Silver colloids with increment of heat transfer applicationSilver colloids with increment of heat transfer application
Metals are good conductors and heat moves readily through them. Thermal conduction appears to be related to electrical conduction in that good conductors of electricity are also good conductors of heat. Heat transfer is the exchange of thermal energy between physical systems. The rate of heat transfer is dependent on the temperatures of the systems and the properties of the intervening medium through which the heat is transferred. Heat transfer will occur in a direction that increases the entropy of the collection of systems. Silver is a soft، white، lustrous transition metal. It possesses the highest electrical conductivity، thermal conductivity and reflectivity of any metal. Silver nanoparticles are among the most commercialized nanoparticles worldwide. Silver surface coating results in increasing heat conduction coefficient of substrate. Silver nanoparticles have larger surface area in comparison to bulk. It results in higher coating heat transfer rate.
Surface coatings which are used for increasing the surface heat transfer, increase heating appliances efficiency. They also transfer the heat faster in heat exchangers than others without coating.
This product is known as a colloidal solution which contains silver nanoparticles and other impurities particles. Spherical particles of silver have the average particle size of 25 nm. It is claimed that the heat transfer performance takes place faster in hot surfaces by spraying this product on them.
By reducing particle size to nano-scale, the surface area to volume ratio of silver particles increases, causing increase in the rate of surface heat transfer.
This colloid should be stored in a cool, dark place as an additional step toward preserving shelf-life and overall quality. Amber colored storage bottles are recommended if storing your silver solution in bright daylight as they protect the silver content from exposure to UV rays which will hurt the stability of the ionic/colloidal silver solution. Do not freeze a colloidal silver solution as this will force the metallic silver content to agglomerate into large complexes of silver, greatly degrading the silver content and integrity.
Silver nanoparticles are environmentally- friendly. The most common negative side effect of colloidal silver on human’s body is a condition called argyria. It causes the skin and eyes to permanently become gray but it does not otherwise affect one's health. It is claimed that silver does not interact with other drugs or herbs. It should be noted that there are limited investigations on safety of nanoproducts because of their new history.
Standard Date : 2016/02/03
Expire Date : 2017/02/01