GloQube Plus Glow discharge system

from Quorum Technologies

The GloQube Plus 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.

Features

Hydrophilic/hydrophobic and negative/positive modes
Fully automatic, short process times
Touch-screen control
Safe vapour delivery using septum-sealed vials
Automatic valving between chambers to prevent cross-contamination

Further information

The GloQube Plus 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 Plus 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 1000 recipes. Typical treatment protocols are available as standard. Furthermore, help files and useful maintenance data is readily available for the user. Log file downloads and software updates are possible via USB-port. The new "Plus" generation update of the GloQube offers not only a new and user-friendly interface but also optimized recipes. The process parameters of the amylamin glow discharge, for example, have been improved. To prevent oxidation of the amylamin, which would render the process ineffective, the chamber is flushed several times with the chemical to remove excess oxygen. After the glow discharge process is finished, the chamber is flushed several times with air and then pumped down again. This is to ensure the safety of the users and prevent poisoning when opening the chamber.

The GloQube Plus can be used for the following processes:

Surface state	Charge	Atmosphere	Typical applications
Hydrophilic	Negative	Air	Carbon coated TEM grids
Hydrophilic	Positive	Air with magnesium acetate post-treatment	Nucleic acid adhesion to carbon films
Hydrophobic	Positive	Alkylamine	Proteins, antibodies and nucleic acids
Hydrophobic	Negative	Air	Positively charged protein molecules, (e.g. ferritin, cytochrome c)

Specifications

Plasma current	1-50 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	1-900 seconds
Pump Hold	0-72 hours
User interface	Intuitive touch screen, up to 1000 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

Applications

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.