TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The substrate comprises hydrogen fluorine-containing sulfonic resin (0.01-10 weight%). The membrane comprises 30-3000 fluorine-containing structural units of formula: -(CF2C(-X)(-Y'))n-CF2CF(-G)- (I) and/or 10-6000 fluorine-containing structural units of formula: -(CF2CF2)a-(CF(-O-(CF2)2SO3)M (power)(1/n)+CF2)c-(CF2CF2)b-(CF(-O-CF2-CF(-CF3)-O-CF2-CF2-SO3)M' (power)(1/m)+-CF2)d. The dispersing agent is chosen from sodium polyphosphate, potassium tripolyphosphate or ammonium polyphosphate.G=O(CF2)mSO3H or O(CF2CFO(-CF3))p(CF2)qSO3H;X=H or F;Y'=H, F or Cl;n=3-15;m=2-5;p=1 or 2;q=2 or 3;M,M'=cerium, manganese, lanthanum, zinc, tungsten, titanium, vanadium, chromium, iron, cobalt, nickel, copper, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, tantalum, rhenium, iridium, platinum, hydrogen, sodium or potassium;n,m=metal valence state;a,b=1 or more;c,d=0 or 1 (where c+d is not equal to 0);(a+b)/(a+b+c+d)=0.5-0.99;and(c+d)/(a+b+c+d)=0.01-0.5.Preferred Process: The silica powder surface modified by fluorine-containing compound is produced by carrying out amination modification of surface hydrogen of silica powder using aminosilane coupling agent to form aminated silica powder, reacting the aminated silica powder with the fluorine-containing carboxylic acid to dehydrate and forming silica powder surface modified by fluorine-containing compound. Preferred Compound: The aminosilane coupling agent is of formula: R5-NH-R4-Si(-O-R1)(-O-R3)-O-R2 (III). The perfluorocarboxylic acid is 1-10C perfluorocarboxylic acid or 1-100C oxygenated carboxylic acid.R1-R3=1-5C alkyl;R4=1-10C fluorine-containing alkyl or 1-10C nitrogenous alkyl, preferably 2-6C fluorine-containing alkyl or 2-6C nitroalkyl;andR5=H or 1-10C alkyl or perfluoroalkane, preferably ( gamma )-aminopropyl triethoxysilane, or aminopropyl trimethoxysilane.Preferred Solvent: The polar solvent is chosen from dimethylformamide, methylformamide, dimethyl sulfoxide, N-methyl pyrrolidone, water, ethanol, methanol, propyl alcohol and isopropanol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The reinforcing fiber is chosen from glass fiber, fluorocarbon polymer fiber, ceramic fiber, quartz fiber, mineral fiber and carbon fiber, preferably quartz fiber or fluorocarbon polymer. The glass fiber is chosen from alkali-resisting glass fiber or alkali-free glass fiber. The fluorocarbon polymer fiber is chosen from polytetrafluoroethylene fiber, polyperfluoromethylisopropyl fiber and polyperfluoroethylene propylene fiber.