Articoli di riviste: "Laser ablation in liquid medium"

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Sierra-Trillo, Maria Isabel, Ralf Thomann, Ingo Krossing, Ralf Hanselmann, Rolf Mülhaupt e Yi Thomann. "Laser Ablation on Isostatic Graphite—A New Way to Create Exfoliated Graphite". Materials 15, n. 16 (9 agosto 2022): 5474. http://dx.doi.org/10.3390/ma15165474.

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In search of a new way to fabricate graphene-like materials, isostatic graphite targets were ablated using high peak power with a nanosecond-pulsed infrared laser. We conducted dry ablations in an argon atmosphere and liquid-phase ablations in the presence of a liquid medium (water or toluene). After the dry ablation, the SEM images of the target showed carbon in the form of a volcano-like grain structure, which seemed to be the result of liquid carbon ejected from the ablation center. No graphite exfoliation could be achieved using dry ablation. When using liquid phase ablation with water or toluene as a liquid medium, no traces of the formation of liquid carbon were found, but cleaner and deeper craters were observed. In particular, when using toluene as a liquid medium, typical graphite exfoliation was found. We believe that due to the extremely high pressure and high temperature induced by the laser pulses, toluene was able to intercalate into the graphite layers. Between the laser pulses, the intercalated toluene was able to flash evaporate and blow-up the graphite, which resulted in exfoliated graphite. Exfoliated graphite was found on the ablated graphite surface, as well as in the toluene medium. The ablation experiments with toluene undertaken in this study demonstrated an effective method of producing micrometer-sized graphene material. When using water as a liquid medium, no massive graphite exfoliation was observed. This meant that under the used laser conditions, toluene was a better intercalant for graphite exfoliation than water.

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Nikov, Ro, N. Nedyalkov, T. Nikova e L. Aleksandrov. "Nanosecond laser ablation of nitride ceramics in liquid". Journal of Physics: Conference Series 2240, n. 1 (1 marzo 2022): 012048. http://dx.doi.org/10.1088/1742-6596/2240/1/012048.

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Abstract The work presents results on nanosecond laser ablation of nitride ceramics immersed in a liquid medium. AlN and Si3N4 ceramic plates were used targets, and double distilled water was used as a liquid medium. Radiation of a nanosecond Nd:YAG laser system was used in the ablation process with the purpose of studying the influence of the laser fluence and number of pulses on the target surface morphology. The morphology and phase composition of the structured surfaces were explored by scanning electron microscopy and X-ray diffraction measurements, respectively. The optical properties of the obtained colloids were investigated by transmission measurements in the UV-Vis spectral ranges.

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Bočáková, Barbora, Martin Necpal e Martin Sahul. "Influence of Liquid Medium on Laser Ablation of Titanium". Research Papers Faculty of Materials Science and Technology Slovak University of Technology 30, n. 50 (1 giugno 2022): 61–70. http://dx.doi.org/10.2478/rput-2022-0008.

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Abstract Titanium grade 2 plates were modified by a pulsed nanosecond laser beam. The aim was to determine the surface properties after the machining process in two different liquid media. The samples were processed in distilled water and paraffin oil. It was found that a surface with half-surface roughness values with a number of cracks was formed in distilled water. The presence of water reduced the size of the heat-affected zone.

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Utsunomiya, Yuji, Takashi Kajiwara, Takashi Nishiyama, Kunihito Nagayama, Shiro Kubota e Motonao Nakahara. "Laser ablation of liquid surface in air induced by laser irradiation through liquid medium". Applied Physics A 101, n. 1 (4 settembre 2010): 137–41. http://dx.doi.org/10.1007/s00339-010-6031-3.

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Mbambo, Makhangela C., Saleh Khamlich, Touria Khamliche, Bakang M. Mothudi e Malik Maaza. "Pulsed Nd:YAG laser assisted fabrication of graphene nanosheets in water". MRS Advances 3, n. 42-43 (2018): 2573–80. http://dx.doi.org/10.1557/adv.2018.275.

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AbstractGraphene nanosheets were prepared by pulsed Nd:YAG laser ablation of graphite target in H2O under ambient conditions. The synthesized graphene nanosheets were characterized by high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), Raman spectroscopy and Selected Area Electron Diffraction (SAED). The obtained structural and morphological analysis confirmed that the graphene nanosheets could be formed in an aqueous medium via one step method where a nanosecond pulsed near-infrared (NIR) laser (λ = 1064 nm) is used to ablate the surface of a pure graphite target. Compared to other used chemical methods to synthesis graphene nanosheets, laser ablation is an easy, versatile, environmental friendly and rapidly growing method for the synthesis of nanostructured materials such as graphene nanosheets. This technique showed normal operation in liquid medium (i.e. water or organic) under ambient conditions. Our study confirmed the great potential of laser ablation in liquid method for the fabrication of graphene nanosheets based nanofluids wich has a potential applicatiuon as a heat transfer fluid.

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Lasemi, Niusha, e Günther Rupprechter. "Chemical and Laser Ablation Synthesis of Monometallic and Bimetallic Ni-Based Nanoparticles". Catalysts 10, n. 12 (11 dicembre 2020): 1453. http://dx.doi.org/10.3390/catal10121453.

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The catalytic properties of nanoparticles depend on their size, shape and surface/defect structure, with the entire catalyst performance being governed by the corresponding distributions. Herein, we present two routes of mono- and bimetallic nanoparticle synthesis that enable control of the structural parameters, i.e., wet-chemical synthesis and laser ablation in liquid-phase. The latter is particularly suited to create defect-rich nanoparticles. Impregnation routes were applied to prepare Ni and NiCu nanoparticles, whereas nano- and femtosecond laser ablation in liquid-phase were employed to prepare Ni and NiAu nanoparticles. The effects of the Ni:Cu ratio in impregnation and of laser fluence and liquid-medium on laser ablation are discussed. The atomic structure and (surface) composition of the nanoparticles were characterized by electron microscopic (BF-TEM, DF-TEM, HRTEM) and spectroscopic/diffraction techniques (EDX, SAED, XPS, IR), complemented by theory (DFT). The chemically synthesized bimetallic NiCu nanoparticles initially had Cu-rich surfaces, which changed to Ni-rich upon reaction. For laser ablation, depending on conditions (fluence, type of liquid), highly defective, ordered, or core/shell-like nanoparticles were produced. The case studies highlight the specific benefits of each preparation method for catalyst synthesis and discuss the potential of nanoparticles produced by pulsed laser ablation for catalytic applications.

