Heterogeneity of Network Structures and Water Dynamics in κ-Carrageenan Gels Probed by Nanoparticle Diffusometry
Journal article, 2018
A set of functionalized nanoparticles (PEGylated dendrimers, d = 2.8-11 nm) was used to probe the structural heterogeneity in Na+/K+ induced κ-carrageenan gels. The self-diffusion behavior of these nanoparticles as observed by 1H pulsed-field gradient NMR, fluorescence recovery after photobleaching, and raster image correlation spectroscopy revealed a fast and a slow component, pointing toward microstructural heterogeneity in the gel network. The self-diffusion behavior of the faster nanoparticles could be modeled with obstruction by a coarse network (average mesh size <100 nm), while the slower-diffusing nanoparticles are trapped in a dense network (lower mesh size limit of 4.6 nm). Overhauser dynamic nuclear polarization-enhanced NMR relaxometry revealed a reduced local solvent water diffusivity near 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)-labeled nanoparticles trapped in the dense network, showing that heterogeneity in the physical network is also reflected in heterogeneous self-diffusivity of water. The observed heterogeneity in mesh sizes and in water self-diffusivity is of interest for understanding and modeling of transport through and release of solutes from heterogeneous biopolymer gels.
Author
Daan W. De Kort
Wageningen University and Research
TI-COAST
E. Schuster
SuMo Biomaterials
RISE Research Institutes of Sweden
Freek J.M. Hoeben
TI-COAST
SyMO-Chem B.V.
Ryan Barnes
University of California
Meike Emondts
University of California
Henk M. Janssen
SyMO-Chem B.V.
TI-COAST
Niklas Lorén
RISE Research Institutes of Sweden
Chalmers, Physics, Eva Olsson Group
SuMo Biomaterials
Songi Han
University of California
Henk Van As
Wageningen University and Research
TI-COAST
John P.M. Van Duynhoven
Unilever
TI-COAST
Wageningen University and Research
Langmuir
07437463 (ISSN) 15205827 (eISSN)
Vol. 34 37 11110-11120Subject Categories
Physical Chemistry
Other Chemistry Topics
Biophysics
Areas of Advance
Materials Science
DOI
10.1021/acs.langmuir.8b01052