A comprehensive review on cellulose nanocrystals and cellulose nanofibers: Pretreatment, preparation, and characterization

Abstract

Crafting ecological materials from green resources is posing a significant challenge for the researchers and scientists around the globe and has resulted in the development of nanocellulose materials, which has paved the way for enriching the basic knowledge and many opportunities on developing biobased materials. This has augmented the utilization of carbohydrate-based organic materials and successfully replacing conventional nonrenewable materials. Cellulose nanomaterials (CNMs) belonging to the newer emerging field of nanomaterials are finding increasing interest among the investigators owing to their environmentally sustainable characteristics like biodegradability, biocompatibility, and potential availability in abundance at a cheaper price. The present review article intends to provide a detailed insight about the advancements and various challenges postured in the field of cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs). The article further discusses about different cellulose fiber extraction sources and their methods, purification processes employed, various sample preparation and drying techniques used for CNCs and CNFs. The article also outlines the various characterization methods practiced for scrutinizing CNCs and CNFs when used in polymer matrix composites. Finally, the benefits of using the CNMs in several potential applications such as paper, oil and gas industries, food packaging and structural sectors, conductive ink and water purification areas, medical and printed electronic fields are highlighted in this extensively reviewed article.

Impact and Tensile Properties of Polyester Nanocomposites Reinforced with Conifer Fiber Cellulose Nanocrystal: A Previous Study Extension

“…They are rod-like particles with transverse dimensions as small as 3–30 nm [ 16 ] and lengths ranging between 100 and 1000 nm. In contrast to NLF, the incorporation of CNCs into polymer matrices usually requires low percentages (<10 wt%) to effectively reinforce nanocomposites [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] for a wide range of applications, including food packing and biomedical devices [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. This has motivated the exponential rise of publications related to CNC nanocomposites in the past decade, as illustrated by the rede curve obtained from Scopus database in Figure 1 .…”

“…Particularly in recent decades, many researches have been carried out on composites reinforced with NFLs produced with fibers in different orientations, usually in amounts higher than 10% as well as their respective fabrics [3][4][5][6]. Another recently emerging potential use of NLF, indicated by the red circles curve in Figure 1, is through the extraction of its cellulose nanocrystals (CNCs) for the reinforcement of nanocomposites [7][8][9][10][11][12][13][14][15]. nanocomposites [7][8][9][10][11][12][13][14][15].…”

Application of nanocellulose composites in the environmental engineering: A review

“…Cellulose nanofiber (CNF), also called nanofibrous cellulose, nanofibrillar cellulose, and nanofibrillated cellulose (NFC), is characterized by its distinctive structure made up of a bundle of stretched cellulose chain molecules with cellulose nanofibrils together with repeating crystalline and amorphous regions [37][38][39]. NFC is composed of a mass of stretched nanofibers of cellulose.…”

Effect of Agro Waste Saline Treated Cellulose Nanofiller on Mechanical, Visco Elastic and Thermal Behaviour of Epoxy Nanocomposites

“…(Mohit & Selvan, 2019;Phanthong et al, 2017). Several investigations have been successfully performed to extract nanocellulose from various parts of plants such as bers, peels, seeds, and lignocellulosic waste materials such as disposal cups, tissue paper, tetra pack, and so on (Nagarajan et al, 2021).…”

“…(Phanthong et al, 2017; X. . But the CNFs are typically derived from plant biomass via a mechanical process such as ball milling, micro uidization cryo crushing, grinding, and high-pressure homogenization (Nagarajan et al, 2021). A higher shear force is generated in this process, resulting in the extraction of CNFs along the longitudinal direction from the raw cellulosic materials (Phanthong et al, 2018).…”