TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Particles: The nanoparticles comprise a material chosen from a metal, a metal oxide and their mixture. The metal is chosen from aluminum, titanium, magnesium, barium, calcium and their alloys. The metal oxide is chosen from titanium oxide, aluminum oxide, zirconium oxide, zinc oxide, barium oxide, strontium oxide, calcium oxide, magnesium oxide, vanadium oxide, chromium oxide, molybdenum oxide and lithium-manganese oxide. The nanoparticles comprise a transparent conductive oxide chosen from cadmium stannate, cadmium indate, zinc stannate (Zn2SnO4 and ZnSnO3), and zinc indium oxide (Zn2In2O5), barium titanate and barium strontium titanate. The nanoparticles comprise carbon nanotubes and or graphene nano-sheets or nanoflake. The sealing layer further comprises inert nanoparticles comprising a material chosen from gold, copper, silver, platinum, silica, wollastonite, mullite, montmorillonite, silicate glass, fluorosilicate glass, fluoroborosilicate glass, aluminosilicate glass, calcium silicate glass, calcium aluminum silicate glass, calcium aluminum fluorosilicate glass, titanium carbide, zirconium carbide, zirconium nitride, silicon carbide, silicon nitride, a metal sulfide, and their mixture. The nanoparticles have a size that is smaller than the average diameter of defects present in the one or more barrier layers. The oxygen and/or moisture sensitive article comprises an electroluminescent electronic component or a solar device. The average size of the nanoparticles is less than one-half the characteristic wavelength of light produced by the electroluminescent electronic component or absorbed by the solar device. The barrier layer comprises indium tin oxide, titanium aluminum nitrate, silicon dioxide, silicon carbide, silicon nitride, titanium dioxide, hafnium oxide, yttrium oxide, tantalum pentoxide and alumina.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Solvent: The organic solvent comprises a mixture of isopropanol and ethyl acetate in molar ratio of 1:3.    TECHNOLOGY FOCUS - POLYMERS - Preferred Layer: The sealing layer consists of encapsulated reactive nanoparticles. At least a portion of encapsulated nanoparticles have aliphatic, alicyclic, aromatic or arylaliphatic compound which is immobilized and has a polar group. The polar group is chosen from hydroxyl, carboxyl, amido, thio, seleno and telluro group. The nanoparticles are encapsulated by a polymeric material (polymer encapsulated nanoparticles). The encapsulation material comprises an oligomer. The encapsulation material is chosen from an organic polymer, inorganic polymer, a water soluble polymer, organic solvent soluble polymer, biological polymer, synthetic polymer and oligomer. A prepolymer is used for encapsulation. The prepolymer is an acrylic oligomer having molecular weight of less than 1000 Da and viscosity of less than 300 cP. The encapsulation material is an organic material including a mercapto group, an epoxy group, an acrylic group, a methacrylate group, an allyl group, a vinyl group, a halogen and an amino group. The encapsulation barrier stack of any of claims 1 to 9, wherein the encapsulation material is cross-linked or cross-linkable, a UV curable, electron beam curable or heat curable material. The nanoparticles are chosen from pigment particles, quantum dots, colloidal particles, and their mixture. The barrier stack further comprises a substrate for supporting the multilayer film. The substrate comprises polyacetate, polypropylene, polyimide, cellophane, poly(1-trimethylsilyl-1-propyne), poly(4-methyl-2-pentyne), polyimide, polycarbonate, polyethylene, polyethersulfone, epoxy resin, polyethylene terepthalate, polystyrene, polyurethane, polyacrylate, and polydimethylphenylene oxide, styrene-divinyl benzene copolymer, polyvinylidene fluoride (PVDF), nylon, nitrocellulose, cellulose, glass, indium tin oxide, nano-clay, silicone, polydimethylsiloxane, biscyclopentadienyl iron, and polyphosphazene. The barrier stack further comprises a planarizing layer and a terminal layer for protecting the multilayer film. The terminal layer comprises an acrylic film. The terminal layer is an oxide layer. The acrylic film is a film in which lithium fluoride and/or magnesium fluoride particles are distributed. The encapsulation barrier stack has water vapor permeation rate of less than 103 g/m2/day, less than 104 g/m2/day, 105 g/m2/day or less than 106 g/m2/day. The sealing layer provides UV filter property, an antireflection property, a light extraction property and an antistatic property. The sealing layer further has a polymer layer does not containing reactive particles or polymer layer in which reactive nanoparticles are distributed in a polymeric matrix. The nanoparticles are colloidal dispersion comprising nanoparticles dispersed in an organic solvent. The nanoparticles are mixed with polymerizable compound in a polar organic solvent. The polymerizable compound is chosen from acrylic acid, methyl acrylate, ethyl acrylate and butyl acrylate. The polymerizable or crosslinkable compound is mixed with nanoparticles in weight ratio of 1:5 or less.