A method for effectively removing minute impurities of 1 m or less in size that are present on a surface of an aluminum nitride single-crystal substrate without etching the surface includes scrubbing a surface of an aluminum nitride single-crystal substrate using a polymer compound material having lower hardness than an aluminum nitride single crystal, and an alkali aqueous solution having 0.01-1 mass % concentration of potassium hydroxide or sodium hydroxide, the alkali aqueous solution being absorbed in the polymer compound material.

A proton exchange composite membrane (PECM) and a method of synthesizing the membrane are disclosed. The PECM may include a PBI membrane doped with an acid, an imidazolium-based dicationic ionic liquid, and a mesoporous material. This PECM can be used as an improved high-temperature polymer electrolyte membrane (HT-PEM) fuel cell. The disclosed fuel cell can provide improved proton conductivity, acid uptake, and thermal stability.

A prepreg including: a thermosetting resin composition (C) containing a thermosetting resin (A) and an inorganic filler (B); and a glass cloth (D) impregnated or coated with the thermosetting resin composition (C); wherein the glass cloth (D) satisfies the following expressions (I) to (III),
(x+y)95(I)
1.9<(X+Y)/(x+y)(II)
t<20(III) wherein the glass cloth (D) is defined by X (threads/inch) representing number of warp yarn per inch; Y (threads/inch) representing number of weft yarn per inch; x (threads) representing number of filament per the warp yarn; y (threads) representing number of filament per the weft yarn; and t (m) representing a thickness, and wherein the content of the inorganic filler (B) in the thermosetting resin composition (C) is from 110 to 700 parts by mass based on 100 parts by mass of the thermosetting resin (A).

A self-healing resin composition of a polymer formed from the reaction between a thermoplastic polymer having terminal functional groups and a benzoxazine compound is provided. Also provided is a method of forming such a self-healing resin composition. A method of self-healing an article is also provided. In such a method, an article may have a rupture, and may be formed from a polymer resulting from reaction between a thermoplastic polymer having terminal functional groups and a benzoxazine compound. The method may include maintaining the article formed from the polymer at a predetermined temperature for a predetermined time such that the rupture is repaired.

A fluorine-containing polybenzimidazole containing a repeating unit represented by the following formula (1):

##STR00001## wherein R.sup.f is SO.sub.2, O, CO, an alkylene group optionally containing a substituent, or a group represented by the following:

##STR00002## wherein two Xs are each individually a hydrogen atom or a monovalent organic group; and R.sup.1 is a divalent organic group. Also disclosed is a polybenzimidazole precursor polyamide, a polybenzimidazole production method, film, flexible wiring board, printed circuit board, and polymer electrolyte membrane.

An electrolyte membrane including (i) a porous mat of nanofibres, wherein the nanofibres are composed of a non-ionically conducting heterocyclic-based polymer, the heterocyclic-based polymer comprising basic functional groups and being soluble in organic solvent; and (ii) an ion-conducting polymer which is a partially- or fully-fluorinated sulphonic acid polymer. The porous mat is essentially fully impregnated with ion-conducting polymer, and the thickness of the porous mat in the electrolyte membrane is distributed across at least 80% of the thickness of the electrolyte membrane. Such a membrane is of use in a proton exchange membrane fuel cell or an electrolyser.

Provided is a resin composition, which comprises 1 to 10 parts by weight of a bifunctional aliphatic long-chain acrylate and 30 to 50 parts by weight of a thermosetting resin. Moreover, an article is also provided, which is made from the resin composition described above. The article may comprise a prepreg, a resin film, a laminate or a printed circuit board.

A method for effectively removing minute impurities of 1 m or less in size that are present on a surface of an aluminum nitride single-crystal substrate without etching the surface includes scrubbing a surface of an aluminum nitride single-crystal substrate using a polymer compound material having lower hardness than an aluminum nitride single crystal, and an alkali aqueous solution having 0.01-1 mass % concentration of potassium hydroxide or sodium hydroxide, the alkali aqueous solution being absorbed in the polymer compound material.

Provided is a resin composition, which comprises 1 to 10 parts by weight of a bifunctional aliphatic long-chain acrylate and 30 to 50 parts by weight of a thermosetting resin. Moreover, an article is also provided, which is made from the resin composition described above. The article may comprise a prepreg, a resin film, a laminate or a printed circuit board.

This invention provides preparations, compositions, products, and applications of photo-crosslinked hydrogels. Component Aa photosensitive polymer derivative, component Bthe photoinitiator, and auxiliary component Cother biocompatible polymer derivative each are respectively dissolved in a biocompatible medium to obtain solution A, solution B, and solution C. The solution A, the solution B, and the optional solution C are mixed homogenously to obtain a hydrogel precursor solution. The hydrogel precursor solution is subject to irradiation of the UV light for photocoupled crosslinking to form a photo-crosslinked hydrogel. The photo-crosslinked hydrogel exhibit rapid speed of photo-curing, strong tissue adhesion, excellent mechanical properties, good biocompatibility, and excellent clinical operability. In addition, this invention also provides a kit for making the photo-crosslinked hydrogel, and applications thereof in tissue engineering, regenerative medicine, 3D printing, and as a carrier of cell, protein, or drug.