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Mendivil, M. I., L. V. García, B. Krishnan, D. Avellaneda, J. A. Martinez e S. Shaji. "CuInGaSe 2 nanoparticles by pulsed laser ablation in liquid medium". Materials Research Bulletin 72 (dicembre 2015): 106–15. http://dx.doi.org/10.1016/j.materresbull.2015.07.038.

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Subhan, Abdul, Abdel-Hamid Ismail Mourad e Yarub Al-Douri. "Influence of Laser Process Parameters, Liquid Medium, and External Field on the Synthesis of Colloidal Metal Nanoparticles Using Pulsed Laser Ablation in Liquid: A Review". Nanomaterials 12, n. 13 (22 giugno 2022): 2144. http://dx.doi.org/10.3390/nano12132144.

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Pulsed laser ablation in liquid, used for nanoparticle synthesis from solid bulk metal targets (a top-down approach), has been a hot topic of research in the past few decades. It is a highly efficient and ‘green’ fabrication method for producing pure, stable, non-toxic (ligand-free), colloidal nanoparticles, which is often challenging using traditional chemical methods. Due to the short time scale interaction between the laser pulses and the target, it is difficult to achieve complete control on the physical characteristics of metallic nanoparticles. Laser process parameters, liquid environment, and external fields vastly effect the shape and structure of nanoparticles for targeted applications. Past reviews on pulsed laser ablation have focused extensively on synthesising different materials using this technique but little attention has been given to explaining the dependency aspect of the process parameters in fine-tuning the nanoparticle characteristics. In this study, we reviewed the state of the art literature available on this technique, which can help the scientific community develop a comprehensive understanding with special insights into the laser ablation mechanism. We further examined the importance of these process parameters in improving the ablation rate and productivity and analysed the morphology, size distribution, and structure of the obtained nanoparticles. Finally, the challenges faced in nanoparticle research and prospects are presented.

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Said, A., L. Sajti, S. Giorgio e W. Marine. "Synthesis of nanohybrid materials by femtosecond laser ablation in liquid medium". Journal of Physics: Conference Series 59 (1 aprile 2007): 259–65. http://dx.doi.org/10.1088/1742-6596/59/1/055.

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Khalaf Ali, Abdulrahman, e Dayah N. Raouf. "Preparation of Silver Nanoparticles by Pulsed Laser Ablation in Liquid Medium". Engineering and Technology Journal 29, n. 15 (1 novembre 2011): 3058–66. http://dx.doi.org/10.30684/etj.29.15.2.

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Parenago, Oleg, Alexey Rybaltovsky, Evgeniy Epifanov, Andrey Shubnyi, Galina Bragina, Alexey Lazhko, Dmitry Khmelenin, Vladimir Yusupov e Nikita Minaev. "Synthesis of Supported Heterogeneous Catalysts by Laser Ablation of Metallic Palladium in Supercritical Carbon Dioxide Medium". Molecules 25, n. 24 (9 dicembre 2020): 5807. http://dx.doi.org/10.3390/molecules25245807.

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To obtain a supported heterogeneous catalyst, laser ablation of metallic palladium in supercritical carbon dioxide was performed in the presence of a carrier, microparticles of γ-alumina. The influence of the ablation process conditions—including supercritical fluid density, ablation, mixing time of the mixture, and laser wavelength—on the completeness and efficiency of the deposition of palladium particles on the surface of the carrier was studied. The obtained composites were investigated by scanning and transmission electron microscopy using energy dispersive spectroscopy. We found that palladium particles were nanosized and had a narrow size distribution (2–8 nm). The synthesized composites revealed high activity as catalysts in the liquid-phase hydrogenation of diphenylacetylene.

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Koinkar, Pankaj, Yu Ohsumi, Makoto Kanazawa, Akihiro Furube, Dnyaneshwar Gavhane e Mahendra A. More. "Field emission properties of laser ablated multi-walled carbon nanotubes". International Journal of Modern Physics B 32, n. 19 (18 luglio 2018): 1840045. http://dx.doi.org/10.1142/s0217979218400453.

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In the present study, the field emission properties of multi-walled carbon nanotubes (MWCNTs) treated with laser ablation have been investigated. The MWCNTs were synthesized by chemical vapor deposition method. The laser ablation treatment was performed in liquid medium for laser ablation time of 40 min and 60 min. The morphology of MWCNTs films was characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The results exhibit that the field emission properties of MWCNTs are dependent on the laser ablation time. The Raman spectra of laser-ablated MWCNTs clearly showed disorder and increase in graphitic content. The SEM and TEM results clearly revealed the separation of MWCNTs after laser ablation treatment. The field emission characteristics of the MWCNTs showed that the turn-on fields and current density are improved for the nanotubes treated with laser ablation. The enhancement in the field emission characteristics of MWCNTs is attributed to the disorder as well as the increase in the aspect ratio which causes more pathways for electron emission.

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Ohsumi, Yu, Pankaj Koinkar, Akihiro Furube, Keh Moh Lin, Subhash Kondawar e Mahendra A. More. "A study on the field emission properties of Bi2Se3 nanostructures prepared by laser ablation". Modern Physics Letters B 33, n. 14n15 (28 maggio 2019): 1940050. http://dx.doi.org/10.1142/s0217984919400505.

