The surfaces of silicon carbide particles subjected to two different passive oxidation treatments have been characterized by immersion calorimetry and vapor adsorption techniques. Surface enthalpies and surface free energies have been computed using semiempirical models and are compared to theoretical estimations. The surface entropy term appears higher than in the case of other solids studied with the same analysis. The definition of the surface entropy term is discussed in order to explain the discrepancy between calculation and experiment. An explanation of results is proposed, which is related to the constitution of silicon oxide layers at the surface of silicon carbide, a fact demonstrated by previous XPS measurements.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/S0021-9797(03)00198-X | DOI Listing |
Graphene 2D Mater
June 2024
NanoSafe, Inc., Blacksburg, VA 24060, USA.
Five commercially available cut-resistant gloves were sourced from four different worldwide manufacturers which were advertised to contain graphene. A method was developed to assess the fibers composing each glove, including dissolution of the constituent fibers using sulfuric acid or liquid paraffin at elevated temperature, to extract and analyze particle additives. Scanning electron microscopy with energy-dispersive X-ray spectroscopy was applied to fibers and extracted particles for morphological and elemental analysis; Raman spectroscopy was applied to discern the composition of carbonaceous materials for the ultimate purpose of identifying any graphenic additives.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Mechanics and Aerospace Engineering, Dalian University of Technology, Dalian 116024, P. R. China.
Ceramic aerogels are promising high-temperature thermal insulation materials due to their outstanding thermal stability and oxidation resistance. However, restricted by nanoparticle-assembled network structures, conventional ceramic aerogels commonly suffer from inherent brittleness, volume shrinkage, and structural collapse at high temperatures. Here, to overcome such obstacles, 3D ultralight and highly porous carbon tube foams (CTFs) were designed and synthesized as the carbonaceous precursors, where melamine foams were used as the sacrificial templates to form the hollow and thin-wall network structures in the CTFs (density: ∼4.
View Article and Find Full Text PDFBraz Oral Res
January 2025
Universidade de São Paulo - USP, School of Dentistry, Department of Operative Dentistry, São Paulo, SP, Brazil.
The aim of this study was to assess the effect of a chlorhexidine digluconate solution (CHX) applied as an antiproteolytic agent for controlling erosive tooth wear or as part of the adhesive treatment on long-term bond strength to eroded dentin. Dentin specimens were abraded with a 600-grit silicon carbide (SiC) paper for 1 min (sound dentin - S), subsequently treated with 2% CHX for 1 min (with excess removed, followed by a 6-hour rest), and eroded by exposure to Coca-Cola for 5 min, three times a day, for 5 days (CHX-treated and eroded dentin - CHXE), or only eroded (eroded dentin - E). The specimens were acid-etched (15 s), rinsed (30 s), dried (15 s), and rehydrated with 1.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2025
Institute of General, Inorganic and Theoretical Chemistry Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria.
Novel anode materials for lithium-ion batteries (LIBs) are constantly being explored to further improve battery performance. In this work, ReaxFF molecular dynamics (MD) simulations are performed to model the early stages in the synthesis of nanostructured silicon carbide (SiC), which is one such promising material. The focus lies on its precursor, silicon oxycarbide glass of composition (SiOC) (17 mol% Si, 28 mol% O, and 54 mol% C), in the following referred to as SiOC.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Mechanical Design and Production, Faculty of Engineering, Cairo University, Giza, 12316, Egypt.
The complementary properties of corrosion resistance and ballistic resistance of AA5083 and AA7075, respectively, explain the significance of welding these two alloys in the marine armor industry. This study investigates a novel Al-SiC matrix reinforcement with a different SiC weight ratio in dissimilar friction stir welding of the AA5083/AA7075 joint at different transverse and rotational speeds. The study deduced that the novel matrix can play an important role in improving strength and ductility simultaneously.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!