TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The method (M1) further involves annealing the gel coated textured substrate, where the step of annealing involves heating the substrate to temperature of 500-1000 degrees C. The method (M2) further involves adding a porosity forming agent to the reaction mixture. Preferred Components: The solidifier is selected from gelatin, sodium acrylate, sodium acryloyldimethyl taurate, isohexadecane, polyoxyethylene (80) sorbitan monooleate, silica gel, polyethylene glycol (PEG) having a molecular mass of 200-1000, low molecular mass organic gelators, charge neutralizers, and/or cellulose derivatives. The amount of solidifier for expediting the sol-gel transition point is 0.0001-0.1 wt.% of the total weight of the sol-gel composition. The solidifier is selected from polyethylene glycol (PEG) having a molecular mass of 200-1000 and hydroxypropylcellulose. The porosity forming agent is selected from self-assembling molecular porogens comprising polyoxyethylene stearyl ether, benzoalkoniumchloride (BAC), cetyltrimethylammoniumbromide (CTAB), 3-glycidoxypropyltrimethoxysilane, polyethyleneglycol (PEG), ammonium lauryl sulfate (ALS), dodecyltrimethylammoniumchloride (DTAC), and/or polyalkyleneoxide modified hepta-methyltrisiloxane. Preferred Composition: The sol-gel composition (C1), further comprises a silicon containing precursor selected from tetraethylorthosilicate (TEOS),3-glycidoxypropyltrimethoxysilane (Glymo), octadecyltrimethoxysilane (OTS), propyltriethoxysilane (PTES), methyltriethoxysilane (MTES), (heptadecafluoro)1,1,2,2-tetrahydrodecyltrimethoxysilane, and/or hexamethyldisilazane (HMDS). The sol-gel composition further comprises at least one of a porosity forming agent and silica nanoparticles and the conformal coating is a porous coating. The composition (C2) comprises (wt.%): silicon containing precursor (1-10), acid or base containing catalyst (0.001-0.1), water (0.001-0.1), alcohol containing solvent (80-95), and solidifier (0.0001-0.1). EXAMPLE - No suitable example given.