Plasmonic Nanobubbles as Transient Vapor Nanobubbles Generated around Plasmonic Nanoparticles

Abstract

We have used short laser pulses to generate transient vapor nanobubbles around plasmonic nanoparticles. The photothermal, mechanical and optical properties of such bubbles were found to be different from those of plasmonic nanoparticle and vapor bubbles as well. This phenomena was considered as a new complex nanosystem -plasmonic nanobubble (PNB). Mechanical and optical scattering properties of PNB depended upon the nanoparticle surface and heat capacity, clusterization state, and the optical pulse length. The generation of the PNB required much higher laser pulse fluence thresholds than the explosive boiling level, and was characterized by the relatively high lower threshold of the minimal size (lifetime) of PNB. Optical scattering by PNB and its diameter (measured as the lifetime) has been varied with the fluence of laser pulse and this has demonstrated the tunable nature of PNB.Keywords vapor nanobubble; photothermal; scattering; pulsed laser; gold nanoparticle; plasmon resonance; vapor bubble Plasmonic nanoparticles (NP) are known for their outstanding photothermal [1][2][3][4][5][6] and optical scattering 1,[7][8][9][10][11][12] properties. These properties result from the interaction of NPs with optical radiation and the surrounding environment, and are characterized through their absorption and scattering cross-sections, respectively, which are well studied as a function of the parameters of NP, environment and optical radiation. [13][14][15][16][17][18][19] Since such interaction usually occurs in some medium (environment) the secondary thermal and hydrodynamic phenomena in such medium may significantly influence the properties of NPs as optical probes and heat sources. Short optical pulses and high-energy excitation of plasmonic NPs create transient and non-stationary thermal fields with vapor-liquid interfaces that significantly influence heat transfer from NP to its environment and create a strong gradient of the refractive index. In addition, vapor layers around NP cause blue shifts and attenuation of the extinction spectrum. 20 The multi-factor and non-stationary nature of the radiation-NP-vapor-liquid system complicates its experimental study and theoretical modeling. Available thermal models 6,17,[21][22][23][24] are applicable mainly for continuous excitation and stationary heat transfer at low temperatures or for very short laser pulses (femto-second range), for a limited number of shapes of NP, and for temperatures that assume constant plasmonic cross-sections and are *Rice University, Physics and Astronomy -MS 61, 6100 Main Street, Houston, TX 77005, dmitri.lapotko@rice.edu . NIH Public AccessAuthor Manuscript ACS Nano. Author manuscript; available in PMC 2011 April 27. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript below the boiling threshold for the environment. Measuring a high transient temperature around individual NPs in a two-phase medium can be quite difficult if not impossible. Experimental methods 8,[21][22][23][24][25] for monitoring the transien...

Femtosecond-pulsed optical heating of gold nanoparticles

“…16 Several experimental and numerical approaches aimed at studying the internal processes of heat generation under pulsed illumination and the subsequent effects observed in the surrounding medium, e.g. temperature and pressure variations, [17][18][19] acoustic wave generation, 18 vibration modes, [20][21][22] , cell apoptosis, 11 drug release 9,23 nanosurgery, 15,24 bubble formation, [25][26][27][28] NP shape modification 29 and melting, [29][30][31] nanosecondpulses for biomedical applications, 32,33 extreme thermodynamics conditions. [33][34][35][36][37] In this paper, we present and use a versatile numerical framework to investigate theoretically and numerically the evolution of the temperature distribution of a gold nanoparticle immersed in water when shined by a femtosecond-pulsed laser.…”

Volumetric solar heating and steam generation via gold nanofluids

“…The calculated steam generation efficiency reached 80%, meaning only 20% of the solar radiation was used to increase the bulk fluid temperature. Later simulation work [44][45][46] showed the possibility of nanobubble formation based on a non-equilibrium phase change assumption.…”

“…As far as the steam generation mechanism is concerned, it has been shown analytically that a minimum radiation flux of 3×10 8 W/m 2 is required to produce nanobubbles on heated nanoparticles [46,49,50], which can only be reached by powerful laser beams. In a separated study, Julien et al [51] showed that 1×10 10 W/m 2 was required to generate a nanobubble on a plasmonic gold nanoparticle.…”

“…In addition to the volumetric heating, direct vapor generation due to localized heating of the As far as the steam generation mechanism is concerned, for nanobubbles to be produced around heated nanoparticles, it has been shown analytically that a minimum radiation flux of 3×10 8 W/m 2 is required to produce nanobubbles on heated nanoparticles [46,49,50], which can may only be reached developed by powerful laser beams. In a separated theoretical study, of the nanobubble development kinetics around plasmonic gold nanoparticle by Julien et al [51] showed that to generate a nanobubble, a flux intensity of around 1×10 10 W/m 2 was required to 5 generate a nanobubble on a plasmonic gold nanoparticle.…”

Controllable Cobalt Oxide/Au Hierarchically Nanostructured Electrode for Nonenzymatic Glucose Sensing

“…Another parameter involved in heat generation is the power of the operating laser as well as whether the laser is run in continuous wave (CW) or pulsed wave (PW) mode when interacting with nanoparticles [150,[159][160][161][162][163]. While there is still some debate as to which mode is best, pulsed mode is generally considered more efficient than continuous mode for heating nanoparticles in photothermal applications [150,[164][165][166][167][168].…”