Adsorption of Xyloglucan onto Cellulose and Cellulase onto Self-assembled Monolayers

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.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Chemistry

Department dc:contributor.department

Chemistry

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2012

Author dc:creator

• Qian, Chen

Chairs dc:contributor.committeechair

• Roman, Maren
• Esker, Alan R.

Committee member dc:contributor.committeemember

• Marand, Hervé L.

• cellulase
• self-assembled monolayers
• xyloglucan
• cellulose thin films
• adsorption

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-05042012-155054

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/42496