Two-dimensional metal nanosheet, preparation method thereof and thermal interface material

Abstract

A two-dimensional metal nanosheet, its preparation method and thermal interface material are provided. The method for preparing the two-dimensional metal nanosheet includes the following steps: S 1 . a mixture containing a nano metal foil and an auxiliary substance is crushed to obtain a dispersion; S 2 . The present application utilizes a high-purity metal foil with a nanoscale thickness in contact with a brittle substance that is easily soluble or easily etched in a liquid environment. Through high-speed mechanical crushing, the two-dimensional metal nanosheet with the same nanoscale thickness can be obtained. The top-down preparation method makes the prepared two-dimensional metal nanosheet free of obvious lattice defects and impurities, and inherits the high intrinsic properties of the original metal film. When it is applied in the field of thermal conductive fillers, the prepared thermal interface material has high thermal conductivity.

What is claimed is: 
     
         1 . A method for preparing a two-dimensional metal nanosheet, comprising the following steps:
 S 1 . crushing a mixture comprising a nano metal foil and an auxiliary substance to obtain a dispersion; and   S 2 , after mixing a material comprising the dispersion and a solvent, performing a solid-liquid separation to obtain the two-dimensional metal nanosheet.   
     
     
         2 . The method according to  claim 1 , wherein in the step S 1 , a thickness of the nano metal foil is in a range from 30 nm to 4000 nm. 
     
     
         3 . The method according to  claim 1 , wherein a thickness of the nano metal foil is in a range from 50 nm to 300 nm. 
     
     
         4 . The method according to  claim 1 , wherein in the step S 1 , the nano metal foil is at least one selected from gold foil, silver foil, copper foil, and aluminum foil. 
     
     
         5 . The method according to  claim 1 , wherein in the step S 1 , the auxiliary substance is easily soluble and/or easily etched in a liquid environment. 
     
     
         6 . The method according to  claim 4 , wherein in the step S 1 , the auxiliary substance is a hard substrate or a brittle substance. 
     
     
         7 . The method according to  claim 4 , wherein the auxiliary substance is at least one selected from sugar, salt, and ceramic. 
     
     
         8 . The method according to  claim 1 , wherein in the step S 1 , a mass ratio of the nano metal foil to the auxiliary substance is in a range from 0.01 to 0.1. 
     
     
         9 . The method according to  claim 1 , wherein in the step S 1 , the crushing is carried out in a wall breaking machine, a mixer, or an ultrasonic machine. 
     
     
         10 . The method according to  claim 1 , wherein crushing conditions are as follows:
 a crushing power is in a range from 600 W to 1000 W;   a crushing time is in a range from 20 min to 60 min.   
     
     
         11 . The method according to  claim 1 , wherein in the step S 2 , the solvent is at least one selected from water, ethanol, dimethyl sulfoxide, and acetone. 
     
     
         12 . The method according to  claim 1 , wherein in the step S 2 , the dispersion and the solvent are mixed and then crushed again. 
     
     
         13 . (canceled) 
     
     
         14 . A thermal interface material, comprising the two-dimensional metal nanosheet obtained by the method according to  claim 1  and a matrix;
 wherein a lateral size of the two-dimensional metal nanosheet is in a range from 2 μm to 100 μm. 
 
     
     
         15 . A method for preparing the thermal interface material according to  claim 14 , comprising the following steps:
 obtaining the thermal interface material by blending a material comprising the two-dimensional metal nanosheet and the matrix.   
     
     
         16 . The method according to  claim 15 , wherein the matrix is a polymer. 
     
     
         17 . The method according to  claim 16 , wherein the polymer is at least one selected from epoxy resin, silicone rubber, and polyolefin. 
     
     
         18 . The method according to  claim 15 , wherein a volume ratio of the two-dimensional metal nanosheet to the matrix is in a range from 15 to 25. 
     
     
         19 . The method according to  claim 15 , wherein blending conditions are as follows:
 a blending temperature is in a range from 60° C. to 100° C.;   a blending time is in a range from 200 min to 400 min.   
     
     
         20 . The method according to  claim 16 , wherein a curing agent is added after the two-dimensional metal nanosheet is blended with the polymer.