Laboratory of Colloid and Surface Chemistry (LCSC)
Important experimental facilities are used and maintained for research and teaching.
Multi-Angle Static and Dynamic Light Scattering Goniometer
This unique multi-angle instrument uses a 2W solid-state laser and a precision goniometer. The 8 independent fiber-optic detectors are fed into independent correlator channels. The instrument also features a fast pseudo-cross correlation for measurements of very fast decay processes. The instrument is mainly used for non-invasive measurements of absolute rate constants.
Compact Static and Dynamic Light Scattering Goniometer
All-purpose light scattering compact goniometer with 20 mW He-Ne laser and an avalanche photo-diode detector. The instrument is used for sample characterization and time-resolved measurements of colloidal stability.
This light scattering instrument involves a back-scattering geometry, and allows very simple sample handling. Concentrated samples can be investigated as well.
This ellipsometer is specially used to measure layer thicknesses, optical constants of substrates, and mass coverages of surfaces.
We have several reflectometers, developed in-house, in our laboratoty. They are mainly used for kinetic measurements.
Adsorption measurements are equally carried out with a microbalance with dissipation monitoring.
Atomic Force Microscopy
The modular closed-loop system under active feedback can be installed on an inverted microscope, and thus permits the observation of the sample during measurement. This instrument is mainly used in conjunction with colloidal probes for direct force measurements and analysis of the molecular pulling events.
Multimode Atomic Force Microscope
Standard multimode instrument with Nanoscope IIIa controller. The main application is imaging of surface structures, particles, and polyelectrolytes. With the NanoLeverAnalyzer we calibate cantilevers, and measure force-distance curves.
A fixed-stage metallurgical microscope combined with a micromanipulator is mainly used for mounting of the colloidal probe. The entire system is installed in a clean room.
High-resolution closed-loop system for imaging and force measurements.
Analytical Techniques
Standard combustion analyzer for nitrogen and carbon used for concentration determinations of polyelectrolytes and latex particle suspensions. The routine detection limit is about 0.05 mg/L.
Precision Automatic Potentiometric Titrator
Several home-built, fully automated titrators are avaible with up to 6 automatic burettes and 4 electrodes. Main applications are potentiometric titrations at constant ionic strength. Conductometric titrations can be carried out as well.
Special purpose instrument involves spectrophotometric detection and is used for determination of polyelectrolyte concentrations. The detection limit is about 2 mg/L.
Other Accessible Instruments
Several instruments are being used in collaboration with other groups. These involve electrophoretic light scattering, ICP-MS, small angle light scaterring, membrane osmometer, and PC cluster. We further use small angle neuton scattering at SINQ.
Last updated September 4, 2010 .
