Measurement technology for functional materials

Magnetic suspension balance (Rubotherm)

The magnetic suspension balance enables the samples to be weighed exactly under test gas atmosphere at high pressure and higher temperatures. The adsorption capacity, i. e. the ability of the sample to store gas molecules, can be determined directly from these measured data. This size is a decisive criterion for the assessment of novel materials for gas storage (e. g. methane and hydrogen storage for mobile applications).

The magnetic suspension balance enables the gravimetric measurement of gas and vapor adsorption on samples under high pressure and temperature. The magnetic suspension balance is used to weigh the sample material at a constant temperature but at different pressures or compositions of the gas atmosphere. The adsorption capacity, i. e. the ability of the sample to store gas molecules, can be determined directly from the measured data. This size is a decisive criterion for the assessment of novel materials for gas storage (e. g. methane and hydrogen storage for mobile applications).

temperature range: 0 °C to 150 °C
pressure range: Vacuum up to 5 bar
resolution: 10 µg
gases: H₂, CH₄, CO₂ and by arrangement
solid and liquid samples, e. g. catalysts, zeolites, activated carbon, alumina, silica, molten sieves

BELSORP-max (BEL Japan, Inc.)

The BELSORP-max device enables volumetric adsorption measurement for the analysis of the specific surface area and pore structure. Both gas and vapor adsorption are possible with this device. Up to 3 samples can be measured simultaneously in a relative pressure range of 10-8 - 0.997 p/p0.

Scope of services

volumetric gas adsorption
possible adsorptive N₂, Ar, Kr, NH₃, CO₂, H₂, CO, O₂, CH₄ and other non-corrosive gases; H₂O, MeOH, EtOH, C₆H₆ and other non-corrosive vapors
specific surface area: > 0.01 m²/g for N₂ at 77 K > 0.0005 m²/g for Kr at 77 K
pore size distribution (BJH): 0.32 - 500 n
measuring cell: 1.8 cm³ volume

Features

determination of specific surface area, pore size distribution (BJH) and pore volume
gas adsorption, vapor adsorption up to 1 bar
simultaneous measurement of 3 samples
adsorption measurement for very low pressures possible (p/p₀ = 10^-8 - 0.997)

Poremaster 33 (Quantachrome) - Mercury Porosimetry

A mercury porosimeter can be used to determine structural and texture properties such as pore size distribution, total pore volume, inner surface, bulk density and absolute density as well as particle size of different materials. The measurement method is suitable for materials with a pore diameter in the range of 0.0064 to 950 µm. The material itself can be measured as a powder, granulate or shaped body.

Thermal desorption (EDU)

The thermal desorption unit (Enrichment and Desorption Unit - EDU) allows enrichment or pre-concentration of gases and vapors below the detection limits. The analytes can then be determined above the detection limit by subsequent (thermal) desorption.

The unit can be operated either directly under ambient conditions or adapted to a gas flow. The necessary adsorbents (e. g. MOFs, zeolites, and activated carbons) are specially adapted to the respective gas components.

This instrument can also be combined with a mass spectrometer (ESS Ecosys) or gas chromatograph. This allows even more sensitive trace gases detection.

Areas of application

enrichment of (trace) gases and vapors
test of new adsorber
separation of undesired components
extraction of individual gas components

Measurement setup for the determination of breakthrough curves

Investigations under application-relevant conditions (pressure, temperature, volume flow) are very helpful for the characterization of functional materials with regard to technical sorption processes.

By the help of the measurement setup, it is possible to obtain breakthrough curves of gas/vapor mixtures as a result of the preferential adsorption of one or more gases/vapors from a carrier gas or gas mixture. This not only enables the effective adsorption performance and kinetics of adsorption to be determined, but is also suited for the adsorption of gas mixtures, co-adsorption or displacement effects and sorption selectivity.

dynamic adsorption / desorption experiments
investigation of co-adsorption and displacement
determination of sorption selectivity
determination of dynamic parameters
investigation of kinetic aspects of adsorber
investigation under process-relevant conditions
investigation of the adsorption data of single and multi-component systems

infraSORP

© Fraunhofer IWS
Rapid testing system to determine the adsorption properties of porous materials

The research area “novel porous materials” finds enormous interest worldwide. Porous materials are often characterized by cost- and time consuming physisorption and breakthrough experiments. Especially in the field of high sample numbers such as high throughput synthesis or quality control, a fast characterization method is required.

The Fraunhofer IWS has developed an optical calorimeter “InfraSORP” which utilizes the adsorption induced heat release for the characterization of porous materials. The working principle enables a simple, cost-, time- and resource saving screening of porous materials for various applications.

Scope of supply

Screening of porous materials regarding structural properties, e.g. inner surface area, pore size
Evaluation of adsorption capacity of porous materials, e.g. for gas storage or filter design
Studies on adsorption kinetics
Stability studies for multiple adsorption-desorption cycling, e.g. for evaluation of water stability of potential materials in dehumidification or adsorption driven heat pumps
Sizing of nanoparticles by surface area adsorption measurement