Uniform TitleProbing the structure of dextran systems and their organization
NameRong, Yunhong (author), Kokini, Jozef (chair), Daun, Henryk (dissertation committee member), Tahkistov, Paul (internal member), Huang, Qingrong (dissertation committee member), Rutgers University, Graduate School - New Brunswick,
DescriptionDextran with molecular weight 9,700 (T10) was dissolved directly in water (66%) at room temperature to form a concentration of three times its overlap concentration. Wide angle x-ray scattering (WAXS) and differential scanning calorimetry were used to monitor the change in the crystallinity of concentrated dextran solutions with time. Dextran solutions (66%) were also probed with steady and dynamic rheological measurements to understand the changes in structure as the concentrated dispersion aged, Finally FTIR was used to understand the molecular origins of the crystalline changes of the concentrated dextran solution.
Concentrated dextran solutions showed a phase transition from clear solution to opaque semi-solid without water losses a result of aging time. Both WAXS and DSC measurements indicated that the sample crystallinity increased with time, and reached a plateau after 4 hours and remained relatively stable after that. FTIR spectra showed an increase of the concentration of hydrogen bonds with time. Rheological measurements indicated that both the storage and loss moduli (G' and G") increased gradually with time and showed a sudden increase at 3-4 hours. These findings provided fundamental understanding of a unique crystalline phase in the liquid state for the behavior of dextran molecules and serve as a model possibly for other carbohydrates in solution and their aggregation, which in turn helps improve the quality of carbohydrates containing concentrated semi-solid foods.
NoteIncludes bibliographical references (p. 151-156).
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.