Contact Angle Measurements of Cellulose based Thin Film composites: wettability, surface free energy and surface hardness

The ultimate objective was to develop new areas to adapt the wetting characteristics of spin-coated cellulose fibers on glass substrates. Therefore, glasses were protected from liquid water through a spin coating process with treated cellulosic triacetate to achieve more hydrophobic surfaces, using well-defined model surfaces based on cellulose components: monolayer and bilayer cellulose triacetate, and the cellulose/TiO2 composite. Cellulose-based surfaces interact with water as well as other liquids rely on the morphology of the surface and the intrinsic characteristics of the material. In this work, the advancing and receding contact angles for water were measured and showed that the cellulose/TiO2 composite films had the lowest contact angle (17.4°). From contact angle measurements the surface-free energy was investigated for the different cellulose surfaces. In order to correlate molecular mechanisms with macroscopic effects, the model surfaces of cellulose were used to improve mechanical and wetting properties. The mechanical properties were done by Superficial hardness. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) were used to characterize the films.