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Laser-Ablative Synthesis of Isotope-Enriched Samarium Oxide Nanoparticles for Nuclear Nanomedicine
摘要： Nuclear nanomedicine is an emerging field, which utilizes nanoformulations of nuclear agents to increase their local concentration at targeted sites for a more effective nuclear therapy at a considerably reduced radiation dosage. This field needs the development of methods for controlled fabrication of nuclear agents carrying nanoparticles with low polydispersity and with high colloidal stability in aqueous dispersions. In this paper, we apply methods of femtosecond (fs) laser ablation in deionized water to fabricate stable aqueous dispersion of 152Sm-enriched samarium oxide nanoparticles (NPs), which can capture neutrons to become 153Sm beta-emitters for nuclear therapy. We show that direct ablation of a 152Sm-enriched samarium oxide target leads to widely size- and shape-dispersed populations of NPs with low colloidal stability. However, by applying a second fs laser fragmentation step to the dispersion of initially formed colloids, we achieve full homogenization of NPs size characteristics, while keeping the same composition. We also demonstrate the possibility for wide-range tuning of the mean size of Sm-based NPs by varying laser energy during the ablation or fragmentation step. The final product presents dispersed solutions of samarium oxide NPs with relatively narrow size distribution, having spherical shape, a controlled mean size between 7 and 70 nm and high colloidal stability. The formed NPs can also be of importance for catalytic and biomedical applications.
关键词： nuclear nanomedicine,samarium (Sm) oxide nanoparticles,pulsed laser ablation in liquids,femtosecond laser ablation and fragmentation
更新于2025-09-16 10:30:52
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Laser additive manufacturing of oxide dispersion strengthened steels using laser-generated nanoparticle-metal composite powders
摘要： A new route for the synthesis of powder composites suitable for processing with laser additive manufacturing is demonstrated. The powder composites, consisting of micrometer-sized stainless steel powder, homogenously decorated with nano-scaled Y2O3 powder particles, are manufactured by laser processing of colloids and electrostatic deposition. Consolidated by laser metal deposition and selective laser melting, the resulting specimens show superior mechanical properties at elevated temperatures, caused by the nano-sized, homogenously distributed dispersoids.
关键词： Laser additive manufacturing,Pulsed laser ablation in liquids,Selective Laser Melting,Oxide dispersion strengthened materials,ODS
更新于2025-09-12 10:27:22
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A new approach to coat PA12 powders with laser-generated nanoparticles for selective laser sintering
摘要： The modification of selective laser sintering (SLS) powder materials by nanoadditives offers the possibility to adapt the powder properties to the laser sintering process or the resulting part properties. To avoid agglomeration of the nanofiller, a new approach in which surfactant-free laser-generated colloidal nanoparticles are adsorbed onto the polymer surface directly in an aqueous solution is demonstrated. Based on this novel approach, polyamide 12 (PA12) powders are decorated with metal and oxide nanoparticles and processed via SLS. Electron microscopy and confocal laser scanning imaging are utilized to analyze the dispersion of the filler.
关键词： selective laser sintering,laser additive manufacturing,polymer powders,pulsed laser ablation in liquids,nanoparticles
更新于2025-09-12 10:27:22
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Effective size separation of laser-generated, surfactant-free nanoparticles by continuous centrifugation
摘要： High-power, nanosecond, pulsed-laser ablation in liquids enables the continuous synthesis of highly-pure colloidal nanoparticles (NPs) at an application-relevant scale. The gained mass-weighted particle size distribution is however often reported to be broad, requiring post treatment like centrifugation to remove undesired particle size fractions. To date, available centrifugation techniques are generally discontinuous, limiting the throughput and hindering economic upscaling. Hence, throughout this paper, a scalable, continuously operating centrifugation of laser-generated platinum nanoparticles in a tubular bowl centrifuge is reported for the first time. To that end, using a 121 W ns-laser, a continuous production of a colloidal suspension of NPs, yet with broad particle size distribution has been employed, yielding productivities of 1 - 2 g/h for gold, silver, and platinum. Subsequent downstream systematic study of relevant centrifugation parameters involved, effective size optimization and respective size sharpness parameters for a maximum Pt nanoparticle diameter of 10 nm are reported. The results of the experimental centrifugation of laser-generated Pt-NPs were in excellent agreement with the theoretically-calculated cut-off diameter. After centrifugation with optimized parameters, the polydispersity indices of the Pt-NPs size distributions were reduced by a factor of six and higher monodispersities were observed.
关键词： continuous process chain,tubular bowl centrifugation,contamination-free nanoparticle processing,Pt-NPs,pulsed laser ablation in liquids
更新于2025-09-12 10:27:22
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ZnO nano-sized particles preparation by laser ablation in liquids
摘要： In this paper, we used laser ablation in liquids to prepare ZnO nanoparticles. In our experiment, the pulsed laser was focused onto the Zn target submerged in water. We used di?erent laser energy to form the ZnO nanoparticles. The size, structure and photoluminescence spectra of ZnO nanoparticles were displayed by using XRD and AFM. The relationship between diameter of ZnO nanoparticles and laser energy was analyzed. In addition, we also studied the variation of photoluminescence spectra of ZnO nanoparticles with di?erent laser energy.
关键词： Laser ablation in liquids,XRD,ZnO nanoparticles,AFM
更新于2025-09-12 10:27:22