Characteristics of unique HBr-hydrolyzed cellulose nanocrystals from freshwater green algae (Cladophora rupestris) and its reinforcement in starch-based film

• Main Authors: Sucaldito, Melvir R., Camacho, Drexel H.
• Format: text
• Published: Animo Repository 2017
• Subjects: Cellulose nanocrystals; Nanofibers; Cladophora; Green algae; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/2555
• Institution: De La Salle University

Cellulose nanocrystals (CNCs) are promising materials that are readily extracted from plants and other cellulose-containing organisms. In this study, CNCs were isolated from freshwater green algae (Cladophora rupestris) thriving in a volcanic lake, using hydrobromic acid (HBr) hydrolysis. Morphological and structural studies revealed highly crystalline CNCs (94.0% crystallinity index) with preferred orientation to [100] lattice plane as shown by XRD measurements and have an average diameter of 20.0 (±4.4) nm as shown by TEM. Thermal studies showed increased temperature for thermal decomposition of CNCs (381.6 °C), which is a result of HBr hydrolysis for CNCs isolation. The isolated CNCs were reinforced into starch based biocomposites via solution casting and evaporation method. Mechanical strength was improved as high as 78% upon addition of 1% cellulose nanocrystals in the films. The produced films are promising materials for their high mechanical strength, biodegradability and availability of raw materials. © 2017 Elsevier Ltd