초록 ▼

Super-hydrophobic and self-cleaning articles produced by imprinting exposed surfaces with suitable fine-grained and/or amorphous metallic embossing dies to transfer a dual surface structure, including ultra-fine features less than or equal to 100 nm embedded in and overlaying a surface topography wi

Super-hydrophobic and self-cleaning articles produced by imprinting exposed surfaces with suitable fine-grained and/or amorphous metallic embossing dies to transfer a dual surface structure, including ultra-fine features less than or equal to 100 nm embedded in and overlaying a surface topography with macro-surface structures greater than or equal to 1 micron are disclosed.

대표청구항 ▼

1. A method for manufacturing an article formed of a polymeric material and having at least one of a hydrophobic and self-cleaning outer surface, the method for manufacturing comprising the steps of: (i) providing an embossing die formed of a metallic material, the metallic material having at least

1. A method for manufacturing an article formed of a polymeric material and having at least one of a hydrophobic and self-cleaning outer surface, the method for manufacturing comprising the steps of: (i) providing an embossing die formed of a metallic material, the metallic material having at least one of a microstructure which is fine-grained with an average grain size between 2 and 5,000 nm and an amorphous microstructure;(ii) incorporating surface structures into at least an exposed metallic material surface portion of the embossing die, the metallic material surface structures increasing the contact angle for water at room temperature to over 90° and rendering the inherently hydrophilic surface of the metallic material hydrophobic; and(iii) imprinting at least a portion of an outer surface of the article directly with the imprinted metallic material surface portion of the embossing die to increase the contact angle for water at room temperature of said outer surface portion of the article to at least 130° and decrease the tilt angle for water at room temperature of said outer surface portion of the article to less than or equal to 25°. 2. The method according to claim 1, wherein the outer surface portion of the article comprises randomly distributed surface structures containing a plurality of micron-sized features, wherein the plurality of micron-sized features further has a substructure comprising of a plurality of nano scale features. 3. The method according to claim 1, wherein the metallic material surface is treated by at least one process selected from the group consisting of chemical etching, electrochemical etching, plasma etching, shot-pending, grinding, machining. 4. The method according to claim 3, wherein the metallic material surface is treated by shot-peening followed by etching. 5. The method according to claim 1, wherein said metallic material is selected from the group of: (i) one or more metals selected from the group consisting of Ag, Al, Au, Co, Cr, Cu, Fe, Ni, Mo, Pd, Pt, Rh, Ru, Sn, Ti W, Zn and Zr,(ii) pure metals or alloys containing at least two of the metals listed in (i), further containing at least one element selected from the group of B, C, H, O, P and S;(iii) any of (i) or (ii) where said metallic coating also contains particulate additions in the volume fraction between 0 and 95% by volume. 6. The method according to claim 5, wherein the metallic material contains particulate addition of at least 1% by volume and said particulate addition is of one or more materials which is a metal selected from the group consisting of Ag, Al, Cu, In, Mg, Si, Sn, Pt, Ti, V, W, Zn; a metal oxide selected from the group consisting of Ag2O, Al2O3, SiO2, SnO2, TiO2, ZnO; a carbide of B, Cr, Bi, Si, W; carbon selected from the group consisting of carbon nanotubes, diamond, graphite, graphite fibers; ceramic, glass; and polymer material selected from the group consisting of PTFE, PVC, PE, PP, ABS, epoxy resin. 7. The method according to claim 1, further comprising imprinting the exposed surface portion of the embossing die with dual-roughness surface structures. 8. The method according to claim 7, wherein the dual-roughness surface structures comprise a primary surface structure and a secondary surface structure at least partially overlaying said primary surface structure, the primary surface structure including surface features having dimensions and a spacing between adjacent primary surface features in the range of 1 micron to 1,000 microns, the secondary surface structure including surface features having dimensions and a spacing between adjacent secondary surface features in the range of 1 nm to less than or equal to 100 nm. 9. The method according to claim 1, wherein said embossing die has an amorphous microstructure. 10. The method according to claim 1, wherein said embossing die comprises at least one metallic material selected from the group consisting of Ni, Co, Cu and Fe. 11. The method according to claim 1, wherein said embossing die comprises at least one element selected from the group consisting of Ni, Co and P. 12. The method according to claim 1, wherein said metallic material is selected from the group of: (i) one or more metals selected from the group consisting of Ag, Au, Co, Cr, Cu, Fe, Ni, Mo, Pd, Pt, Rh, Ru, Sn, Ti W, Zn and Zr,(ii) pure metals or alloys containing at least two of the metals listed in (i), further containing at least one element selected from the group of B, C, H, O, P and S;(iii) any of (i) or (ii) where said metallic coating also contains particulate additions in the volume fraction between 0 and 95% by volume. 13. A method for manufacturing an article formed of a polymeric material and having at least one of a hydrophobic and self-cleaning outer surface, the method for manufacturing comprising the steps of: (i) providing an embossing die formed of a metallic material, the metallic material having at least one of a microstructure which is fine-grained with an average grain size between 2 and 5,000 nm and an amorphous microstructure;(ii) imprinting surface structures into at least an exposed metallic material surface of the embossing die to define a textured surface portion by first shot-peening the metallic material surface and followed by etching the metallic material surface, the metallic material surface structures increasing the contact angle for water at room temperature of said textured surface portion by at least 40% as compared to a smooth surface portion of the metallic material surface having a surface roughness (Ra) less than or equal to 0.25 microns thereby rendering the inherently hydrophilic surface of the metallic material hydrophobic; and(iii) imprinting at least a portion of an outer surface of the article with the textured metallic material surface portion of the embossing die to increase the contact angle for water at room temperature of said outer surface portion of the article to at least 130° and decrease the tilt angle for water at room temperature of said outer surface portion of the article to less than or equal to 25°. 14. The method according to claim 13, further comprising imprinting the exposed surface of the embossing die with dual-roughness surface structures wherein the dual-roughness surface structures comprise primary surface structures and secondary surface structures at least partially overlaying said primary surface structures, a linear population of said primary surface structures being in the range of 5 to 1000 per mm.