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One of the effective methods known as pulse laser ablation in liquid (PLAL), in which a solid target material is immersed in an organic solvent and laser beam is irradiated through liquid on a target material, is a direct method used to generate nanoparticles in liquid medium. The present work is focused on the preparation of bismuth selenide (Bi2Se3) nanoparticles using PLAL to study their field emission characteristics. The PLAL was performed under nanosecond (ns) laser with different ablation time of 120 min and 240 min. The field emission characteristics were measured in the planer “diode” configuration in all metal ultra-high vacuum (UHV) chamber. The prepared Bi2Se3 nanoparticles were analyzed with different characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-visible spectroscopy in order to study the surface morphology and structural information. The generation of Bi2Se3 nanoparticles is found after PLAL, which clearly suggests that bulk Bi2Se3 microsheet is transformed into Bi2Se3 nanoparticles. The X-ray spectra and UV spectra show the formation of nanoparticles upon laser ablation. The improvement in the field emission properties is found for laser-ablated Bi2Se3 nanoparticles. The field emission characteristics lead to increase in current density, which can be ascribed to the reduction in size of Bi2Se3 nanoparticles due to laser ablation. The prepared Bi2Se3 nanoparticles could be considered for novel applications in optoelectronics devices.

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Shahzada, Shaista, Anbarin Fatima, Asma Nazir, Arshad Mehmood, Mazhar Mehmood e Ali Nadeem. "Structural and optical properties of TiO2–Ge nanoparticles prepared through laser ablation in liquid medium". Canadian Journal of Physics 95, n. 7 (luglio 2017): 645–49. http://dx.doi.org/10.1139/cjp-2016-0578.

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Quantum dot (QD) composite nanoparticles of titania germanium (TiO2–Ge) were fabricated by pulsed laser ablation of composite targets of TiO2–Ge immersed in deionized water. The single phase crystallanity, lattice parameters, and the evaluation of crystallite size of nanoparticles was investigated by X-ray diffraction (XRD). The morphology of the samples was analyzed through scanning electron microscopic studies. The average particle size calculated through XRD and measured through scanning electron microscope is in the range from 18 to 29 nm and are in agreement with each other. Compositional study was carried out through electron dispersive X-ray analysis showing that the ablation rate of Ge is smaller than TiO2. Optical properties were measured by UV–visible transmission spectra and Raman spectroscopy. The band gap of composite particles varies from the UV to the visible range by varying concentration of Ge QDs. This work shows that pulsed laser ablation in liquid media is an easy approach to synthesize ultrafine, contamination-free nanosized material, which is difficult to produce by other conventional methods.

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Iida, Yasuo, Akira Tsuge, Yoshinori Uwamino, Hisashi Morikawa e Toshio Ishizuka. "Laser ablation in a liquid medium as a technique for solid sampling". Journal of Analytical Atomic Spectrometry 6, n. 7 (1991): 541. http://dx.doi.org/10.1039/ja9910600541.

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Soliman, Wafaa, Sara El-Ansary e Yehia Badr. "Impact of Liquid Medium on Laser Ablation Mechanism: Surface Heating and Cooling". Lasers in Manufacturing and Materials Processing 5, n. 4 (2 ottobre 2018): 430–38. http://dx.doi.org/10.1007/s40516-018-0073-3.

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Yehia, Sașa-Alexandra, Lavinia Gabriela Carpen, Flavian Stokker-Cheregi, Corneliu Poroșnicu, Veronica Sătulu, Cornel Staicu, Bogdan Butoi et al. "Laser ablation of a solid target in liquid medium for beryllium nanoparticles synthesis". Nuclear Materials and Energy 31 (giugno 2022): 101160. http://dx.doi.org/10.1016/j.nme.2022.101160.

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Ishikawa, Yoshie, Kenji Kawaguchi, Yoshiki Shimizu, Takeshi Sasaki e Naoto Koshizaki. "Preparation of Fe–Pt alloy particles by pulsed laser ablation in liquid medium". Chemical Physics Letters 428, n. 4-6 (settembre 2006): 426–29. http://dx.doi.org/10.1016/j.cplett.2006.07.076.

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Flores-Castañeda, Mariela MFC, Enrique Campos González, Irvin Ruiz-Aguilar, Enrique Camps, M. Patricia Cruces, Emilio Pimentel e Marco A. Camacho López. "Insecticide activity of bifenthrin nanoparticles synthesized by laser ablation of solids in liquids". Superficies y Vacío 32 (21 dicembre 2019): 27–30. http://dx.doi.org/10.47566/2019_syv32_1-010027.

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Organic nanoparticles of bifenthrin (agricultural insecticide) were successfully synthesized by the laser ablation of solids in liquids (LASL) technique, using as liquid medium a solution of a polymeric surfactant at 0.1 %. The results showed that the use of the surfactant improves the stability of the organic nanoparticles 18 times as compared to those synthesized in water. The characterization by UV-Vis spectroscopy allowed evaluating the stability of colloids, as well as determining the concentration of nanoparticles in the medium. In the characterization by TEM and HRTEM was possible to observe nanoparticles with the most probable size of 5 nm and interplanar distances which correspond to the crystalline structure of the starting material. Mass coupled gas chromatography technique was used to corroborate the chemical composition of nanoparticles. Results of biological tests using Drosophila Melanogaster fly, showed that the use of the nanostructured compound is effective in lower doses than those used in agriculture in the form of bulk material.

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Dai, Jiangyun, Guoying Feng, Shutong Wang, Hong Zhang, Shengyu Dai e Shouhuan Zhou. "Transparent NaGdF 4 :Nd 3+ colloid prepared by femtosecond laser ablation as a liquid laser medium". Optics & Laser Technology 92 (luglio 2017): 202–5. http://dx.doi.org/10.1016/j.optlastec.2017.01.008.

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Restuccia, Nancy, e Lorenzo Torrisi. "Nanoparticles generated by laser in liquids as contrast medium and radiotherapy intensifiers". EPJ Web of Conferences 167 (2018): 04007. http://dx.doi.org/10.1051/epjconf/201816704007.

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The synthesis of Au and Ag nanoparticles (NP) though laser ablation in liquids as a function the laser parameters is presented. Spherical NPs with diameter distribution within 1 and 100 nm were prepared by laser ablation in water. The nanoparticles characterization was performed using optical spectroscopy and electronic microscopy (SEM and TEM) measurements. Studies of the possible use of metallic nanoparticles as intensifier of diagnostics imaging contrast medium and absorbing dose from ionizing radiations in traditional radiotherapy and protontherapy are presented. Examples of in vitro (in tissue equivalent materials) and in vivo (in mice), were conducted thank to simulation programs permitting to evaluate the enhancement of efficiency in imaging and therapy as a function of the NPs concentrations and irradiation conditions.

