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Self-Organized Film...
Abstract
Ämnesord
Stäng
- The possibility of forming self-organized films using only charge-stabilized dispersions of cellulose I nanofibrils with opposite charges is presented, that is, the multilayers were composed solely of anionically and cationically modified microfibrillated cellulose (MFC) with a low degree of substitution. The build-up behavior and the properties of the layer-by-layer (LbL)-constructed films were studied using a quartz crystal microbalance with dissipation (QCM-D) and stagnation point adsorption reflectometry (SPAR). The adsorption behavior of cationic/anionic MFC was compared with that of polyethyleneimine (PEI)/anionic MFC. The water contents of five bilayers of cationic/anionic MFC and PEI/anionic MFC were approximately 70 and 50%, respectively. The MFC surface coverage was studied by atomic force microscopy (AFM) measurements, which clearly showed a more dense fibrillar structure in the five bilayer PEI/anionic MFC than in the five bilayer cationic/anionic MFC. The forces between the cellulose-based multilayers were examined using the AFM colloidal probe technique. The forces on approach were characterized by a combination of electrostatic and steric repulsion. The wet adhesive forces were very long-range and were characterized by multiple adhesive events. Surfaces covered by PEU/anionic MFC multilayers required more energy to be separated than surfaces covered by cationic/anionic MFC multilayers.
Ämnesord
- NATURVETENSKAP -- Kemi -- Polymerkemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Polymer Chemistry (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Nanoteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Nano-technology (hsv//eng)
Nyckelord
- quartz-crystal microbalance
- dual-polarization interferometry
- polyelectrolyte multilayer films
- atomic-force microscope
- microfibrillated cellulose
- silica surfaces
- paper strength
- cationic
- polyelectrolytes
- viscoelastic properties
- adhesive properties
- Polymer chemistry
- Polymerkemi
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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