Nanostructural Deformation in Brittle-Ductile Compounds and Its Application in Fabricating Ductile Nanoparticles

Abstract

The ball-milling process involves both fracturing and welding of particles. Particles of ductile materials are very likely to attach to each other when entrapped between balls.Therefore, conventional milling methods fail to grind ductile materials into nanoparticles. However, using brittle particles together with the starting materials, one can fracture and highly activate ductile particles through planetary ball milling. During the milling process, brittle particles are easily fractured down, and their sharp edges chop the particles of the ductile materials incessantly into pieces until both ductile and brittle particles are nano-sized (a process which is unlikely, if not impossible, to accomplish by ball milling of ductile materials alone). In this chapter, the effects of ball milling of ductile materials (e.g., graphite, aluminum, and zinc) together with a brittle material (here, NaCl), for preparation of metal nanoparticles or metal oxide nanoparticles are investigated. A theoretical explanation of the mechanism is also presented based on the facts and practical measurements.

Titanium Dioxide Nanomaterial Ink Production Through Laser Ablation Synthesis in Solution for Printed Electronics Applications

“…High-resolution TEM imaging was performed to further characterize the particles (Figure 1b). Some inherent defects were observed within larger particles, and the interplanar spacing was measured to be 3.60 Å, which agrees with those reported in literature, [9,10] and is indicative of the (101) crystal plane of anatase-phase TiO 2 . Additionally, NP diameter distribution analysis was performed (Figure 1c), resulting in an average diameter of 10.88 nm and a standard deviation of 10.39 nm.…”

“…[ 8 ] Although effective, these methods have significant drawbacks, such as using carrier gases or solvents, [ 9 ] using chemicals to create a reaction, [ 6 ] and managing mechanical properties that prevent some ductile materials from being milled. [ 10 ] These methods often include toxic chemicals and chemical precursors, consume large amounts of energy, and require high pressures and temperatures. [ 11 ] Synthesis methods for transition metals, in particular, most often include wet chemical synthesis, [ 5,12 ] reduction of organic precursors, [ 13 ] electrochemical synthesis, [ 14 ] and metal vapor synthesis.…”

Activated Reactive Consolidation Method as a New Approach to Enhanced Thermoelectric Properties of n-Type Nanostructured Mg2Si

“…In this step, the size of magnesium particles reduced. This may be attributed to the presence of silicon nanoparticles serving as nanochoppers. − Magnesium is much more ductile and softer than silicon . Hence, silicon particles can easily chop magnesium particles into pieces during the mechanical activation process.…”

“…By increasing the amount of starting materials interface and decreasing the diffusion distance, it is possible to reduce the time and temperature needed for accomplishing the solid-state reaction. This can be achieved by ball-milling of brittle–ductile materials leading to the preparation of either nanoparticles , or highly activated ductile nanoparticles, which significantly facilitate the exothermic reactions at low temperatures and in a short time. − This strategy results in the preparation of single-phase MgO-free Mg 2 Si with a well-controlled chemical composition . Since nondoped Mg 2 Si has successfully been synthesized at low temperature for a short time in the previous work, the carrier concentration then needs to be tuned to attain high thermoelectric performance via this strategy.…”