Adv Polym Sci (2014) 256: 25–66
DOI: 10.1007/12_2012_205
# Springer-Verlag Berlin Heidelberg 2013
Published online: 24 August 2013
Polyelectrolyte Complexes in Flocculation
Applications
Gudrun Petzold and Simona Schwarz
Abstract This review concentrates on the interactions between oppositely charged
polyelectrolytes and on the formation of complexes, which can be used for different
applications such as paper retention or water treatment. Three different possibilities
for the appearance of polyelectrolyte complexes (PECs) in flocculation applications
are described. Starting with the “classical” dual system (step-by-step addition of
polycation and polyanion to a negatively charged suspension of fibers or particles),
the interaction between a “soluble polyanion” (such as anionic trash) with polycation is described as well as the formation of well-defined pre-mixed PECs and
their application as flocculants.
The influence of several parameters related to the characteristics of the solid
materials (e.g., charge, particle size), the polyelectrolyte (e.g., type of charge,
charge density, molar mass, hydrophobicity) and the flocculation regime (e.g.,
order of addition, pH, ionic strength) are discussed.
Research in this area shows great potential. Over the past 30 years, dual systems
have been applied mainly in the paper industry. The application of PECs, described as
particle-forming flocculants, provides new possibilities in solid–liquid separation
processes. For an effective system, the application parameters have to be optimized
(e.g. polymer type, concentration, charge, molecular weight). Therefore, direct and
efficient methods for the characterization of the flocculation behavior (sedimentation
velocity, packing density of the sludge, particle size distribution) are necessary and
will be described.
Finally, the most advanced applications for PECs are discussed.
Keywords Dual system Á Flocculation Á Polyanion Á Polycation Á Polyelectrolyte
complex Á Pre-mixed complexes
G. Petzold and S. Schwarz (*)
Leibniz-Institut fu ¨r Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
e-mail: simsch@ipfdd.de
DOI: 10.1007/12_2012_205
# Springer-Verlag Berlin Heidelberg 2013
Published online: 24 August 2013
Polyelectrolyte Complexes in Flocculation
Applications
Gudrun Petzold and Simona Schwarz
Abstract This review concentrates on the interactions between oppositely charged
polyelectrolytes and on the formation of complexes, which can be used for different
applications such as paper retention or water treatment. Three different possibilities
for the appearance of polyelectrolyte complexes (PECs) in flocculation applications
are described. Starting with the “classical” dual system (step-by-step addition of
polycation and polyanion to a negatively charged suspension of fibers or particles),
the interaction between a “soluble polyanion” (such as anionic trash) with polycation is described as well as the formation of well-defined pre-mixed PECs and
their application as flocculants.
The influence of several parameters related to the characteristics of the solid
materials (e.g., charge, particle size), the polyelectrolyte (e.g., type of charge,
charge density, molar mass, hydrophobicity) and the flocculation regime (e.g.,
order of addition, pH, ionic strength) are discussed.
Research in this area shows great potential. Over the past 30 years, dual systems
have been applied mainly in the paper industry. The application of PECs, described as
particle-forming flocculants, provides new possibilities in solid–liquid separation
processes. For an effective system, the application parameters have to be optimized
(e.g. polymer type, concentration, charge, molecular weight). Therefore, direct and
efficient methods for the characterization of the flocculation behavior (sedimentation
velocity, packing density of the sludge, particle size distribution) are necessary and
will be described.
Finally, the most advanced applications for PECs are discussed.
Keywords Dual system Á Flocculation Á Polyanion Á Polycation Á Polyelectrolyte
complex Á Pre-mixed complexes
G. Petzold and S. Schwarz (*)
Leibniz-Institut fu ¨r Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
e-mail: simsch@ipfdd.de