TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Membrane: The forward osmosis membrane comprises a form selected from flat sheet, hollow fiber or tubular. When the forward osmosis membrane is in hollow fiber form, the thin film is polymerized on an internal or external surface of the hollow fiber. The thickness of the forward osmosis membrane is 20-400 mu m. The forward osmosis membrane further comprises a porous smooth layer formed on a side of the porous support layer opposite the side of the porous support layer on which the thin film is polymerized; and a hydrophilic polymeric layer on top of the thin film. In the forward osmosis membrane, the nanomaterials are dispersed in the hydrophilic layer. In the forward osmosis membrane, the thin film is configured to be permeable to water and relatively impermeable to impurities. In the forward osmosis membrane, the thin film is configured to be relatively impermeable to impurities comprising: dissolved, dispersed, or suspended solids; monovalent, divalent, trivalent ions of sodium, potassium, magnesium, calcium, iron, aluminum ion, silicate, dissolved organics, or nonionized dissolved solids with a molecular weight of greater than 200 Daltons, where the thickness of the thin film is 30 nm to 3 mu m. In the forward osmosis membrane, sizes of the nanomaterials are in less than 500 nm. In the forward osmosis membrane, a weight percentage of the nanomaterials by weight of the matrix polymer in at least one of the porous support layer and the thin film is 0.01-20 wt.%. Preferred Method: In the method (M1), forming the porous support layer comprises casting the porous support layer on a rotating drum. Casting the porous support layer on the rotating drum comprises either casting the polymer solution directly on a surface of the rotating drum while pulling a polymeric fabric into the polymer solution, thereby embedding the polymeric fabric in the polymer solution; or casting the polymer solution on a polymeric fabric laid on a surface of the rotating drum. The method (M1) further involves modifying a surface of the porous support layer by treatment with at least one of plasma, UV light, or a solvent. In the method (M1), dispersing the nanomateriais in the porous support layer comprises providing preformed nanomateriais in the polymer solution for the phase inversion. In the method (M1), dispersing the nanomateriais in the porous support layer comprises providing nanomaterial precursors in the polymer solution and in-situ forming the nanomateriais by chemical reactions during the phase inversion. In the method (M1), dispersing the nanomateriais in the thin film comprises providing preformed nanomateriais in the liquid. In the method (M1), dispersing the nanomateriais in the thin film comprises providing nanomaterial precursors in the liquid and in-situ forming the nanomateriais by chemical reactions during the interfacial polymerization. The method (M1) further involves forming a porous smooth layer formed on a side of the porous support layer opposite the side of the porous support layer on which the thin film is polymerized; forming a hydrophilic polymeric layer on top of the thin film; dispersing the nanomaterials in the hydrophilic polymeric layer; and subjecting the porous support layer to a post-treatment process to reduce pore size. Preferred Components: The nanomaterials are in the form of nanoparticles, nanofiber, nanowire, nanotube, or nanospheres. The nanomaterials are inorganics and organics. The nanomaterials comprise salts of silver, gold, zinc, copper, sodium, titanium, silicon, aluminum, zirconium, indium, tin, magnesium, calcium, their oxide, and their alloy; or mesoporous materials of the oxide of aluminum, titania, silicon, magnesium, strontium, beryllium, mesoporous molecular sieve, aluminosilicate, aluminophopsphate, or zeolite; or dendrimers, graphite, graphene, carbon nanotubes, or fullerene. The nanomateriais are surface modified nanomateriais. The nanomaterial precursors comprise metal alkoxide, titanium tetra isopropoxide (TTIP), tetrabutyl titanate (TnBT), tetraethyl orthosilicate (TEOS), bis(triethoxy silyl)ethane (BTESE), phenyltriethoxysilane (PhTES), methyltriethoxysilane (MeTES), octyltriethoxysilane (OcTES), or octadecyltrimethoxysilane (OdTMS).