Water Droplet Coalescence Behavior on Lubricant Infused Surfaces

Abstract

Water droplet coalescence behavior on lubricant-infused surfaces has been previously observed to be inconsistent. I thus completed an independent study that aimed to observe trends and patterns that may contribute to this erratic behavior. Originally, the experimental plan consisted of conducting experiments to learn more about the effects of surface structure, temperature gradients, and oil film thickness. During this independent study, we examined the noncoalescence times of water droplets on superhydrophobic surfaces coated with silicone 50 cSt and Krytox 102 oils. Through experiments, we found that Krytox 102 oil leads to shorter noncoalescence times when compared to those of silicone 50 cSt, however the observed times for both oils vary. The range of observed times on Krytox 102 oil is 0.1 s to 12.76 s, and approximately 1 min on silicone 50 cSt oil. This difference is likely caused by the oil chemistry, molecular orientation at the interface or charging effects. Additional experiments must be conducted to confirm this hypothesis, which could include studies of oil film thickness, different fluid combinations, and molecular-scale modelling.