A method utilizes easily obtained carbon as carbon source for sintering, followed by high energy ball milling process with planetary ball mill for high energy homogenous mixing of the carbon source, solvent and nano-level silicon dioxide powder, along with a high energy ball milling process repeatedly performed using different sized ball mill beads, so as to formulate a spray granulation slurry with the optimal viscosity, to complete the process of micronization of carbon source evenly encapsulated by silicon dioxide powders. The optimal ratio of C/SiO.sub.2 is 1-2.5 to produce a spherical silicon dioxide powder (40-50 m) evenly encapsulated by the carbon source. The powder is then subjected to a high temperature (1450) sintering process under nitrogen gas. Lastly, the sintered silicon nitride powder is subjected to homogenizing carbon removal process in a rotational high temperature furnace to complete the fabricating process.

A method that uses a pressurized reactive medium composed of inert solvents such as pressurized liquid or supercritical fluid carbon dioxide (C02), and sulfur hexafluoride (SF6) and reactive dissolved species ozone (03) and/or boron trifluoride (BF3) and general boron trihalogenides (BX3) to react with two-dimensional (2D) layered materials and thereby synthesize covalently oxygen and/or BX3 functionalized exfoliated 2D layered materials. When 2D layered materials are dispersed in these reactive liquids or fluids by ultrasound sonication or high shear mixing, a simultaneous covalent functionalization and exfoliation of the 2D layered materials happens. Following attainment of the required extent of functionalization and exfoliation, the unreacted 03, BX3, SF6 and C02 can be easily removed as gases by decompression leaving behind the solid phase, thereby leading to efficient and economical production of functionalized and exfoliated 2D layered materials.

Described herein are precursors and methods for forming silicon-containing films. In one aspect, there is provided a precursor of Formula I: ##STR00001##
wherein R.sup.1 is selected from linear or branched C.sub.3 to C.sub.10 alkyl group, linear or branched C.sub.3 to C.sub.10 alkenyl group, linear or branched C.sub.3 to C.sub.10 alkynyl group, C.sub.1 to C.sub.6 dialkylamino group, electron withdrawing group, and C.sub.6 to C.sub.10 aryl group; R.sup.2 is selected from hydrogen, linear or branched C.sub.1 to C.sub.10 alkyl group, linear or branched C.sub.3 to C.sub.6 alkenyl group, linear or branched C.sub.3 to C.sub.6 alkynyl group, C.sub.1 to C.sub.6 dialkylamino group, C.sub.6 to C.sub.10 aryl group, linear or branched C.sub.1 to C.sub.6 fluorinated alkyl group, electron withdrawing group, and C.sub.4 to C.sub.10 aryl group; optionally wherein R.sup.1 and R.sup.2 are linked together to form ring selected from substituted or unsubstituted aromatic ring or substituted or unsubstituted aliphatic ring; and n=1 or 2.

A preparation method of carbon nitride modified with perylenetetracarboxylic dianhydride/graphene oxide aerogel composite material includes: (1) preparing carbon nitride nanosheets by calcination using dicyandiamide as raw material; (2) reacting perylenetetracarboxylic dianhydride and carbon nitride nanosheets in imidazole to prepare carbon nitride modified with perylenetetracarboxylic dianhydride; (3) dispersing said carbon nitride modified with perylenetetracarboxylic dianhydride and graphene oxide into deionized water, freeze-drying after the reaction to obtain carbon nitride modified with perylenetetracarboxylic dianhydride/graphene oxide aerogel composite material.

A complex carbonitride powder contains Ti as a main component element and at least one additional element selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, and Si. The complex carbonitride powder includes a plurality of complex carbonitride particles containing Ti and the additional element. The plurality of complex carbonitride particles include a plurality of homogeneous composition particles where average concentrations of Ti and the additional element in each complex carbonitride particle have a difference in a range of greater than or equal to 5 atom % and less than or equal to 5 atom % from average concentrations of Ti and the additional element in the whole complex carbonitride powder. A cross-sectional area of the homogeneous composition particles is greater than or equal to 90% of a cross-sectional area of the complex carbonitride particles 1p.

