Liquid Surface X-ray Scattering: Langmuir Trough

The Langmuir Trough was custom built for the liquid surface scattering measurements. The main features include:

  • Multi-trough inserts: Different trough size/volumes using multiple-trough inserts.
  • Temperature control: a Lakeshore, Model 330 is used to control sample temperature, and has the capability for both heating and cooling. (Maximum temperature ~40°C)
  • Sealing: near-hermetic sealing allows for the introduction of helium into the sample environment, thereby minimizing ozone production (monitored by an oxygen sensor) and x-ray absorption.
  • Software: a widely used package from Nima Technology Inc. controls the barrier motion and Wilhelmy plate pressure sensor readout.
  • Common operational modes: isothermal compressions and constant pressure or area control.
  • Compression: a compression ratio of 10:1 may be achieved withoutsimultaneous x-ray measurement, and up to 5:1 for measurements with x-rays.

The trough is currently available for general users. When not in use for x-ray experiments, the trough may be used offline in 15ID-C hutch

 


Technical Specifications

 

Dimensions of liquid footprint without the barrier:

  • Length: 42.0 cm
  • Width: 8.9 cm
  • Usable Area (no x-rays): 35-335 cm2
  • Usable Area (x-rays): 120-335 cm2
    (actual min. area may be reduced slightly more)
  • Depth (no meniscus): 7.0 mm
  • Recommended Fill Volume: 350 mL
  • Barrier speed range: 0.01 – 0.5 mm/s
  • Control software: Nima v5.16

 


User Help

The following documents are available online for consultation:

Langmuir Trough with the larger trough insert (shown with the top lid removed). Trough is made from Teflon. X-rays go through the polyimide windows on the right.

Langmuir Trough with larger trough insert removed, replaced with a small trough insert sitting on top of a mini-magnetic stirring instrument.

Acknowledgments

The following people contributed to the design and construction of this trough: Binhua Lin, David Schultz, C. Pullins, J. Gebhardt (NSF’s ChemMatCARS), Ka Yee Lee, Maria Ratajczak, GuoHui Wu, Canay Ege, Steve Danauskas, (U of Chicago Chemistry) and Mark Schlossman (UIC Physics). The upgrade of the trough to accommodate multi-trough inserts is done by Frank Westferro and Harold Brewer.

Liquid Surface Contact

Wei Bu
(630) 252-0470
bu@cars.uchicago.edu

Langmuir Trough mounted on the liquid surface spectrometer in station 15 ID-C. X-rays go from right to left.