TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The silane-based solution comprises a silane selected from propyltriethoxysilane (PTES), octadecyltrimethoxysilane (OTS), (heptadecafluoro)-1,1,2,2-tetrahydrodecyltrimethoxysilane and/or hexamethyldisilazane (HMDS).    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The sol-gel composition comprises porosity forming agent (0.1-5 wt.%); and the sol-gel composition further comprises a film forming precursor selected from tetraethylorthosilicate (TEOS), 3-glycidoxypropyltrimethoxysilane (Glymo), octadecyltrimethoxysilane (OTS), propyltriethoxysilane (PTES), methyltriethoxysilane (MTES), (heptadecafluoro) 1,1,2,2-tetrahydrodecyltrimethoxysilane and/or hexamethyldisilazane (HMDS) (preferably TEOS). The composition (C1) comprises (wt.%): film forming precursor (0.1-10); acid or base containing catalyst (0.001-0.1); water (0.001-1); alcohol containing solvent (80-95); and at least one porosity forming agent (0.1-5). The composition (C1) further comprises a stabilizer (S1) selected from polyoxyethylene stearyl ether, cetyltrimethylammoniumbromide (CTAB), 3-glycidoxypropyltrimethoxysilane, polyethyleneglycol (PEG), ammonium lauryl sulfate (ALS), dodecyltrimethylammoniumchloride (DTAC), benzoalkonium chloride (BAC), and/or polyalkyleneoxide modified hepta-methyltrisiloxane. Preferred Method: The method (M1) further involves drying the sol-gel composition coated on the substrate to form a gel on the substrate; exposing the porous coating to a silane-based solution to improve the hydrophobicity of the porous coating; and exposing the porous coating to plasma to seal the pores of the porous coating. Annealing of the coated substrate to remove at least one porosity forming agent involves heating the coated substrate (preferably glass substrate) to greater than 500 degrees C. The method (M2) further involves using the stabilizer (S1); heating the reaction mixture to 50-60 degrees C; cooling the heated reaction mixture to room temperature; and adding additional alcohol containing solvent to the cooled reaction mixture prior to adding at least one porosity forming agent. Preferred Components: The porosity forming agent is a dendrimer selected from poly(amidoamine) (PAMAM) dendrimers, poly(propylene imine) (PPI) dendrimers, bis-MPA dendrimers, and/or trimethylol propane (TMP)-cored dendrimers; or organic nanocrystal selected from tetracene, 60C fullerene and/or anthracene nanocrystals (preferably anthracene). EXAMPLE - Tetraethylorthosilicate (TEOS) corresponding to 3% total ash content (based on equivalent weight of silica produced) in the final formulation was mixed with water (2 times stoichiometric amount based on TEOS), nitric acid (0.02 times the molar TEOS amount) and n-propanol (10-100 times molar TEOS). The solution was stirred for 24 hours at room temperature or elevated temperature (50-60 degrees C). The solution was cooled to room temperature and mixed with an additional amount of n-propanol to bring the total ash content of the solution to 3%. DNT-102 (RTM: dendrimer) (molecular weight of 458 and diameter of 1.9 nm) was added to this solution at 3% mass level to act as a porosity forming agent. The solution was either dip (coating speed of approximately 10 mm/sec) or spin coated (1000-1400 revolutions per minute (rpm)) on pre-cleaned borosilicate (BSG) or sodalime glass to achieve a film thickness of around approximately 150 nm after annealing. The glass substrate was dried at 150 degrees C for 30 minutes in an oven to evaporate all the solvent and then annealed at 625-650 degrees C for 6 minutes to obtain a porous coated glass substrate.