Standard Calibration Particles for Diffusing Wave Spectroscopy

 
 

When measuring DWS in transmission mode, the transport mean free path l* of the sample must be known. The DWS RheoLab allows automatic determination of the transport mean free path l* of a given sample by measuring a calibration standard. We recommend latex (polystyrene) particles.

LS Instruments offers perfectly monodisperse spherical Latex particles well suited for DWS calibration.

 

Latex tracer particles suited for DWS microrheology.

 
 

Latex (polystyrene) particles

Batch 1:

mean diameter:           222 nm  (hydrodynamic size, measured by DLS)

size polydispersity:      < 4% (standard deviation / mean)

zeta potential:             -66 mV (Smoluchowski approximation)

solvent:                       distilled water with 1 mM sodium azide to prevent bacterial growth

 

Batch 2:

mean diameter:           212 nm  (hydrodynamic size, measured by DLS)

size polydispersity:      < 4% (standard deviation / mean)

zeta potential:             -66 mV (Smoluchowski approximation)

solvent:                       distilled water with 1 mM sodium azide to prevent bacterial growth

 

Both batches have been extensively dialysed against distilled water to remove surfactant from the synthesis.

Transmission Electron Microscope image of latex particles. The image shows that the sample is monodisperse.

Left: Electron microscope image of the latex particles of batch 1. Right: Measured (circles) and extrapolated (line) dependency of the transport mean free path l* on the particle concentration for aqueous suspensions of particles of batch 1.

 

 

Pricing (for batch 1 or batch 2):

10ml with approx. 2% particle concentration (weight fraction):            180 CHF

 

Excluding shipping costs and any taxes that may apply.

Concerning shipping costs, please contact