Title page for ETD etd-05042012-155054

Type of Document Master's Thesis
Author Qian, Chen
Author's Email Address cqian7@vt.edu
URN etd-05042012-155054
Title Adsorption of Xyloglucan onto Cellulose and Cellulase onto Self-assembled Monolayers
Degree Master of Science
Department Chemistry
Advisory Committee
Advisor Name Title
Roman, Maren Committee Chair
Esker, Alan R. Committee Co-Chair
Marand, Hervé L. Committee Member
  • cellulase
  • self-assembled monolayers
  • xyloglucan
  • cellulose thin films
  • adsorption
Date of Defense 2012-04-19
Availability restricted
Adsorption of xyloglucan (XG) onto thin desulfated nanocrystalline cellulose (DNC) films was studied by surface plasmon resonance spectroscopy (SPR), quartz crystal microbalance with dissipation monitoring (QCM-D), and atomic force microscopy (AFM) measurements. These studies were compared to adsorption studies of XG onto thin sulfated nanocrystalline cellulose (SNC) films and regenerated cellulose (RC) films performed by others. Collectively, these studies show the accessible surface area is the key factor for the differences in surface concentrations observed for XG adsorbed onto the three cellulose surfaces. XG penetrated into the porous nanocrystalline cellulose films. In contrast, XG was confined to the surfaces of the smooth, non-porous RC films. Surprisingly surface charge and cellulose morphology played a limited role on XG adsorption.

The effect of the non-ionic surfactant Tween 80 on the adsorption of cellulase onto alkane thiol self-assembled monolayers (SAMs) on gold was also studied. Methyl (-CH3), hydroxyl

(-OH) and carboxyl (-COOH) terminated SAMs were prepared. Adsorption of cellulase onto untreated and Tween 80-treated SAMs were monitored by SPR, QCM-D and AFM. The results indicated cellulase adsorption onto SAM-CH3 and SAM-COOH were driven by strong hydrophobic and electrostatic interactions, however, hydrogen bonding between cellulase and SAM-OH was weak. Tween 80 effectively hindered the adsorption of cellulase onto hydrophobic SAM-CH3 substrates. In contrast, it had almost no effect on the adsorption of cellulase onto SAM-OH and SAM-COOH substrates because of its reversible adsorption on these substrates.

  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
[VT] Qian_C_T_2012.pdf 3.09 Mb 00:14:17 00:07:21 00:06:26 00:03:13 00:00:16
[VT] Qian_C_T_2012_Copyright.pdf 2.89 Mb 00:13:22 00:06:52 00:06:00 00:03:00 00:00:15
[VT] indicates that a file or directory is accessible from the Virginia Tech campus network only.

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.