GLOW DISCHARGE: K100X Glow Discharge System 
Hydrophilisation: Freshly
made Carbon support films tend to have a hydrophobic surface which
inhibits the spreading of suspensions of particles in negative staining
solutions. However, after Glow Discharge treatment with Air, the Carbon
Film is made Hydrophilic and Negatively charged, thus allowing easy
spreading of aqueous suspensions. With subsequent Magnesium Acetate
treatment the surface is made Hydrophilic and Positively charged.
In addition to Glow Discharge treatment
using air, other Process Gasses may be used to modify surface properties.
For example, if Alkylamine is used as a process gas, the Carbon Film
surface will become Hydrophobic and positively charged. On the other
hand, using Methanol as a Process Gas results in the surface becoming
Hydrophobic and Negatively charged.
Such treatments can facilitate the
optional absorption of selected Biomolecules.
Glow Disharge
Summary
| Atmosphere |
|
Surface |
|
Charge |
| Air |
|
Hydrophilic |
|
Negative |
| Air |
|
Hydrophilic |
|
Positive (With subsequent
Magnesium Acetate Treatment) |
| Alkylamine |
|
Hydrophobic |
|
Positive |
| Methanol |
|
Hydrophobic |
|
Negative |
Surface Cleaning
In many instances, surfaces need to be
completely cleared of contamination films or deposits. This applies
particularly to EM components where such deposits impair the maintenance
of a clean vacuum system.
A Glow Discharge treatment can be used to
clean such components of undesirable residues.
D.C. Glow
Discharge
In the DC+ Mode, the Glow Discharge
system can draw up 1.5Kv. This allows high efficiency ion etching of the
specimen surface to remove, for example, oxide or resist layers.
Glow Discharge
The Polarity of the Head can be switched
from Positive to Negative with respect to Earth, for Carbon Film Surface
Treatment or Surface Etching of Metallic Specimens.
Specifications
of the K100X Glow Discharge Unit:
Plasma Voltage - 0 -
1000V Variable DC @ 100mA.
Electrode Polarity - +DC or -DC with Stainless Steel
Electrode 60mm Dia.
Chamber (Glass) - 165mm Dia x 125mm H.
Safety Shield - Polycarbonate.
H.T. Vacuum Interlock.
Needle Valve Bleed Control.
Instrument Case: - 450mm W x 350mm D x 175mm H.
Weight: - 18.0Kg.
Services.
Electrical Supply. - 230V 50 Hz 6 Amp Max Supply. 115V
60 Hz12 Amp max. Supply.
Vacuum Pump - No. 5 Pump or similar (Approx. 6m3/Hour)
pumping speed. Oil Mist Filter, Vacuum Hose, (Included with Instrument.)
