Hindawi Publishing Corporation ISRN Physical Chemistry Volume 2013, Article ID 547378, 7 pages http://dx.doi.org/10.1155/2013/547378 Research Article Influence of Surfactants and Dissolved Gases on the Silver Nanoparticle Plasmon Resonance Absorption Spectra Formed by the Laser Ablation Processes Ming Jing Chua 1 and Yoshinori Murakami 2 1 Department of Materials Science, Nagaoka National College of Technology, Nagaoka, Niigata 940-2188, Japan 2 Department of General Science, Hachinohe National College of Technology, Hachinohe, Aomori 039-1104, Japan Correspondence should be addressed to Yoshinori Murakami; murakami-g@hachinohe-ct.ac.jp Received 10 April 2013; Accepted 15 May 2013 Academic Editors: D. Knopf, T. Panczyk, and S. Sasaki Copyright © 2013 M. J. Chua and Y. Murakami. Tis 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. Te silver nanoparticles were fabricated by the focused laser irradiation to silver rod immersed in various kinds of surfactant aqueous solutions. It was found that anionic and cationic surfactants showed diferent roles on the silver nanoparticle growth during the focused laser irradiation processes. Silver nanoparticle synthesis in an amphoteric surfactant aqueous solution was also carried out using the same techniques, and it was found that the spectral shifs for these surface plasmon bands showed complicated behaviors against the concentration of amphoteric surfactants as well as pH. Furthermore, the infuence of the gas dissolved in a solution on the silver nanoparticle growth during the focused laser irradiation processes was investigated. With increasing the gas pressure of CO 2 , the surface plasmon bands of silver nanoparticles were shifed to longer wavelength, suggesting that the dissolved gas of CO 2 in a solution enhances the silver nanoparticle growth. Te plausible mechanism was proposed to understand the reason of such enhancement of silver nanoparticle growth by increasing the dissolved gas in a solution. 1. Introduction Nanoscale materials have attracted much attention due to their unique properties being diferent from their bulk mat- erials [1]. For example, gold and silver nanoparticles have been used in various analytical techniques such as catalysis, biosensing, recording media, and photoscience. From the production point of view, chemical reduction of metal ions is mostly commonly employed in the preparation of metal nanoparticles in solution. In the last few years, a new metho- dology based on the laser ablation of bulk metal in water appeared for generating metal nanoparticles. Te use of sur- factants, especially, which covers the particles during their condensation, promotes improved size uniformity as well as reduces the coalescence during the fabrication of nanopar- ticles using such laser ablation techniques. Mafun´ e et al. [2] reported for the frst time that the size distribution of silver nanoparticles produced by the laser ablation varied with the addition of sodium dodecyl sulfate (denoted by SDS hereafer) in water, and they also reported that the size became smaller and narrower with increasing the concen- tration of SDS. Te authors also attempted the formation of stable platinum nanoparticles using the laser ablation of platinum plate in water and found that the particle diameter of platinum nanoparticles decreased with increasing the concentration of SDS [3]. Although the efects of the anionic surfactants of SDS on the size distribution of the laser ablated metal nanoparticles have been thoroughly investigated, very few works have been done for the infuences on the other anionic and cationic surfactants. As an example of the investigations on the infuence of a cationic surfactants, Chen and Yeh [4] have investigated the particle diameters of silver nanoparticles formed by the laser ablation of silver rod from the enlarged transmission electron photographs and found that the particle diameters were 4.2 nm and 7.8 nm with the addition of the anionic SDS and the cationic cetyltrimethylammonium bromide (denoted by CTAB hereafer), respectively. Tey concluded that the