GloQube Glow discharge system
from Quorum Technologies
The GloQube is a compact, easy to use, stand-alone glow discharge system. The primary application of the system is the hydrophilisation (wetting) of carbon-coated TEM support films and grids. Glow discharge treatment with air will make surfaces negatively charged and hydrophilic and allow the spread of aqueous solutions.
|Hydrophilic/hydrophobic and negative/positive modes|
|Fully automatic, short process times|
|Safe vapour delivery using septum-sealed vials|
|Automatic valving between chambers to prevent cross-contamination|
The GloQube has two independent vacuum chambers: a clean chamber for applications requiring hydrophobic/hydrophilic conversion, typically using air as the process gas, and a vapour chamber designed for hydrophilic/hydrophobic (negative or positive) conversions, typically using reagents such as methanol and alkylamine.
With operator safety and ease of use firmly in mind, reusable septum-sealed reagent vials are used. Loading and removing reagents is both convenient and reliable and ensures minimal user contact with the reagents. The vial is located in its holder and inserted into a shielded needle using a simple twist-and-push home motion.
Each chamber can accommodate two 25 x 75 mm glass microscopes slides. Loading could not be easier using draw-style chamber doors and specimen stages. The stages are height adjustable and fitted with removable glass slide holders. For additional convenience – and to allow easy access for chamber cleaning – the stages can be completely removed.
Automatic valving between the two chambers maintains cleanliness by preventing cross-contamination. At the end of a process run, automatic "soft" venting to atmosphere through filtered inlets ensures that delicate samples, such as TEM grids, are not disturbed.
The GloQube requires a single vacuum pump working in the 0.1 to 1 mbar range. A typical pump time to operational vacuum is 60 seconds. A 750 mm flexible stainless vacuum hose is supplied.
The intuitive touch screen allows users to easily input and store up to 100 recipes. Typical treatment protocols are available as standard. Furthermore, help files and useful maintenance data is readily available for the user. Software updates can be done via an ethernet communications port.
The GloQube can be used for the following processes:
|Surface state||Charge||Atmosphere||Typical applications|
|Negative||Air||Carbon coated TEM grids|
|Positive||Air with magnesium acetate post-treatment||Nucleic acid adhesion to carbon films|
|Positive||Alkylamine||Proteins, antibodies and nucleic acids|
|Negative||Air||Positively charged protein molecules, (e.g. ferritin, cytochrome c)|
|Plasma current||1-40 mA|
|HV power supply||30 W|
|Maximum voltage||800 V|
|Electrode polarity||DC + / DC – modi (in both chambers possible)|
|Sample stage (1 per chamber)||125 x 100 mm (4.9” x 3.94”) for two 25 x 75 mm (1” x 3”) slides|
|Sample stage operational heights||Adjustable 12.5 mm (0.5”), 22.5 mm (0.9”) or 35 mm (1.38”)|
|Process time||1-600 seconds|
|User interface||Intuitive touch screen, up to 100 user recipes can be stored|
|Vacuum control/ working range||Pirani-Messröhre, 0,1 - 1 mbar|
|Pump minimum requirements||6 m3/hr, 3600 l/m, 0.03 mbar ultimate vacuum|
|Chamber vent inlets||Reagents are contained in reusable sealed glass vials to minimise exposure to hazards|
|Chamber size||100 mm B x 100 mm H x 127 mm T (3.94” x 3.94” x 5”)|
|Instrument size/weight||350 mm B x 336 mm H x 364 mm T (13.2" x 14.3” x 13.8”) / 19.5 kg (42.9 lbs.)|
|Power requirements||120 V 60 Hz, 15 A oder 230 V 50 Hz, 10 A|
Surface modification of carbon coated TEM grids and films
Glow discharge is used to alter the properties of sample surfaces. TEM carbon support films are hydrophobic (“water-hating”) after fabrication. After treatment with glow discharge, they become hydrophilic (“water-loving”), thus allowing an even spread of aqueous solutions.
Surface Modification (hydrophilic/hydrophobic)
Depending on whether the sample surface needs to be hydrophobic or hydrophilic and positively or negatively charged, different surface treatments need to be performed:
- Hydrophilic-positive: treatment in air with magnesium acetate post-treatment to allow nucleic acid adhesion to carbon films.
- Hydrophobic-positive: treatment with alkylamine for proteins, antibodies and nucleic acids.
- Hydrophobic-negative: treatment in air for positively charged protein molecules, (e.g. ferritin and cytochrome c).
By changing the surface properties of a substrate, you can, for example, increase the bond strength of polymers to the substrate.