Title page for ETD etd-09172013-215119


Type of Document Master's Thesis
Author Ni, Ying
URN etd-09172013-215119
Title Arabinoglucuronoxylan and Arabinoxylan Adsorption onto Regenerated Cellulose Films
Degree Master of Science
Department Chemistry
Advisory Committee
Advisor Name Title
Alan R. Esker Committee Chair
Louis A. Madsen Committee Member
Maren Roman Committee Member
Keywords
  • Arabinoglucuronoxylan
  • Regenerated cellulose thin films
  • Arabinoxylan
  • Adsorption
  • SPR
  • QCM-D
Date of Defense 2013-09-03
Availability unrestricted
Abstract
Cellulose and hemicelluloses have attracted increasing interest as renewable biopolymers because of their abundance. Furthermore, the recognition of biomass as a sustainable and renewable source of biofuels has driven research into the assembly and disassembly of polymers within plant cell walls. Cellulose thin films are useful in the study of interactions between cellulose and hemicelluloses, and quartz crystal microbalances with dissipation monitoring (QCM-D), surface plasmon resonance (SPR) and atomic force microscopy (AFM) are widely used to investigate polymer adsorption/desorption at liquid/solid interfaces.

In this study, smooth trimethylsilyl cellulose (TMSC) films were spincoated onto gold QCM-D sensors and hydrolyzed into ultrathin cellulose films upon exposure to aqueous HCl vapor. The adsorption of arabinoglucuronoxylan (AGX) and arabinoxylan (AX) onto these cellulose surfaces was studied. The effects of structure, molar mass and ionic strength of the solution were considered. Increasing ionic strength increased AGX and AX adsorption onto cellulose. While AGX showed greater adsorption onto cellulose than AX by QCM-D, the trend was reversed in SPR experiments. The combination of QCM-D and SPR data showed a greater amount of water was trapped within the AX films. Both adsorbed AGX and AX films were subsequently visualized by AFM. Images from AFM showed AGX and AX adsorbed as aggregates from water, while AGX and AX adsorbed from CaCl2 yielded smaller xylan particles with more numerous globular structures on the cellulose surfaces. Images from AFM of xylan films on bare gold surfaces also showed layers of uniform aggregates that were consistent with AX and AGX aggregation in solution.

In this study, smooth trimethylsilyl cellulose (TMSC) films were spincoated onto gold QCM-D sensors and hydrolyzed into ultrathin cellulose films upon exposure to aqueous HCl vapor. The adsorption of arabinoglucuronoxylan (AGX) and arabinoxylan (AX) onto these cellulose surfaces was studied. The effects of structure, molar mass and ionic strength of the solution were considered. Increasing ionic strength increased AGX and AX adsorption onto cellulose. While AGX showed greater adsorption onto cellulose than AX by QCM-D, the trend was reversed in SPR experiments. The combination of QCM-D and SPR data showed a greater amount of water was trapped within the AX films. Both adsorbed AGX and AX films were subsequently visualized by AFM. Images from AFM showed AGX and AX adsorbed as aggregates from water, while AGX and AX adsorbed from CaCl2 yielded smaller xylan particles with more numerous globular structures on the cellulose surfaces. Images from AFM of xylan films on bare gold surfaces also showed layers of uniform aggregates that were consistent with AX and AGX aggregation in solution.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Ni_Y_T_2013.pdf 17.84 Mb 01:22:36 00:42:28 00:37:10 00:18:35 00:01:35

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.