Extended Surfaces Nanopatterned with Functionalized Cavities for Positioning Nanoparticles

Abstract

This contribution reports a method delivering inorganic nanopatterned and functional surfaces from the ion beam etching of mesoporous thin films. The nanoscaled patterns are spherical or cylindrical cavities that are arranged on a macroscale. A variety of chemical functions can be grafted selectively in the cavities to add specific interactions with functional nanoparticles to be positioned. The process opens a simple route to localize and organize functional spherical or linear nanoparticles on extended surfaces.

Direct Observation of the Outermost Surfaces of Mesoporous Silica Thin Films by High Resolution Ultralow Voltage Scanning Electron Microscopy

“…Their potential applications include scaffolds/matrices for nanoreplication and sensing materials, nanopatterns for data storage media, and electro-optical devices. 14,15,28 The present study indicates that etching of film surfaces under controlled conditions and direct ultralow energy SEM observation are suitable for characterizing the surfaces of silica thin films. These results also contribute to a deeper understanding of SEM measurements and the expansion of the applications of SEM.…”

“…It is important to choose a landing voltage that allows for clear and accurate SEM characterization of surface structures because thin silica layers covering the surfaces prevent the use of surface mesopores. 14,15 In this paper, we have shown that landing voltages exert a significant effect on SEM images, especially when imaging the surface of nanomaterials. Ultralow voltage HR-SEM is sensitive to the structure and thickness of the surface and is useful for defining surface features.…”

“…15 Dourdain et al fabricated a dot pattern on a silica thin film for use in highly integrated data storage devices. 14 They positioned magnetic nanoparticles in open mesopores in the surface of a 3-dimensional (3D) mesoporous silica thin film after the removal of the surface silica layer by dry etching with Ar ions. We previously reported that the outermost mesostructured surfaces of 2D mesoporous silica thin films can be used as a mold for the formation of 2D striped nanopatterns of copper thin films after removal of the surface layers by wet etching.…”

“…Several previous studies on mesoporous silica thin films prepared by evaporation-induced self-assembly (EISA) have schematically noted the presence of thin, nonporous, silica layers on the surfaces of the films on the basis of generally accepted formation mechanisms of mesostructured silica . The presence of these surface silica layers has been suggested by cross-sectional transmission electron microscopy (TEM) observations − and X-ray reflectivity (XRR) measurements , of mesoporous silica thin films. Because these layers are generally recognized to be nonporous, it is necessary to remove them using an etching method in order to open up the surface mesopores, thereby allowing their use in applications such as nanopatterning and nanoreplication …”

“…The presence of these surface silica layers has been suggested by cross-sectional transmission electron microscopy (TEM) observations − and X-ray reflectivity (XRR) measurements , of mesoporous silica thin films. Because these layers are generally recognized to be nonporous, it is necessary to remove them using an etching method in order to open up the surface mesopores, thereby allowing their use in applications such as nanopatterning and nanoreplication …”