Kailong Fan’s research while affiliated with Zhejiang University and other places

Small organic molecules are essential building blocks of our universe, from cosmic dust to planetary surfaces to life. Compared to their well-known gaseous and liquid forms that have been extensively studied, small organic molecules in the form of ice at low temperatures receive much less attention. Here, we show that supercooled small-molecule droplets can be drawn into highly uniform amorphous ice microfibers with lengths up to 5 cm and diameters down to 200 nm. In the experimental test, these fiber-like ices manifest excellent mechanical flexibilities with elastic strain up to 3.3%. Meanwhile, they can guide light with loss down to 0.025 dB/cm that approaches the material absorption limit and offer high optical nonlinearity for low-threshold supercontinuum generation. Notable temperature-dependent Young’s modulus and icing-induced refractive-index increase are also found. These results may open a promising category of low-temperature materials for both scientific research and technological applications.

Owing to its unique structure, morphology, and crystal quality, low-dimensional (L-D) ice has attracted increasing attention in recent years. With a size (at least in one dimension) between that of a single water molecule and a snowflake, L-D ice does not only appear as an intermediate state during the dimensional change but can also manifest extraordinary characteristics, from its molecular structures to its physical properties, which offer exciting opportunities for a better understanding and utilization of ice. In this article, we start with a brief introduction to the crystal growth, structure, and typical characterization techniques of ice and then review recent progress in the study of crystal growth, molecular structures, phase morphologies, and physical properties of zero-, one-, and two-dimensional (0-, 1-, and 2D) ice. Extraordinary behaviors of ice in low dimensions and extreme conditions are highlighted. Finally, the future outlook for the physical study and technological applications of L-D ice is briefly discussed. Expected final online publication date for the Annual Review of Materials Research, Volume 53 is July 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.