Using a conventional Raman experimental apparatus, we demonstrate that the photoluminescent (PL) yield from ultrasonication-exfoliated transition metal dichalcogenides (TMDs) (MoS and WS) can be increased by up to 8-fold by means of a laser etching procedure. This laser etching process allows us to controllably pattern and reduce the number of layers of the solution-exfoliated material, overcoming the key drawback to solvent-based exfoliation of two-dimensional (2D) semiconducting materials for applications in optoelectronics. The successful laser thinning of the exfoliated 2D crystals was investigated systematically by changes in both Raman and PL spectra. A simple proof-of-principle of the scalability of this laser etching technique for solution-exfoliated TMD crystals was also demonstrated. As well as being applicable for individual materials, it is also possible to use this simple laser etching technique to investigate the structure of solution-generated van der Waals heterostructures, consisting of layers of both MoS and WS.
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http://dx.doi.org/10.1021/acsomega.6b00294 | DOI Listing |
J Stomatol Oral Maxillofac Surg
December 2024
Reader, Department of Periodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai 600077, Tamil Nadu, India.. Electronic address:
Purpose: This in-vitro study aimed to compare the shear bond strength (SBS) of cobalt-chromium (Co-Cr) crowns on Corticobasal® implant abutments, evaluating the effects of two surface treatments and two luting agents.
Materials And Methods: Thirty Co-Cr crowns were fabricated using CAD-CAM technology with a direct metal laser sintering process and divided into three groups based on surface treatment: Group I (untreated), Group II (sandblasted with 50 μm Al₂O₃), and Group III (Er: YAG laser etching). Each group was further subdivided based on luting cement: Sub group A (GC Fuji Plus) and Sub group B (Rely X U200).
Int J Periodontics Restorative Dent
December 2024
Purpose: This study is designed to explore the effect of Er,Cr:YSGG laser tooth etching versus that of conventional tooth surface treatment on the shear bond strength of ceramic laminate veneers.
Methods: Seventy-six maxillary premolars were assigned to two groups (n = 38) according to the type of enamel surface treatment approach. Group 1: samples treated with the conventional acid-etch protocol.
Adv Colloid Interface Sci
December 2024
School of Materials Science and Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China.
Photothermal conversion materials (PCMs) are crucial component in solar-thermal energy technologies. Although various PCMs with excellent sunlight harvesting have been developed for colorful solar-thermal applications, uniform and large-scale production of PCMs remains a challenge, and the PCMs prepared through the conventional methods are often non-site specific. Laser processing technology (LPT), as an efficient, convenient, green and sustainable technology, can directly create micro/nano structures and patterns at specific locations on materials surface, attracting widespread attention in photo-to-thermal applications.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Metal Forming, Welding and Metrology, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, 50-370 Wrocław, Poland.
This article presents research on advanced surface preparation methods for sintered carbides (WC-Co, grade B2) commonly used in the tool industry, particularly in the context of bonding these materials with C45 steel using adhesives. Sintered carbides are widely used due to their high hardness, wear resistance, and good ductility, making them ideal for manufacturing tools operating in harsh conditions. Traditional bonding methods, such as brazing and welding, often result in stresses and cracks.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan.
A triboelectric nanogenerator (TENG) is a kind of energy harvester which converts mechanical energy into electrical energy with electron transfer and transport between two different materials during cycling tribology. To increase the contact area between tribo-layers and enhance the output of TENGs, many studies prepare patterned micro/nanostructured tribo-layers using semiconductor processes like lithography and etching at high cost and with long processing times. Here, we propose a new method to quickly produce high-aspect-ratio (HAR) microneedles of polydimethylsiloxane (PDMS) for TENG triboelectric layers using a two-pulse laser-ablated polymethyl methacrylate mold and casting.
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