Transparent Organogel Films Showing Extremely Efficient and Durable Anti-Icing Performance.

Accumulation of ice and snow on solid surfaces causes destructive problems in our daily life. Therefore, the development of functional coatings/surfaces that can effectively prevent ice/snow adhesion by natural forces, such as airflow, vibration, solar radiation, or gravity, is in high demand. In this study, transparent organogel films possessing negligible ice adhesion strength were successfully designed by a simple cross-linking of poly(dimethylsiloxane) (PDMS) in the presence of commercially available oils. Both the molecular weights (MWs) of the infusing oils and their contents in the PDMS matrices have proven to be key parameters for primarily determining the cross-linking density of PDMS matrices and syneresis/nonsyneresis behaviors of our samples, which closely reflected the final surface static/dynamic dewetting and anti-icing properties. By tuning only these two parameters, three different types of transparent organogel films, that is, nonsyneresis organogel (NSG), self-lubricating organogel (SLUG-I, infused with highly mobile oils), and SLUG-II (infused with viscous oils) films, were prepared. Among them, on the SLUG-I films, the lubricating oils were found to be continuously released from the PDMS matrices through syneresis for more than 1 year. Due to this unusual syneresis behavior, the ice adhesion strength became virtually zero, and this excellent anti-icing property also remained almost unchanged even after several cycles of icing/deicing testing. On the other hand, in the case of SLUG-II films, as the lubricated oil layers were too viscous, ice had trouble sliding off the surfaces by gravity. In contrast to these SLUG films, ice adhesion strength on NSG films was markedly decreased by increasing the amount of the infusing oils. In spite of NSG films having no distinct mobile oil layer, the ice adhesion strength reached its minimum of only about 5 kPa.