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.

The present invention discloses a polyvinylidene fluoride hollow fiber membrane and a preparation method thereof. The hollow fiber membrane comprises 30%-50% of polyvinylidene fluoride resin, 40%-60% of inorganic molecular solution in-situ pore-forming agent and 5%-20% of organic diluent. The preparation method comprises preparing the inorganic molecular solution in-situ pore-forming agent formed from organic sol, mixing the inorganic molecular solution in-situ pore-forming agent formed from the organic sol with high-molecular polymer resin and the organic diluent to obtain a material A,extruding hollow fibers through a forming mold, stretching on line by 2-3 times to obtain hollow fiber filaments, extracting the hollow fiber filaments with an organic solvent to remove all organic matters, removing inorganic matters dispersed in the hollow fiber filaments by using an acid or alkaline solution to form a porous membrane and cleaning the porous membrane, setting and performing heat treatment to obtain the polyvinylidene fluoride hollow fiber membrane.

The present invention discloses a polyvinylidene fluoride hollow fiber membrane and a preparation method thereof. The hollow fiber membrane comprises 30%-50% of polyvinylidene fluoride resin, 40%-60% of inorganic molecular solution in-situ pore-forming agent and 5%-20% of organic diluent. The preparation method comprises preparing the inorganic molecular solution in-situ pore-forming agent formed from organic sol, mixing the inorganic molecular solution in-situ pore-forming agent formed from the organic sol with high-molecular polymer resin and the organic diluent to obtain a material A,extruding hollow fibers through a forming mold, stretching on line by 2-3 times to obtain hollow fiber filaments, extracting the hollow fiber filaments with an organic solvent to remove all organic matters, removing inorganic matters dispersed in the hollow fiber filaments by using an acid or alkaline solution to form a porous membrane and cleaning the porous membrane, setting and performing heat treatment to obtain the polyvinylidene fluoride hollow fiber membrane.

A method of preparing a fluoroelastomer capable of being vulcanized by using peroxide, the method comprising: in the presence of an initiator and a chain transfer agent, conducting emulsion polymerization reaction on comonomers to obtain a fluoroelastomer. The preparation method utilizes alkyl iodide RI.sub.x as the chain transfer agent, and introduces the atom I into the molecular structure of the polymer during the reaction, the atom I acting as a crosslinking point during peroxide vulcanization. The fluoroelastomer obtained via the preparation method greatly improves the performance after being vulcanized; in addition, due to the low cost and extensive sources of alkyl iodide, the preparation method also simplifies the manufacturing process, reduces cost, and has wide application prospects.

A method of preparing a fluoroelastomer capable of being vulcanized by using peroxide, the method comprising: in the presence of an initiator and a chain transfer agent, conducting emulsion polymerization reaction on comonomers to obtain a fluoroelastomer. The preparation method utilizes alkyl iodide RI.sub.x as the chain transfer agent, and introduces the atom I into the molecular structure of the polymer during the reaction, the atom I acting as a crosslinking point during peroxide vulcanization. The fluoroelastomer obtained via the preparation method greatly improves the performance after being vulcanized; in addition, due to the low cost and extensive sources of alkyl iodide, the preparation method also simplifies the manufacturing process, reduces cost, and has wide application prospects.

A piezoelectric polyvinylidene fluoride (PVDF) material, a method for manufacturing the same, and a fingerprint recognition module are provided. The polyvinylidene PVDF material includes PVDF, a first solvent, a second solvent, a fluorosurfactant, and an inducing material. Material of the inducing material is one of carbon nanotubes, carbon black, and gold nanorods. Because of the high anisotropy of the inducing material, molecular orientation of the PVDF material is induced, thereby improving piezoelectric performance of the piezoelectric PVDF material. Problems of conventional piezoelectric PVDF materials, which are used in ultrasonic fingerprint recognition modules, such as poor piezoelectric performance and high-energy loss are improved.

A piezoelectric polyvinylidene fluoride (PVDF) material, a method for manufacturing the same, and a fingerprint recognition module are provided. The polyvinylidene PVDF material includes PVDF, a first solvent, a second solvent, a fluorosurfactant, and an inducing material. Material of the inducing material is one of carbon nanotubes, carbon black, and gold nanorods. Because of the high anisotropy of the inducing material, molecular orientation of the PVDF material is induced, thereby improving piezoelectric performance of the piezoelectric PVDF material. Problems of conventional piezoelectric PVDF materials, which are used in ultrasonic fingerprint recognition modules, such as poor piezoelectric performance and high-energy loss are improved.

A binder and a slurry suitable for use in the production of an electrode in a sulfide-based solid-state battery. The binder contains sulfide-based solid electrolyte particles, and is a fluorine-containing elastomer in which resin end functional groups satisfy:

0.01≤([—CH.sub.2OH]+[—COOH])/([—CH.sub.3]+[—CF.sub.2H]+[—CH.sub.2OH]+[—CH.sub.2I]+[—OC(O)RH]+[—COOH]≤0.25

where R represents an alkyl group with 1 to 20 carbon atoms. Also disclosed is an electrode including an electrode active material layer formed using the slurry and a lithium-ion secondary solid state battery including the electrode.

A binder and a slurry suitable for use in the production of an electrode in a sulfide-based solid-state battery. The binder contains sulfide-based solid electrolyte particles, and is a fluorine-containing elastomer in which resin end functional groups satisfy:

0.01≤([—CH.sub.2OH]+[—COOH])/([—CH.sub.3]+[—CF.sub.2H]+[—CH.sub.2OH]+[—CH.sub.2I]+[—OC(O)RH]+[—COOH]≤0.25

where R represents an alkyl group with 1 to 20 carbon atoms. Also disclosed is an electrode including an electrode active material layer formed using the slurry and a lithium-ion secondary solid state battery including the electrode.

A method for producing a fluorine-containing elastomer, which includes carrying out an emulsion polymerization of a fluorine-containing monomer in an aqueous medium in the presence of (A) a fluorine-containing compound containing a functional group capable of reaction by radical polymerization and a hydrophilic group and (B) a hydrocarbon surfactant to provide a fluorine-containing elastomer.