Slippery Lubricant Infused Porous Surface Generated by Self-Assembly Mechanism of a Composite Organogel for Low Ice Adhesion

Abstract

In recent years, researchers have developed coatings and strategies to solve the problems caused by ice formation and accretion on surfaces. These problems are present in various fields such as aviation, waterborne transportation, and also in industrial sectors, such as energy production. Among the new technologies developed, one solution has proven to be very effective in decreasing ice adhesion. This new type of surface is defined as a slippery lubricant infused porous surface (SLIPS) and is generally structured as a porous structure infused with a lubricant. Importantly, the SLIPS have a distinctive superficial oil layer stabilized by capillary force due to the porous structure under the oil layer. It is due to this superficial oil layer that SLIPSs has proven effective as a passive icephobic coating. In this study, the goal was to develop and study the properties of a SLIPS-like coating with a self- assembled mechanism generated by a composite organogel for low ice adhesion. This self-assembled mechanism could be summarized as follows: once the suspension of porous SiO2 (PS) particles, solvent, polymer, and oil is placed on the substrate surface, the evaporation of the solvent then pushes the oil onto the top of the coating while the polymer and the PS particles adhere to the substrate. The development of the coating began with the synthesis of the PS particles. To improve the synthesis procedure, an oven (rather than a centrifuge) was used in the final step of the process that separates the PS particles from the solution. Two important findings are reported. First, the agglomeration of the PS particles is higher when the oven is used instead of the centrifuge. Second, the presence of a severe agglomeration of the PS particles was found when the diameter was less than ~800 nm. In the next stage of the study, the surfaces of the PS particles were functionalized. The functionalization reaction was proven by the analysis of the surface chemistry of the PS particles before and after the reaction, thus showing the disappearance of free hydroxyl groups on the surface of the PS particles. Finally, after an experimental study to find a suitable polymer matrix using a trial and error approach, the self-assembled SLIPS coating was produced and applied with a paintbrush. To prove the self-assembled mechanism, the structure of the coatings was analyzed by wetting and by ATR-FTIR. Then, all the coatings were analyzed by measuring their ice adhesion and their resistance using an accelerated weather test. This study found that the self-assembled SLIPS showed low values of ice adhesion (12±5.9 KPa), but relatively poor weathering resistance. Further work is needed to investigate the exposure of the coatings to environmental conditions.