High performance and sustainable CNF membrane via facile in-situ envelopment of hydrochar for water treatment.

In this study, cellulose nanofiber (CNF) membranes for water treatment are prepared via in-situ hydrothermal carbonization of glucose in a CNF suspension. The in-situ carbonized CNFs were fabricated into the membranes via dead-end filtration under hydraulic pressure (1 bar). The in-situ carbonized CNF membranes showed high pure water flux (56.25 L·h-1·m-2) without critical flux drop for 12 h of membrane fabrication. The hydrochar chemically bonded with CNF enhanced the durability of CNF during membrane fabrication. Owing to the strong and stable electrostatic interaction between the target dye and hydrochar, the in-situ carbonized membrane also displayed excellent dye rejection for dilute and concentrated solutions, with high selectivity and good reusability. This study provides a successful strategy for fabricating an all-carbohydrate-based high-performance water treatment membrane.

Carbon dot/cellulose nanofiber composite: Dataset for its water treatment performance.

Carbon dot (CD) obtained via one-step hydrothermal carbonization was attached to cellulose nanofiber (CNF) via physical blending and in-situ synthesis. The data represent the morphological, chemical and optical differences of the samples, according to the amount and introducing method of CD. The morphological durability of the samples was also shown. The water treatment membrane performance was analysed using methylene blue as a representative pollutant. The related article was published in Carbohydr. Polym. 255 (2021) 117387.

In-situ synthesis of carbon dot at cellulose nanofiber for durable water treatment membrane with high selectivity.

In this work, carbon dot (CD) was in-situ synthesized and attached to cellulose nanofiber (CNF) via hydrothermal process. The in-situ synthesized CD uniformly enveloped the CNF surface by means of amide bonding, without significant changes of the chemical structure of CNF. The prepared CD@CNF composite showed rough and bumpy morphology. The attached CD increased the interaction between the fibers and enhanced the thermal stability and the dimensional stability in aqueous solution. CD@CNF showed excellent performance as a dye-rejection membrane with high-water flux (∼32 LMH bar-1) and high rejection rate (∼99.8 %), as well as the selective removal of cationic dye. This study suggests a novel synthesizing method of durable CNF membrane by envelopment of CD for effective water treatment.