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Journal of Nanomaterials
Volume 2015 (2015), Article ID 219013, 9 pages
http://dx.doi.org/10.1155/2015/219013
Research Article

Facile Method to Prepare Superhydrophobic and Water Repellent Cellulosic Paper

1Department of Management and Conservation of Ecclesiastical Cultural Heritage Objects, University Ecclesiastical Academy of Thessaloniki, 54250 Thessaloniki, Greece
2Lab of Mechanics and Materials, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
3Department of Civil Engineering, University of Arizona, Tucson, AZ 85781, USA

Received 3 December 2014; Revised 26 January 2015; Accepted 26 January 2015

Academic Editor: Enrico Bergamaschi

Copyright © 2015 Ioannis Karapanagiotis 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

Silica nanoparticles (7 nm) were dispersed in solutions of a silane/siloxane mixture. The dispersions were applied, by brush, on four types of paper: (i) modern, unprinted (blank) paper, (ii) modern paper where a text was printed using a common laser jet printer, (iii) a handmade paper sheet detached from an old book, and (iv) Japanese tissue paper. It is shown that superhydrophobicity and water repellency were achieved on the surface of the deposited films, when high particle concentrations were used (≥1% w/v), corresponding to high static ( ≈ 162°) and low tilt ( < 3°) contact angles. To interpret these results, scanning electron microscopy (SEM) was employed to observe the surface morphologies of the siloxane-nanoparticle films. Static contact angles, measured on surfaces that were prepared from dilute dispersions (particle concentration <1% w/v), increased with particle concentration and attained a maximum value (162°) which corresponds to superhydrophobicity. Increasing further the particle concentration did not have any effect on . Colourimetric measurements showed that the superhydrophobic films had negligible effects on the aesthetic appearance of the treated papers. Furthermore, it is shown that the superhydrophobic character of the siloxane-nanoparticle films was stable over a wide range of pH.