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Al-Azawi, Mohammed A., Noriah Bidin, Mohamed Bououdina, Abdelelah Alshanableh e Ethar Y. Salih. "The Effects of Liquid Environment on Ablation Efficiency and Morphology of Gold Nanoparticles Prepared by Laser Ablation Technique". Journal of Nano Research 37 (dicembre 2015): 99–108. http://dx.doi.org/10.4028/www.scientific.net/jnanor.37.99.

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Gold (Au) nanoparticles (NPs) were prepared by pulsed laser (Nd:YAG, 1064 nm) ablation of an individual target in deionized water (DIW), pure ethanol, and mixture of DIW and ethanol with different concentrations of ethanol. The effects of ambient liquid environment on ablation efficiency, stability, and size of Au NPs were experimentally investigated. The optical spectral characterization and morphological observations were determined by UV-Vis spectrophotometer and transmission electron microscopy, respectively. Particles are nearly spherical in shape in all liquid environments. The ablation experiment was initially performed by using DIW as the reference sample. The obtained Au NPs have an average particle size of about 18.71±7.50 nm. The comparison of the experimental results with the reference sample after a storage time of 48 h revealed that Au NPs in pure ethanol medium were not stable and exhibited much lower ablation efficiency and broader size distribution with an average particle size of 23.83±11.65 nm. Addition of ethanol with different volumes to the DIW significantly improved Au NPs properties in the mixture. The optimum ethanol concentration in the mixture was determined to be 70 vol%, which yielded the maximum ablation efficiency, rather narrow size distribution, and controllable size (12.43±8.10 nm) of Au NPs. A simple method for controlling the properties of Au NPs produced in the binary mixture of DIW-ethanol by laser ablation technique is presented.

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Avicenna, Syifa, Iis Nurhasanah e Ali Khumaeni. "Synthesis of Colloidal Silver Nanoparticles in Various Liquid Media Using Pulse Laser Ablation Method and Its Antibacterial Properties". Indonesian Journal of Chemistry 21, n. 3 (18 marzo 2021): 761. http://dx.doi.org/10.22146/ijc.60344.

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The silver nanoparticles (AgNPs) have been applied as an antibacterial agent in consumer products, cosmetics, and food industries. In this present work, AgNPs were synthesized in various mediums of polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and chitosan using the pulse laser ablation synthesis method. Experimentally, a pulse Nd:YAG laser beam (1064 nm, 7 ns, 30 mJ) was directed using a silver mirror and focused using a quartz lens with a focal length of 30 mm on a silver metal plate placed in a petri dish containing liquid mediums for 120 min to produce colloidal silver nanoparticles. The results certified that All AgNPs have a spherical shape with polydisperse size in all media, including PVP, PEG, and chitosan. The smallest AgNPs have been produced in PVP medium with an averaged smallest size of 11.62 nm. Based on this result, PVP is the preferred medium to produce AgNPs with the smallest size and good stability. The produced silver nanoparticles have been successfully employed as an antibacterial agent, which is experimentally demonstrated by using Escherichia coli and Staphylococcus aureus. The result certified that the produced silver nanoparticles could effectively kill the bacteria with a killing percentage of 99.6 to 100%.

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Biswas, Krishanu, Puspendu Kumar Das e Kamanio Chattopadhyay. "Microstructural evolution in laser-ablation-deposited Fe–25 at.% Ge thin film". Journal of Materials Research 21, n. 1 (1 gennaio 2006): 174–84. http://dx.doi.org/10.1557/jmr.2006.0023.

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Films with Fe–25 at.% Ge composition are deposited by the process of laser ablation on single crystal NaCl and Cu substrates at room temperature. Both the vapor and liquid droplets generated in this process are quenched on the substrate. The microstructures of the embedded droplets show size as well as composition dependence. The hierarchy of phase evolution from amorphous to body-centered cubic (bcc) to DO3 has been observed as a function of size. Some of the medium-sized droplets also show direct formation of ordered DO19 phase from the starting liquid. The evolution of disordered bcc structure in some of the droplets indicates disorder trapping during liquid to solid transformation. The microstructural evolution is analyzed on the basis of heat transfer mechanisms and continuous growth model in the solidifying droplets.

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Nyabadza, Anesu, Mercedes Vazquez e Dermot Brabazon. "A Review of Bimetallic and Monometallic Nanoparticle Synthesis via Laser Ablation in Liquid". Crystals 13, n. 2 (1 febbraio 2023): 253. http://dx.doi.org/10.3390/cryst13020253.

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Pulsed laser ablation in liquid (PLAL) is a physical and top-down approach used to fabricate nanoparticles (NPs). Herein, the research methods and current trends in PLAL literature are reviewed, including the recent uses of PLAL for fabricating bimetallic nanoparticles (BNPs) and composites. BNPs have gained attention owing to their advanced physicochemical properties over monometallic NPs. PLAL involves the irradiation of a solid target (usually a rod, plate, or thin film) under a liquid medium. The liquid collects the ejected NPs resulting from the laser processing, which produces a colloid that can be in various applications, including plasmon sensing, energy harvesting, and drug delivery. The most used fabrication techniques, including the use of microorganisms, do not have precise NP size control and require the separation of the microorganisms from the produced NPs. PLAL is quicker at producing NPs than bottom-up methods. The drawbacks of PLAL include the need to find the required laser processing parameters, which requires extensive experimentation, and the complex and non-linear relationships between the inputs and the outputs (e.g., NP size).

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Kazakevich, P. V., P. S. Yares’ko, V. S. Kazakevich e D. A. Kamynina. "Gold nanoparticle production by laser ablation in liquid nitrogen medium followed by cryogenic medium substitution with ethanol". Bulletin of the Lebedev Physics Institute 41, n. 9 (settembre 2014): 269–74. http://dx.doi.org/10.3103/s1068335614090061.

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Salim, Ali Aqeel, e Noriah Bidin. "Pulse Q-switched Nd:YAG laser ablation grown cinnamon nanomorphologies: Influence of different liquid medium". Journal of Molecular Structure 1149 (dicembre 2017): 694–700. http://dx.doi.org/10.1016/j.molstruc.2017.08.055.

