Structural modification of bacterial cellulose fibrils under ultrasonic irradiation

• Published in: Carbohydrate polymers Vol. 150; pp. 5 - 12
• Main Authors: Paximada, Paraskevi, Dimitrakopoulou, Eleni Alkmini, Tsouko, Erminda, Koutinas, Apostolos A., Fasseas, C., Mandala, Ioanna G.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 05.10.2016
• Subjects: Acetobacteraceae - chemistry; Bacteria; Bacterial; Cellulose; Cellulose - chemistry; Elasticity; Fibrils; Rheology; Sonication; Suspension; Ultrasounds; Viscosity; Water - chemistry; Ultrasounds; Bacterial; Suspension; Rheology; Fibrils; Cellulose
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2016.04.125

•Short US treatment leads to a decrease in BC fibril dimensions.•Increase in stability, viscosity and thixotropy of BC suspensions.•Improvement of the physical properties of BC suspensions. Ιn the present study we investigated ultrasounds as a pretreatment process for bacterial cellulose (BC) aqueous suspensions. BC suspensions (0.1–1% wt) subjected to an ultrasonic treatment for different time intervals. Untreated BC presented an extensively entangled fibril network. When a sonication time of 1min was applied BC fibrils appeared less bundled and dropped in width from 110nm to 60nm. For a longer treatment (3–5min) the width of the fibrils increased again to 100nm attributed to an entanglement of their structure. The water holding capacity (WHC) and ζ-potnential of the suspensions was proportional to the sonication time. Their viscosity and stability were also affected; an increase could be seen at short treatments, while a decrease was obvious at longer ones. Concluding, a long ultrasonic irradiation led to similar BC characteristics as the untreated, but a short treatment may be a pre-handling method for improving BC properties.