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Virus cross-infection via surfaces poses a serious threat to public health. Inspired by natural sulfated polysaccharides and antiviral peptides, we prepared multivalent virus blocking nanomaterials by introducing amino acids to sulfated cellulose nanofibrils (SCNFs) via the Mannich reaction. The antiviral activity of the resulting amino acid-modified sulfated nanocellulose was significantly improved. Specifically, 1 h treatment with arginine modified SCNFs at a concentration of 0.1 g/mL led to a complete inactivation of the phage-X174 (reduction by more than three orders of magnitude). Atomic force microscope showed that amino acid-modified sulfated nanofibrils can bind phage-X174 to form linear clusters, thus preventing the virus from infecting the host. When we coated wrapping paper and the inside of a face-mask with our amino acid-modified SCNFs, phage-X174 was completely deactivated on the coated surfaces, demonstrating the potential of our approach for use in the packaging and personal protective equipment industries. This work provides an environmentally friendly and cost-efficient approach to fabricating multivalent nanomaterials for antiviral applications. [Display omitted] • Amino acids were successfully introduced to SCNFs by the Mannich reaction. • Amino acid-modified SCNFs could greatly enhance the antiviral performance. • Bio-inspired virus-blocking nanomaterials were fabricated without toxic solvent. [ABSTRACT FROM AUTHOR]

Cellulose provides promising alternatives to synthetic plastics to achieve a low carbon footprint and biodegradable materials, which have significant positive impacts on environmental protection and on human health. In this work, sulfated holocellulose fibers and sulfated holocellulose nanofibrils (SHCNFs) are prepared using a combination of delignification with derivatization to achieve high fiber yield, superior recycling performance, and less energy consumption of the final products by means of preserving hemicellulose. Derivatization of the surface with sulfate groups provides a further means to avoid excessive aggregation between adjacent cellulose surfaces. Interestingly, hemicellulose increases the accessibility of holocellulose fibers and reduces the embodied energy during sulfate esterification. The presence of hemicellulose imparts high optical transmittance, mechanical performance (ultimate strength, 390 MPa; Young's modulus, 33 GPa), and recyclability for SHCNFs. This combination of two treatments can unlock the greater potential of cellulose as a sustainable material over its entire life cycle. [Display omitted] [ABSTRACT FROM AUTHOR]

A high-yield and straightforward method is proposed to obtain an electromagnetic interference (EMI) shielding film based on multilayered Ti 3 C 2 T x (m-Ti 3 C 2 T x). Holocellulose nanofibrils modified by sulfamic acid (SHCNF) with unique "core-shell" structure can act as a dispersant and a binder to assist in exfoliating m-Ti 3 C 2 T x into delaminated-Ti 3 C 2 T x (d-Ti 3 C 2 T x) and fabricate flexible Ti 3 C 2 T x /SHCNF composite films with a high-yield value. The "brick-and-mortar" composite films exhibit a superior electromagnetic interference (EMI) shielding effectiveness (SE) of 45.02 dB with an ultrathin thickness of 40 μm at the 12.4 GHz. Moreover, these flexible and strong integrated Ti 3 C 2 T x /SHCNF composite films also display excellent specific EMI SE of SSE/t (4437 dB cm2 g−1) and high EMI shielding efficiency (99.996%). Therefore, the SHCNF-assisted method provides a cost-effective approach to fabricate a strong and flexible MXene-based nanocomposite films toward EMI shielding application. [Display omitted] • Holocellulose nanofibrils assisted in exfoliating multilayered Ti 3 C 2 T x. • The Ti 3 C 2 T x /SHCNF film exhibited superior mechanical properties. • The film presented excellent specific EMI shielding efficiency. [ABSTRACT FROM AUTHOR]

Liquid metal (LM) nanodroplets and MXene nanosheets are integrated with sulfonated bacterial nanocellulose (BNC) and acrylic acid (AA). Upon fast sonication, AA polymerization leads to a crosslinked composite hydrogel in which BNC exfoliates Mxene, forming organized conductive pathways. Soft conducting properties are achieved in the presence of colloidally stable core-shell LM nanodroplets. Due to the unique gelation mechanism and the effect of Mxene, the hydrogels spontaneously undergo surface wrinkling, which improves their electrical sensitivity (GF = 8.09). The hydrogels are further shown to display interfacial adhesion to a variety of surfaces, ultra-elasticity (tailorable elongation, from 1000 % to 3200 %), indentation resistance and self-healing capabilities. Such properties are demonstrated in wearable, force mapping, multi-sensing and patternable electroluminescence devices. [Display omitted] • Nanocellulose-supported LM/MXene composite hydrogels are formed by one-step sonication. • The polymer matrix effectively disperses core-shell LM nanodroplets and MXene nanosheets. • The hydrogels display ultra-elasticity, indentation resistance and self-healing properties. • The composite hydrogel is demonstrated for sensing, force mapping and electroluminescence. [ABSTRACT FROM AUTHOR]