Synthesis of Nickel Nanowires with Tunable Characteristics

A one-step synthesis of magnetic nickel nanowires (NiNWs) with tunable characteristics is reported. The method is simple and easy to be conducted, leading to high compatibility with scaling-up. It is discovered that the size and morphology of NiNWs can be adjusted by tuning the reaction temperature, time length, as well as surfactant concentration. It is found that the products have shown high purity which remained after being stored for several months. A remarkable enhanced saturation magnetization of the product was also observed, compared to that of bulk nickel. By providing both practical experimental details and in-depth mechanism, the work introduced in this paper may advance the mass production and further applications of NiNWs

Synthesis of Nickel Nanowires with Tunable Characteristics

A one-step synthesis of magnetic nickel nanowires (NiNWs) with tunable characteristics is reported. The method is simple and easy to be conducted, leading to high compatibility with scaling-up. It is discovered that the size and morphology of NiNWs can be adjusted by tuning the reaction temperature, time length, as well as surfactant concentration. It is found that the products have shown high purity which remained after being stored for several months. A remarkable enhanced saturation magnetization of the product was also observed, compared to that of bulk nickel. By providing both practical experimental details and in-depth mechanism, the work introduced in this paper may advance the mass production and further applications of NiNWs

A novel nickel nanowire based magnetorheological material

The aim of this work is to fabricate and investigate nickel nanowires (NiNWs) as a novel magnetorheological material and determine how the aspect ratio of these magnetic particles influences its magnetic properties. The latest methods for synthesizing NiNWs and nickel nanospheres (NiNSs) are presented and the corresponding magnetorheological fluids (MRF) are obtained. Materials were characterized so that the properties of NiNWs could be compared to NiNSs. As different size NiNWs were fabricated, their saturation magnetization values increased as the size increased. Moreover, MRF containing NiNWs processed shear stress 15 times as strong as the one with the same volume of NiNSs, although the saturation magnetization of NiNWs was smaller than NiNSs. MRF containing magnetic particles with more saturation magnetization and smaller coercivity usually has a stronger MR effect. Our result is interesting, and further finite element simulations were utilized to analyze the possible mechanisms. The simulation indicated that the large aspect ratio of NiNWs helped to align the particles into columns and also caused the magnetized direction of particles to deviate from the direction of the applied field, thus restoring the torque and achieving a large shear stress. Furthermore, MRF with higher fraction of NiNWs has a more stable suspension, and NiNWs disperse much better than NiNSs with the same volume

Calcium Carbonate Mineralization in a Surface-Tension-Confined Droplets Array

Calcium carbonate biomimetic crystallization remains a topic of interest with respect to biomineralization areas in recent research. It is not easy to conduct high-throughput experiments with only a few macromolecule reagents using conventional experimental methods. However, the emergence of microdroplet array technology provides the possibility to solve these issues efficiently. In this article, surface-tension-confined droplet arrays were used to fabricate calcium carbonate. It was found that calcium carbonate crystallization can be conducted in surface-tension-confined droplets. Defects were found on the surface of some crystals, which were caused by liquid flow inside the droplet and the rapid drop in droplet height during the evaporation. The diameter and number of crystals were related to the droplet diameter. Polyacrylic acid (PAA), added as a modified organic molecule control, changed the CaCO3 morphology from calcite to vaterite. The material products of the above experiments were compared with bulk-synthesized calcium carbonate by scanning electron microscopy (SEM), Raman spectroscopy and other characterization methods. Our work proves the possibility of performing biomimetic crystallization and biomineralization experiments on surface-tension-confined microdroplet arrays