Research Article Optimization of Spraying Process via Response Surface Method for Fabrication of Cellulose Nanofiber (CNF) Film Norah Salem Alsaiari, 1 Kirubanandan Shanmugam , 2 Hariharan Mothilal, 3 Daoud Ali, 4 and S. Venkatesa Prabhu 5,6 1 Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia 2 Department of Biotechnology and Research Cell, Sree Sastha Institute of Engineering and Technology (Affiliated to Anna University, Chennai), Chembarambakkam, 600123, Chennai, India 3 Department of Biotechnology, Sree Sastha Institute of Engineering and Technology (Affiliated to Anna University, Chennai), Chembarambakkam, Chennai 600123, India 4 Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia 5 Department of Chemical Engineering, College of Biological and Chemical Engineering, Addis Ababa Science and Technology University, Ethiopia 6 Center of Excellence for Bioprocess and Biotechnology, Addis Ababa Science and Technology University, Ethiopia Correspondence should be addressed to Kirubanandan Shanmugam; kirubanandan.shanmugam@gmail.com and S. Venkatesa Prabhu; venkatesa.prabhu@aastu.edu.et Received 15 March 2022; Accepted 5 May 2022; Published 24 May 2022 Academic Editor: R. Lakshmipathy Copyright © 2022 Norah Salem Alsaiari et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 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. 1. Introduction Cellulose nanofiber (CNF) is a carbohydrate nanomaterial derived from the cellulose, and it can be used as a base bio- material for fabrication for films [1], coating [2], gels, mem- branes [3], and substrates for flexible electronics [4]. CNF has become a potential alternative to replace the synthetic plastics [1], and it is an ecofriendly biomaterial having excel- lence in their biodegradability in the soil [5]. CNF was pro- duced via delaminating cellulose fibers through mechanical [6], chemical [7], or biological methods [8, 9]. The width of nanofibrils in CNF varied from 5 nm to ~73 nm [4] and acts as a building block for fabrication of CNF films. Cellu- lose nanofibrils offer a considerable value in aspect ratio and mechanical strength. The reduction of fibers from mac- roscale to nanoscale improves flexibility and gives large spe- cific surface area and biodegradability [7]. In addition to that, cellulose nanofibers give high mechanical strength with Hindawi Journal of Nanomaterials Volume 2022, Article ID 5242808, 10 pages https://doi.org/10.1155/2022/5242808