Powders are today's raw materials for the preparation of materials and devices in various fields and are widely used in lithium-ion batteries, catalysis, electronic components, pharmaceuticals, and other applications.
The composition and microstructure of the raw material powders determine the properties of the material. The particle size distribution ratio, shape, porosity, and specific surface of the raw material powders can match the unique properties of the material.
Therefore, the regulation of the microstructure of the raw material powder is a prerequisite for obtaining excellent performance materials. The use of scanning electron microscopy allows observation of the specific surface morphology of the powder and precise analysis of the particle size to optimize the preparation process of the powder.
Application of scanning electron microscopy in MOFs materials
In the field of catalysis, the construction of metal-organic backbone materials (MOFs) to substantially improve the surface catalytic performance has become one of the hot research topics today. MOFs have the unique advantages of high metal loading, porous structure and catalytic sites, and have great potential as cluster catalysts. Using the CIQTEK Tungsten Filament Scanning Electron Microscope, it can be observed that the MOFs material shows regular cubic shape and the presence of fine particles adsorbed on the surface (Figure 1). The electron microscope possesses a resolution of up to 3 nm and excellent imaging quality, and uniform high-brightness SEM maps can be obtained in different fields of view, which can clearly observe the folds, pores, and particle loading on the surface of MOFs materials.
Figure 1 MOFs material / 15 kV/ETD
Scanning electron microscopy in silver powder materials
In the manufacture of electronic components, electronic paste, as a basic material for manufacturing electronic components, has certain rheological and thixotropic properties, and is a basic functional material integrating materials, chemical and electronic technologies, and the preparation of silver powder is the key to manufacturing silver conductive paste. Using the SEM5000 field emission scanning electron microscope independently developed by CIQTEK, relying on the high voltage tunneling technology, the space charge effect is drastically reduced, and irregular silver powder clustering with each other can be observed (Figure 2). And the SEM5000 has high resolution, so that details can still be seen even at 100,000x magnification.
Figure 2 Silver powder/5 kV/Inlens
Scanning electron microscopy in lithium iron phosphate
Lithium-ion batteries are rapidly occupying the mainstream market because of their high specific energy, long cycle life, no memory effect, and high safety. The use of electron microscopy to observe the positive and negative electrode morphology of lithium-ion batteries is important to improve the specific capacity of lithium-ion batteries. Among them, lithium iron phosphate batteries are favored due to many advantages such as excellent cycle performance, relatively low price, and guaranteed safety performance. The spherical lithium iron phosphate particles consisting of primary particle agglomerates observed by CIQTEK Field Emission Scanning Electron Microscope SEM5000 (Figure 3) have clear surface particles and imaging with three-dimensional sense.
Figure 3 Lithium iron phosphate / 15 kV/ETD
Scanning electron microscopy in graphite materials
The anode material is also one of the core components of lithium-ion batteries, and its structure and properties play a key role in the performance of the battery. Among the many carbon-based anode materials, graphite-based materials are the most widely used anode materials in commercial applications. The lamellar structure and particle size distribution of graphite anode can be clearly characterized using the SEM3200 tungsten filament scanning electron microscope of CIQTEK, which still has excellent imaging quality at low voltage (Figure 4).
Figure 4 Graphite negative electrode/5 kV/ETD
Application of scanning electron microscopy in montmorillonite dispersion
The use of scanning electron microscopy is also indispensable to observe the powder particles of pharmaceuticals. Among them, montmorillonite dispersion has an extremely strong immobilizing and inhibiting effect on viruses and germs in the digestive tract and the toxins and gases they produce, which can render them non-pathogenic. The surface of montmorillonite was observed to have a lamellar structure with fine lamellar crystalline masses attached to the surface using the CIQTEK Field Emission Scanning Electron Microscope SEM5000 (Figure 5).
Figure 5 Montmorillonite loose powder/3 kV/ETD
Application of scanning electron microscopy in magnesium stearate
Pharmaceutical magnesium stearate is an organic compound, which is a fine white non-sanding powder with a slippery sensation in contact with skin, mainly used as a lubricant for tablets, with the advantages of strong lubricating effect, light weight and good adhesion. The magnesium stearate powder was mainly in the form of flakes (Figure 6), and the flakes were interrelated with each other, as observed by the CIQTEK Field Emission Scanning Electron Microscope SEM5000. Although magnesium stearate is a non-conductive organic material, it still has high resolution imaging at low voltage mode when using SEM5000. The lubricious texture of magnesium stearate may also be related to the flake structure as shown by the surface morphology.
Figure 6 Magnesium stearate / 1 kV/ETD