In this study, we report silver nanoparticles (Ag NPs) modified with sodium triphosphate (STTP) (Ag-STPP NPs) prepared by a simple surface modification and chemical reduction method. It was confirmed by 31P NMR spectroscopy that STPP was successfully introduced to the surface of Ag NPs. It was revealed by conductivity change measurements, bacterial growth kinetics and antibacterial efficiency tests that Ag-STPP NPs still retained the strong antibacterial ability. It was demonstrated by hemolysis assays, red blood cell morphology measurements, plasma recalcification time and in vitro clotting times that Ag-STPP NPs had improved hemocompatibility. It was also implied by cell viability measurements that Ag-STPP NPs possessed low cytotoxicity and high cytocompatibility. These findings, combined with the low-cost and ease of synthesis, make Ag-STPP NPs a promising candidate for biomedical applications.

In this study, commercial AZ31B magnesium alloy was used to compare the differences between the microstructure, texture, and mechanical properties of conventional solidification (as homogenized AZ31) and rapid solidification (as RS AZ31). The results demonstrate that a rapidly solidified microstructure leads to better performance after hot extrusion with a medium extrusion rate (6 m/min) and extrusion temperature (250 °C). The average grain size of as-homogenized AZ31 extruded rod is 100 μm after annealing and 4.6 μm after extrusion, respectively, but that of the as-RS AZ31 extruded rod is only about 5 μm and 1.1 μm, correspondingly. The as-RS AZ31 extruded rod attains a high average yield strength of 289.6 MPa, which is superior to the as-homogenized AZ31 extruded rod, and is improved by 81.3% in comparison. The as-RS AZ31 extruded rod shows a more random crystallographic orientation and has an unconventional weak texture component in <112¯1>/<202¯1> direction, which has not been reported yet, while the as-homogenized AZ31 extruded rod has an expected texture with prismatic <101¯0>/<1¯21¯0>//ED.

Low-temperature and high-speed extrusion of wrought magnesium alloy is an urgent problem. Mg-2.5Al-2Ca-1Sn alloys were extruded at 260 ℃ with different ram speeds (2.0,4.0 and 6.0 mm/s). The effects of extrusion speed on the microstructure and mechanical properties of the alloys were systematically investigated. It's worth noting that all the three extruded alloys were fully dynamic recrystallized (DRXed).With the increase of extrusion speed from 2 mm/s to 6 mm/s, the DRXed grain size are increased from 1.25 μm to 1.94 μm, average second phase particles are augmented from 0.79 μm to 0.89 μm and the volume fraction of second phase increases from 6.4% to 18.6%.The extruded alloys with three different extrusion speeds all show excellent comprehensive mechanical properties because of fine grain size, fully recrystallization and homogeneously dispersed second phase particles. The tensile yield strength (TYS) and ultimate tensile strength (UTS) decreased from 285 MPa,304 MPa to 217 MPa,264 MPa while the elongation increased from 11.4 % to 20 % when the ram speed rised from 2.0 mm/s to 6.0 mm/s.