Wetting kinetics of oil mixtures on fluorinated model cellulose surfaces

• Published in: Journal of colloid and interface science Vol. 317; no. 2; pp. 556 - 567
• Main Authors: Aulin, Christian, Shchukarev, Andrei, Lindqvist, Josefina, Malmström, Eva, Wågberg, Lars, Lindström, Tom
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 2008; Elsevier
• Subjects: Adsorption; AFM; Cellulosa- och pappersteknik; Cellulose and paper engineering; Cellulose surface; Chemical engineering; Chemical process and manufacturing engineering; Chemistry; Colloidal state and disperse state; Contact angle; Exact sciences and technology; Fluorosurfactant; General and physical chemistry; Kemisk process- och produktionsteknik; Kemiteknik; MFC; Multilayer; Oil resistance; Surface physical chemistry; TECHNOLOGY; TEKNIKVETENSKAP; Wetting; XPS; Fluorosurfactant; Adsorption; Multilayer; Wetting; AFM; Cellulose surface; Oil resistance; XPS; MFC; Contact angle; Atomic force microscopy; Cellulose; Fluorine compound; X ray; Resistance; Oil; Photoelectron spectrometry; Models; Kinetics; oil resistance; adsorption; multilayer; wetting; contact angle; cellulose surface; fluorosurfactant
• ISSN: 0021-9797; 1095-7103; 1095-7103
• DOI: 10.1016/j.jcis.2007.09.096

The wetting of two different model cellulose surfaces has been studied; a regenerated cellulose (RG) surface prepared by spin-coating, and a novel multilayer film of poly(ethyleneimine) and a carboxymethylated microfibrillated cellulose (MFC). The cellulose films were characterized in detail using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM indicates smooth and continuous films on a nanometer scale and the RMS roughness of the RG cellulose and MFC surfaces was determined to be 3 and 6 nm, respectively. The cellulose films were modified by coating with various amounts of an anionic fluorosurfactant, perfluorooctadecanoic acid, or covalently modified with pentadecafluorooctanyl chloride. The fluorinated cellulose films were used to follow the spreading mechanisms of three different oil mixtures. The viscosity and surface tension of the oils were found to be essential parameters governing the spreading kinetics on these surfaces. XPS and dispersive surface energy measurements were made on the cellulose films coated with perfluorooctadecanoic acid. A strong correlation was found between the surface concentration of fluorine, the dispersive surface energy and the contact angle of castor oil on the surface. A dispersive surface energy less than 18 mN/m was required in order for the cellulose surface to be non-wetting ( θ e > 90 ° ) by castor oil. AFM tapping mode image of a bilayer of PEI/MFC on silica in the height mode. The scanned surface area was 1 μm 2 (left) and dispersive surface energy of fluorinated regenerated cellulose surfaces vs atomic fluorine concentration (right).