K850 critical point dryer

K850Critical point dryer

Critical point drying (sometimes referred to as supercritical drying, abbreviated asCPD）It's entering the scanning electron microscope（SEM）A traditional method of dehydrating and drying aquatic biological tissues prior to observation. The basic principle is that in a closed container, as the temperature increases, the evaporation rate accelerates, the gas phase density increases, and the liquid phase density decreases; When the temperature increases to a specific value, the density of the gas and liquid phases becomes equal, the interface disappears, and the surface tension becomes zero. The temperature and pressure at this point are called the critical point. The condition of zero surface stress can be used for drying biological samples to avoid damage, distortion, and false structural information caused by surface stress on the samples.

We often need to dehydrate biological samples, however, the critical point of water is+374℃ and3212 psiIt is very inconvenient to reach this critical point and it is easy to damage the sample. The most common and effective critical point drying medium isCO2Its critical point is at+31℃ and1072 psiBecauseCO2Not easily miscible with water, usually the sample needs to be dehydrated by ethanol gradient first, and then mixed with these two substances (ethanolCO2）Ethanol in the sample can be replaced by a miscible "medium" such as ethyl acetate or acetone. This is how to dry the medium (liquid)CO2）When converting from liquid to gas, the sample can be dried at the critical point without surface stress. The pre displacement treatment and final critical point drying process are as follows:

Wet water sample → gradient dehydration → ethanol wet sample → replacement with acetone wet sample → replacement with liquid stateCO2Wet sample → critical point drying → dry sample

K850The carbon dioxide critical point dryer uses thermoelectric heating and adiabatic cooling methods to ensure accurate determination of the critical point and avoid pressure or temperature exceeding. The chamber is vertical in shape and is loaded with samples at the top, ensuring that the samples are not covered during the drying process; There is a side observation window that allows for intuitive observation of the carbon dioxide liquid level line.

Instrument features:

•Vertical chamber with top filling and bottom releasing

•Adiabatic cooling and thermoelectric heating

•Using a fine needle valve with a scale to reduce pressure and release air

•Equipped with a side observation window

•Stirring system for increasing dissolution exchange

•Real time digital display of temperature; Thermal separation protection with over temperature self stop function

•Equipped with pressure safety protection and pressure reducing valve

Standard sample basket available12A separate sample hole (diameter)8 mm xheight8 mm）Double layered drawer design for easy entry and exitK850Replace and transfer the chamber. For larger samples, it is recommended to use a single large sample basket. If critical point drying is required for very small or fine samples, a porous leakage crucible can be used.

oursCPDThe product line also includes those with horizontal chambersE3100Critical point dryer; greaterK850WMThe critical point dryer is designed for semiconductor applications and can perform critical point drying6Inch wafers. In addition, we also offer two freeze-drying machines: one using Peltier semiconductor refrigeration and the other using mechanical pumping for vacuum extractionK750X, as well as the use of liquid nitrogen refrigeration and turbo molecular pump vacuum extractionK775XThese dryer products are exclusively designed for scientific research purposes.