Superabsorbent nanocomposite hydrogels made of carboxylated cellulose nanofibrils and CMC-g-p(AA-co-AM)

• Published in: Carbohydrate polymers 2013-09, Vol.97 (2), p.429-435
• Main Authors: Zhou, Yiming, Fu, Shiyu, Zhang, Liangliang, Zhan, Huaiyu
• Format: Article
• Language: English
• Subjects: Applied sciences; Carboxylated cellulose nanofibrils; cellulosic fibers; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Fourier transform infrared spectroscopy; hydrocolloids; nanocomposites; Polymer industry, paints, wood; scanning electron microscopes; scanning electron microscopy; Superabsorbent nanocomposite hydrogels; Swelling behaviors; Technology of polymers; temperature; TEMPO-mediation oxidation; water holding capacity; water uptake
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2013.04.088

•CMC-g-p(AA-co-AM)/CCNF hydrogels were directly synthesized, without intermediate.•The swelling behaviors of the two hydrogels (with and without CCNFs) were compared.•The water uptake capacity of the hydrogels increased with increasing CCNF content.•The incorporation of CCNFs improved salt resistance properties of the hydrogels.•The CCNF hydrogels presented better pH response and water retention capacity. Superabsorbents based on carboxylated cellulose nanofibrils (CCNFs) and carboxymethyl cellulose-g-poly(acrylic acid-co-acrylamide) were synthesized. A series of experiments were performed to evaluate the influence of factors such as CCNFs amount, solution pH, temperature, salt solution type and concentration on the swelling behaviors of the hydrogels. The water uptake of the hydrogels strongly depended on the CCNF content, the swelling capacity in distilled water increased dramatically from 245.8 to 458.7g/g with the addition of CCNFs up to 2.5wt%. Furthermore, the incorporation of CCNFs improved salt resistance properties of the hydrogels with slower deswelling rate and higher water retention capacity at deswelling equilibrium. Besides, the CCNF nanocomposite hydrogels presented better responsive behavior in relation to pH presence and showed an increase in water retention capacity at various temperatures. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) were employed to examine the structure and morphologies of the prepared superabsorbent hydrogels.