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Expansion of laser-induced plume after the passage of a counter shock wave through a background gas
摘要： Double-pulsed laser ablation with two targets and lasers in a background gas is a method to form nanoparticle complex. Effects of pulse delay between two lasers on plume expansion dynamics are discussed. The germanium and silicon targets were set parallel to each other and irradiated by two YAG lasers. The germanium target was irradiated followed by irradiation of the silicon target with delay time, td. We found that the expansion distance of delayed silicon plume is enhanced for 2 μs ≤ td ≤ 50 μs, compared to that when only the silicon target is irradiated. For td = 200 μs, the expansion distance of delayed silicon plume is similar to that when only the silicon target is irradiated. We discuss the expansion dynamics of the delayed silicon plume based on the effect of the density distribution induced by the primary germanium plume. Our results indicate that the effect of primary germanium plume remains up to about td = 50 μs, and it disappears by td = 200 μs.
关键词： Shock wave,Pulsed laser ablation,Plume expansion,Pulsed laser deposition
更新于2025-09-23 15:21:01
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Pulsed laser ablation route assisted copper oxide nanoparticles doped in Polyethylene Oxide/Polyvinyl pyrrolidone blend for enhancement the electrical conductivity
摘要： Polyethylene Oxide/Polyvinyl pyrrolidone blend was doped by Copper Oxide Nanoparticles (CuONPs) prepared by laser ablation process. Synthesized Copper oxide nanoparticles were prepared by ablating pure copper plate immersed in DDW by nanosecond Nd:YAG laser in different times. PEO/PVP/CuONPs nanocomposites have been synthesized via casting technique. Effect of CuONPs doping on enhancing PEO/PVP have been obtained. The influence of various times of laser ablation on the properties of the synthesized nanocomposite films was analyzed via several techniques. SEM and XRD proved the interaction between PEO/PVP blend and CuONPs. The presence of the distinctive absorption peak at UV-Vis range at 277 nm was due to copper oxide surface plasmon resonance (SPR). The direct and indirect optical band gap values illustrate a decrease following doping of copper oxide inside PEO/PVP matrix. Dielectric constant and dielectric loss activity gradually diminished as the frequency rises. AC conductivity were increased as laser time increased.
关键词： Copper oxide nanoparticles,Pulsed laser ablation,Ac conductivity,PEO/PVP
更新于2025-09-23 15:21:01
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Preparation and Characterization of Metal-Organic Frameworks and its Composites Eu <sub/>2</sub> O <sub/>3</sub> @[Zn <sub/>2</sub> (bdc) <sub/>2</sub> dabco] (ZBDh) via Pulsed Laser Ablation in Flow Liquid
摘要： This work reports the compounds of [Zn2(bdc)2dabco] (ZBDh) and [Zn2(bdc)2dabco] (ZBDt) and the composite Eu2O3@[Zn2(bdc)2dabco](ZBDh) synthesized by pulsed laser ablation in flowing liquid. At an appropriate reactants concentration of reactants, the phase ZDBh transforms into phase ZDBt by an increase of the irradiation time from 4 to 40 mins. The results show that the Eu2O3 nanoparticles with an average size of 3.17 nm are uniformly distributed among the crystal and the BET specific surface area of the composite Eu2O3@[Zn2(bdc)2dabco] (ZBDh) is 1621 m2/g, which is larger than that of compound [Zn2(bdc)2dabco] (ZBDh). Moreover, the composite Eu2O3@[Zn2(bdc)2dabco](ZBDh) can emit very intense characteristic fluorescence at 613 nm of Eu3+ ion under ultraviolet radiation and can be used for detecting of methanol molecules in fluorescence sensing because of its fluorescence intensity at 613 nm is sensitive to the content of methanol in solvent.
关键词： pulsed laser ablation,metal-organic frameworks,Eu2O3 nanoparticles,fluorescence sensing,methanol detection
更新于2025-09-23 15:21:01
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Color tunable upconversion luminescence and optical thermometry properties of mixed Gd2O3:Yb3+/Ho3+/Er3+ nanoparticles prepared via laser ablation in liquid
摘要： The mixtures of Gd2O3:Yb3+/Er3+ and Gd2O3:Yb3+/Ho3+ nanoparticles were successfully prepared via pulsed laser ablation in liquid followed by solution mixing. Under excitation of 980 nm diode laser, tunable color from green to red emission was achieved. Based on the thermal linked energy levels, the temperature sensitive upconversion emission was observed. The fluorescence intensity ratio (FIR) of I513–530 nm/I530–580 nm increased as the elevation of temperature. The absolute sensitivity and relative sensitivity were derived from temperature dependent FIR. The results show that the mixture of Gd2O3:Yb3+/Er3+ and Gd2O3:Yb3+/Ho3+ nanoparticles are not only potential candidates for multicolor upconversion luminescence but also promising optical materials for non-contact optical thermometry.