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The matrix material for the hydrophilic polymeric layer comprises triethylene glycol, or diethylene glycol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The matrix material for the hydrophilic polymeric layer comprises polyvinyl alcohol, polyvinyl pyrrole, polyvinyl pyrrolidone, polyethylene glycol or saponified polyethylene-vinyl acetate copolymer. The matrix material for the thin film comprises polyamide, aromatic polyamide, polypiperazine polyamide, polybenzimidazole, polyether, polyester, polyether-urea, polyvinyl alcohol, polyvinyl pyrrole, polyvinyl pyrrolidone, polyethylene glycol, saponified polyethylene-vinyl acetate copolymer, triethylene glycol or diethylene glycol and its copolymer. The porous support layer comprises a polymeric fabric selected from a woven polymeric fabric screen and a non-woven polymeric fabric mesh. The thickness of the polymeric fabric is 1-200 (preferably 10-100) mu m. The material of the polymeric fabric comprises hydrophilic polymer, hydrophobic polymer, polyester, polypropylene, acrylics, cotton, cellulose, or nylon. The surface of the polymeric fabric is modified by treatment with at least one of plasma, UV light, or a solvent. The matrix material for the porous support layer comprises a natural polymer or synthetic polymers, polysulfone, polyethersulfone, sulfonated polysulfone, poly(ether sulfone ketone), poly(ether ethyl ketone), poly(phthalazinone ether sulfone ketone), polyacrylonitrile, polypropylene, cellulose acetate, cellulose diacetate, cellulose triacetate, polyvinyl alcohol, polyvinyl pyrrole, polyvinyl pyrrolidone, polyethylene glycol, saponified polyethylene- vinyl acetate copolymer, triethylene glycol, diethylene glycol, polyaniline, or Pluronic F127 (RTM: nonionic surfactant). EXAMPLE - Preparation of a forward osmosis membrane was carried as follows: a porous support layer was prepared by dissolving polysulfone (PSf) beads (9 g) in N,N-dimethylformamide (DMF) (96 ml) containing polyvinyl pyrrole (PVP) (0.5%) and Pluronic F127 (RTM: nonionic surfactant) (0.3%) in a glass bottle. Then, Degussa P25 (RTM: TiO2 nanoparticles) (0.3 g) were dispersed in the DMF before its addition to the PSf polymer. The solution was then agitated ultrasonically for 24 hours until complete dissolution, forming the cast solution which was then set aside for 2 days to eliminate air bubbles. The cast solution was then spread over a non-woven polyester (PET) fabric that was attached to a glass plate and wetted by the solvent of DMF. The glass plate was immediately immersed in tap water at room temperature to induce phase inversion. After 30 minutes, the non-woven PET fabric supported PSf nanocomposite porous support layer was removed from the water bath and separated from the glass plate. The porous support layer dispersed with nanocomposites was washed thoroughly with tap water and stored at 5 degrees C. The above obtained porous support layer was immersed in an aqueous solution of m-phenylenediamine (MPD) (3 wt.%) which contains other additives like triethyl amine (TEA), 10-champhor sulfonic acid (CSA), sodium lauryl sulfate (SLS), and isopropanol for 25 seconds. Excess MPD solution was removed from the surface of the porous support layer using an air knife. The aqueous MPD saturated porous support layer was then immersed in trimesoyl chloride (TMC) solution (0.15 wt.%) in isoparaffin containing phenyl triethoxy silane (PhTES) at 3 wt.% concentrations for 60 seconds to form the thin film. The resulting membrane was cured in deionized water at 50 degrees C for 20 minutes, then rinsed with a NaOCl aqueous solution (200 ppm) for 120 seconds, followed by rinsing for 30 seconds with a NaHSO3 aqueous solution (1000 ppm), before a final heat curing step at 90 degrees C for 60 seconds to obtain forward osmosis membrane. The final forward osmosis membrane formed was rinsed thoroughly with deionized water and stored in deionized water at 4 degrees C. Finally, the thin film nanocomposite forward osmosis membrane was immersed in glycerol solution (50 wt.%) for another 24 hours and then dried in air at room temperature.