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).

Magnetic suspension balance
© Rubotherm
Magnetic suspension balance

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.

BELSORP-max
BELSORP-max

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.

Thermal desorption unit (Enrichment and Desorption Unit - EDU)
© Fraunhofer IWS Dresden
Thermal desorption unit (Enrichment and Desorption Unit - EDU)

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

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