Andree V, Niopek D, Müller C, Eiselt JP, Foh N, Rzany A, Hensel B (2021)
Publication Type: Journal article
Publication year: 2021
Book Volume: 8
Article Number: 025402
Journal Issue: 2
Bacterial nanocellulose (BNC) is a promising material for the use in medical implants.BNCdoes not induce unwanted reactions in vivo, is long term stable and possesses unique mechanical properties. However, to make the most of these features,BNCmust be carefully processed. Details of the cultivation and post-synthetic methods offer various ways to control the properties of BNC. The focus of this work is put on drying of the BNC. Different unconstrained drying methods (climate chamber at 23°C, oven at 100°C, freeze-drying) and constrained drying under excertion of uniaxial pressure at various temperatures have been investigated. The reduction of the high water content of nativeBNC (≈98%) causes a thickness reduction of the samples. For oven or climate chamber drying a thickness reduction of 98% is observed, while freeze-drying widely preserves the nano- or micro-structure of the fibrous material and leads to a thickness reduction of only≈13%. During drying or pressing at high temperature (100°C), i.e. by evaporation of the water, intermolecular hydrogen bonds are formed and interconnect the individual fibres and strands. Consequently mechanical stiffening is observed in tensile tests at small strains. After drying, a densified cellulose nano-fibre network is observed by scanning electron microscopy. Due to the irreversibility of drying by evaporation, the water content and water retention capacity ofBNCare not recovered by rehydration. Applying uniaxial pressure before drying further enhances the irreversible reinforcement of the fibre network, while this is not the case when pressing the samples after drying. The presented results show that the properties ofBNC can be widely controlled by post-processing steps. Thus, taylor-madeBNCcan be produced for biomedical applications.
APA:
Andree, V., Niopek, D., Müller, C., Eiselt, J.-P., Foh, N., Rzany, A., & Hensel, B. (2021). Influence of drying methods on the physical properties of bacterial nanocellulose. Materials Research Express, 8(2). https://doi.org/10.1088/2053-1591/abe016
MLA:
Andree, Verena, et al. "Influence of drying methods on the physical properties of bacterial nanocellulose." Materials Research Express 8.2 (2021).
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