Mineral Synthesis Laboratory

Our section employs a wide range of nature-inspired or nature-mimicking mineral synthesis, as well as entirely artificial synthetic approaches, to produce various minerals and study their formation and/or transformation. To enable this research, our labs are equipped to perform inorganic and organic material synthesis and characterization using a wide-range spectroscopic and scattering techniques. More detailed information about our labs and analytical capabilities can be found in the individual descriptions below.

Thermolyne bench-top muffle oven
Hettich centrifuge (Universal 320)
Nabertherm L24/11 muffle furnace
Binder ovens
Retsch MM 400 mixer mill
Elmasonic S 40
Precision and analytical balances
Hydrothermal cells heated either conductively (right) or by microwave irradiation (left)
Reflux setup / hotplate stirrers

Location: C358 and C360

This lab is dedicated to mineral synthesis and other experiments using mostly inorganic chemistry or hydrothermal synthesis methods. The lab is equipped with standard chemical laboratory equipment such as analytical balance, centrifuge, fume hood, furnaces, hotplate stirrers, ovens, pH meters and reflux setups, as well as mixer mill and sonicator bath. Hydrothermal synthesis is possible in closed Teflon lined cells heated either conductively or by microwave irradiation.

Microlab 600 series diluter
Stuart block heater
Eppendorf centrifuge (5910 R)
IKA shaker KS 4000 i control
Setup for liquid degassing to remove O2
Binder oven
Precision and analytical balances

Location: C164

This lab is dedicated for the synthesis of redox-active iron mineral phases, as well as their interaction with redox-sensitive trace elements (e.g., As, Cr,) and anaerobic microbes, under oxygen-limited conditions. It is equipped with two anaerobic chamber workstations, setup for liquid degassing to remove O2, sample autodiluter for trace element analysis and standard chemical laboratory equipment such as analytical balance, autotitrator, centrifuge, fume hood, hotplate stirrer, shaking incubator, oven, dry block heater and pH meters.

 

Main equipment:

COY Vinyl Anaerobic Chamber

Contact: Dr. Jeffrey Paulo Perez

The anaerobic chamber (97% N2 / 3% H2, Coy Lab Products) is a heavy duty, flexible vinyl chamber that allows us to synthesize Fe(II)-bearing iron mineral phases (e.g., nZVI, green rust, magnetite, iron sulfides) that oxidize in air. The chamber has a strict anoxic atmosphere (< 5 ppm O2), which is maintained by the catalytic reduction of O2 using H2 (~3%) by the reusable palladium-coated alumina Stak-Pak in front of recirculating fans. The humidity in the chamber is also kept low by extra alumina desiccant Stak-Pak. The H2 levels inside the chamber is kept at ~3% at all times using an automatic gas mix infuser that is connected to an H2/O2 gas monitor (CAM-12).

Our anaerobic chamber has two workstations separated by a vacuum airlock which allows rapid sample transfer without changes in chamber atmosphere. One of the workstations is used for mineral synthesis and is equipped with multi-position stirrers and an autotitrator. The other workstation is mainly used for mineral processing and anoxic sample preparation for solid-state characterization. Since there are two separate workstations, it is also possible to operate them under different gas atmospheres (i.e., one with 97% N2 / 3% H2 and the other with 87% N2 / 10% CO2 / 3% H2).


Small-scale chemostat reactor

Contact: Dr. Jeffrey Paulo Perez

Our small-scale chemostat reactor (miniBio, Applikon) allows us to investigate mineral formation and transformation reactions under in situ and real time conditions.

Contact: Dr. Roberts Blukis

Location: C359

This lab is dedicated to mineral and mineral precursor synthesis using organic chemistry or advanced inorganic chemistry methods requiring special conditions, such as anoxic and/or anhydrous atmosphere or the use of hazardous chemicals. For this purpose it contains all the equipment necessary to perform almost any chemical process reasonably expected in synthetic chemistry. The lab is also used to produce starting materials to be used in other projects if obtaining them commercially is impractical or not possible. The lab contains the following significant equipment: Ar/Vacuum manifold (Schlenk line) and Büchi R-100 Rotary evaporator.

This lab is used to perform analysis on both synthetic and natural samples. The lab is equipped with a very diverse suite of spectroscopic and scattering instruments to determine material chemical composition, structure, surface area and grain size.

 

Main equipment:

Powder X-ray diffractometer STOE StadiP

Contact: Dr. Roberts Blukis

Location: B360

Our powder X-ray diffractometer (XRD) consists of two individual instruments capable of X-ray scattering analysis using both Cu (λ=1.54 Å) and Ag radiation (λ=0.56 Å) in transmission geometry. XRD can be used to analyze both crystalline and amorphous samples by measuring either conventional diffraction patterns or high Q-range total scattering patterns for pair distribution function (PDF) analysis. Measurements can be performed in room or elevated temperature up to 800 ⁰C.

