Table of Contents
Laser Chemistry
Volume 2006, Article ID 31862, 5 pages
http://dx.doi.org/10.1155/2006/31862
Research Article

Characterization of Laser-Generated Microparticles by Means of a Dust Monitor and SEM Imaging

1Institute for Physics and Meteorology, Hohenheim University, Garbenstraße 30, Stuttgart 70599, Germany
2Division VI.4 Surface Technologies, Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, Berlin 12205, Germany

Received 13 September 2006; Revised 9 November 2006; Accepted 16 November 2006

Academic Editor: Costas Fotakis

Copyright © 2006 Roland Wurster et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Nanosecond laser (1064 nm wavelength) cleaning of artificially soiled paper as a model sample simulating a real-world artwork was performed. During the cleaning process, the ejection of particles was monitored in situ by means of a dust monitor (8 size classes, ranging from 0.3 μm to >2 μm) and ex situ using a mini-cascade impactor (MKI, 5 stages). The cleaning result was analyzed by scanning electron microscopy (SEM) considering possible laser-induced damages to the substrate. Size distributions of emitted particles were measured depending on the processing parameters: laser fluence, F, and pulse number per spot, N. High numbers of large (>2 μm) particles were collected by the mini-cascade impactor indicating a gas dynamical liftoff process. Obviously, these particles were not affected by the laser-matter interaction. The different methods (SEM, MKI, and dust monitor) are compared with respect to their usefulness for a proper interpretation of the cleaning results.