DEVELOPMENT OF AGRICULTURALLY-DERIVED BIOPOLYMER COMPOSITES FOR NON-FOOD APPLICATIONS
Location: Bioproduct Chemistry and Engineering Research
Title: Self-assembled films of cellulose nanofibrils and poly(o-ethoxyaniline)
Submitted to: Colloid and Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 8, 2008
Publication Date: September 1, 2008
Citation: Medeiros, E.S., Mattoso, L.H., Bernardes-Filho, R., Wood, D.F., Orts, W.J. 2008. Self-assembled films of cellulose nanofibrils and poly(o-ethoxyaniline). Colloid and Polymer Science. 286(11)1265-1272.
Interpretive Summary: Self-assembled nanostructures, especially those based on conducting polymers, have been used in a relatively large number of applications including sensors and biosensors, batteries, light emitting diodes, electroluminescent displays, and coatings; however, their widespread use is limited by (1) difficulties in their manufacture and (2) their relative instability. In this work, nanostructured films of poly(o-ethoxyaniline) (POEA) alternated with ag-derived cellulose nanofibers (CnF) are produced by self-assembly (SA) at different pH values, a technique that creates alternately charged materials assembled with a precise control of film architecture. These new materials, and the new knowledge from these studies, gives us a better understanding of the interactions between these two types of materials, i.e., poly(o-ethoxyaniline) and cellulose nanofibers. Optimizing the combination of these in self-assembled nanostructures has many potential applications specifically in creating stable, easy-to-produce nanostructured materials such as conducting fibers.
Nanostructured films of poly(o-ethoxyaniline) (POEA) alternated with cellulose nanofibers (CnF) were successfully produced by self-assembly (SA) at different pH values and investigated by atomic force microscopy (AFM) and UVVis Spectroscopy. The results show that it was possible to build up films by alternating POEA and CnF layers with relatively precise architectural control by controlling the number of layers and pH. Comparison of alternated layers of POEA and CnF with multi-immersions of POEA at different pHs, as measured by the ratio between slopes of the straight lines of deposited amount of polymer versus the number of self-assembled layers, results show that alternate deposition at pH 2 has a four-fold increase in the slope. Alternatively, at pH 5 there is no significant difference whether the deposition is alternated (POEA/CnF) or not (POEA).