Total Lab Supplies - Everything for your laboratory

Total Lab Supplies - Everything for your laboratory
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Showing posts with label vapour. Show all posts
Showing posts with label vapour. Show all posts

Monday, 19 June 2017

Solar paint offers endless energy from water vapor

Researchers have developed a solar paint that can absorb water vapour and split it to generate hydrogen - the cleanest source of energy.

The paint contains a newly developed compound that acts like silica gel, which is used in sachets to absorb moisture and keep food, medicines and electronics fresh and dry.

Sun with sunspots and limb darkening as seen in visible light with solar filter. By Geoff Elston [CC BY 4.0 (http://creativecommons.org/licenses/by/4.0)], via Wikimedia Commons
But unlike silica gel, the new material, synthetic molybdenum-sulphide, also acts as a semi-conductor and catalyses the splitting of water molecules into hydrogen and oxygen.

Lead researcher Dr Torben Daeneke, from RMIT University in Melbourne, Australia, said: "We found that mixing the compound with titanium oxide particles leads to a sunlight-absorbing paint that produces hydrogen fuel from solar energy and moist air.

"Titanium oxide is the white pigment that is already commonly used in wall paint, meaning that the simple addition of the new material can convert a brick wall into energy harvesting and fuel production real estate.

"Our new development has a big range of advantages," he said. "There's no need for clean or filtered water to feed the system. Any place that has water vapour in the air, even remote areas far from water, can produce fuel."

His colleague, Distinguished Professor Kourosh Kalantar-zadeh, said hydrogen was the cleanest source of energy and could be used in fuel cells as well as conventional combustion engines as an alternative to fossil fuels.

"This system can also be used in very dry but hot climates near oceans. The sea water is evaporated by the hot sunlight and the vapour can then be absorbed to produce fuel.

"This is an extraordinary concept - making fuel from the sun and water vapour in the air."

For more information visit:-

Friday, 9 May 2014

What is a Rotary Evaporator?

A rotary evaporator is a device used in laboratories for the efficient and gentle removal of solvents from samples by evaporation. Scientists often talk about a sample being evaporated under reduced pressure - ie in a rotary evaporator.

Rotary evaporators are also used in molecular cooking for the preparation of distillates and extracts.
 

The main components of a rotary evaporator are:
  1. A motor unit that rotates the evaporation flask or vial containing the user's sample.
  2. A vapour duct that is the axis for sample rotation, and is a vacuum-tight conduit for the vapour being drawn off of the sample.
  3. A vacuum system, to substantially reduce the pressure within the evaporator system.
  4. A heated fluid bath (generally water) to heat the sample.
  5. A condenser with either a coil passing coolant, or a "cold finger" into which coolant mixtures such as dry ice and acetone are placed.
  6. A condensate-collecting flask at the bottom of the condenser, to catch the distilling solvent after it re-condenses.
  7. A mechanical or motorised mechanism to quickly lift the evaporation flask from the heating bath.
The vacuum system used with rotary evaporators can be as simple as a water aspirator with a trap immersed in a cold bath (for non-toxic solvents), or as complex as a regulated mechanical vacuum pump with refrigerated trap.

Glassware used in the vapour stream and condenser can be simple or complex, depending upon the goals of the evaporation, and any propensities the dissolved compounds might give to the mixture (e.g., to foam or "bump").

Commercial instruments are available that include the basic features, and various traps are manufactured to insert between the evaporation flask and the vapour duct. Modern equipment often adds features such as digital control of vacuum such as the KNF SC950 unit shown below, digital display of temperature and rotational speed, and vapour temperature sensing.

Users of rotary evaporators must take precautions to avoid contact with rotating parts, particularly entanglement of loose clothing, hair, or necklaces. Under these circumstances, the winding action of the rotating parts can draw the users into the apparatus resulting in breakage of glassware, burns, and chemical exposure. Extra caution must also be applied to operations with air reactive materials, especially when under vacuum. A leak can draw air into the apparatus and a violent reaction can occur.  Care must also be taken to avoid implosions resulting from use of glassware that contains flaws, such as star-cracks. Explosions may occur from concentrating unstable impurities during evaporation.


What would it be like... if you could just disappear from the daily lab routine? As easily and quickly as liquid escapes from the rotary evaporator? This is the fantasy in the IKA image video above.

For more information visit:-
http://en.wikipedia.org/wiki/Rotary_evaporator
https://www.prlabs.co.uk/news/article.php?Id=120
http://www.knf.co.uk/products/laboratory-pumps/product/categories/vacuum-pump-systems/
http://www.ika.com/Products-Lab-Eq/Rotary-Evaporators-Rotary-evaporator-distilling-distillation-cph-35/
http://www.heidolph-instruments.com/products/rotary-evaporators/
http://www.stuart-equipment.com/category.asp?dsl=118&mnu=23

All available through P&R Labpak Limited