Elongated Copper Nanoparticles Coated with a Zwitterionic Surfactant

Abstract

A sonochemical approach to the preparation of elongated copper nanoparticles coated with a zwitterionic surfactant, cetyltrimethylammonium p-toluene sulfonate (CTAPTS) is reported. A shape transition of the copper nanoparticles is found to occur due to the presence of an organized medium, consisting of a cylindrical, interconnected network of threadlike micelles. Transmission electron micrographs (TEM) show the presence of elongated copper nanoparticles coated with the surfactant. UV-visible spectroscopic studies point to the elongation of the copper nanoparticles and to the adsorption of the CTAPTS on the surface of the copper nanoparticles, which is corroborated by IR and NMR spectral studies. A monolayer coating of the surfactant is formed on the surface of the elongated copper nanoparticles. This is confirmed by comparing the weight loss obtained in thermogravimetric analysis with that obtained theoretically.

Formation of Cu and Cu2O Nanoparticles by Variation of the Surface Ligand: Preparation, Structure, and Insulating-to-Metallic Transition

“…Interestingly, dodecanethiolprotected nanoparticles show a sharp intense plasmon peak while lauric acid-capped nanoparticles show the lowest intensity peak at the same wavelength, perhaps due to the extent of delocalization caused by size variation. Also, the decrease in the absorbance indicates a decrease in the copper particle quantity, revealing the possibility of oxide formation with time on the copper particle surface (26). Another additional feature, prominent in these short wavelength plasmon peaks is the presence of a shoulder at lower wavelength arising due to the flocculation of the Cu nanoparticles after dispersion in the solvent.…”

Copper Nanoparticles Prepared from Oxalic Precursors

“…Unlike various other authors [2,4,5,[7][8][9][10][11][12], we did not use coating agents. One population of the particles synthesized is composed of pure copper metal.…”

“…Thus, a protective coating is applied on the metallic particles to avoid oxidation [9]. Moreover, to stabilize the nanometric size of the particles, they have generally been encapsulated by different organic or inorganic compounds [2,4,5,7,8,[10][11][12]. In the literature, pure metal copper nanoparticles about 15 nm in size have been synthesized coupling chemical and physical methods.…”

Synthesis of nanoparticles using a pulsed electrical discharge in a liquid

“…In the spectrum of sample 2, there is a very weak absorption peak with center at λ ≈ 289 nm. This plasmon peak may be connected with the presence of copper nanoparticles of sizes under 4 nm [32,33]. Although, as shown below, the electron microscope studies confirm the presence of fine particles in the sample, according to x-ray diffraction data there is no copper in sample 1.…”