New insight on nanoparticle colloidal gel formation
The research team in question comprises Qingteng Zhang, Eric M Dufresne, Suresh Narayanan, and Alec Sandy of the Argonne National Laboratory outside Chicago, Illinois; Divya Bahadur and Subramanian Ramakrishnan of FAMU-FSU College of Engineering in Tallahassee, Florida; Pawel Grybos, Piotr Kmon, Piotr Maj, and Robert Szczygiel of AGH University of Science and Technology in Krakow, Poland; and Robert L. Leheny of Johns Hopkins University in Baltimore, Maryland.
The team published their work on colloidal gel formation in the peer-reviewed scientific journal Physical Review Letters last fall in an article entitled, “Dynamic Scaling of Colloidal Gel Formation at Intermediate Concentrations.”
How
The researches wanted a visual and technical understanding of why nanoparticle gels take longer to form than other colloidal gels.
To do this, they “studied [the] transformation from fluid to gel in aqueous suspensions of nanometer-scale silica particles. Taking advantage of newly developed x-ray scattering capabilities and the ability to precisely tune the strength of the particle attractions, the scientists were able to track the evolution in the microscopic organization and mobility of the particles and correlate these properties with the time-dependent macroscopic mechanical behavior of the suspensions,” as a press item about the research from the Argonne National Laboratory explains.
What
Using a XPCS-suitable area detector for measurements, that the international team developed in coordination with the AGH University of Science and Technology, the researchers were able to measure and record the progress of various gel formations.
They observed that regardless of particle size and regardless of quench temperature, gels form by going through the same series of shapes.
“The rate of formation implied…is a far stronger function of ΔT [the change in gel temperature] than expected from the attraction strength between colloids,” explains the article abstract. “We interpret this strong temperature dependence in terms of cooperative bonding required to form stable gels via energetically favored, local structures.”
The work looks to be a good next step in understanding nanoparticle colloidal gel formation. And the tool and techniques established by the researchers and the AGH University of Science and Technology are expected to make future studies faster and more informative.
The complete article is online and available by subscription here.