In an aspect, the present disclosure provides a heat-treated transition metal carbonitride MXene film annealed at high temperatures and a polymer composite comprising the same. In another aspect, the present disclosure provides a method for producing a heat-treated transition metal carbonitride MXene film comprising: obtaining a MXene aqueous solution containing dispersed 2-dimensional (2D) MXenes through an acid etching process; filtering the obtained MXene aqueous solution through a vacuum filtration process to produce a free-standing film; and annealing the produced free-standing film at high temperatures to obtain a heat-treated transition metal carbonitride MXene film. In still another aspect, the present disclosure provides an electromagnetic interference (EMI) shielding method comprising: superposing a coating comprising a heat-treated transition metal carbonitride MXene film on at least one surface of an object in a contact or non-contact manner.

A coated cutting tool, comprising: a substrate; and a coating layer formed on the substrate, wherein the coating layer includes a lower part layer and an upper part layer formed on the lower part layer, the lower part layer has an average thickness of 2.0 m or more and 15.0 m or less, and is formed of a Ti oxycarbonitride layer including a compound having a composition represented by formula (1) below:

Ti(C.sub.1-x-yN.sub.xO.sub.y)(1)

(where, x denotes an atomic ratio of an N element based on a total of a C element, the N element, and an O element, y denotes an atomic ratio of the O element based on a total of the C element, the N element, and the O element, and 0.35x0.60 and 0.01y0.10 are satisfied),
a FWHM of a rocking curve of a plane (4,2,2) of the lower part layer, which is obtained through X-ray diffraction, is 20 or less, the upper part layer is formed of an -aluminum oxide layer having an average thickness of 1.0 m or more and 15.0 m or less, and a FWHM of a rocking curve of a plane (0,0,12) of the upper part layer, which is obtained through X-ray diffraction, is 20 or less.

The present invention is directed to compositions comprising at least one layer or at least two layers, each layer comprising a substantially two-dimensional array of crystal cells, having first and second surfaces, each crystal cell having the empirical formula of M.sub.n+1X.sub.n, where M, X, and n are described in the specification, and devices incorporating these compositions.

Described herein are precursors and methods for forming silicon-containing films. In one aspect, there is provided a precursor of Formula I:

##STR00001##

wherein R.sup.1 is selected from linear or branched C.sub.3 to C.sub.10 alkyl group, linear or branched C.sub.3 to C.sub.10 alkenyl group, linear or branched C.sub.3 to C.sub.10 alkynyl group, C.sub.1 to C.sub.6 dialkylamino group, electron withdrawing group, and C.sub.6 to C.sub.10 aryl group; R.sup.2 is selected from hydrogen, linear or branched C.sub.1 to C.sub.10 alkyl group, linear or branched C.sub.3 to C.sub.6 alkenyl group, linear or branched C.sub.3 to C.sub.6 alkynyl group, C.sub.1 to C.sub.6 dialkylamino group, C.sub.6 to C.sub.10 aryl group, linear or branched C.sub.1 to C.sub.6 fluorinated alkyl group, electron withdrawing group, and C.sub.4 to C.sub.10 aryl group; optionally wherein R.sup.1 and R.sup.2 are linked together to form ring selected from substituted or unsubstituted aromatic ring or substituted or unsubstituted aliphatic ring; and n=1 or 2.

Hydridosilapyrroles and hydridosilaazapyrrole are a new class of heterocyclic compounds having a silicon bound to carbon and nitrogen atoms within the ring system and one or two hydrogen atoms on the silicon atom. The compounds have formula (I): ##STR00001##
in which R is a substituted or unsubstituted organic group and R is an alkyl group. These compounds react with a variety of organic and inorganic hydroxyl groups by a ring-opening reaction and may be used to produce silicon nitride or silicon carbonitride films.