Nanocellulose from Mankamana-3 corncob biomass: Synthesis, characterization, surface modification and potential applications

This study characterizes corncob from the Nepali variety Mankamana-3, an abundantly available agricultural waste, extracts nanocellulose from it, modifies the nanocellulose with copper nanoparticles, and explores its potential application. The corncobs were mechanically processed into fine powder, delignified by base hydrolysis, bleached and then subjected to acid hydrolysis to obtain nanocellulose fibrils. The corncob contained similar to 38.86 % cellulose, similar to 22.02 % lignin, similar to 34.89 % hemicellulose, similar to 0.97 % moisture, similar to 3.33 % ash with minimal moisture content (0.97 %). Transmission electron microscopy imaging confirmed nanocellulose fibers with an average diameter of 28.2 +/- 2.57 nm. X-ray diffraction results revealed the existence of both cellulose I and cellulose II polymorphs in nanocellulose with 66.55 % crystallinity index (CrI). Further, copper nanoparticles were grown on nanocellulose fibrils, which showed significant antimicrobial activity against E. coli, S. aureus and C. albicans, and prolonged stability in the ambient environment. The corncob biomass-derived nanocellulose could potentially replace conventional inorganic supports for growing various nanoparticles.