Functionalization and performance enhancement of composite films prepared by cellulose nanocrystals/resilin-CBD /hydrophobically modified chitosan

• Main Authors: JIA-YOU LIN, 林家右
• Other Authors: Cheng-Kang Lee
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/9evz48

碩士 === 國立臺灣科技大學 === 化學工程系 === 107 === Cellulose Nanocrystals (CNCs) are highly crystalline rod-like nanomaterials can readily form stable colloidal suspensions in deionized water. However, the transparent dry film obtained via simple evaporation-induced self-assembly of coated CNCs suspension will readily dissolve in water due to the presence of strong anionic SO3- groups on the surface of CNCs. Besides, the dry CNCs film is not tough enough to endure the repeated bending. In order to improve these drawbacks, we created CBD-resilin 1 and CBD-resilin 1-CBD fusion proteins by fusing one or two cellulose binding domain (CBD) with elastic protein resilin 1. The biomimetic composite films could be acquired by drying the mixture consisted of CBD fusions proteins, CNCs solution and 1% of the glycerol. Due to the elasticity of the resilin 1, the strain-at-break of the biocompoiste films increased by 42% and 85% respectively in comparison with the pure CNCs film. Water durable and transparent CNCs@CNF and CNCs@HMCS composite films can be generated by drying the mixture containing CNCs, chitin nanofiber (CNF), and hydrophobically modified chitosan (HMCS) respectively. The charge neutralization of the biocomposite film caused by the cationic amino groups of CNF and HMCS contributes to the water durability of the composite films. Especially, the presene of hydrophobicity of C12 hydrocarbon tail grafted on HMCS increased the water contact angle of CNCs@HMCS film from 53.27 to 84.96. Additionally, the HMCS doped CNCs film can effectively adsorb methyl orange with capacity of 181.95 1.14 mg /g and kill at least 70% of E-coli. It indicates the composite still maintained the dye adsorption and antimicrobial activity of HMCS. Not only the better thermal stability of the transparent CNCs@HMCS composite film could be achieved, but its mechanical properties were signigicantly impoved with Young’s modulus (GPa), tensile strength (Mpa) and strain-at-break (%) increased 95%, 66% and 93% respectively as compared with CNCs film.