As researchers discover new and widespread applications for stimulus-responsive
microgels, known as "smart polymers", the Zetasizer
Nano system from Malvern Instruments is fast emerging as their system of
choice for particle characterization. As the first commercial instrument to
include the hardware and software for combined dynamic, static, and electrophoretic
light scattering measurements, the Zetasizer Nano satisfies a unique mix of
requirements associated with this rapidly expanding field.
Agar microgels coated with a bi-layer of chitosan and fluorescein labelled alginate imaged by confocal microscopy.
Microgels are particles of cross-linked polymer networks dispersed in a medium,
such as water. These polymers, which range from 100 nm to 1 µm in diameter,
can undergo rapid, reversible and dramatic phase transitions when triggered
by slight environmental variations in temperature, pH or ionic strength. Medical
applications for smart polymers range from diagnosis to intelligent distribution
of drugs and actuators (such as artificial muscles and valves), while other
sectors are benefiting from new technologies for microelectronic sensors and
environmentally adaptive clothing.
The Zetasizer Nano series enables the study of very small, weakly scattering
particles such as polymers at low concentrations. Its novel arrangement of optics
maximises detection of scattered light while maintaining signal quality. The
wide range of sample properties available for measurement with the Zetasizer
Nano system include, particle size, molecular weight, and zeta potential.
A unique cell chamber means the Zetasizer Nano specifications for sample size
and concentration exceed those for any other commercially available dynamic
light scattering instrument. The system offers measurement in the size range
of 0.6 nm to 6 µm, and a concentration range of 0.1 mg/mL lysozyme to
40% w/v.