Yearly Archives: 2024

‘Bi-layer CBN-based Composites Reinforced With Oxide And Non-oxide Microfibers Of Refractory Compounds | Scientific … – Nature.com’

Nature.com May 02, 2024

Research into new composites utilizing cubic boron nitride PcBN shows promise for enhancing cutting tool performance. The unique properties of these materials stem from the addition of microfibers made of refractory compounds to their structure. This study looks at developing two-layer composites based on cBN group BL reinforced with SiCw and Al2O3w microfibers. The goal is to improve tool stability when cutting hardened steels with impact loads. PcBN composite samples were made by sintering a mixture of cBN powder with bundles and microfibers under 7.7 GPa pressure. Bond material selection was based on analyzing the relationship between Poisson39s ratio 951 and plasticity parameter GB. The density Young39s modulus Poisson39s ratio and hardness of the composites were determined and the microstructure of samples with TiCN bond was studied. Tool-life tests were conducted on two-layer cutting inserts made of PcBN reinforced with SiCw and Al2O3w microfibers during the machining of hardened KhVG steel HRC 55 under impact loads at cutting speeds of 100 and 200ampnbspmmin.

‘MXene/AgNW Composite Material For Selective And Efficient Removal Of Radioactive Cesium And Iodine From Water … – Nature.com’

Nature.com Nov 11, 2023

Toxic fission products such as cesium 137Cs and iodine 129I are of great concern because of their long half-lives and high solubility in water. The simultaneous removal of Cs and I using a single adsorbent is an area of increasing interest. In this study MXenesilver nanowire AgNW composite was synthesized through physical mixing and employed for simultaneous removal of iodide I8722 and cesium Cs ions from contaminated water. The MXeneAgNW composite demonstrated excellent adsorption capacities of 84.70 and 26.22ampnbspmgg for I8722 and Cs respectively. The experimental data supported the hypothesis of multilayer adsorption of Cs owing to the inter-lamellar structures and the presence of heterogeneous adsorption sites in MXene. The interaction between I8722 and the AgNW involved chemisorption followed by monolayer adsorption. MXeneAgNW composite material exhibited promising results in the presence of competitive ions under extreme pH conditions. Thus synthesized composite materials holds promising potential as an adsorbent for the remediation of radioactive liquid waste.

‘Ultralight Crystalline Hybrid Composite Material For Highly Efficient Sequestration Of Radioiodine – Nature.com’

Nature.com Feb 10, 2024

Considering the importance of sustainable nuclear energy effective management of radioactive nuclear waste such as sequestration of radioiodine has inflicted a significant research attention in recent years. Despite the fact that materials have been reported for the adsorption of iodine development of effective adsorbent with significantly improved segregation properties for widespread practical applications still remain exceedingly difficult due to lack of proper design strategies. Herein utilizing unique hybridization synthetic strategy a composite crystalline aerogel material has been fabricated by covalent stepping of an amino-functionalized stable cationic discrete metal-organic polyhedra with dual-pore containing imine-functionalized covalent organic framework. The ultralight hybrid composite exhibits large surface area with hierarchical macro-micro porosity and multifunctional binding sites which collectively interact with iodine. The developed nano-adsorbent demonstrate ultrahigh vapor and aqueous-phase iodine adsorption capacities of 9.988201g.g87221 and 4.748201g.g87221 respectively in static conditions with fast adsorption kinetics high retention efficiency reusability and recovery. The development of effective adsorbents of radioiodine nuclear waste remains difficult due to the lack of proper material design strategies. Here the authors report an ultralight hierarchically porous crystalline multifunctional hybrid nanocomposite for ultrafast entrapment of iodine and polyiodide species under both static and dynamic condition.