title: Towards a super-strainable paper using the Layer-by-Layer technique.
abstract: The Layer-by-Layer technique was used to build a polyelectrolyte multilayer on the surface of pulp fibres. The treated fibres were then used to prepare paper sheets and the mechanical properties of these sheets were evaluated as a function of the number of bi-layers on the fibres. Two different systems were studied: polyethyleneimine (PEI)/nanofibrillated cellulose (NFC), and polyallylamine hydrochloride (PAH)/hyaluronic acid (HA). Model experiments using dual polarization interferometry and SiO₂ surfaces showed that the two systems gave different thicknesses for a given number of layers. The outer layer was found to be a key parameter in the PEI/NFC system, whereas it was less important in the PAH/HA system. The mechanical properties of the sheets made from the PAH/HA treated fibres were significantly greater than those made from untreated fibres, reaching 70 Nm/g in tensile index and 6.5% in strain at break. Such a modification could be very useful for 3D forming of paper, opening new perspectives in for example the packaging industry, with a renewable and biodegradable product as a potential substitute for some of the traditional oil-based plastics.
authors.affiliation: Division of Fibre Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. Electronic address: marais@kth.se.
authors.forename: Andrew
authors.initials: A
authors.lastname: Marais
authors.forename: Simon
authors.initials: S
authors.lastname: Utsel
authors.forename: Emil
authors.initials: E
authors.lastname: Gustafsson
authors.forename: Lars
authors.initials: L
authors.lastname: Wågberg
keywords: Hyaluronic acid; Layer-by-Layer; Polyelectrolyte multilayer; Strain at break; Tensile index