Magnetic Rotational Spectroscopy with Nanorods to Probe Time-Dependent Rheology of Microdroplets (Postprint)
Abstract
Characterization of polymers during polymerization is a challenge. Especially difficult is to study kinetics of gel formation inside tiny droplets. In many cases, viscosity of these fluids increases exponentially fast. In this paper, the rheological properties of fluids were evaluated by examining the behavior of magnetic nanorods in rotating magnetic field. We proposed a theory describing the rotation of a magnetic nanorod in a fluid when its viscosity increases with time exponentially fast. To confirm the theory, we studied the rheology of poly(2-hydroxyethyl-methacrylate) (HEMA)-based hydrogel undergoing photopolymerization and cross-linking with diethylene dlycol dimethacylate (DEGDMA). We showed that magnetic rotational spectroscopy provides rich physico-chemical information about the gelation process. . . . . Remarkably, one can analyze not only the liquid state of the polymer, but the gel as well. Since the probing nanorods are measured in nanometers, this method can be used for the in vivo mapping of the rheological properties of biofluids and polymers on a microscopic level at short time intervals when other methods fail short.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 10, 2012
- Accession Number
- ADA599847
Entities
People
- Alexander Tokarev
- Igor Luzinov
- Jeffery R. Owens
- Konstantin G Kornev
Organizations
- Air Force Research Laboratory