Surface structure having function freezing delay and icing layer separation and manufacturing method thereof

Abstract

Provided is a surface structure having freezing-delaying performance and freezing layer-separating performance. The surface structure includes a microstructural layer formed in the form of microscale irregularities and a plurality of nanopores formed in the microstructural layer. A freezing-delaying layer is formed on a surface of the microstructural layer to delay a freezing phenomenon. Also, a hygroscopic material is accommodated in the nanopores, so that when a surface of the freezing-delaying layer starts to freeze, the hygroscopic material is discharged from the nanopores to form a hygroscopic material film, and thus adhesion between the freezing-delaying layer and ice is reduced to allow the ice to be detached from the freezing-delaying layer.

What is claimed is: 
     
         1 . A surface structure comprising:
 a microstructural layer formed on a surface of a metal substrate in the form of microscale irregularities; and   a plurality of nanopores formed in the microstructural layer,   wherein the plurality of nanopores are formed in directions substantially perpendicular to upper and side surfaces of the microstructural layer.   
     
     
         2 . The surface structure of  claim 1 , further comprising a freezing-delaying layer formed on a surface of the microstructural layer. 
     
     
         3 . The surface structure of  claim 2 , further comprising a hygroscopic material accommodated in the plurality of nanopores. 
     
     
         4 . The surface structure of  claim 1 , wherein the metal substrate includes aluminum (Al). 
     
     
         5 . The surface structure of  claim 2 , wherein the freezing-delaying layer is formed by depositing a material including polydimethylsiloxane to a thickness of 1 nm to 20 nm through physical vapor deposition. 
     
     
         6 . The surface structure of  claim 2 , wherein the freezing-delaying layer includes fluorine (F). 
     
     
         7 . The surface structure of  claim 1 , wherein the microstructural layer includes a flat surface and a side surface which are continuous and the same or different from each other, and the flat surface has a horizontal length of 500 nm to 5 μm. 
     
     
         8 . The surface structure of  claim 1 , wherein the plurality of nanopores have a diameter of 10 nm to 50 nm. 
     
     
         9 . The surface structure of  claim 3 , wherein the hygroscopic material is discharged from the plurality of nanopores to form a hygroscopic material film when a surface of the freezing-delaying layer starts to freeze, and thus adhesion between the surface to of the freezing-delaying layer and ice is reduced to allow the ice to be detached from the freezing-delaying layer. 
     
     
         10 . A method of preparing a surface structure, comprising:
 forming a microstructural layer on a surface of a metal substrate in the form of microscale irregularities by etching the metal substrate with an acid solution;   forming a plurality of nanopores in the microstructural layer by anodizing the metal substrate; and   forming a freezing-delaying layer on a surface of the microstructural layer,   wherein the freezing-delaying layer is formed of a material including polydimethylsiloxane.   
     
     
         11 . The method of  claim 10 , wherein the freezing-delaying layer is formed with a thickness of 1 nm to 20 nm by physical vapor deposition. 
     
     
         12 . The method of  claim 10 , wherein the metal substrate includes aluminum (Al). 
     
     
         13 . The method of  claim 10 , wherein, in the formation of a freezing-delaying layer, the freezing-delaying layer is formed by vaporizing a cured fragment of polydimethylsiloxane through heating at 200° C. to 300° C. for 1 minute to 3 hours and depositing the vaporized polydimethylsiloxane on the metal substrate through physical vapor deposition. 
     
     
         14 . The method of  claim 10 , further comprising drying the metal substrate between the formation of a microstructural layer and the formation of nanopores. 
     
     
         15 . The method of  claim 10 , further comprising accommodating a hygroscopic material in the nanopores between the formation of nanopores and the formation of a freezing-delaying layer. 
     
     
         16 . The method of  claim 15 , wherein the hygroscopic material is discharged from the nanopores to form a hygroscopic material film when a surface of the freezing-delaying layer starts to freeze, and thus adhesion between the surface of the freezing-delaying layer and ice is reduced to allow the ice to be detached from the freezing-delaying layer. 
     
     
         17 . An aircraft part comprising the surface structure of  claim 3 . 
     
     
         18 . A heat exchanger comprising the surface structure of  claim 3 .