abstract
All-cellulose composites (ACCs) are promising sustainable alternatives to petroleum-based materials, but their functionalization and property control remains challenging. In this study, multifunctional ACCs were fabricated from bacterial nanocellulose (BNC) membranes via controlled partial dissolution using an aqueous NaOH/urea system. By varying dissolution time (5–20 min), composites with tunable structure and performance were produced without toxic solvents. Increasing dissolution times yielded thinner, denser, and more translucent films, with visible-light transmittance up to ∼56% at 700 nm and reduced crystallinity (85% to ∼79%). Mechanical properties were tunable, with Young’s modulus decreased from 1.63 to 0.76 GPa, tensile strength from ∼150 to 46 MPa, and elongation at break increased from ∼11% to ∼17%. Partial dissolution also enhanced enzymatic biodegradability, enabling complete degradation within 4–7 days. The optimal sample (BNC-ACC10) was further functionalized with phytic acid (1.0–10.0% v/v), a bio-based additive, to introduce active properties. These composites showed strong antioxidant activity (up to 64% DPPH scavenging), antibacterial effects against Staphylococcus aureus (MRSA) and Escherichia coli, and improved flame retardancy. Despite slight reductions in stiffness, films retained structural integrity and transparency. This eco-engineering strategy enables scalable production of multifunctional, fully cellulosic nanocomposites with potential applications in textiles, packaging, and biomedical fields.
authors
Maria C. Teixeira, João P.F. Carvalho, Cátia Vieira, Adelaide Almeida, Carla Vilela, Armando J.D. Silvestre, Carmen S.R. Freire
our authors
Armando Jorge Domingues Silvestre
Full professor
Carla Vilela
Assistant Professor
Carmen Sofia da Rocha Freire Barros
Coordinating Researcher
João Pedro Fernandes Carvalho
PhD Student
Maria do Céu Esteves Amaral Teixeira
PhD StudentProjects
Bioeconomia para Têxtil e Vestuário (BE@T)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
PRR CICECO - Instituto de Materiais de Aveiro (Equipar+ CICECO)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
acknowledgements
The authors acknowledge the financial support from integrated project be@t – Textile Bioeconomy (TC-C12-i01, Sustainable Bioeconomy No. 02/C12- i01.01/2022), promoted by the Recovery and Resilience Plan (RRP), Next Generation EU, for the period 2021 – 2026. This work was also developed within the scope of projects CICECO – Aveiro Institute of Materials, UID/50011/2025 (DOI 10.54499/UID/50011/2025) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) & UID/PRR/50011/2025 (DOI 10.54499/UID/PRR/50011/2025), and projects CESAM - Centre for Environmental and Marine Studies - UID/50017/2025 (doi.org/10.54499/UID/50017/2025) and LA/P/0094/2020 (doi.org/10.54499/LA/P/0094/2020), financed by national funds through the FCT/MEC (PIDDAC).