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Approaches for Nanomaterial Lab Scale Synthesis and Manufacturing
Published in Dhiraj Sud, Anil Kumar Singla, Munish Kumar Gupta, Nanomaterials in Manufacturing Processes, 2023
Nidhi Sharotri, Deepali Sharma
In laser ablation process, the material is removed from liquid or solid surface by irradiating laser beam (Wang et al., 2006). In this method, the material is heated by using laser beam and finally evaporates at low laser flux, in spite of forming material plasma when high laser flux is applied. That is why this method is known for the removal of materials with laser. The extent of the material eliminated is directly dependent on the depth where laser energy is engrossed and the total ablated material mass from the target is termed “ablation rate.” This mechanism is responsible for the usage of laser method for the fabrication of nanostructures (Liang et al., 2004). The advantages of laser ablation method are as follows:The competency of creating multicomponent materials with a specified stoichiometry.The atomizer (laser spark) can be utilized to generate mesoporous films.The porosity of the films can be tailored by the change in the rate of flow of carrier gas.This technique helps in the synthesis of lithium, silicon, carbon, and ZrO2 and SnO2 films.
Laser Machining of Metals
Published in V. K. Jain, Advanced Machining Science, 2023
Laser ablation usually involves intense vaporization of the target surface. Initially, the vaporizing atoms/molecules have their velocity vectors pointing away from the surface. Due to the collisions among the vapor particles, the velocity distribution in the vicinity of the vaporizing surface approaches equilibrium. This layer is called the Knudsen layer, which is of the order of several mean free paths and is often treated as a discontinuity. Due to this, the evaporating vapor plume exerts a recoil pressure on the irradiated surface. As a result of the plasma recoil pressure, the liquid portion in the target is pushed downward, as shown in Figure 7.12. This causes displacement of the molten metal into regions surrounding the ablation zone. This is also referred to as melt displacement or liquid splashing.
Atomistic Simulations of the Generation of Nanoparticles in Short-Pulse Laser Ablation of Metals: Effect of Background Gas and Liquid Environments
Published in Ion N. Mihailescu, Anna Paola Caricato, Pulsed Laser Ablation, 2018
Cheng-Yu Shih, Chengping Wu, Han Wu, Maxim V. Shugaev, Leonid V. Zhigilei
“Laser ablation” is a term used to describe material removal from a target irradiated by a laser pulse. A wide range of practical applications of laser ablation includes generation of chemically clean and environmentally friendly nanoparticles [1]. The production of nanoparticles through direct laser ablation of an irradiated target eliminates the need for chemical precursors and presents a number of important advantages over conventional multistep chemical synthesis methods that introduce contamination from intermediate reactants and/or produce agglomerated structures with degraded functionality. The size, shape, structure, and composition of nanoparticles generated by laser ablation can be controlled by changing the target structure and composition [2], varying the background gas environment [3, 4], or mixing ablation plumes generated by double-pulse irradiation [5, 6]. Short-pulse (fs-ps) laser sources are especially suitable for nanoparticle production due to more localized and intense laser heating compared to nanosecond laser pulses [7–10] that increase the fraction of nanoparticles in the ablation plume [11–14].
Attapulgite supported nanoscale zero-valent iron in wastewater treatment and groundwater remediation: synthesis, application, performance and limitation
Published in Environmental Technology Reviews, 2022
Emmanuella Anang, Liu Hong, Xianyuan Fan, Ebenezer Nestle Asamoah
In the laser ablation method, nZVI is synthesized on a small scale where irradiation of an iron metal target and laser pulse melts. The metal nZVI particles are formed when the hot metal atoms cool at standard temperature [31]. A major disadvantage associated with use of the laser ablation method is that the nanoparticles easily oxidize in the presence of water or oxygen, hence the need for a support. In the hydrogen reduction of natural goethite method, natural goethite is installed into a quartz tube under a stable flow rate of hydrogen at 100 mL/min and different temperatures (between 245 and 655 °C) for 6 h. The hydrogen flow rate diminishes when the furnace reaches 25 °C. The nZVI particles are then moved out of the furnace into a sample bag [74]. These methods can be adopted in the synthesis of A-nZVI in order to investigate its feasibility and effectiveness in removing contaminants in aqueous solutions.
Experimental investigation of deep-hole micro-drilling of glass using LIPAA process
Published in Materials and Manufacturing Processes, 2022
Naser Abbasi, Mohammad Reza Razfar, S. Mehdi Rezaei, Khosro Madanipour, Mohsen Khajehzadeh
For many conductive and non-conductive materials, pulsed laser ablation is one of the most widely used tools for machining (drilling, channeling, texturing surfaces). Due to the optical nature of the laser, machining of transparent materials to laser light is one of the main problems in using this powerful tool for such materials. Glass as a transparent material to the laser light with unique properties such as corrosion resistance and stability in various conditions is widely used in many industries such as microfluidics, [1,2] micro-pumps, [3] MEMS, [4] optics .[5] Up to this date, researchers have conducted various research to use lasers to facilitate glass machining processes. Parameters under investigation include speed, production cost and machining conditions.
Recent progress on the surface finishing of metals and alloys to achieve superhydrophobic surfaces: a critical review
Published in Transactions of the IMF, 2021
Ali Raza Shaikh, Jian Qu, Minchen Zhou, Christian K. Y. Mulbah
The process of removing material from the solid surface by irradiating it with a laser beam is known as the laser ablation method. When the laser flux is low, the material is heated by the absorbed laser energy to be evaporated or sublimated. When the laser flux is high, the material is usually converted to plasma. The laser technique can produce stable coatings as compared with some chemical methods. The WCA of laser-processed surfaces can be varied from medium to high values. Recently, Zhou et al.97 prepared SHSs by kinetic pulsed laser ablation on a Cu mesh in ambient air with high controllability. Laser ablation created microgrooves directly on the Cu mesh with nanoparticles by the laser-induced plasma species and nucleation of air molecules as shown in Figure 11. The maximum WCA was 160.3° characterised by the oil-repellent property. The as-prepared surface was able to maintain its durability in a an aggressive pH environment.