关键词： Gd2O3 nanoparticles,Color tunable emission,Pulsed laser ablation in liquid,Optical thermometry,Upconversion luminescence
更新于2025-09-23 15:21:01
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A low-temperature limit for growth of ZnO nanowires by using of laser ablation processes
摘要： The contribution deals with growth of ZnO nanowires on metal catalysts by using of pulsed laser deposition and with the influence of growth temperature. The process of nanowires preparation comprised two technological steps—both were based on pulsed laser ablation processes: (1) production of metal nanoparticles by laser ablation in liquids and (2) pulsed laser deposition of ZnO nanowires by ablation of ZnO target on substrate with metal nanoparticles. Nanoparticles from various metals (Au, Ag, Ni, Cu, Al, Mg, Zn, Sn and BiSn alloy) were prepared by pulsed laser ablation at 1064 nm in deionised water. Colloids contained metal nanoparticles were applied on Si (100) substrates, and after drying, nanoparticles served as catalysts of VLS crystallisation. Temperatures in interval 600—200 °C were experimentally compared for the nanowires growth with applied ablation laser working at 248 nm. The lowest achieved temperature value for growth of ZnO nanowires was 425–450 °C. However, among applied metals Cu and Al nanoparticles only successfully catalysed ZnO nanowires at this temperature. Properties of prepared samples were investigated by scanning electron microscopy and photoluminescence. Experimental results revealed that along with the growth temperature, selection of proper metal catalyst is also important factor for nanowires crystallisation.
关键词： Nanoparticles,Zinc oxide,Pulsed laser ablation,Nanowires,Directed growth
更新于2025-09-23 15:21:01
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Plasma charging effect on the nanoparticles releasing from the cavitation bubble to the solution during nanosecond Pulsed Laser Ablation in Liquid
摘要： The laser induced plasma during the nanosecond Pulsed Laser Ablation in Liquid (PLAL) plays a crucial role in the nanoparticles (NPs) formation and charging. It was demonstrated that during the plasma phase evolution, once the NPs are formed, they are charged with the excess of plasma electrons. Immediately after the plasma phase extinguishes, the NPs will be released in the induced vapor bubble, generated by the fast energy exchanges between the plasma and the liquid. The excess of charge in the NPs preserves them from the agglomeration during the bubble evolution and can induces an electrostatic pressure able to eject the particles outside the cavitation bubble. In this work, the plasma charging effect on the particle releasing in solution, during the bubble evolution, has been investigated. Temporal evolution of laser induced bubble on silver target immersed in water has been measured with the shadowgraph technique. Then, starting from the experimental bubble radius evolution, the releasing of the NPs from the cavitation bubble to the liquid has been modeled by comparing the electrostatic pressure of the charged NPs cloud and the pressure of the cavitation bubble. The following discussion proposes a new insight of the mechanism of NPs releasing in solution.
关键词： Laser Ablation Synthesis in Solution (LASIS),Cavitation bubble,NPs releasing,Pulsed Laser Ablation in Liquid (PLAL),NP formation
更新于2025-09-23 15:19:57
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Optical control of layered nanomaterial generation by pulsed-laser ablation in liquids
摘要： Pulsed-laser ablation in liquids capitalizes on combining chemical and optical control to rapidly generate size, composition, and phase-controlled nanostructures, without the need for surfactants. Very high temperatures, which we determined to be ca. (8,400 ± 1,300) K, pressures, and ion densities exist in the laser-induced liquid-confined plasma. These unique conditions, coupled with the rapid cooling during which nanoparticles are formed, permitted access to new extreme regions of materials’ phase diagrams. This way, we produced metastable layered copper and zinc hydroxide-based nanocrystals with interesting physical properties that can serve as precursors for two-dimensional inorganic semiconductor nanomaterials.
