Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China.
Hong Kong University of Science and Technology, Shenzhen Research Institute, Shenzhen 518057, China.
Sci Adv. 2023 Mar 15;9(11):eadf1101. doi: 10.1126/sciadv.adf1101. Epub 2023 Mar 17.
The nature of liquid-to-glass transition is a major puzzle in science. A similar challenge exists in glass-to-liquid transition, i.e., glass melting, especially for the poorly investigated surface effects. Here, we assemble colloidal glasses by vapor deposition and melt them by tuning particle attractions. The structural and dynamic parameters saturate at different depths, which define a surface liquid layer and an intermediate glassy layer. The power-law growth of both layers and melting front behaviors at different heating rates are similar to crystal premelting and melting, suggesting that premelting and melting can be generalized to amorphous solids. The measured single-particle kinetics reveal various features and confirm theoretical predictions for glass surface layer.
液态向玻璃态转变的本质是科学中的一个主要难题。玻璃态向液态转变，即玻璃熔化，同样存在类似的挑战，特别是对于研究甚少的表面效应。在这里，我们通过蒸汽沉积组装胶体玻璃，并通过调节粒子吸引力将其熔化。结构和动力学参数在不同的深度处达到饱和，从而定义了表面液体层和中间玻璃态层。两个层的幂律增长和不同加热速率下的熔化前沿行为与晶体的预熔和熔化相似，这表明预熔和熔化可以推广到非晶态固体。所测量的单个粒子动力学揭示了各种特征，并证实了玻璃表面层的理论预测。
