To study flow properties, use has been made of a new Anton-Paar
Physica MCR501 rheometer at ISIS for simultaneous small angle neutron
scattering (SANS) and rheometry measurements on the Loq instrument. The
rheometer is a controlled stress / strain instrument with a custom built
quartz Couette geometry (in which a fluid can be sheared between two
concentric cylinders). Parallel studies with an identical instrument
using cone-and-plate geometry have also been performed at Diamond I22.
It
has been found that using mixtures of Pluronic block copolymers,
commercial poly(ethylene oxide)-poly(propylene oxide) surfactants, the
phase behaviour and hence the rheological properties (such as the gel
stiffness and deformation under shear) can be manipulated, opening up
potential new applications.
Future work will focus on other soft materials including peptide fibrils.
GE Newby, IW Hamley (University of Reading), SM King (ISIS)
Contact: Prof I Hamley, i.w.hamley@reading.ac.uk
Research date: December 2008
Further Information
Newby et al., J. Coll. Int. Sci. 329 (2008) 54