The Micromeritics Gemini VII machine is used to characterize the active and support surfaces of catalysts, to determine the surface areas of adsorbents, and to determine the porosity and gas (e.g. carbon dioxide) storage capacity of various nanomaterials (zeolites, MOFs, etc.).

Materials with low surface areas such as powdered metals, glass fibers, and natural organic materials can also be analyzed.

Capabilities/Accessories

• Available gases for adsorption and surface area measurements are
  • high purity N2
  • high purity CO2
• Temperature range:
  • standard bath (liquid N2): -196 °C
  • variable temperature bath: -30 – 130 °
  • Pressure range: 10-2 – 800 Torr
  • Degas with flowing N2 at the temperature of max. 400 °C

The Micromeritics ASAP 2020 machines are used to characterize the active and support surfaces of catalysts, to determine the surface areas of adsorbents, and to determine the porosity and gas (e.g. carbon dioxide) storage capacity of various nanomaterials (zeolites, MOFs, etc.).

Materials with low surface areas such as powdered metals, glass fibers, and natural organic materials can also be analyzed.

Capabilities/Accessories

• Permanently connected gases for adsorption and surface area measurements are
  • high purity N2 (Unit 1 and Unit 2)
  • high purity CO2 (Unit 1 and Unit 2)
  • krypton (Unit 1),
  • methane (Unit 1)
  • argon (Unit 1)
• Temperature range:
  • standard bath (liquid N2): -196 °
  • variable temperature bath: -30 – 130 °C.
• Pressure range: 10-6 – 800 Torr.
• Vapor adsorption option (only for Unit 2): adsorption of water vapor, hydrocarbons etc. can be carried out at different temperatures by the aid of the cryo-compact circulator and variable temperature bath (-30 – 130 °C).
• The Rate of Adsorption Option (only for Unit 2) allows the user to measure how quickly (or slowly) a sample adsorbs each dose of gas. Time resolution: 1 s.

Example/Application areas

Related publications:

Liu, Q., Cheung, O., Garcia-Bennett, A. E., Hedin, N.: Aluminophosphates for CO2 Separation. ChemSusChem 4 (2011) 91-97.

Akhtar, F., Ojuva, A., Wirawan, S.K., Hedlund, J., Bergström, L. Hierarchically porous binder-free silicalite-1 discs: A novel support for all-zeolite membranes (2011) Journal of Materials Chemistry, 21 (24), pp. 8822-8828.

Z. Bacsik, N. Ahlsten, A. Ziadi, G. Zhao, A. E. Garcia-Bennett, B. Martin-Matute, N. Hedin
Mechanisms and kinetics for sorption of CO2 on bicontinuous mesoporous silica modified with n-propylamine, Langmuir 2011, 27, 11118-11128.

Size, zeta potential and molecular weight measurement are possible in same system. Dynamic Light Scattering (DLS) is used to measure particle size and molecule size. This technique measures the diffusion of particles moving under Brownian motion, and converts this to size and a size distribution.

Laser Doppler Micro-electrophoresis is the technique used to measure zeta potential. An electric field is applied to a solution of molecules or a dispersion of particles, which will then move with a velocity related to their zeta potential. This velocity is measured using a laser interferometric technique. Static Light Scattering is used to determine the molecular weight of proteins and polymers.

Capabilities/Accessories

• Size measurement from 0.6 nm – 6000 nm
• Sample concentrations from 0.1 ppm to 40% w/v
• Disposable capillary cell for zeta potential measurements to completely eliminate cross contamination are available

Example/Application areas

Publications:

Spray drying of TiO2 nanoparticles into redispersible granules
Faure, B; Lindelov, JS; Wahlberg, M; Adkins, N; Jackson, P; Bergstrom, L
2010 | POWDER TECHNOLOGY | 203 (384-388)

Colloidal aspects relating to direct incorporation of TiO2 nanoparticles into mesoporous spheres by an aerosol-assisted process.
Petr O Vasiliev; Bertrand Faure; Jovice Boon Sing Ng; Lennart Bergstrom
2008 | Journal of Colloid and Interface Science | 319 (144-151)

Quartz Crystal Microbalance with Dissipation monitoring QCM-D, Biolinscientific, allows measurements of very small mass changes and energy loss at the surface of an electrode. The QCM-D enables you to study molecular interactions at surfaces and interfaces in real-time.

This provides information on the viscoelastic properties of the system under study. Typical measurements are molecules adsorption, swelling, crosslinking and collapse at the sensor surface. The electrochemistry module E-QCMD enables to study changes in materials properties upon application of electrochemical potentials.

Capabilities/Accessories

• Four QCM-D chambers equipped with a microfluidic setup, enabled by a peristaltic pump.
• QSense full liquid handling set.
• Resolution is 300 datapoints per second with a limit of detection of 1.34 ng/cm2. 
• EQCM-D chamber, equipped with a platinum as counter and Ag/AgCl as reference electrode, enabling electrochemical measurements when connected to a potentiostat.

Example/Application areas

Examples and application areas can be found in the publications “Mixing Insulating Commodity Polymers with Semiconducting n‐type Polymers Enables High‐Performance Electrochemical Transistors”, written by Zeglio, E. et al., and “QCM‐D assay for quantifying the swelling, biodegradation, and protein adsorption of intelligent nanogels” written by Clegg, J. R et al.

Contact manager for user training.