关键词： LTE spectra,optical control,electron temperature,layered nanocrystals,Pulsed-laser ablation in liquids,laser-induced plasma
更新于2025-09-23 15:19:57
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Metal organic frameworks composite Eu2O3@[Zn2(1,4-ndc)2dabco] synthesized by pulsed laser ablation in flowing liquid and its fluorescent sensing of fatty alcohol with different branch chains
摘要： This work reports the metal organic frameworks composite Eu2O3@[Zn2(1,4-ndc)2dabco] synthesized by pulsed laser ablation in flowing liquid. Powder X-ray Diffraction (PXRD) and SEM were used to characterize its structure and morphology. The results show that the Eu2O3 nanoparticles with the average particle size of 3.08 nm are uniformly distributed among the crystal and the BET specific surface area of the composite Eu2O3@[Zn2(1,4-ndc)2dabco] is 1087 m2/g. At 296 K, the adsorption capacities of C2H2 on composite are up to 117.3 cm3/g, which is larger than that of the compound [Zn2(1,4-ndc)2dabco]. The C2H6/CH4 selectivity of the composite Eu2O3@[Zn2(1,4-ndc)2dabco] is 25.9 and much higher than that of some familiar MOFs materials. Moreover, the composite Eu2O3@[Zn2(1,4-ndc)2dabco] can emit very intense characteristic fluorescence at 613 nm of Eu3t ion under ultraviolet radiation and can be used for detecting of fatty alcohols with different branch chains in fluorescence sensing because of its fluorescence intensity at 613 nm is sensitive to fatty alcohol with different carbon chains. The luminescence based sensing mechanism of the composite Eu2O3@[Zn2(1,4-ndc)2dabco] was discussed.
关键词： Flowing liquid,MOFs composites,Adsorption,Fatty alcohol with different branch chains,Pulsed laser ablation,Fluorescent sensing
更新于2025-09-23 15:19:57
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Polyvinyl Alcohol/Silver nanoparticles film prepared via pulsed laser ablation: An eco-friendly nano-catalyst for 4-nitrophenol degradation
摘要： This work attempts to introduce an eco-friendly nano-catalyst PVA/AgNPs portable film for 4-nitrophenol degradation. Silver nanoparticles (AgNPs) doped Polyvinyl Alcohol (PVA) film has been synthesized via one-potential pulsed laser ablation in liquids (PLAL) technique. The structural, optical, and morphological studies of the synthesized PVA/AgNPs nanocomposite film have been characterized by different techniques such as; XRD, FT-IR, UVeVis, PL, FE-SEM, and EDAX. From X-ray diffraction technique (XRD), it is approved that the synthesized PVA/AgNPs film is polycrystalline with cubic structure form. From UVeVisible spectroscopy, the energy band gap was determined by using tauc relation, which was found to be 3.7eV for direct transition. From morphological study, FE-SEM photos of the synthesized PVA/AgNPs film show the homogeneous distributed spherical-like shape of silver nanoparticles in PVA. The qualitative and semi-quantitative elemental analysis of the prepared samples via EDAX technique confirmed the embedding of the silver nanoparticles in the PVA structure. The amazing performance of the prepared PVA/AgNPs film in catalytic degradation activity for 4-nitrophenol reduction has been investigated, which lead to degrade 93% of 4-nitrrophenol in 25 min.
关键词： Silver nanoparticles,Catalytic degradation,PVA,Pulsed laser ablation,Nitrophenols
更新于2025-09-23 15:19:57
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Silver and copper oxide nanoparticles-decorated graphene oxide via pulsed laser ablation technique: Preparation, characterization, and photoactivated antibacterial activity
摘要： Graphene oxide, silver and copper oxide nanoparticles display photoactivated antibacterial behavior owing to their ability to generate charge carriers via light exposure. In this work, silver nanoparticles (AgNPs) and copper oxide nanoparticles (CuONPs) were embedded through graphene oxide (GO) using laser ablation technique. The microstructural behavior of the synthesized compositions has been investigated via XRD and TEM. The optical properties were studied by (UV–Vis), while the antibacterial properties were investigated in addition to the cell viability towards normal cell line (HFB4) in vitro. The antibacterial activity of GO was enhanced significantly with addition nanoparticles; by meaning, the inhibition zone enlarged from 5.4 mm with pure GO to be around 11.2 mm against E. coli with contribution of CuONPs. This trend of enhancement suggests that GO could be a great platform for different kinds of photo-activated antibacterial to be recommended for versatile biomedical applications.
关键词： CuO,Ag,Pulsed laser ablation,Graphene oxide,Antibacterial activity,Bacterial resistance
更新于2025-09-23 15:19:57