Optimization of Spraying Process via Response Surface Method for Fabrication of Cellulose Nanofiber (CNF) Film

Abstract

Cellulose nanofiber (CNF) is a sustainable bionanomaterial which has fibril’s width varying from 5 nm to ~73 nm with an average length of 8 μm. It can be used as a base material for various functional materials such as barrier, flexible electronic substrates, and membrane etc. Though several methods such as solvent casting and vacuum filtration are available for the production of CNF film in laboratory scale, the major constraints are film formation time, shrinkage on the film, and poor uniformity. Spraying CNF suspension is one of the emerging methods which forms the film rapidly. The present investigation deals with the optimization of critical parameters such as CNF suspension concentration, velocity of the conveyor, and spray distance involved in the spraying process via central composite design (CCD) in the response surface methodology (RSM). The influence of these parameters on the basis weight and thickness of the CNF film was evaluated from the linear models. It concludes that the CNF suspension concentration is a strong parameter for controlling the basis weight and the thickness of the CNF film. The developed linear models were validated with experimental data confirming that it was a good fit. Given this correspondence, these models may be used for scaling up the spraying process for the fast production of CNF film.