TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The nanoparticle is titanium dioxide, aluminum oxide, silicon dioxide, copper oxide, magnesium oxide, lithium aluminate, zirconium dioxide, carbon nano tube, boron nitride, silicon carbide, silicon nitride, tungsten carbide, boron carbide, aluminum nitride, iron oxide, barium titanate, molybdenum disulfide, alpha -vanadium oxide, lead titanate, titanium diboride, calcium metasilicate, molecular sieve zeolite socony mobil-5, clay or kaolin, and has particle diameter of 1-200 nm. The organic solvent is n,n-dimethylformamide, n,n-dimethylacetamide and/or dimethyl sulfoxide. The electrolyte in electrolyte solution comprises lithium salt and organic solvent. The lithium salt is lithium hexafluorophosphate, lithium perchlorate or lithium tetrafluoroborate. The organic solvent is ethylene carbonate, carbonic allyl ester, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate or vinylene carbonate. The concentration of liquid electrolyte is 0.8-1.5 mole/l.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The electrostatic spinning process is carried out with voltage of 5-20 kV, receive distance of 6 to 15 cm, and nozzle moving speed of 5-6 mm/s for 1-20 hours. The flow rate of mixture is increased or decreased at constant amplitude of 0.01-0.5 ml/minute with uniform interval of 0.5-60 minutes. The electrostatic spinning nozzle has inner diameter of 0.2-1 mm.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The copolymerization process comprises mixing the acrylonitrile monomer and butyl methacrylate monomer in inert atmosphere of -18 degrees C, adding 1x 10-5-1x 10-2 of sodium bisulfite and potassium persulfate in a ratio of 5-15:1 into 3-10 mole/l of mixture, then carrying out polymerization reaction at 40-100 degrees C for 2-10 hours, washing the copolymers Aa and Ab to purify. The copolymers Aa and Ab have acrylonitrile monomer and butyl methacrylate monomer in a ratio of 99:1- 87:13 and 85:15-70:30, respectively. The annealing treatment is carried out at 30-60 degrees C for 30-120 minutes to obtain polymer film with thickness of 0.01-110 mu m. Preferred Components: The molecular amount of copolymer Aa and Ab is 500000 to 2000000 g/mole. The nanoparticle and copolymer Aa and Ab are present in an amount of 1-25 wt.% and 3-15 wt.%, respectively.