Cu radiation is more suitable for general structure analysis of crystalline samples. Samples may be analysed in either Debye-Scherrer (capillary) or flat plate geometries. Multi-sample changers are available for both geometries. The Cu-XRD is fitted with a curved Ge (111) monochromator in the incident beam and the scattered X-rays are detected with a DECTRIS MYTHEN2 R 1k photon counting detector.

Ag radiation is more suitable for PDF measurements or materials that are fluorescent in the Cu X-Ray radiation such as Fe-rich materials. Samples may be analyzed in either Debye-Scherrer (capillary) or flat plate geometries. A high temperature furnace is available for samples in Debye-Scherrer geometry. The Ag-XRD is fitted with a curved Ge (111) monochromator in the incident beam and the scattered X-rays are detected with two DECTRIS MYTHEN2 R 1k photon counting detectors.


FTIR spectrometer ThermoFisher Nicolet iS5

Contact: Dr. Roberts Blukis

Location: C356

The IR spectrometer is used for fast routine IR spectra acquisition in the 4000-400 cm-1 range with a maximum resolution of 0.9 cm-1, although in practice higher resolution than 4 cm-1 is seldom necessary. IR spectra can be measured on both liquid and solid samples. The measurements are usually performed using the diamond attenuated total reflectance (ATR) accessory that allows to obtain a spectra in a few minutes with no sample preparation of very small (<1 mg) sample quantities. Measurements of KBr pellets or similar samples in transmission geometry are also possible. List of accessories available:

  • iD7 diamond ATR (most commonly used)
  • iD1 transmission
  • iD1 in-situ probe with Si ATR tip
  • iD Foundation multi-bounce ATR with either ZnSe or Ge prism

UV-Visible spectrophotometer ThermoFisher Evolution 220

Contact: Dr. Jeffrey Paulo Perez

Location: C356

The UV-Visible (UV/VIS) spectrophotometer measures absorption of light in 190-1100 nm range. Measurements are possible in either ex-situ mode in cuvettes or in-situ using an external probe. The instrument is mostly used for the determination of elemental concentrations (e.g., Fe2+, As, Si, P) using well-established colorimetric methods. In addition, the spectrophotometer can also be used for the in situ and real-time monitoring of the nucleation, crystallization and growth of minerals, and is equipped with Single Cell Peltier System for temperature control and sample stirring.


Particlemetrix STABINO particle charge mapping

Particlemetrix STABINO particle charge mapping

Contact: Dr. Thais Couasnon

Location: C356

This device is used for ζ-potential measurements of colloidal solutions.


Micromeritics Gemini VII gas sorption analyzer

Contact: Dr. Jeffrey Paulo Perez

Location: C358

The gas sorption analyzer is used to determine surface area and pore volume of solid materials. Measurements are usually done using nitrogen gas at the boiling point of nitrogen (77 K). The surface area of the material is determined by measuring the amount of gas sorbed onto the surfaces (cm3 N2 STP per g solid) at increasing pressures (adsorption) or decreasing pressures (desorption). The obtained N2 sorption isotherm at varying pressures can be used to distinguish between varying surfaces, outer surfaces, macro-, meso- and microporous surfaces. The BET (Brunauer, Emmett and Teller) theory is commonly used to determine the specific surface area of most solid materials. For porous materials with very narrow micropores (<2 nm), other adsorbent gases need to be used such as argon at 87 K for zeolites and MOFs, and carbon dioxide at 273 K for carbonaceous materials (i.e., activated carbon, nano- and mesoporous carbons).

 

Related publication:

Hövelmann, J., Stawski, T., Besselink, R., Freeman, H., Dietmann, K. M., Mayanna, S., Pauw, B. R., Benning, L. G. (2019). A template-free and low temperature method for the synthesis of mesoporous magnesium phosphate with uniform pore structure and high surface area. Nanoscale, 11, 14, 6939-6951. DOI: 10.1039/C8NR09205B


Optical Microscopes

Location: C356

For general sample examination, optical microscopes (potentially with immersion oil) are also available in the Mineral Characterisation Lab. Microscopes available:

  • ZEISS Stemi 305
  • Zeiss Axio Scope.A1
  • Leica DM2000

Contact

Roberts Blukis
Scientist
Dr. Roberts Blukis
Interface Geochemistry
Telegrafenberg
Building A 71, Room 224
14473 Potsdam
+49 331 288-27532
Profile
Jeffrey Paulo Perez
Scientist
Dr. Jeffrey Paulo Perez
Interface Geochemistry
Telegrafenberg
Building A 71, Room 216
14473 Potsdam
+49 331 288-27536
Profile
Thais Couasnon
Scientist
Dr. Thais Couasnon
Interface Geochemistry
Telegrafenberg
Building A 71, Room 224
14473 Potsdam
Profile