Fig. 2

Effect of xanthan on lubricant evaporation. a, Evaporation time of the freshly lubricant impregnated nanoporous surfaces for different xanthan concentrations; 0 wt% implies pure water. The inset shows a comparison of the evaporation times of the freshly lubricant impregnated surfaces (circles, depicting the average time) with the regenerated lubricant impregnated surfaces. The regenerated lubricant is obtained by soaking the dry polymer coated nanoporous surfaces in water, which allows the polymer to re-dissolve in the water. b, SEM images of 40 nm surfaces dried after imbibing a xanthan-water solution with 0.04 wt% xanthan. After drying the xanthan gum coats the particle and assists in retaining water. c, SEM images of 40 nm surfaces dried after imbibing a xanthan-water solution with 0.15 wt% xanthan.