Surface Energy Characterization (iGC)
Inverse Gas Chromatography (iGC) is a gas-solid technique for characterizing surface and bulk properties of powders, particulates, fibers, and semi solids.
What is iGC
Unlike traditional analytical techniques, iGC works by injecting vapor pulses with known properties through packed gas chromatography columns to characterize unknown surface/bulk properties of the solid sample.
- Reliability
As the world’s only purpose-built iGC device, the iGC-SEA enables reliable and repeatable measurement of Surface Energy of solids, enabling far more insight and versatility than alternative Contact Angle techniques.
What is Surface Energy?
Surface energy γ, is the principal characteristic measured by IGC. The surface energy of a solid is analogous to the surface tension of liquid and it is a measure of attractive intermolecular forces on a solid surface. It is the same intermolecular forces that are responsible for the attraction between powder particles and other solid, liquid, and vapor molecules which can occur via long-range van der Waals forces (dispersion forces) and short-range chemical forces (polar forces).
Surface energy maps predict wetting, spreading, and dispersion behaviour, enabling optimisation of coatings, inks, formulations, and powder-liquid mixing performance.
Powder Flowability By quantifying cohesive surface interactions, iGC can be used to predict flow behaviour, agglomeration, and handling performance, supporting optimisation of processing, transport, and formulation stability.
Measuring adhesive and cohesive forces predicts bonding, detachment, and powder agglomeration behaviour, enabling rational design of formulations, coatings, and particle interactions.
Surface energy reflects underlying surface chemistry, including polarity and acid–base characteristics. It enables detection of surface treatments or functionalisation, linking chemical composition to material performance and interfacial interactions.
iGC-SEA
Inverse Gas Chromatography Surface Energy Analyzer
The iGC-SEA is a purpose-built system designed for precision and repeatability. Its core innovation is the injection manifold system which generates accurate solvent pulse sizes across a large concentration range, resulting in accurate determination of surface energy heterogeneity distributions at high and low sample surface coverages.
The fully automated iGC-SEA can be operated at different solvent vapor, flow rates, temperature, humidity, and column conditions. The impact of humidity and temperature can be determined for the physicochemical properties of solids such as surface Tg, BET-specific surface area, surface energy, wettability, adhesion and, cohesion.
- Unique Experiment Control & Analysis Software
- Humidity, Partial Pressure, and Temp Control
- Accurately Measure a Wide Range of Surface & Bulk Properties
Founding Principle
An experiment consists of a series of vapor pulses injections eluting through a column packed with the sample under examination. The vapor’s retention time is measured by a Flame Ionization Detector (FID).
Varying the vapor probe molecule, flow rate, temperature, or column conditions helps to determine a wide range of surface and bulk properties of the sample. Contrary to traditional Contact Angle methods where limitations exist for non-planar materials, iGC the preferred proven method for complex solids.
- Comparing the iGC-SEA to Contact Angle and Atomic Force Microscopy
FEATURE
SAMPLE FORM
MEASUREMENT
REPRODUCIBILITY
CONDITIONS
MAPPING
iGC-SEA
Sample Form:
Powder, fibers, films, nanoparticles, semi-solids
Measurement:
Vapor adsorption isotherm
Reproducibility:
Very good (RSD%=1)
Conditions:
Controllable T and %RH
Mapping:
Heterogeneity well established
CONTACT ANGLE (CA)
Sample Form:
Flat samples (easy), Particulate (difficult)
Measurement:
Liquid-solid contact
Reproducibility:
Varies, hysteresis issues
Conditions:
Typically ambient
Mapping:
Possible but impractical
ATOMIC FORCE MICROSCOPY
Sample Form:
Flat smooth (easy), Particulate (difficult)
Measurement:
Contact/adhesive force
Reproducibility:
Significant data scatter
Conditions:
Poor humidity control
Mapping:
Impractical (data variability)
- Comparing the iGC-SEA to a Traditional Home Build iGC
FEATURE
INJECTED PHASE
THROUGHPUT
DATA ANALYSIS
FLOW CONTROL
HUMIDITY CONTROL
SAMPLE SIZE
HOME BUILT iGC
Injected Phase:
Liquid (requires tool) or Vapor
Throughput:
Single sample
Data Analysis:
Manual peak analysis
Flow Control:
Soap bubble meter
HUMIDITY CONTROL:
Rare
SAMPLE SIZE:
10mg to ≈1g
iGC-SEA
Injected Phase:
Vapor (Precise)
Throughput:
Twin sample holders
Data Analysis:
Automatic physicochemical data
Flow Control:
Mass Flow Controller
HUMIDITY CONTROL:
Standard Option
SAMPLE SIZE:
1mg to 10g
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World-class gravimetric vapor sorption analyzers and inverse gas chromatography instruments designed for precision.