METHOD OF PREPARING NANOSHEET TUNGSTEN DISULFIDE

Abstract

A method of preparing a nanosheet tungsten disulfide. The method includes: heating a mixture including tungsten hexachloride, a sulfur source, and a surface modifier to a temperature of between 100 and 200 C. for at least 60 min. The sulfur source is thioacetamide or thiourea. The surface modifier is a C.sub.6-40 straight-chain or branched fatty acid, aliphatic amine, or a mixture thereof.

Claims

1. A method, comprising: heating a mixture comprising tungsten hexachloride, a sulfur source, and a surface modifier to a temperature of between 100 and 200 C. for at least 60 min; wherein: the sulfur source is thioacetamide or thiourea; and the surface modifier is a C.sub.6-40 straight-chain or branched fatty acid, aliphatic amine, or a mixture thereof.

2. The method of claim 1, wherein a molar ratio of the tungsten hexachloride to the thioacetamide or thiourea is 1:2, and a weight ratio of the tungsten hexachloride to the surface modifier is 1:50.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is an X-ray diffraction (XRD) of a nanosheet tungsten disulfide prepared according to a method of preparing a nanosheet tungsten disulfide as described in the disclosure; and

[0011] FIG. 2 is a transmission electron microscope (TEM) image of a nanosheet tungsten disulfide prepared according to a method of preparing a nanosheet tungsten disulfide as described in the disclosure.

DETAILED DESCRIPTION

[0012] To further illustrate, embodiments detailing a method of preparing a nanosheet tungsten disulfide are described below. It should be noted that the following embodiments are intended to describe and not to limit the disclosure.

Example 1

[0013] 3.9656 g of tungsten hexachloride, 20 g of oleylamine, and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5026 g of thioacetamide. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

[0014] FIG. 1 is an X-ray diffraction of the nanosheet tungsten disulfide. In the figure, the diffraction peaks at 32.665, 49.087 and 57.424 are identical to the Joint Committee on Powder Diffraction Standards (JCPDF, 08-0237) of tungsten disulfide, and correspond to the characteristic diffraction planes (100), (105), and (110) of ammonium dithiotungstate, respectively. The results show that the tungsten disulfide is successfully prepared and has a two-dimensional lamellar structure.

[0015] FIG. 2 is a transmission electron microscope (TEM) image of the nanosheet tungsten disulfide. As shown in FIG. 2, the prepared nanosheet tungsten disulfide has uniform particle sizes. The high resolution image shows that the synthesized product is well-crystallized and has a lamellar structure. The selected area electron diffraction pattern (SAEDP) is shown to be consistent with the X-ray diffraction results. Thus, the product is tungsten disulfide.

[0016] The nanosheet tungsten disulfide was added to base oil of polyalphaolefin (PAO6) or/and diisooctyl sebacate (DIOS), and the concentration of the nanosheet tungsten disulfide was 3.0 wt. %. Allow the mixture to stand for 2 months, and no precipitate was produced.

Example 2

[0017] 3.9656 g of tungsten hexachloride, 25 g of oleylamine, 10 g of octadecene, and 1.5026 g of thioacetamide were added to a 500-mL flask. The resulting mixture was heated to 120 C., held for 10 min. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 3

[0018] 3.9656 g of tungsten hexachloride, 25 g of oleylamine, 10 g of octadecene and 1.5026 g of thioacetamide were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min. The mixture was heated to 200 C., and the temperature was held for 2 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 4

[0019] 3.9656 g of tungsten hexachloride, 25 g of stearic acid, 10 g of octadecene and 1.5026 g of thioacetamide were added to a 500-mL flask. The resulting mixture was heated to 160 C., held for 10 min. The mixture was heated to 200 C., and the temperature was held for an hour. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 5

[0020] 3.9656 g of tungsten hexachloride, 25 g of oleylamine, and 1.5026 g of thioacetamide were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 6

[0021] 3.9656 g of tungsten hexachloride, 25 g of oleylamine, 10 g of octadecene and 1.5224 g of thiourea were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 7

[0022] 3.9656 g of tungsten hexachloride, 20 g of oleylamine, and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5224 g of thiourea. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 8

[0023] 3.9656 g of tungsten hexachloride, 20 g of stearic acid, and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5026 g of thioacetamide. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 9

[0024] 3.9656 g of tungsten hexachloride, 20 g of heptadecyl-amine, and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5026 g of thioacetamide. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 10

[0025] 3.9656 g of tungsten hexachloride, 1 g of oleylamine, 10 g of oleic acid, and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5026 g of thioacetamide. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 11

[0026] 3.9656 g of tungsten hexachloride, 20 g of n-octylamine, and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5026 g of thioacetamide. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 12

[0027] 3.9656 g of tungsten hexachloride, 20 g of oleylamine, 10 g of octadecylamine and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5224 g of thiourea. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

Example 13

[0028] 3.9656 g of tungsten hexachloride, 20 g of octadecylamine, 10 g of oleic acid, and 10 g of octadecene were added to a 500-mL flask. The resulting mixture was heated to 140 C., held for 10 min, followed by addition of 5 g of an oleylamine solution comprising 1.5026 g of thioacetamide. The mixture was heated to 200 C., and the temperature was held for 3 hours. The produced product was centrifuged and washed with ethyl alcohol, to yield a black semisolid paste, that is, a nanosheet tungsten disulfide.

[0029] The nanosheet tungsten disulfides prepared in Examples 2 to 13 were determined by XRD and transmission electron microscopy. It was found that the products obtained were of high purity and were nanosheet tungsten disulfides with uniform particle sizes and two-dimensional lamellar structure. The nanosheet tungsten disulfides were added to polyalphaolefin 6 (PAO6) or/and diisooctyl sebacate (DIOS), and the concentration of the nanosheet tungsten disulfide was 2.0 wt. %. Allow the mixture to stand for 2 months, and no precipitate was produced.

[0030] It will be obvious to those skilled in the art that changes and modifications may be made, and therefore, the aim in the appended claims is to cover all such changes and modifications.