Cellulose Nanofibrils from Corncobs and Their Nanocomposite with Alginate: Study of Swelling Behavior

In this study, isolated cellulose from corncobs was oxidized using 2,2,6-tetramethyl-1-piperidinyl oxy (TEMPO) to produce cellulose nanofibrils. Cellulose nanofibrils were characterized by FTIR, PSA, and zeta potential to determine their chemical structure, particle size, and surface charge. Subsequently, the obtained cellulose nanofibrils were incorporated into the alginate matrix to produce composite beads. The effects of cellulose nanofibrils and alginate composition in composite beads were studied on the physical properties such as diameter size, morphology, drying rate, and swelling behavior. The result figures out a new chemical structure in the cellulose nanofibrils spectrum after the treatment process. The content of surface charges increases three times after the treatment process, from 0.2 to 0.64 mmol/g. The average size of cellulose nanofibril suspension particles was 153,4, with a polydispersity index of 0.044 (the nanofiber range). The zeta potential value is-46.3 mV, demonstrating the good stability and dispersibility of the cellulose nanofibril particles. The diameter of composite Alginate-Cellulose Nanofibril (AC) beads was reduced from 4.003 to 3.078 mm in AC20 by increasing the cellulose nanofibril concentration. The capacity of alginate beads to absorb water was 30% higher than that of the composite AC beads. Based on SEM analysis, the morphology of AC beads was found to be finer and denser than that of alginate beads. The swelling kinetics of the beads indicate that the diffusion mechanism is a Fickian diffusion mechanism. Furthermore, cellulose nanofibril-added beads can potentially be used as smart materials in bioactive encapsulated applications owing to having good swelling properties.