We study new forms of molecular solids through kinetically-controlled phase transformation. For example, we recently discovered the growth of carbon dioxide (CO2) whiskers at low temperatures (-70 degree C to -65 degree C) and moderate pressure (4.4 bar to 1.0 bar). Their axial growth was assessed by optical video analysis. The identities of these whiskers were confirmed as CO2 solids by Raman spectroscopy. A vapor– solid growth mechanism was proposed based on the influence of the relative humidity on the growth.
Below is a video showing the growth of CO2 whiskers:
Funding support: National Science Foundation (Grant #: CHE 1665324).