is highly common in daily life. The spreading and evaporation behavior of droplets is widely applied across numerous fields， such as inkjet printing， thin-film coating， and forensic science. Since these applications have distinct requirements for the final distribution of deposits left after droplet evaporation， and because the spreading and evaporation stages dictate the ultimate area of these deposits， investigating droplet spreading and evaporation behavior is of great significance for controlling internal deposit distribution.In this study， a solution of 30 wt% glycerol–n-propanol was utilized to analyze the spreading and evaporation characteristics of droplets on hydrophilic glass substrates at temperatures of 25， 30， 40， and 50°C. High-speed cameras， stereomicroscopes， and infrared thermal imagers were employed to measure the evolution of droplet geometry and surface temperature distribution， facilitating a comparison of the dynamic behavior of droplets under different substrate temperatures. The results indicate that increasing the substrate temperature accelerates both droplet spreading and evaporation， with the maximum spreading diameter increasing monotonically with temperature. Furthermore， following the initial inertial and viscous spreading stages， a "re-spreading" phenomenon emerged， which became more pronounced as the substrate temperature rose. These findings suggest that high temperatures induce changes in droplet viscosity and internal concentration， which may alter the internal force balance of the droplet and consequently influence its spreading behavior.
