title: Silica coating of polymer nanowires produced via nanoimprint lithography from femtosecond laser machined templates.
abstract: In this paper we report on the fabrication of regular arrays of silica nanoneedles by deposition of a thin layer of silica on patterned arrays of polymer nanowires (or polymer nanohair). An array of high-aspect-ratio nanoscale diameter holes of depths greater than 10 µm was produced at the surface of a fused silica wafer by an amplified femtosecond laser system operated in single-pulse mode. Cellulose acetate (CA) film was imprinted into the nanoholes and peeled off to form a patterned array of standing CA nanowires, a negative replica of the laser machined nanoholes. The cellulose acetate replica was then coated with silica in a chemical vapor deposition process using silicon tetrachloride vapor at 65 °C. Field emission scanning electron microscopy, focused ion beam sectioning, energy dispersive x-ray analysis and Fourier-transform infrared spectroscopy were used to characterize the silica nanoneedles. Precisely patterned, functionalized arrays of standing silica nanoneedles are useful for a number of applications.
authors.affiliation: Center for Laser Applications, University of Tennessee Space Institute, 411 B H Goethert Parkway, Tullahoma, TN 37388, USA.
authors.forename: Deepak
authors.initials: D
authors.lastname: Rajput
authors.forename: Lino
authors.initials: L
authors.lastname: Costa
authors.forename: Alexander
authors.initials: A
authors.lastname: Terekhov
authors.forename: Kathleen
authors.initials: K
authors.lastname: Lansford
authors.forename: William
authors.initials: W
authors.lastname: Hofmeister
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: C005062:acetylcellulose; D012822:Silicon Dioxide; D002482:Cellulose