Sustainable high yield production of cellulose nanomaterials for easy-cleaning surfaces of cellulose-based materials

Cellulose nanomaterials with high yield and desired properties were sustainably produced using a facile recyclable acid treatment (oxalic acid) with mineral acid catalysis at ambient pressure. The resultant nanocellulose was uniform in dimensions (diameter and length distributions) and highly dispersible in the aqueous phase. The nanocellulose with yield up to 33.9%, a zeta potential of -53.9 mV, and 100% volume stability (24 h) was achieved via oxalic acid treatment in conjunction with sulfuric acid addition. The coating of such nanocellulose on paper created a uniform and dense layer on the surface, which lowered Gurley air permeability (i.e., prolonging the time required for air flow from 3.9 to 681.9 s per 100 mL). Moreover, the coated paper showed a complete grease barrier after 48 h and presented easy-cleaning behavior. The approach developed in this work offers an adoptable guidance to design green and sustainable easy-cleaning surfaces. In turn, this approach will provide potential applications of nanocellulose for green based packaging and environmental protection.