Candle-based process for creating a stable superhydrophobic surface

Abstract

A superhydrophobic surface with stability against moderate drop impact was quickly created with only a candle. There was no further need for any additional solvent, further surface treatment, drying process or post-treatment process. The fabrication is very simple. A surface is coated with a candle paraffin wax and then sooted with a candle flame. The paraffin wax was used to fix the fragile candle soot. This paraffin wax-fixed candle soot (PFCS) coating showed improved drop impact durability by up to a factor of 50, compared to a bare soot coating without a paraffin wax treatment. Thermal stability, compression tolerance, and pH tolerance of the PFCS coating were tested. The mechanism behind the PFCS coating and durability enhancement of the coating is explained. The simple PFCS coating method can be applied to various surfaces, such as metal, ceramic, wood, plastic and even paper. We provide proof-of-concept demonstrations in the application of this PFCS coating method. We foresee PFCS coating as opening up a new avenue for the development of an inexpensive and quick process for the fabrication of superhydrophobic surfaces.