Tah Indrajit, Mutneja Anoop, Karmakar Smarajit
Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, Pennsylvania 19104, United States.
Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500107, India.
ACS Omega. 2021 Mar 8;6(11):7229-7239. doi: 10.1021/acsomega.0c04831. eCollection 2021 Mar 23.
Glasses are ubiquitous in nature. Many common items such as ketchups, cosmetic products, toothpaste, etc. and metallic glasses are examples of such glassy materials whose dynamical and rheological properties matter in our daily life. The dynamics of these glass-forming systems are known to be very sluggish and heterogeneous, but a detailed understanding of the origin of such slowing down is still lacking. Slow heterogeneous dynamics occur in a wide variety of systems at scales ranging from microscopic to macroscopic. Polymeric liquids, granular material, such as powder and sand, gels, and foams and also metallic alloys show such complex glassy dynamics at appropriate conditions. Recently, the existence of dynamical heterogeneity has also been found in biological systems starting from collective cell migration in a monolayer of cells to embryonic morphogenesis, cancer invasion, and wound healing. Extensive research in the past decade or so lead to the understanding that there are growing dynamic and static correlation lengths associated with the observed dynamical heterogeneity and rapid rise in viscosity. In this review, we have highlighted the recent developments on measuring these correlation lengths in glass-forming liquids and their possible implications in the physics of the glass transition.
玻璃在自然界中无处不在。许多常见物品，如番茄酱、化妆品、牙膏等，以及金属玻璃都是这类玻璃态材料的例子，其动力学和流变学性质在我们的日常生活中至关重要。已知这些玻璃形成系统的动力学非常缓慢且不均匀，但对这种减速起源的详细理解仍然缺乏。缓慢的非均匀动力学在从微观到宏观的各种尺度的系统中都会出现。聚合物液体、颗粒材料（如粉末和沙子）、凝胶、泡沫以及金属合金在适当条件下都表现出这种复杂的玻璃态动力学。最近，从单层细胞中的集体细胞迁移到胚胎形态发生、癌症侵袭和伤口愈合等生物系统中也发现了动力学非均匀性的存在。在过去十年左右的广泛研究使人们认识到，与观察到的动力学非均匀性和粘度的快速上升相关的动态和静态相关长度在不断增加。在这篇综述中，我们重点介绍了在玻璃形成液体中测量这些相关长度的最新进展及其在玻璃转变物理学中的可能影响。
