Engineering performance of tungsten network reinforced copper matrix composites synthesized by selective laser melting and infiltration.

To solve poor engineering performance of copper-tungsten alloys operated at high temperatures, 3D network tungsten frameworks were prepared using a selective laser melting (SLM) process, and then copper was melted and diffused into these tungsten network structures to form copper matrix composites with different copper contents (i.e. Cu-10vol%W and Cu-30vol%W). Their mechanical/electrical properties and arc ablation performance were characterized. Results showed the obtained CuW composites were dense with good interfacial bonding, and the connected Cu phases formed a heat conduction channel and improved electrical and thermal conductivities of the composites. Electrical conductivities of Cu-30W and Cu-10W composites were 44.7% and 80.3% IACS, and their thermal conductivities at 25°C were 247.5 and 375.4 W/(m·K), respectively. The W-skeleton grid structure in the composites showed enhanced effects on impact toughness and anti-friction/wear resistance. Tensile strengths of Cu-30W and Cu-10W composites measured at 300°C were 95 MPa and 135 MPa, and their impact toughness values were 11.25 and 15.25 J/cm2, respectively. For the arc ablation performance, the copper phase of CuW composite was identified as the key influencing phase, whereas the W skeleton effectively hindered the spread of arc spots, inhibited quick melting of copper phases, and played effective support and protection functions.

W network reinforced Cu matrix composites were prepared by combining 3D printing technology and fusion technology, which significantly improved the thermal and mechanical properties of Cu matrix composites. We find that the interconnected Cu phases improves the thermal properties of the composites, and the mesh W skeleton improves the mechanical properties.

Ultrasensitive Visual Tracking of Toxic Cyanide Ions in Biological Samples Using Biocompatible Metal-Organic Frameworks Architectures.

The extraordinary accumulation of cyanide ions within biological cells is a severe health risk. Detecting and tracking toxic cyanide ions within these cells by simple and ultrasensitive methodologies are of immense curiosity. Here, continuous tracking of ultimate levels of CN--ions in HeLa cells was reported employing biocompatible branching molecular architectures (BMAs). These BMAs were engineered by decorating colorant-laden dendritic branch within and around the molecular building hollows of the geode-shelled nanorods of organic-inorganic Al-frameworks. Batch-contact methods were utilized to assess the potential of hollow-nest architecture for inhibition/evaluation of toxicant CN--ions within HeLa cells. The nanorod BMAs revealed significant potential capabilities in monitoring and tracking of CN- ions (88 parts per trillion) in biological trials within seconds. These results demonstrated sufficient evidence for the compatibility of BMAs during HeLa cell exposure. Under specific conditions, the BMAs were utilized for in-vitro fluorescence tracking/sensing of CN- in HeLa cells. The cliff swallow nest with massive mouths may have the potential to reduce the health hazards associated with toxicant exposure in biological cells.

Fluorescent sensor/tracker for biocompatible and real-time monitoring of ultra-trace arsenic toxicants in living cells.

Real-time monitoring and tracking of extreme toxins that penetrate into living cells by using biocompatible, low-cost visual detection via fluorescent monitors are vitally essential to reduce health hazards. Herein, we report a simple engineering design of biocompatible and fluorescent sensors/trackers for real-time monitoring and ultra-trace tracking (up to ppb) of extremely toxic substances (such as arsenic species) in living cells. The biocompatible As(V) sensor (BAS) design is fabricated via successful dressing/decoration process of 2-hydroxy 5-methyl isophthalaldehyde fluorescent receptor into hierarchical organic-inorganic carriers that have micro-hollow geodes, swirled caves and nest-shaped cages, and uniform cubic structures. The BAS monitors show evidence for the selective trapping/detecting/tracking of As(V) species in biological cells (i.e., HeLa cells) despite the coexistence of highly competitive and interfered species. Our simple batch-contact sensing assays shows real-space evidence of the continuous monitoring of As(V) species in HeLa cells with ultra-sensitive detection (i.e., with a low detection limit of 0.149 ppb) and rapid recognition (i.e., in the order of seconds). Significantly, the BAS monitors did not affect the cell population and achieved low cytotoxicity and high cell viability during the monitoring/tracking process inside HeLa cells. The high biocompatibility of BAS remarkably allows precise quantification and real-time monitoring/tracking of toxicant targets in living cells.