We’re pleased to announce successful installation and training for a new LS Instruments DWS Rheolab at the laboratories at the Institute of Biomedical Engineering at Oxford University.
The DWS RheoLab is a compact stand-alone instrument that allows optical rheology based on Diffusing Wave Spectroscopy (DWS) in a wide range of systems such as dispersions, slurries, emulsions, gels, foams and liquid crystals. Application is possible to all homogenous transparent and opaque substances. DWS is particularly suited for white samples, because they do not require any sample preparation. In case of transparent systems you simply need to mix the sample with a small amount of tracer particles. So far DWS has been predominantly applied in academic research in few specialized laboratories. With the DWS RheoLab by LS Instruments however, you no longer need to be an expert in the field of light scattering: the user friendly software solution provides automatic microrheology measurement and analysis for a huge range of soft materials. The DWS RheoLab measures the Mean Square Displacement as well as G’(ω) and G’’(ω) in 1 to 5 minutes with excellent reproducibility. Storage G’(ω) and loss moduli G’’(ω) can be measured from 1 Pa to 50 kPa in an unmatched frequency range from 0.1 to 106 Hz and on a wide range of viscosities extending from 0.1 mPa∙s to 1000 Pa∙s. With the pseudo cross-correlation upgrade the frequency range can be even further extended to 0.1-107 Hz. Furthermore the patented “Two-Cell Echo Technology” (EU Patent 1720000) cuts measurement times to only a few minutes even for slowly relaxing and solid-like materials.
Diffusing Wave Spectroscopy (DWS) probes the dynamics in a sample on a nanometer-scale using laser light (not to be confused with the related, but inferior DLS microrheology). It measures the temporal fluctuations of light that is multiple scattered from particles embedded in the sample undergoing Brownian motion. The statistical analysis of these fluctuations allows the extraction of the microrheological properties of the sample. For homogenous samples these are in agreement with bulk rheology. It is thus a fast, contact free technique to measure rheological properties
As part of the arrangement between IBME, Merrow Scientific and Willow Analytical we are able to use the system for sample testing.
Contact us to discuss your application in more detail