Buildup of Polyelectrolyte Multilayers of Polyethyleneimine and Microfibrillated Cellulose Studied by in situ Dual Polarization Interferometry and Quartz Crystal Microbalance with Dissipation
2008 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 24, no 6, 2509-2518 p.Article in journal (Refereed) Published
Polyethyleneimine (PEI) and Microfibrillated cellulose (MFC) have been used to buildup polyelectrolyte multilayers (PEM) on silicone oxide and silicone oxynitride surfaces at different pH values and with different electrolyte and polyelectrolyte/colloid concns. of the components. Consecutive adsorption on these surfaces was studied by in situ dual-polarization interferometry (DPI) and quartz crystal microbalance measurements. The adsorption data obtained from both the techniques showed a steady buildup of multilayers. High pH and electrolyte concn. of the PEI soln. was found to be beneficial for achieving a high adsorbed amt. of PEI, and hence of MFC, during the buildup of the multilayer. On the other hand, an increase in the electrolyte concn. of the MFC dispersion was found to inhibit the adsorption of MFC onto PEI. The adsorbed amt. of MFC was independent of the bulk MFC concn. in the investigated concn. range (15-250 mg/L). At. force microscopy measurements were used to image a MFC-treated silicone oxynitride chip from DPI measurements. The surface was found to be almost fully covered by randomly oriented microfibrils after the adsorption of only one bilayer of PEI/MFC. The surface roughness expressed as the rms-roughness over 1 μm2 was calcd. to be 4.6 nm (1 bilayer). The adsorbed amt. of PEI and MFC and the amt. of water entrapped by the individual layers in the multilayer structures were estd. by combining results from the two anal. techniques using the de Feijter formula. These results indicate a total water content of ca. 41% in the PEM.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2008. Vol. 24, no 6, 2509-2518 p.
PAPER STRENGTH PROPERTIES; ADSORPTION PROPERTIES; SILICA SURFACES; WOOD FIBERS; THIN-FILMS; PROTEIN; ELLIPSOMETRY; KINETICS; GROWTH
IdentifiersURN: urn:nbn:se:kth:diva-70183DOI: 10.1021/la7032884ISI: 000253941000036ScopusID: 2-s2.0-42149121363OAI: oai:DiVA.org:kth-70183DiVA: diva2:486016
QC 201202072012-02-072012-01-302012-03-13Bibliographically approved