Bacterial cellulose nanocrystals produced under different hydrolysis conditions: Properties and morphological features. (2nd January 2017)

• Record Type: Journal Article
• Authors: Vasconcelos, Niédja Fittipaldi; Feitosa, Judith Pessoa Andrade; da Gama, Francisco Miguel Portela; Morais, João Paulo Saraiva; Andrade, Fábia Karine; de Souza Filho, Men de Sá Moreira; Rosa, Morsyleide de Freitas
• Is Part Of: Carbohydrate polymers. Volume 155(2016)
• Page Start: 425
• Page End: 431
• Publication Date: 2017-01-02
• Subjects: Hydrolysis -- Sulfuric acid -- Hydrochloric acid -- Cellulose nanocrystals -- Bacterial cellulose; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2016.08.090
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: The approach for extracting cellulose nanocrystals provided greater versatility and functionality to bacterial cellulose. Extraction of the nanocrystals was successfully obtained only by mild purification and means of acid hydrolysis reaction. Extraction of the nanocrystals was obtained without using chlorine processes (as described in the process from plants). The combined use of sulfuric and hydrochloric acids resulted in nanocrystals with high purity and thermal stability. The results obtained encourage the use as polymer reinforcing agent as a potential application in biomaterials. Abstract: Bacterial cellulose (BC) is a polymer with interesting physical properties owing to the regular and uniform structure of its nanofibers, which are formed by amorphous (disordered) and crystalline (ordered) regions. Through hydrolysis with strong acids, it is possible to transform BC into a stable suspension of cellulose nanocrystals, adding new functionality to the material. The aim of this work was to evaluate the effects of inorganic acids on the production of BC nanocrystals (BCNCs). Acid hydrolysis was performed using different H2 SO4 concentrations and reaction times, and combined hydrolysis with H2 SO4 and HCl was also investigated. The obtained cellulose nanostructures were needle-like with lengths ranging between 622 and 1322 nm, and diameters ranging between 33.7 and 44.3 nm. The nanocrystals had a crystallinity index higher than native BC, and all BCNC suspensions exhibited zeta potential moduli greater than 30 mV, indicating good colloidal stability. The mixture of acids resulted in improved thermal stability without decreased crystallinity.