International Journal of

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Micro size craters were created by interaction of nanosecond laser beam with titanium target in liquid media. The dimension of crater i.e. depth and width is important in some applications such as micromachining. When the interaction occurs in liquid environment, the ablated materials from the target expand into the liquid. The ablated material can affect the interaction process if the ablated material concentration increases. In this paper, we study the effect of ablated materials in liquids on the crater width. The crater dimension was characterized by using an optical microscope. The results show that not only the type of environment liquid is important in the final size of the created craters, but also the laser fluence and the liquid depth in which the interaction takes place is important in the crater size.

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In this study, we investigated the production of silver nanoparticles by pulsed Nd: YAG laser ablation with λ=532nm in distilled water. The sodium citrate used to control the size of nanoparticles (Nps). The sample containing Ag NPs was characterized by linear absorption spectroscopy (UV-Visible spectroscopy) and transmission electron microscopy (TEM observation). The behavior of nonlinear optical properties of silver nanoparticles was studied using the Z-Scan method at two optimum numbers of the laser pulses and four optimum laser energy densities. In the Z-Scan method, the nonlinear thermal properties of Ag NPs were investigated under exposure to nanosecond laser pulse at λ=532nm. They were gained by fitting theoretical and experimental data. The values of the nonlinear refractive index (n₂) and the nonlinear absorption coefficient (β ) were compared concerning to two optimum numbers and four optimum energy densities. The results of the nonlinear refractive index showed a negative value for each sample, this means that samples act as a divergent lens, and the thermal self-defocusing effect can be the main factor of nonlinear behavior. Following the comparison of two quantities, n₂ and β , we found that the nonlinear refractive index increased when the number of laser pulses light increased. In addition, the nonlinear absorption coefficient decreased when the number of laser pulses light increased. As a result, the application of these Ag NPs for optical switching devices was investigated, which demonstrated that the large Ag NPs are applicable tools for optical switching devices.

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In this research, an attempt is made to approach a specific type of carbon, such as graphene or carbon nanotubes by using pulsed laser ablation technique in deionized water environment with changing the laser factors such as wavelength and fluence. Nd:YAG laser with two wavelengths of 1064 and 532 nm and three fluence of 0.8, 1 and 1.2 J/cm² were selected that number of pulses was 5000 with a frequency of 10 Hz to be irradiated on the graphite target at about 10 minutes. The medium was distilled water. Graphite was located in the 40 ml of distilled water.
The effects of wavelength and fluence of the laser have been experimentally investigated on types of carbon characteristics with different analysis such as Raman scattering spectrum, FE-SEM images, UV–Vis-NIR spectrum and X-ray diffraction (XRD). By using the mentioned analysis, the type of synthesized nano carbon is studied.
This study evaluates the effects of the pulse energy and laser wavelength on properties of synthesized carbon nanoparticle in laser ablation method in medium of distilled water.

 

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In this research, palladium nanoparticles (Pd NPs) were first synthesized using laser ablation in the deionized (DI) water environment. Also, metal-organic framework (MOF) was produced using the solvothermal method at a temperature of 150°C. To accumulate Pd NPs on the synthesized MOF, ultrasonic and magnetic stirring methods were used. Different analytical methods were used to investigate the structure and morphology of the synthesized nanocomposite. Also, the sensitivity of the synthesized nanocomposite to ethanol and methanol organic vapors was investigated. The results showed an increase in the response of the MOF in the presence of nanoparticles.

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In recent years, global climate change and population growth have exacerbated freshwater shortages. To address this issue, harvesting water from atmospheric fog has emerged as a promising technique. Inspired by natural processes, the fabrication of hybrid hydrophilic (HI) and superhydrophobic (SHB) surfaces has gained significant attention for enhancing water harvesting efficiency. This study presents a simple, cost-effective laser ablation method for creating wettability contrast surfaces with triangular and parallel patterns on brass metal. Through X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM), we investigated the structural and morphological effects on the wettability behavior of irradiated and non-irradiated brass. Additionally, we examined the influence of pattern shapes on water harvesting efficiency. Our findings indicate that triangular patterns significantly enhance water harvesting performance compared to parallel patterns.