Adv Polym Sci (2014) 256: 1–24
DOI: 10.1007/12_2012_206
# Springer-Verlag Berlin Heidelberg 2013
Published online: 15 June 2013
Polyelectrolyte Complexes for Tailoring
of Wood Fibre Surfaces
Caroline Ankerfors and Lars Wa ˚gberg
Abstract The use of polyelectrolyte complexes (PECs) provides new opportunities
for surface engineering of solid particles in aqueous environments to functionalize
the solids either for use in interactive products or to tailor their adhesive interactions
in the dry and/or wet state. This chapter describes the use of PECs in paper-making
applications where the PECs are used for tailoring the surfaces of wood-based fibres.
Initially a detailed description of the adsorption process is given, in more general
terms, and in this respect both in situ formed and pre-formed complexes are
considered. When using in situ formed complexes, which were intentionally formed
by the addition of oppositely charged polymers, it was established that the order of
addition of the two polyelectrolytes was important, and by adding the polycation first
a more extensive fibre flocculation was found. PECs can also form in situ by the
interaction between polyelectrolytes added and polyelectrolytes already present in
the fibre suspension originating from the wood material, e.g. lignosulphonates or
hemicelluloses. In this respect the complexation can be detrimental for process
efficiency and/or product quality depending on the charge balance between the
components, and when using the PECs for fibre engineering it is not recommended
to rely on in situ PEC formation. Instead the PECs should be pre-formed before
addition to the fibres. The use of pre-formed PECs in the paper-making process is
described as three sub-processes: PEC formation, adsorption onto surfaces, and the
effect on the adhesion between surfaces. The addition of PECs, and adsorption to the
fibres, prior to formation of the paper network structure has shown to result in a
significant increase in joint strength between the fibres and to an increased strength
C. Ankerfors
Swerea KIMAB, Box 7047, 164 07 Kista, Sweden
L. Wa ˚gberg (*)
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology,
Teknikringen 56, 100 44 Stockholm, Sweden
The Wallenberg Wood Science Centre (WWSC), KTH Royal Institute of Technology,
Teknikringen 56, 100 44 Stockholm, Sweden
e-mail: wagberg@kth.se
DOI: 10.1007/12_2012_206
# Springer-Verlag Berlin Heidelberg 2013
Published online: 15 June 2013
Polyelectrolyte Complexes for Tailoring
of Wood Fibre Surfaces
Caroline Ankerfors and Lars Wa ˚gberg
Abstract The use of polyelectrolyte complexes (PECs) provides new opportunities
for surface engineering of solid particles in aqueous environments to functionalize
the solids either for use in interactive products or to tailor their adhesive interactions
in the dry and/or wet state. This chapter describes the use of PECs in paper-making
applications where the PECs are used for tailoring the surfaces of wood-based fibres.
Initially a detailed description of the adsorption process is given, in more general
terms, and in this respect both in situ formed and pre-formed complexes are
considered. When using in situ formed complexes, which were intentionally formed
by the addition of oppositely charged polymers, it was established that the order of
addition of the two polyelectrolytes was important, and by adding the polycation first
a more extensive fibre flocculation was found. PECs can also form in situ by the
interaction between polyelectrolytes added and polyelectrolytes already present in
the fibre suspension originating from the wood material, e.g. lignosulphonates or
hemicelluloses. In this respect the complexation can be detrimental for process
efficiency and/or product quality depending on the charge balance between the
components, and when using the PECs for fibre engineering it is not recommended
to rely on in situ PEC formation. Instead the PECs should be pre-formed before
addition to the fibres. The use of pre-formed PECs in the paper-making process is
described as three sub-processes: PEC formation, adsorption onto surfaces, and the
effect on the adhesion between surfaces. The addition of PECs, and adsorption to the
fibres, prior to formation of the paper network structure has shown to result in a
significant increase in joint strength between the fibres and to an increased strength
C. Ankerfors
Swerea KIMAB, Box 7047, 164 07 Kista, Sweden
L. Wa ˚gberg (*)
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology,
Teknikringen 56, 100 44 Stockholm, Sweden
The Wallenberg Wood Science Centre (WWSC), KTH Royal Institute of Technology,
Teknikringen 56, 100 44 Stockholm, Sweden
e-mail: wagberg@kth.se