(137d) Emerging Cellulose Nanocrystals for Threshold Scale Inhibition: A Step Forward in Universal Biomass-Based Crystal Engineering

Scales, sparingly soluble inorganic salts, are formed in aqueous systems with high levels of hardness and alkalinity. The precipitation and adsorption of scale in industrial unites have turned into a major issue, imposing considerable operational and economic losses to industries. The current gold standard in scale prevention involves phosphonated macromolecules, which have raised a red flag due to severe anthropogenic side effects, such as acidification and eutrophication. Here, we provide a conceptual solution to engineer the building blocks of plant cell walls, cellulose fibrils, at nanoscale, to overcome the structural and chemical limitations of conventional nanocelluloses. We have developed the first family of threshold cellulose-based scale inhibitors with promising capabilities in inhibiting and modifying calcium carbonate, the most common type of scale. Cellulose fibrils are disintegrated into dicarboxylic acid functionalized biopolymers and hairy nanocelluloses, which, at ppm concentrations, are able to completely prevent the calcium carbonate crystallization under electrochemically stimulated harsh scaling conditions, where an additivefree system fully scales in less than 0.5 h. The nanostructure and chemistry of cellulose nanocrystals are investigated to shed light on the mechanism of scale inhibition, detailing the inevitable structural limitation of conventional nanocelluloses and the promising role of dicarboxylated cellulose. The outcome of this research may translate into a universal biomass-based sustainable, green solution for the (i) long-lasting scaling challenge of water-based industries, (ii) efficient design of inorganic–organic biomimetic nanocomposites, and (iii) improved solubility of sparingly soluble species based on the most abundant biopolymer in the world.