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García Guillén, Grisel, Veronica Anahi Zuñiga Ibarra, Maria Isabel Mendivil Palma, Bindu Krishnan, David Avellaneda Avellaneda e Sadasivan Shaji. "Effects of Liquid Medium and Ablation Wavelength on the Properties of Cadmium Sulfide Nanoparticles Formed by Pulsed-Laser Ablation". ChemPhysChem 18, n. 9 (25 novembre 2016): 1035–46. http://dx.doi.org/10.1002/cphc.201601056.

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Liang, Yoshiki Shimizu, Mitsutoshi Masuda, Takeshi Sasaki e Naoto Koshizaki. "Preparation of Layered Zinc Hydroxide/Surfactant Nanocomposite by Pulsed-Laser Ablation in a Liquid Medium". Chemistry of Materials 16, n. 6 (marzo 2004): 963–65. http://dx.doi.org/10.1021/cm034706e.

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Nath, Manashi, C. N. R. Rao, Ronit Popovitz-Biro, Angi Albu-Yaron e Reshef Tenne. "Nanoparticles Produced by Laser Ablation of HfS3in Liquid Medium: Inorganic Fullerene-Like Structures of Hf2S". Chemistry of Materials 16, n. 11 (giugno 2004): 2238–43. http://dx.doi.org/10.1021/cm035246s.

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Mhin, Sung Wook, Jeong Ho Ryu, Kang Min Kim, Gyeong Seon Park, Han Wool Ryu, Kwang Bo Shim, Takeshi Sasaki e Naoto Koshizaki. "Simple synthetic route for hydroxyapatite colloidal nanoparticles via a Nd:YAG laser ablation in liquid medium". Applied Physics A 96, n. 2 (11 aprile 2009): 435–40. http://dx.doi.org/10.1007/s00339-009-5219-x.

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Nyabadza, Anesu, Mercedes Vázquez, Brian Fitzpatrick e Dermot Brabazon. "Effect of liquid medium and laser processing parameters on the fabrication of carbon nanoparticles via pulsed laser ablation in liquid towards paper electronics". Colloids and Surfaces A: Physicochemical and Engineering Aspects 636 (marzo 2022): 128151. http://dx.doi.org/10.1016/j.colsurfa.2021.128151.

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Jasim, Awatif Sabir, e Awrad Subhi Mahmood. "Preparation of Copper Nanoparticles Using Different Media by Pulsed Laser Ablation and Study of Their Physical Properties". Journal for Research in Applied Sciences and Biotechnology 2, n. 4 (9 settembre 2023): 122–25. http://dx.doi.org/10.55544/jrasb.2.4.17.

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In this study, copper nanoparticles (CuNPs) were prepared using the pulsed laser ablation method, and the study was conducted under the effect of changing the liquid medium (ethanol, deionized water, distilled water) with a number of pulses (700p/s) and using a (Q-switched Nd-YAG) laser. At a wavelength of 532nm and an energy of 100mJ, the results of the samples prepared in a medium (ethanol, distilled water, deionized water) showed the average radii of CuNPs (58.3, 61.6, 46.1 nm, respectively) with a spherical shape. The spectrum of copper at (3250 to 3550 ) is mainly due to the expansion of (O-H) the clear hydroxyl group and under the conditions of the three solvents (ethanol, deionized water, distilled water). The XRD results showed that the CuO nanoparticles are free of impurities and crystallized High and the crystallite size was calculated at 2theta (20.094, 19.949, 38.045) nm for the samples in (deionized water, distilled water, and ethanol), respectively.

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Saadah, Fatkhiyatus, Rizka Zakiyatul Miskiyah e Ali Khumaeni. "Zinc Oxide Nanoparticles (ZnONPs) Photocatalyst using Pulse Laser Ablation Method for Antibacterial in Water Polluted". Journal of Physics and Its Applications 2, n. 2 (6 giugno 2020): 102–6. http://dx.doi.org/10.14710/jpa.v2i2.8001.

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Synthesis of zinc oxide nanoparticles by pulse laser ablation method has been successed carried out. Synthesis was carried out in aquades medium with a repetition rate variation of 5 Hz, 10 Hz and 15 Hz pulse laser yielding brown colloids. The higher laser repetition rate, the colloidal color will be more dark brown. Characterization of zinc oxide nanoparticles includes UV-Vis, SEM-EDX, FTIR and XRD. The image of SEM shows that zinc oxide nanoparticles have a round shape. Measurement of particle distribution with imageJ software from SEM images showed that ZnO nanoparticles were 23.63 nm, 12.13 nm and 5.59 nm for 5 Hz, 10 Hz and 15 Hz shots. The EDX spectrum analysis results show that only Zn and O atoms in the ZnO nanoparticles colloid are synthesized. FTIR results showed that sprocket ZnO was formed at wave number 457 cm-1 and 545 cm-1. The XRD analysis results also show some peaks known as the ZnO phase. This indicates that ZnO nanoparticles have been formed. The testing of the antibacterial activity of ZnO nanoparticles using a liquid dilution method with nanoparticle concentrations of 40 ppm, 60 ppm and 80 ppm. The test results showed the percentage of degradation of Escherichia coli bacteria at concentrations of 40 ppm, 60 ppm and 80 ppm respectively at 89.60%, 97.76% and 98, 70%.

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Liu, Peisheng, Weiping Cai e Haibo Zeng. "Fabrication and Size-Dependent Optical Properties of FeO Nanoparticles Induced by Laser Ablation in a Liquid Medium". Journal of Physical Chemistry C 112, n. 9 (marzo 2008): 3261–66. http://dx.doi.org/10.1021/jp709714a.

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Relvas, M. S., M. R. N. Soares, S. O. Pereira, A. V. Girão, F. M. Costa e T. Monteiro. "Trends in Cr3+ red emissions from ZnGa2O4 nanostructures produced by pulsed laser ablation in a liquid medium". Journal of Physics and Chemistry of Solids 129 (giugno 2019): 413–23. http://dx.doi.org/10.1016/j.jpcs.2019.01.022.

