Wyatt Technology Corporation, the world leader in absolute macromolecular characterization instrumentation and software, has been chosen by the University of Navarra for its instruments to characterize phase transitions and structures in micellar polymeric systems. Wyatt Technology's dynamic light scattering instrument, the DynaPro, facilitated the detection of aggregation in early stages of micellization of pluronic polymeric surfactant due to temperature effects, pH, salinity concentration and composition.

The DynaPro from Wyatt Technology offers scientists the ability to measure small volumes of dilute protein samples. These novel dynamic light scattering (DLS) instruments have been indispensable tools for scientists examining protein structure. One of the key strengths of DLS technology is its capability of detecting aggregation early due to temperature effects, pH, salinity concentration or composition. The unique temperature control capability of the DynaPro allows for accelerated stability, thermal melting and temperature studies of multiple samples to be performed in parallel and with improved response time. The DynaPro achieves simultaneous and rapid evaluation of the total scattering intensity and the hydrodynamic radii spectrum in micellar polymeric systems with temperature in a non-invasive fashion.

For the application at the University of Navarra, the system was used for the micellization of a Pluronic® polymeric surfactant with temperature. These amphiphiles are low molecular weight linear triblock copolymers of polyethylene oxide (PEO) and polypropylene oxide (PPO), with structures PEO-PPO-PEO, in which the hydrophilic character is controlled according to the PEO block length. Pluronic F108 was chosen which was a central block of 52 PO monomers and PEO wings of 131 EO.

The results demonstrate that, at a low temperature, the polymeric surfactant exists in monomer form. The onset of micellization can be easily perceived both in the intensity and in the hydrodynamic radius obtained by the cumulants method of Wyatt Technology's DYNAMICS software. The regularization analysis of DYNAMICS provides the size spectrum of the sample and reveals a new peak corresponding to the micelles. A copy of the new application note, entitled "Critical Micellization Temperature (CMT) of Block Copolymers of PEO and PPO", is available to download free-of-charge via www.wyatt.com.

For more information on Wyatt Technology's DynaPro instrument and its DYNAMICS® data collection and analysis software or to obtain a copy of this application note, please visit www.wyatt.com