RT Journal Article T1 Gel Point as Measurement of Dispersion Degree of Nano-Cellulose Suspensions and Its Application in Papermaking A1 Sánchez Salvador, José Luis A1 Balea Martín, Ana A1 Negro Álvarez, Carlos Manuel A1 Monte Lara, María Concepción A1 Blanco Suárez, Ángeles AB The dispersion degree of cellulose micro and nanofibrils (CMFs/CNFs) in water suspensions is key to understand and optimize their effectiveness in several applications. In this study, we proposed a method, based on gel point (Øg), to calculate both aspect ratio and dispersion degree. This methodology was validated through the morphological characterization of CMFs/CNFs by Transmission Electronic Microscopy. The influence of dispersion degree on the reinforcement of recycled cardboard has also been evaluated by stirring CMF/CNF suspensions at different speeds. Results show that as stirring speed increases, Øg decreased to a minimum value, in which the aspect ratio is maximum. Then, Øg increased again. Suspensions with lower Øg, in the intermediate region of agitation present very good dispersion behavior with an open and spongy network structure, in which nanofibril clusters are totally dispersed. Higher stirring speeds shorten the nanofibrils and the networks collapse. Results show that the dispersion of the nanocellulose at the minimum Øg before their addition to the pulp, produces higher mechanical properties, even higher than when CNFs and pulp are agitated together. This method allows for the determination of the CMF/CNF dispersion, to maximize their behavior as strength agents. This knowledge would be crucial to understand why some industrial trials did not give satisfactory results. PB MPDI SN 2079-4991 YR 2022 FD 2022-02-26 LK https://hdl.handle.net/20.500.14352/72518 UL https://hdl.handle.net/20.500.14352/72518 LA eng NO Ministerio de Ciencia e Innovación (MICINN) NO Universidad Complutense de Madrid/Banco de Santander DS Docta Complutense RD 26 ago 2024