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Choudhury, Kaushik, R. K. Singh, P. Kumar, Mukesh Ranjan, Atul Srivastava e Ajai Kumar. "Effect of confined geometry on the size distribution of nanoparticles produced by laser ablation in liquid medium". Nano-Structures & Nano-Objects 17 (febbraio 2019): 129–37. http://dx.doi.org/10.1016/j.nanoso.2018.12.006.

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Bajaj, Geetika, e R. K. Soni. "Effect of liquid medium on size and shape of nanoparticles prepared by pulsed laser ablation of tin". Applied Physics A 97, n. 2 (7 maggio 2009): 481–87. http://dx.doi.org/10.1007/s00339-009-5248-5.

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Mahdieh, Mohammad Hossein, e Behzad Fattahi. "Size properties of colloidal nanoparticles produced by nanosecond pulsed laser ablation and studying the effects of liquid medium and laser fluence". Applied Surface Science 329 (febbraio 2015): 47–57. http://dx.doi.org/10.1016/j.apsusc.2014.12.069.

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Fedorenko, L. "Self-Organization Processes of Nanostructure Formation by Laser Radiation in Metal". Advanced Materials Research 222 (aprile 2011): 18–23. http://dx.doi.org/10.4028/www.scientific.net/amr.222.18.

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Abstract (sommario):

The current state of knowledge about mechanisms of metal nano-particles (NP) formation processes induced by the interaction of high-energy laser beam with surface of the metallic lattices (Au, Ag, Cu) is presented. The review includes an evaluation of the contribution of self-organized effects into the processes of the metal nano-structurization depending on the laser mode, external factors and internal parameters of an active zone. It was noticed that intensive pulsed laser illumination enabled to stimulate nano-fragmentation at the fluencies near and above the melting threshold of the metal in different mediums The laser induced processes of metallic particles formation by ablation of the metal target with consequent NP sizes stabilization by precise temperature tuning in the active zone, local plasmon resonance in liquids, and microablation mechanism in metal films in the conditions of surface plasmon resonance (SPR) due to self-organization effects are considered. Comparative analysis of the laser nano-technologies in air, vacuum, rarefied gas and liquid environments showed the advantages of self-organization in NP generation processes based on the SPR effects and their perspectives.

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Qona’ah, Ana, Iis Nurhasanah e Ali Khumaeni. "Synthesis of Tin Oxide Nanoparticles by Pulsed Laser Ablation Method Using Low-Energy Nd: YAG Laser as an Antibacterial Agent". Journal of Nano Research 68 (29 giugno 2021): 114–22. http://dx.doi.org/10.4028/www.scientific.net/jnanor.68.114.

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Tin oxide nanoparticles (SnNPs) are very useful to be employed as an antibacterial agent for both gram-positive and gram-negative bacteria. In this present work, the synthesis of SnNPs was successfully carried out using the neodymium yttrium aluminum garnet (Nd:YAG) laser with a wavelength of 1064 nm, pulse duration of 7 ns, and a laser frequency of 10 Hz. Experimentally, a pulse Nd:YAG laser was directed and focused on a high-purity tin (Sn) metal, immersed in various liquid media including pure water and ethylene glycol. A brownish colloidal colour was produced both in pure water and ethylene glycol liquid media. Characterizations of tin oxide nanoparticles were made using UV-Vis, EDX, FTIR, and TEM. UV-Vis characterization produced absorbance values in pure water and ethylene glycol media of 1.314 a.u. and 1.119 a.u., respectively. TEM images show that the shape of tin oxide nanoparticles produced is spherical. Measurement of nanoparticle size distribution was made using image-J software and the average diameter of nano-size in the ethylene glycol medium is 12.55 nm, which is smaller than the size in the pure water of 19.98 nm. The EDX spectrum analysis results show that there are only Sn and O atoms in colloidal tin oxide nanoparticles (SnNPs). FTIR results show the formation of tin oxide (SnO2) spectrum at the wavenumber of 629.03 cm-1. The produced colloidal SnNPs were then applied as an antibacterial agent of E. coli using the disk diffusion method. Results certified that various concentrations of SnNPs of 10 ppm, 20 ppm, and 30 ppm gain the diameter of inhibition zone (DIZ) in sequence 6.50 mm, 6.75 mm, and 9.50 mm. Based on these experimental results, it shows that the higher the concentration of SnNPs given, the greater the ability to degrade and inhibit bacteria.

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Kadhum, Mohammed, Tahseen Mubarak e Nadia Jassim. "Structural and Fluorescence Properties of TiO2/Ag Nanoparticles Bilayers". Diyala Journal For Pure Science 17, n. 3 (1 luglio 2021): 55–70. http://dx.doi.org/10.24237/djps.17.03.557c.

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The optical properties of the TiO2 / Ag hybrid nanoparticles were improved as the particles were prepared with a pulsed liquid laser ablation (PLAL) technology. The effect of number of pulses (450) on the structural and optical properties of nanoparticles prepared in distilled water (DW) as growth media was examined using a Q-Switched Nd-YAG laser with wavelength (1064 nm), ablation energy (530 mJ) and repetition rate (1Hz). The distance between the target and the lens (10 cm). Several were used for the diagnosis such as X-ray diffraction analysis, fourier infrared transformations, TEM assays and fluorescence of the prepared samples. The results of X-ray diffraction analysis of the silver nanoparticles deposited on a glass slide showed that the crystal system is cubic and polycrystalline, with the direction being dominated by [111] at the level of the crystals. The results of X-ray diffraction analysis of a solution of titanium dioxide nanoparticles deposited on a glass slide revealed the presence of a quadrangular crystal system, indicating the presence of titanium dioxide particles in (rutile), and that the prevailing trend for crystalline levels is [110]. The functional groups of (TiO2 / Ag) were determined in the liquid medium by the (FTIR) technique. Also, TEM images showed the presence of nanoparticles and microparticles in an almost spherical shape. The fluorescence measurement of (TiO2 / Ag) hybrid particles showed that through the graph the peak values of (284.1) and (418.3) nm. This is roughly identical to the absorption spectrum results of a hybrid silver and titanium dioxide nanoparticle solution.

