Nonlinear Dependences of Optical Properties of Spherical Core–Shell Silver–Gold and Gold–Silver Nanoparticles on Their Parameters

ABSTRACTLaser welding of transparent high performance polymer foils requires an additional absorption layer at the interface of both foils. This paper demonstrates that metallic nano-particles, e.g. gold, silver or copper, can act as such an absorption layer. Silver nanoparticles were deposited on the surface of 200 μm thick ethylene tetrafluoroethylene (ETFE) polymer foils by evaporation processes or by magnetron sputtering. For their additional mechanical stabilization, thin films produced by plasma polymerisation of hexamethyldisilazane or PTFE-polymer sputtering were deposited on top of the metal nanoparticles. Laser irradiation of the coated foil together with the untreated joining partner was performed by a continuous wave diode laser at a wavelength of 808 nm. With the defocused laser, the foils were welded and finally a nearly transparent welding seam was achieved. The nanostructure and the optical properties of the nanoparticle layer before laser irradiation were determined and compared with the nanostructure and the optical properties of the polymer metal nanocomposite after laser welding.

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Polymer-embedded gold and gold/silver nanoparticle-modified electrodes and their applications in catalysis and sensors

Pure and Applied Chemistry ◽

10.1351/pac-con-11-03-04 ◽

2011 ◽

Vol 83 (11) ◽

pp. 2041-2053 ◽

Cited By ~ 13

Author(s):

Shanmugam Manivannan ◽

Ramasamy Ramaraj

Keyword(s):

Gold Nanoparticles ◽

Silver Nanoparticles ◽

Sol Gel ◽

Simultaneous Detection ◽

Modified Electrodes ◽

Core Shell ◽

Electrochemical Characteristics ◽

Amine Functionalized ◽

Gold Silver ◽

Vis Spectroscopy

Metal nanoparticles encapsulated by silicate sol-gel matrix find numerous applications particularly in electrocatalysis and sensors. In our previous reports, we have reported the mono- and bi-metal gold, silver, and core/shell gold/silver nanoparticles embedded in functionalized silicate sol-gel matrices. Modified electrodes were fabricated using mono- and bi-metallic gold, silver, and core/shell gold/silver nanoparticles embedded in silicate sol-gel, and they were used for the electrocatalysis and sensing of H2O2 and simultaneous detection of hydrazine, sulfite, and nitrite. We have prepared the gold nanoparticles encapsulated by amine-functionalized silicate sol-gel matrix in a single step without using any external reducing agents. The gold nanoparticles were also synthesized by using amine-functionalized silane monomer in the presence of β-cyclodextrin (β-CD), resulting in metal/polymer core/shell nanostructures. This nanocomposite material showed a synergistic stabilizing effect when compared to either silicate sol-gel matrix or β-CD alone as stabilizer. The synthesized gold nanoparticles were characterized using UV–vis spectroscopy and high-resolution transmission electron microscopy. Modified electrodes were prepared by using the gold nanoparticles embedded in silicate sol-gel matrix, and their electrochemical characteristics were studied.

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