Self-organized films from cellulose I Nanofibrils using the layer-by-layer technique

Biomacromolecules. 2010 Apr 12;11(4):872-82. doi: 10.1021/bm100075e.

Abstract

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 PEI/anionic MFC multilayers required more energy to be separated than surfaces covered by cationic/anionic MFC multilayers.

MeSH terms

  • Cellulose / chemistry*
  • Crystallization
  • Microscopy, Atomic Force
  • Nanoparticles / chemistry*
  • Photoelectron Spectroscopy
  • Polyethyleneimine / chemistry*
  • Quartz / chemistry*
  • Surface Properties
  • Water / chemistry

Substances

  • Water
  • Quartz
  • Polyethyleneimine
  • Cellulose