Combination method for monitoring the characteristics of aqueous suspensions of metallic nanoparticles

Abstract

We have used a combination of physical diagnostics methods (laser probe, absorption spectroscopy, transmission electron microscopy) to study an aqueous suspension of silver nanoparticles, formed by laser ablation of a metal target in the atmosphere. We have established that application of the methods described allows us to obtain the most complete information about the state of nanosized metal particles in optically transparent media.Key words: aqueous suspension of metal nanoparticles, laser ablation, laser probe, absorption spectroscopy, atomic force microscopy, transmission electron microscopy, surface plasmon resonance. Introduction.A direction in science and technology that has been very much in demand in recent years is associated with preparation of nanostructural materials and their adoption in various areas of the national economy. The range of potential applications of such materials is quite broad: from pharmaceuticals to electronics. Such interest in nanotechnologies is due to the specific properties of nanostructures. The range of potential applications of such materials is quite broad: from pharmaceutical science to electronics. Such interest in nanotechnologies is due to the specific properties of nanostructures. For example, the mechanical, electrical, magnetic, optical, and chemical properties of many metals change substantially on going to nanostructures.Depending on the goals for obtaining the metal nanoparticles, very different methods can be used: chemical reduction of metals in solutions of their salts [1], implantation of metal ions in a matrix [2], electrical discharge (spark [3] and arc [4]) between metal electrodes in liquids, laser ablation in liquid media [5] and in the atmosphere [6]. Accordingly, adequate measurement of such a critical parameter as the effective sizes of the nanosized particles obtained becomes more important.This work was devoted to study of the possibility of combining existing methods for diagnostics of smallsized metallic systems with the goal of obtaining reliable information on the presence of metal nanoparticles and their sizes in optically transparent media. As the object of study, we used an aqueous suspension of silver nanoparticles obtained by laser ablation of the metal in the atmosphere by exposure to single pulses of high-power laser radiation in the frequency mode.The Experiment. Preparation of the suspensions of silver nanoparticles (laser ablation in the atmosphere). As we know, when a metal is exposed to laser radiation of moderate power density (10

Diagnostics of aqueous colloids of noble metals by extinction modeling based on mie theory

“…Furthermore, Fig. 1b and d shows red shifts of λ max that were mentioned several times in the literature [2,3,6,7,16] and are due to a reduction of electron density on the particle surface as their size increases.…”

Formation and complex investigation of spectral-morphologic parameters of Ag nanoscale phase in polymer film

“…As a result, the SPR spectrum experiences a red shift. It must be noted that a red shift caused by aggregation over time of Ag particles in colloidal solutions has been reported [9]. This was not typical of the sample containing PVA and indicated that colloidal solutions of Ag are more stable in the presence of PVA.…”

“…This enables the most complete information about the state and properties of the metal nanophase to be obtained [9]. In the present work, we used transmission electron microscopy (TEM), single-wave laser probing of transparent ultradispersed media, and SPR absorption spectroscopy for these purposes.…”

“…The experimental conditions for forming both types of samples are well known. Intermediate investigations using the complex method published previously were made in order to compare the properties of these types of samples [9].…”

Investigation of Noble Metals Colloidal Systems Formed by Laser Synthesis at Air

“…Studies in [3,7] evaluate the basic parameters of the evolving ultrafine phase, according to them the size of particles belongs to the nanometer range of 30-140 nm and shows the relatively high level of concentration (10 11 -10 13 cm −3 ). According to research works [8,9], the technique of laser synthesis can penetrate the metal nanoparticles formed in the ELT in optically clear solution, thereby forming colloidal systems of the treated metal material.…”