Probe diffusion in phase-separated bicontinuous biopolymer gels
Artikel i vetenskaplig tidskrift, 2014

Probe diffusion was determined in phase separated bicontinuous gels prepared by acid-induced gelation of the whey protein isolate-gellan gum system. The topological characterization of the phase-separated gel systems is achieved by confocal microscopy and the diffusion measurements are performed using pulsed field gradient (PFG) NMR and fluorescence recovery after photo-bleaching (FRAP). These two techniques gave complementary information about the mass transport at different time- and length scales, PFG NMR provided global diffusion rates in the gel systems, while FRAP enabled the measurements of diffusion in different phases of the phase-separated gels. The results revealed that the phase-separated gel with the largest characteristic wavelength had the fastest diffusion coefficient, while the gel with smaller microstructures had a slower probe diffusion rate. By using the diffusion data obtained by FRAP and the structural data from confocal microscopy, modelling through the lattice-Boltzmann framework was carried out to simulate the global diffusion and verify the validity of the experimental measurements. With this approach it was found that discrepancies between the two experimental techniques can be rationalized in terms of probe distribution between the different phases of the system. The combination of different techniques allowed the determination of diffusion in a phase-separated biopolymer gel and gave a clearer picture of this complex system. We also illustrate the difficulties that can arise if precautions are not taken to understand the system-probe interactions.

Författare

Sophia Fransson

SuMo Biomaterials

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Romain Bordes

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

SuMo Biomaterials

Tobias Gebäck

SuMo Biomaterials

Chalmers, Matematiska vetenskaper, Matematik

Göteborgs universitet

Diana Bernin

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

SuMo Biomaterials

Göteborgs universitet

E. Schuster

Swedish Institute for Food and Biotechnology

Chalmers University of Technology

Niklas Lorén

Swedish Institute for Food and Biotechnology

Chalmers University of Technology

Anne-Marie Hermansson

SuMo Biomaterials

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Soft Matter

1744-683X (ISSN) 1744-6848 (eISSN)

Vol. 10 8276-8287

Ämneskategorier

Fysikalisk kemi

Annan kemi

DOI

10.1039/c4sm01513d