ORIGINAL PAPER A study on the interaction of cationized chitosan with cellulose surfaces Tijana Ristic ´ • Tamilselvan Mohan • Rupert Kargl • Silvo Hribernik • Ales ˇ Dolis ˇka • Karin Stana-Kleinschek • Lidija Fras Received: 12 December 2013 / Accepted: 16 April 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract This investigation describes the interac- tion of trimethyl chitosans (TMCs) with surfaces of cellulose thin films. The irreversible deposition/ adsorption of TMCs with different degrees of cationization was studied with regards to the salt concentration and pH. As substrates, cellulose thin films were prepared by spin coating from trimeth- ylsilyl cellulose and subsequent regeneration to pure cellulose. The pH-dependent zeta potential of cel- lulose thin films and the charge of TMCs were determined by streaming potential and potentiomet- ric charge titration methods. A quartz crystal microbalance with dissipation monitoring was further used as a nanogram sensitive balance to detect the amount of deposited TMCs and the swelling of the bound layers. The morphology of the coatings was additionally characterized by atomic force microscopy and related to the adsorption results. A lower degree of cationization leads to higher amounts of deposited TMCs at all salt concentrations. Higher amounts of salt increase the deposition of TMCs. Protonation of primary amino groups results in the immobilization of less material at lower pH values. The results from this work can further be extended to the modifica- tion of regenerated cellulosic materials to obtain surfaces, with amino- and trimethylammoni- um moieties. Keywords Cellulose thin films  QCM-D  Cationized chitosan  AFM  Polymer adsorption Introduction The use of cellulose and other polysaccharides in the form of paper, textiles and packaging films is exten- sive. As a result, improvements and extensions of the properties of these materials are highly desired and are the subjects of continuing research (Eriksson et al. 2006; Jin et al. 2012; Findenig et al. 2012). One Member of the European Polysaccharide Network of Excellence (EPNOE). Electronic supplementary material The online version of this article (doi:10.1007/s10570-014-0267-6) contains supple- mentary material, which is available to authorized users. T. Ristic ´  R. Kargl (&)  S. Hribernik  A. Dolis ˇka  K. Stana-Kleinschek  L. Fras Laboratory for Characterization and Processing of Polymers, Faculty of Mechanical Engineering, University of Maribor, Smetanova Ulica 17, 2000 Maribor, Slovenia e-mail: rupert.kargl@um.si T. Ristic ´ Tosama, Production of Medical Supplies, Vir, S ˇ aranovic ˇeva 35, 1230 Domz ˇale, Slovenia T. Mohan Institute of Chemistry, University Graz, Heinrichstraße 28/III, 8010 Graz, Austria e-mail: tamilselvan.mohan@uni-graz.at 123 Cellulose DOI 10.1007/s10570-014-0267-6