Modulation of morphology, water uptake/retention, and rheological properties by in-situ modification of bacterial cellulose with the addition of biopolymers

Kalyani, Peddapapannagari and Khandelwal, Mudrika (2021) Modulation of morphology, water uptake/retention, and rheological properties by in-situ modification of bacterial cellulose with the addition of biopolymers. Cellulose, 28 (17). pp. 11025-11036. ISSN 0969-0239

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Abstract

In situ modification of bacterial cellulose (BC) allows structural and morphological tuning which determines the crucial properties such as water absorption/retention and rheological behaviour. This work reports the effect of in situ modification carried out by adding two biopolymers Agar and Chitosan to the standard culture media for bacterial cellulose synthesis. The agar modified BC (Agar-BC) form a BC network with reduced pore volume, and a much denser network, leading to lesser water absorption and further lower retention time than BC. Agar-BC also demonstrates a higher storage modulus, while the yield point is observed at a lower shear strain. This indicates a behaviour similar to that of a crosslinked polymer with a low strain onset of plasticity. On the other hand, chitosan-modified BC (Chitosan-BC) also exhibits a lower pore volume with a lower densely packed structure and with lower swellability and water retention reduced to 1 h (7 h for BC). Chitosan-BC presents a lower modulus with a yield strain similar to that of unmodified BC. The water absorption-retention behaviour is discussed in detail considering the relative pore shape-size distribution, fibre dimension and surface area. The mechanism of viscoelastic deformation for each of the cases is explained. © 2021, The Author(s), under exclusive licence to Springer Nature B.V.

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IITH Creators:

IITH Creators	ORCiD
Khandelwal, Mudrika	UNSPECIFIED

Item Type:

Article

Additional Information:

We thank Pankaj Choubey and Tithi Basu from IIT Hyderabad for assisting in rheological measurements. We also acknowledge financial support from AT&T CSR funds and SERB, India. We would also like to acknowledge the FIST-I funding for SEM to MSME, IITH.

Uncontrolled Keywords:

Agar; Bacterial cellulose; Biopolymers; Chitosan; Rheology; Surface morphology

Subjects:

Materials Engineering > Materials engineering

Divisions:

Department of Material Science Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

09 Sep 2022 04:37

Last Modified:

09 Sep 2022 04:37