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Alkallas, Fatemah H., Hoda A. Ahmed, Tahani A. Alrebdi, Rami Adel Pashameah, Salhah H. Alrefaee, Emaan Alsubhe, Amira Ben Gouider Trabelsi, Ayman M. Mostafa e Eman A. Mwafy. "Removal of Ni(II) Ions by Poly(Vinyl Alcohol)/Al2O3 Nanocomposite Film via Laser Ablation in Liquid". Membranes 12, n. 7 (27 giugno 2022): 660. http://dx.doi.org/10.3390/membranes12070660.

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Al2O3-poly(vinyl alcohol) nanocomposite (Al2O3-PVA nanocomposite) was generated in a single step using an eco-friendly method based on the pulsed laser ablation approach immersed in PVA solution to be applicable for the removal of Ni(II) from aqueous solution, followed by making a physicochemical characterization by SEM, XRD, FT-IR, and EDX. After that, the effect of adsorption parameters, such as pH, contact time, initial concentration of Ni(II), and medium temperature, were investigated for removal Ni(II) ions. The results showed that the adsorption was increased when pH was 5.3, and the process was initially relatively quick, with maximum adsorption detected within 90 min of contact time with the endothermic sorption process. Moreover, the pseudo-second-order rate kinetics (k2 = 9.9 × 10−4 g mg−1 min−1) exhibited greater agreement than that of the pseudo-first-order. For that, the Ni(II) was effectively collected by Al2O3-PVA nanocomposite prepared by an eco-friendly and simple method for the production of clean water to protect public health.

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Borshchov, V. M., O. M. Listratenko, M. A. Protsenko, I. T. Tymchuk, O. V. Kravchenko, O. V. Syddia, M. I. Slipchenko e B. M. Chichkov. "Dispersion of nanoparticles in optically transparent polymer matrices". Radiotekhnika, n. 204 (9 aprile 2021): 105–14. http://dx.doi.org/10.30837/rt.2021.1.204.12.

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Search and analysis of results of theoretical and experimental studies, materials of dissertations, literature sources and patents in the field of optical and optoelectronic instrumentation were carried out. Obtained data and recommendations on the development of methods for dispersing nanoparticles into polymer matrices for the creation of optically transparent nan composites for use in many fields of science and technology are generalized. Analysis of considered results makes it possible to conclude that for creating hybrid organic-inorganic composites with high level of dispersion of inorganic component, it is necessary to solve problems relating to compatibility of components and stabilization of filler nanoparticles in polymer matrix. Due to the limited range of hydrophilic polymers capable of forming composites with nanoparticles without stabilizers, the main approaches to the preparation of hybrid composites are using modifying additives of surfactants, as well as complex chemical reactions on the surface of inorganic filler nanoparticles. Such methods of obtaining nanocomposites with nanoparticles are laborious and involve formation of by-products and additional purification. It is shown that titanium dioxide (TiO2) and zinc oxide (ZnO) are of great interest among a large number of nanodispersed fillers of polymer matrices in preparing composite materials. There are many methods for synthesis of ZnO and TiO2 nanoparticles with various shapes and sizes, including laser ablation method, which is convenient and universal method for preparing nanosuspensions of solid-phase materials in liquid. Advantages over other methods for nanoparticle synthesis, such as the simplicity of method, environmental friendliness, low cost, and the ability to obtain cleaner colloidal solutions without using surfactants and other impurities, have made laser ablation in a liquid medium very popular among researchers.

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Hikmantiyah, Nurul, Eko Hidayanto e Ali Khumaeni. "Synthesis of Zn-Fe nanoparticles using pulse laser ablation as a contrast agent in magnetic resonance imaging". Journal of Physics and Its Applications 2, n. 1 (12 dicembre 2019): 79. http://dx.doi.org/10.14710/jpa.v2i1.6458.

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Synthesis of zinc oxide nanoparticles, iron oxide nanoparticles and Zn-Fe nanoparticles using pulse laser ablation method has been conducted. Experimentally, a pulse Nd:YAG laser (1064 nm, 7 ns, 35 mJ) was directed and focused on a metal plates of pure Zn and Fe, which are placed in the liquid medium of polyvinyl pyrrolidone (PVP). The PVP functions as a stabilizer agent. The results show that the produced nanoparticles have a spherical shape with an averaged diameter of Zn-Fe nanoparticles of 13 nm. FTIR and XRD test results of Zn-Fe nanoparticles show characteristics of Zn-Fe compounds. The examination of Zn-Fe nanoparticles as MRI contrast agents was carried out by varying the concentration of nanoparticles. Cenh calculation results showed the highest contrast enhancement occurred at a concentration of 1.25 mM with a value of 64.26% for T1 weighted images, and 81.52% for T2 weighted images. The SNR calculation results show the highest value at a concentration of 1.25 mM of 70.52 for T1 weighted images. The highest SNR value in the T2 weighted image at a concentration of 0.156 mM of 165.09.

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Dougherty, Atika, Clint Harper, Ferry Iskandar, Idam Arif e Geoff Dougherty. "In situ functionalization of gadolinium oxide nanoparticles with polyethylene glycol (PEG) by pulsed laser ablation in a liquid medium (PLAL)". Journal of Science: Advanced Materials and Devices 3, n. 4 (dicembre 2018): 419–27. http://dx.doi.org/10.1016/j.jsamd.2018.08.003.

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Scardaci, Vittorio, Marcello Condorelli, Matteo Barcellona, Luca Salemi, Mario Pulvirenti, Maria Elena Fragalà e Giuseppe Compagnini. "Fast One-Step Synthesis of Anisotropic Silver Nanoparticles". Applied Sciences 11, n. 19 (26 settembre 2021): 8949. http://dx.doi.org/10.3390/app11198949.

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The shape control of metal nanoparticles, along with the size, is critical for most of their applications as they control their optical properties. Anisotropic metal nanoparticles show superior performance in a number of applications compared to spherical ones. Shape control is usually achieved by a two-step process, where the first involves the formation of spherical nanoparticles and the second is about the actual shape transformation. In this paper, we report on a fast and facile synthesis of silver nanoplates in a single step, involving laser ablation of a silver target in a liquid medium while this is exposed to light irradiation and hydrogen peroxide flow. We obtained anisotropic particles with a mixture of shapes, of 70–80 nm in size and 10–20 nm in thickness, which showed a plasmon sensitivity greater than 200 nm/RIU.

