Surface modification of silica spheres with 3-(Trimethoxysilyl)propylmethacrylate (TMSPM) has been performed at ambient condition. However, the FTIR spectra and field emission scanning electron microscope (FESEM) images show no evidence of the surface modification. The reaction temperatures were varied from 60 to 80 °C with various reaction periods. Small absorption shoulder of the C=O stretching vibration was at 1700 cm^-1, and slightly increased with the increase of the reaction time at 60 °C. The clear absorption peak appeared at 1698 cm^-1 for the spheres reacted for 80 min at 70 °C and shifted toward 1720 cm^-1 with the increase the reaction time. Strong absorption peak showed at 1698 cm^-1 and shifted toward 1725 cm^-1 with the increase of the reaction time at 80 °C. The spheres were dispersed to methanol and added photoinitiator (Irgacure-184). The solution was poured to a patterned glass substrate and exposed to the 254 nm UV-light during a self-assembly process. A large area and crack-free silica sphere film was formed. To increase the mechanical stability, a cellulose acetate solution was spin-coated to the film. The film was lift-off from the glass substrate to analyze the surface nanostructures. The surface nanostructures were maintained, and the film is stable enough to use as a mold to duplicate the nanopattern and flexible.

Date Published: 12 September 2014
PDF: 5 pages
Proc. SPIE 9160, Metamaterials: Fundamentals and Applications 2014, 916021 (12 September 2014); doi: 10.1117/12.2061456

Published in SPIE Proceedings Vol. 9160:
Metamaterials: Fundamentals and Applications 2014
Nader Engheta; Mikhail A. Noginov; Nikolay I. Zheludev, Editor(s)