Metallic Nanoparticles, Pyrolysis

The preparation of metallic nanoparticles was discussed in the last article, metallic nanoparticles part II (Top-Down and Bottom-Up). It was mentioned that there are two approaches for their preparation, top-down approach and bottom-up approach. The most used approach is the bottom-up approach in which the preparation of the nanoparticles is started from atomic level to the nano-scale. Here we discuss some of the used methods for this approach.
Bottom-up approach depends on the synthesis of the metallic nanoparticles starting from the atoms of the metals. The main principle is to transfer the metallic substance into atoms in a process called nucleation and then to control the growth of the atoms until they reach the desired nano-size. Nucleation can be reached by the extensive heat of the metals in the gas phase or by the reduction of the metallic complexes in liquid phase conditions where the growth can be controlled by surfactant or stabilizer. The main methods for the preparation of the metallic nanoparticles in the gas phase are Pyrolysis, Gas condensation (Chemical Vapor Deposition), and Laser ablation. Here we discuss the preparation of the metallic nanoparticles by Pyrolysis and we leave the discussion of the other method for the next blogs.
In Pyrolysis the precursor is prepared in a precursor solution and heated in specific process to evaporate the solvent and form the nanoparticles. The most used method is spray pyrolysis in which the solution undergoes aerosol process that atomizes the precursor solution and heats the droplets to produce solid particles.

Image retrieved from: Advanced Powder Technology 20 (2009) 283–292, doi:10.1016/j.apt.2009.07.001

Different metallic, metallic oxide nanoparticles and nanocomposite particles can be prepared by this method. The shape and the size of the prepared nanoparticles can be adjusted by adjusting the composite of the precursor solution and the heat of the furnace. Some of the shapes that can be obtained are dense nanoparticles, shell-structured nanoparticles, hallow nanoparticles, and foam nanoparticles. Examples of nanoparticles and composite that are produced by pyrolysis are, Co (Cobalt Nanoparticles), Cu (Cupper Nanoparticles), Fe (Iron nanoparticles), Ti (Titanium Nanoparticles), TiO (Titanium Oxide Nanoparticles), Bi2O3 (Bismuth Oxide Nanoparticles), ZnO (Zinc Oxide Nanoparticles), ZnO/SiO2 (Zinc Oxide / Silicon Oxide Nanocomposite).

Posted by Mohammed ZABARA on November 30, 2016

https://nanografi.com/blog/metallic-nanoparticles-part-iii-pyrolysis/

Carbon Nanotube Threads

Since its discovery, carbon nanotube (CNT) has attracted many interests in different technology fields due to its extraordinary properties. Properties such as, high strength, great electrical and thermal conductivity, light weight and flexibility made CNT one of the best materials for wide range of applications. However, from its name it can be understood that CNT is a nanoscale material which is very small to be applied for the production of daily products. Researchers all around the world are working on finding methods and techniques which could produce new materials with the extraordinary properties of CNT. Image retrieved from: https://worldindustrialreporter.com/strong-light-flexible-carbon-nanotubes-threads-with-ultrahigh-conductivity/ One of these research is focusing on the production of high strength threads that can be used in the manufacturing of fabrics, cables and ropes. An international group of scientists were able to produce a flexible conductive thread th...

Multi Walled Carbon Nanotube Dispersions

Carbon nanotubes (CNTs) have attracted enormous attention in recent years due to its unique physical, electronic, optical and potential applications in materials science and nanotechnology. The van der Waals interaction between tubes, however, makes CNTs aggregate in most organic solvents and aqueous solutions, which is the major limitation of their practical applications.Various approaches have been studied to alter the CNT surface to promote the dispersion of individual nanotubes and prevent their reaggregation. On the basis of this widely accepted viewpoint, numerous techniques such as covalent bonding, surfactant coating and polymer wrapping have been developed for surface modification or sidewall functionalization.These methods, however, are complicated, time-consuming and cause permanent damage to the CNT structure and properties of the surface, which produces residues of the dispersion agent for the final product. Figure: Single Walled Carbon Nanotube (SWCNT) It ha...

Magnesium Oxide Nanoparticles/Nanopowder and Applications

General Information about Magnesium Oxide Magnesium oxide which has the chemical formula of MgO, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of Magnesium. It is a white powder at room temperature. Magnesium Oxide has very high melting point (2825 o C) and boiling point (3600 o C). Magnesium Oxide Nanoparticles/Nanopowder an...

Nanografi Nanotechnology

Search This Blog