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Imran, Hadeel J., Kadhim A. Aadim e Kadhim A. Hubeatir. "Two–step pulsed laser ablation for preparation NiO@ZnO core-shell nanostructure and evaluation of their antibacterial activity". Advances in Natural Sciences: Nanoscience and Nanotechnology 14, n. 4 (18 ottobre 2023): 045003. http://dx.doi.org/10.1088/2043-6262/ad010c.

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Abstract The excessive use of antibiotics led to the appearance of many strains of resistant bacteria, so it became necessary to use new antibacterial techniques. The aim of this work is the synthesis of novel core–shell NPs (NiO@ZnO) for antibacterial applications. A novel NiO@ZnO core–shell nanomaterial with a nanosize and uniform shape has been synthesised using the two-step pulsed laser ablation in liquid (PLAL) method. The first step is the laser ablation of the nickel target and the production of NiO NPs (core) colloidal, followed by the second step, the ablation of ZnO (shell) inside NiO NPs colloidal. The transmission electron microscopy results approve the formation of NiO@ZnO core–shell NPs with an average particle size of 54.4 nm for NiO particles and 60.7 nm for the NiO@ZnO core–shell. The antibacterial activity was examined against the pathogenic bacterial strains E. coli and S. aureus. We found that in the case of NiO, the inhibition rates were 62.4 and 59.2% for E. coli and S. aureus, respectively. While with NiO@ZnO NPs, this result was improved to 74.8% for E. coli and 71.2% for S. aureus. So, it was found that using the core–shell NPs increased the antibacterial activity of NPs, and the use of NiO NPs and core approved their effect as antibacterial agents due to their special properties. This behaviour is primarily because of the accumulation of the NiO@ZnO NPs on the surface of the bacteria, which leads to cytotoxic bacteria and a relatively increased ZnO, causing cell death. Furthermore, the use of a NiO@ZnO core–shell material will inhibit the bacteria from nourishing themselves on the culture medium. Therefore, core shelling metal oxides with another metal oxide or other material improves their antibacterial activity compared with using them alone.

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Shahi, Fatemeh, Parviz Parvin, Seyedeh Zahra Mortazavi, Ali Reyhani, Mohtada Sadrzadeh, Ali Moafi, Mahdi Ebrahimi e Mohammadreza Aghaei. "In-Situ Generation of Nitrogen-Doped MoS2 Quantum Dots Using Laser Ablation in Cryogenic Medium for Hydrogen Evolution Reaction". Energies 16, n. 1 (31 dicembre 2022): 455. http://dx.doi.org/10.3390/en16010455.

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Here, nitrogen doped molybdenum disulfide quantum dots (N-MoS2 QDs) are fabricated by making use of the pulsed laser ablation (PLA) process in liquid nitrogen (LN2) as a dopant agent. In fact, LN2 contributes the rapid condensation of the plasma plume to form MoS2 QDs, optimizing the conditions for the synthesis of N-doped MoS2 with p-type property. The structural/optical features of the synthesized products are studied using transmission electron microscopy (TEM), absorption spectroscopy, photoluminescence (PL) spectroscopy techniques, and X-ray photoelectron spectroscopy (XPS). The TEM image shows the creation of MoS2 QDs with 5.5 nm average size. UV-vis and PL spectroscopy confirm the formation of N-MoS2 QDs according to the dominant peaks. The Tuck plot gives a direct band-gap of 4.34 eV for MoS2 QDs. Furthermore, XPS spectroscopy reveals Mo-N bonding, indicating nitrogen doping as evidence of p-type MoS2 QDs. Thus, PLA provides a single-stage way to the clean and green synthesis of the MoS2 QDs suspension without a need for high vacuum devices and additional chemical components. Regarding the pristine MoS2, the N-MoS2 QDs benefit from a low overpotential of −0.35 V at −10 mA/cm2 per µg alongside a low Tafel slope of 300 mV/dec. Subsequently, the lower Rct value of N-MoS2 QDs verifies the enhancement of the charge transfer kinetics mainly due to the elevated electronic conductivity. Furthermore, the quasi-rectangular cyclic voltammetry (CV) as well as the larger current window demonstrate a notable electrocatalytic activity. The former is based on the enhanced active sites in favor of N-MoS2 QDs against other samples of interest. Thereby, it is discovered that the N-doped MoS2 QD acts as an effective catalyst to notably improve the performance of the hydrogen evolution reaction (HER).

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Khumaeni, Ali, Wahyu Setia Budi, Syifa Avicenna, Muflihatul Muniroh, Novi Kusumaningrum, Oktarina Damayanti e Shoimatul Fitria. "GOLD AND SILVER NANOPARTICLES AS COMPUTED TOMOGRAPHY (CT) CONTRAST AGENTS PRODUCED BY A PULSED LASER ABLATION TECHNIQUE: STUDY In-vitro AND In-vivo". RASAYAN Journal of Chemistry 16, n. 01 (2023): 502–8. http://dx.doi.org/10.31788/rjc.2023.1618202.

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High-purity metal nanoparticles such as gold and silver nanoparticles become an interesting subject for application in the medical field. Using the laser ablation approach, these nanoparticles were successfully synthesized in this present work. Experimentally, a pulse neodymium yttrium aluminum garnet laser (1064 nm, 30 mJ, 10 Hz) was used to irradiate high-purity metals immersed in an iodine liquid medium. Purple, yellow, and dark purple colloidal nanoparticles of Au, Ag, and Au-Ag were successfully synthesized. The results certified that all nanoparticles have a spherical shape; Au nanoparticles had an average diameter of 26 nm and a standard deviation of 4 nm, while Ag nanoparticles had an average diameter of 24 nm and a standard deviation of 5 nm. The diameter distribution of AuAg nanoparticles is extraordinarily vast, ranging from 18 to 80 nm. Colloids of mixed Au-Ag nanoparticles had the highest Hounsfield Units (HU) value in an in vivo test, with a value of 302. This was supported by the results of an in vitro contrast enhancement evaluation, which determined that a mixture of Au-Ag nanoparticles provided the best contrast enhancement compared to other colloids. These results confirmed that the Au-Ag nanoparticles are very suitable as contrast agents in CT.

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