Impact of heat drying on the physical and environmental characteristics of the nanocellulose-based films produced via spray deposition technique

Abstract: Nanocellulose (NC) and NC-based composites have gained considerable attention in recent years due to their biodegradability and recyclability. Spray deposition has emerged as a potential technique to produce NC films due to the rapidity and simplicity of the process. The major hurdle regarding the efficient production of NC-based films is the drying process. The aim of the current study is to significantly reduce the drying time of NC films and consequently examine the impact of drying on their mechanical characteristics, barrier and environmental performance. The NC films produced by spray deposition were dried at 50 °C, 75 °C and 100 °C and their characteristics were compared with the films produced via the same method at ambient temperature (28 ± 2 °C). Heating the films in an oven up to 75 °C had a negligible effect on mechanical characteristics while slightly improving the barrier properties as compared with the ambient dried films. However, the dimensional stability was only achieved when the temperature was below 75 °C. Drying could be accomplished at the faster drying rate and the NC films found to have lower embodied energy in comparison with the conventional packaging materials.