Surface modification by polyelectrolyte complexes: Influence of modification procedure, polyelectrolyte components, and substrates

• Published in: Journal of applied polymer science Vol. 65; no. 1; pp. 41 - 50
• Main Authors: Kramer, G., Buchhammer, H.-M., Lunkwitz, K.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 05.07.1997; Wiley
• Subjects: adsorption; Applied sciences; Exact sciences and technology; interface; Organic polymers; Physicochemistry of polymers; polyelectrolyte; polyelectrolyte complex; Properties and characterization; Solution and gel properties; substrate; Stoichiometry; Surface charge; Liquid solid adsorption; Silicates; Experimental study; Polyelectrolyte; Allyl resin; Charged particle; Electrokinetic potential; Interpolymer; Maleic acid copolymer; Aqueous solution; Quaternary ammonium polymer; Polyethylene imine; Styrene copolymer
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/(SICI)1097-4628(19970705)65:1<41::AID-APP6>3.0.CO;2-Q

The complex formation between oppositely charged polyelectrolytes (PEL) and their interaction with negatively charged silicate powders have been investigated. The PEL studied were poly(ethyleneimine)s, poly(diallyldimethylammonium chloride), and copolymers of maleic acid and propylene or styrene. PEL complexes (PEC) are formed by a combination of aqueous PEL solutions containing definite amounts of charges (n−, polyanion; n+, polycation). The point of zero charge of the PEC depended on the selection of different PEL. Changing the molar ratio n−/n+ permitted the preparation of nonstoichiometric PEC (nPEC). Preformed cationic nPEC were used to modify the silicate powders (variation A). The nPEC were able to generate a strongly cationic surface charge in most cases. It is concluded that the preformed PEC adsorbs roughly with the same stoichiometry on the surface as in solution. Changes of the mechanism and a strong enhancement of the attainable cationic surface charge density could be observed by a two‐step modification procedure (variation B). The influence of the surface charge density of the untreated substrates on the extent of surface modification for both variations is also described. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 41–50, 1997