Gold Nanoparticle-Assisted Laser Surface Modification of Borosilicate Glass Substrates

Abstract

This paper describes the photomodification of borosilicate glass substrates assembled with 40 nm diameter gold nanoparticles (Au NPs) with surface coverages ranging from 17 to 23% on excitation of the localized surface plasmon band of the NPs with a 532 nm nanosecond pulsed-laser beam. The laser irradiation allowed the splitting and fusion of NPs on the substrate surface and, at the same time, the formation of craters of less than 10 nm diameter at various places following one laser shot with a relatively high intensity of 460 or 370 mJ • cm -2 • pulse -1 but well below the breakdown threshold of 25-40 J • cm -2 • pulse -1 . The formation of the craters was more and more distinctly observed by continuous irradiations. The number density, average diameter, and the surface coverage of the craters were not linearly dependent on the laser shot number but exhibited the saturation behavior due to the consumption of Au NPs. The threshold laser energy for the crater formation was dependent on the accumulated number of laser shots: a greater number of laser shots were necessary to form craters as the laser fluence decreases. Most interestingly, the laser-irradiated areas of the substrate exhibited a greater susceptibility to the wet chemical etching with aqueous hydrogen fluoride. The mechanism of the laser modification and a possible application to nanofabrication on glass surfaces by utilizing Au NPs were discussed on the basis of the scanning electron microscopy (SEM) observation as well as the extinction and light scattering spectroscopic measurements.

Explosive, oscillatory, and Leidenfrost boiling at the nanoscale

“…However, extended or repeated irradiation at powers sufficient for boiling will cause irreversible damage to the nanoparticle: in particular, after minutes of irradiation at high power, lower powers no longer show the familiar explosive nucleate boiling events. surface structure and/or contact area with the substrate, they might be fragmenting [23], or they may be sinking into the substrate [24]. Any one of these possibilities would change the optical and thermal properties in hardto-predict ways.…”

“…We cannot tell in what way the particles change during long experiments. They might be melting, which could involve changing surface structure and/or contact area with the substrate, they might be fragmenting [23], or they may be sinking into the substrate [24]. Any one of these possibilities would change the optical and thermal properties in hardto-predict ways.…”

Gold Nanoparticles Allow Optoplasmonic Evaporation from Open Silica Cells with a Logarithmic Approach to Steady-State Thermal Profiles

“…This thermal energy is transferred to the NP environment by phonon-phonon coupling. 7,10,11 This effect allows many potential uses for these materials in biomedical therapeutics including noninvasive photothermal tumor cell ablation [12][13][14] or targeted release of encapsulated materials, 15 local protein or RNA unfolding, 16 nanoscale substrate modification, 17 nanomaterials modification, [18][19][20] and improved performance of catalytic systems. 8,21,22 Considerable experimental and computational work has been done to measure and predict the thermal and optical behavior of AuNPs under high-power, pulsed laser irradiation with large temperature increases in aqueous solutions [23][24][25][26][27][28][29] as well as in live cells.…”

Formation of nitrile species on Ag nanostructures supported on a-Al2O3: a new corrosion route for silver exposed to the atmosphere

“…leading to a reduction of the number density of NPs. In addition, big and almost black areas appear that relate to the break of the a-Al 2 O 3 buffer layer [17,23]. For the thickest sample (Figures 5c and 5d), the laser produces the break-up of the layer into round NPs as described in Figure 1 and the NPs show negligible changes upon aging.…”