Aerosol Diffusion Charger
The same measurement principle as used for the epiphaniometer is applied in aerosol diffusion chargers but without the requirement for a radioactive source Ions are produced in a carrier gas by electrical discharge The ions attach to the surface of the particles, which are then collected in an electrically insulated particle filter The electric charge is converted to a direct current DC voltage signal in an electrometer amplifier Studies have shown that these devices provide a good estimate of...
The Brunauer Emmett Teller BET Method
The BET method is named for the three scientists who recognized that particulate surface area can be determined based on the volume of gas that will adsorb to the surface of a given mass of sample The BET equation relates the volume of gas adsorbed to form a monolayer, the size of the gas molecules, and the mass of the material to derive surface area per unit mass Commercial analyzers are available that perform this measurement, which may be used during development and production In a...
Types Of Nanomaterials And Applications
New applications of nanotechnology appear constantly. The Nanotechnology Consumer Products Inventory maintained by the Woodrow Wilson Institute listed over 500 consumer products containing nanomaterials as of June 2007 1 . The inventory grew from 212 to 502 products between March 2006 and June 2007, demonstrating the explosive growth of this market Those products represent an extraordinarily wide range of applications The list of products below demonstrates the range by example...