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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]