A nanocomposite blend membrane and fabrication methods for making the nanocomposite membrane are disclosed. The nanocomposite blend membrane can be utilized in fuel cells. The nanocomposite blend membrane may include a blend polymer with a first sulfonated polymer and a second sulfonated polymer, as well as sulfonated tungsten trioxide (WO.sub.3) nanoparticles.

A positive electrode for a lithium ion secondary battery, including a positive electrode current collector, a conductive layer which is disposed directly or indirectly on the positive electrode current collector, and which includes a conductive particle, a polymer particle, and a fluororesin or a resin including a structural unit derived from a nitrile group-containing monomer, and a positive electrode active material layer disposed directly or indirectly on the conductive layer, as well as a lithium ion secondary battery using the same.

A positive electrode for a lithium ion secondary battery, including a positive electrode current collector, a conductive layer which is disposed directly or indirectly on the positive electrode current collector, and which includes a conductive particle, a polymer particle, and a fluororesin or a resin including a structural unit derived from a nitrile group-containing monomer, and a positive electrode active material layer disposed directly or indirectly on the conductive layer, as well as a lithium ion secondary battery using the same.

The invention relates to aqueous dispersions of fluoropolymers comprising recurring units derived from vinylidene fluoride (VDF) in an amount of from 60% to 82% in moles and recurring units derived from trifluoroethylene (TrFE) in an amount of from 18% to 40% in moles, with respect to the total moles of recurring units, said fluoropolymers possessing an improved thermodynamic ordered structure in the ferroelectric phase.

The invention relates to aqueous dispersions of fluoropolymers comprising recurring units derived from vinylidene fluoride (VDF) in an amount of from 60% to 82% in moles and recurring units derived from trifluoroethylene (TrFE) in an amount of from 18% to 40% in moles, with respect to the total moles of recurring units, said fluoropolymers possessing an improved thermodynamic ordered structure in the ferroelectric phase.

A method for producing an aqueous dispersion of a fluorine-containing elastomer, which includes polymerizing a fluorine-containing monomer in the presence of a fluorine-free compound (1) represented by general formula (1): CR.sup.1X.sup.1═CX.sup.2—R.sup.2—COOM and an aqueous medium, to produce an aqueous dispersion of the fluorine-containing elastomer containing —CH.sub.2— in a main chain. Also disclosed is an aqueous dispersion of the fluorine-containing elastomer and a composition containing the fluorine-containing elastomer.

A method for producing an aqueous dispersion of a fluorine-containing elastomer, which includes polymerizing a fluorine-containing monomer in the presence of a fluorine-free compound (1) represented by general formula (1): CR.sup.1X.sup.1═CX.sup.2—R.sup.2—COOM and an aqueous medium, to produce an aqueous dispersion of the fluorine-containing elastomer containing —CH.sub.2— in a main chain. Also disclosed is an aqueous dispersion of the fluorine-containing elastomer and a composition containing the fluorine-containing elastomer.

Provided is a method for producing an aqueous dispersion of a fluorine-containing elastomer, comprising polymerizing a fluorine-containing monomer in the presence of a compound (1) having a triple bond and a hydrophilic group and an aqueous medium to produce an aqueous dispersion of a fluorine-containing elastomer.

Provided is a method for producing an aqueous dispersion of a fluorine-containing elastomer, comprising polymerizing a fluorine-containing monomer in the presence of a compound (1) having a triple bond and a hydrophilic group and an aqueous medium to produce an aqueous dispersion of a fluorine-containing elastomer.

Provided is a method for producing an aqueous dispersion of a fluorine-containing elastomer, comprising polymerizing a fluorine-containing monomer in the presence of a fluorine-containing compound (1) represented by general formula (1) and an aqueous medium to produce an aqueous dispersion of a fluorine-containing elastomer:

CX.sup.1X.sup.2═CX.sup.3—Z  General formula (1):

wherein X.sup.1 to X.sup.3 are each independently H, F, or a fluorine-containing alkyl group; when X.sup.1 and X.sup.2 are both H, X.sup.3 is F or a fluorine-containing alkyl group; Z is a group represented by —COOM, —SO.sub.3M, —OSO.sub.3M, —PO(OM).sub.2, —OPO(OM).sub.2, —BO(OM).sub.2, or —OBO(OM).sub.2; M is H, a metal atom, NR.sup.1.sub.4, optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium; and R.sup.1 is independently H or an organic group, and any two R.sup.1 are optionally bonded to each other to form a ring.