Hydrophobization, smoothing, and barrier improvements of cellulose nanofibril films by sol–gel coatings
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Single-layer films from cellulose nanofibrils on a plastic support were coated with sol–gel coated with inorganic–organic copolymers (ORMOCER®s), consisting of inorganic Si–O–Si-based networks combined with ceramic (Al–O– and Zr–O–) groups and special organic fluoroalkyl chain containing functional groups. Sol–gel coatings decreased the surface hydrophilicity and water vapor transmission rate. The water contact angle of uncoated films was 24°, indicating high affinity between water and the cellulose nanofibrils. All sol–gel coatings tested increased the surface hydrophobicity with the contact angles ranging between 54° and 102°. The water vapor transmission rates varied between 230 and 410 g/m2/day. With UV curable highly organically crosslinked coating, the water vapor transmission rate was decreased by 77% as compared to uncoated film. The uncoated film had oxygen transmission rates of 0.7 and 107 cc/m2/day at 50% and 80% RH, respectively. At high humidity conditions, the films tended to swell, thus allowing permeation to increase. Sol–gel coatings significantly improved the oxygen barrier properties especially at 80% RH. The transmission rates varied between 0.4 and 0.5 cc/m2/day (50% RH) and between 51 and 86 cc/m2/day (80% RH).
KeywordsCellulose nanofibrils Sol–gel Film Coating
This work was supported by the European Union Seventh Framework Programme (FP7/2007-2013) with a Grant Number NMP2013-10-608746. Anette Pedersen is acknowledged for preparation of the SEM specimens.
- 1.Johansson, C, Bras, J, Mondragon, I, Nechita, P, Plackett, D, Simon, P, Gregor Svetec, D, Virtanen, S, Giacinti Baschetti, M, Breen, C, Clegg, F, Aucejo, S, “Renewable Fibers and Bio-Based Materials for Packaging Applications—A Review of Recent Developments.” BioResources, 7 2506–2552 (2012)CrossRefGoogle Scholar
- 4.Tammelin, T, Vartiainen, J, “Nanocellulose Films and Barriers.” In: Oksman, K, Mathew, AP, Bismarck, A, Rojas, O, Sain, M (eds.) Handbook of Green Materials. Processing Technologies, Properties and Applications. World Scientific Publishing, Singapore (2014)Google Scholar
- 6.Vartiainen, J, Vähä-Nissi, M, Harlin, A, “Biopolymer Films and Coatings in Packaging Applications: A Review of Recent Developments.” Mater. Sci. Appl., 5 (10) 708–718 (2014)Google Scholar
- 14.Spoljaric, S, Salminen, A, Luong, N, Lahtinen, P, Vartiainen, J, Tammelin, T, Seppälä, J, “Nanofibrillated Cellulose, Poly(vinyl alcohol), Montmorillonite Clay Hybrid Nanocomposites with Superior Barrier and Thermomechanical Properties.” Polym. Compos., 35 (6) 1117–1131 (2013)Google Scholar
- 23.Greiwe, K, “Korrosionsbeständige Schutzbeschichtung für Messingoberflächen.” Farbe Lack, 97 368–371 (1991)Google Scholar
- 26.Tammelin T, Salminen A, Hippi U, “Method for the Preparation of NFC Films on Supports.” Patent WO2013/060934 (2013)Google Scholar
- 30.Plackett, D, Anturi, H, Hedenqvist, M, Ankerfors, M, Gällstedt, M, Lindström, T, Siro, I, “Physical Properties and Morphology of Films Prepared from Microfibrillated Cellulose and Microfibrillated Cellulose in Combination with Amylopectin.” J. Appl. Polym. Sci., 117 3601–3609 (2012)Google Scholar
- 34.Vartiainen, J, Tuominen, M, Nättinen, K, “Bio-Hybrid Nanocomposite Coatings from Sonicated Chitosan and Nanoclay.” J. Appl. Polym. Sci., 116 3638–3647 (2010)Google Scholar
- 35.Spence, K, Venditti, R, Rojas, O, Pawlak, J, Hubbe, M, “Water Vapor Barrier Properties of Coated and Filled Microfibrillated Cellulose Composite Films.” BioResources, 6 (4) 4370–4388 (2011)Google Scholar