Preparation and Characterization of Nanocrystalline Cellulose from Cladophora sp. Algae

Nanomaterial is one of the recent technological advancements that attracts the attention of many scientists. Many advanced properties could emerge from the utilization of materials on this scale. Nanocrystalline cellulose (NCC) is a cellulose-based nanomaterial currently gaining attention because of its remarkable properties. NCC was prepared by removing the amorphous part of cellulose through acid hydrolysis. Cladophora is a type of algae with a fiber-like body, that could grow rapidly and widely available in the Indonesian coastal area, which is considered a nuisance and has no known high economic value. Cladophora can be used as an alternative source of cellulose because it has a high amount of cellulose. Cellulose could be extracted from Cladophora using 17.5% of NaOH at 100°C, 1 M sulfuric acid hydrolysis at 100°C, and bleaching with 5% hydrogen peroxide at 100°C. Nanocrystalline cellulose could be extracted by sulfuric acid hydrolysis at 100°C, with a concentration of 2 M, 3 M, and 5 M. The duration of the process for each concentration, varied for 5, 10, and 15 hours. X-Ray Diffraction (XRD), Particle Size Analyzer (PSA), Transmission Electron Microscopy (TEM), and Fourier Transform Infrared (FTIR) spectroscopy were used to characterize the resulting hydrolyzed product. The result showed that the increase in acid concentration and processing duration increased the crystallinity while decreased particle length and cellulose diameter. The highest crystallinity and smallest particle size were 96.36% and 189.2 nm, obtained by acid hydrolysis in 5 M sulfuric acid for 15 hours.