Methods of preparation of omniphobic surfaces

A method for preparing a material having an omniphobic porous surface, the method comprising:

• providing a porous substrate;
• adjusting the average pore size and porosity of the porous substrate through controlled deposition of a first layer, wherein the controlled deposition comprises performing initiated chemical vapor deposition (iCVD) under reaction-limited conditions with a first monomer in the presence of a first initiator at a first substrate temperature, a first filament temperature, a first pressure, and a first monomer to initiator ratio, and wherein the first layer is a conformal coating;
• assembling a reentrant structure on the porous substrate through controlled deposition of a second layer, wherein the controlled deposition comprises performing iCVD under diffusion-limited conditions with a second monomer in the presence of a second initiator at a second substrate temperature, a second filament temperature, a second pressure, and a second monomer to initiator ratio, and wherein the second layer is a non-conformal coating;
• and
• engineering the surface energy of the reentrant structure, wherein the engineering comprises grafting a third layer onto the second layer, wherein the grafting comprises performing iCVD under reaction-limited conditions with a third monomer in the presence of a third initiator at a third substrate temperature, a third filament temperature, a third pressure, and a third monomer to initiator ratio, and wherein the third layer is a conformal coating.