Versatile synthesis of cellulose film with excellent electrothermal/photothermal dual responsiveness by introducing MXene and small molecule self-assembled nanosphere.

Plant-derived biomaterials have great application prospects in solving environmental pollution and sustainable resource utilization, but the insufficient mechanical strength and lack of functional responsiveness often limit their further development. Inspired by natural small molecules functionalization, a vacuum-assisted filtration nanofibrillated cellulose (NFC)-based film with excellent antibacterial properties, mechanical strength, and electrothermal/photothermal dual-responsiveness was fabricated. As a natural bioactive molecule, antibacterial cinnamaldehyde (CA) is grafted onto tannic acid (TA) rich in pyrogallols via a small molecule self-assembly strategy, and then co-assembled with zinc acetate (ZA) through ion crosslinking to synthesize the functional TACA@ZA nanospheres. After incorporating the MXene and TACA@ZA, an inorganic-organic 3D network system was established in the NFC matrix through dynamic intermolecular hydrogen bonding and strong ionic cross-linking. The mechanical strength and toughness of hybrid composites are remarkably improved by 83.6 % and 418.9 %, respectively. Due to the synergistic effects of MXene and TACA@ZA, the designed NFC-based film also shows significantly enhanced antibacterial activity, UV-blocking ability, as well as photothermal and electrothermal performance. This bioinspired small molecule functionalization strategy opens an innovative design concept for the fabrication of multirole NFC-based biomaterials, which has great application prospects in the commercial fields of multifunctional adhesives, electronic devices, UV shielding coatings, and antibacterial materials.

Deep eutectic supramolecular polymer functionalized MXene for enhancing mechanical properties, photothermal conversion, and bacterial inactivation of cellulose textiles.

Two-dimensional (2D) transition metal carbides (Ti3C2Tx MXene) have gained significant attention for their potential in constructing diverse functional materials, However, MXene is easily oxidized and weakly bound to the cellulose matrix, which pose challenges in developing MXene-decorated non-woven fabric with strong bonding and stable thermal management properties. Herein, we successfully prepared deep eutectic supramolecular polymer (DESP) functionalized MXene to address these issues. MXene can be wrapped with DESP to be insulated from water and protected from being oxidized. Subsequently, we achieved an efficient in-situ deposition of DESP-functionalized MXene onto fibers through a combination of dip coating and photopolymerization technique. The resulting nonwoven fabric (CNs-DESP@M) exhibited excellent photothermal conversion properties along with rapid thermal response and functional stability. Interestingly, the interface bonding between MXene and the fiber surface was significantly enhanced due to the abundant pyrogallol groups in DESP, resulting in the composite textile exhibiting commendable mechanical properties (2.68 MPa). Moreover, the as-prepared textile demonstrates outstanding bactericidal efficacy against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The multifunctional textile, created through a facile and efficient approach, demonstrates remarkable potential for applications in smart textiles, catering to the diverse needs of individuals in the future.

Functionalized cellulose nanofibrils based supramolecular system-assisted molding enabled strong, antibacterial chitosan bioplastics.

Bioplastics are considered as potential alternatives to non-renewable and non-biodegradable petroleum-based plastics. Inspired by ionic and amphiphilic properties of mussel protein, we proposed a versatile and facile strategy for the fabrication of a high-performance chitosan (CS) composite film. This technique incorporates a cationic hyperbranched polyamide (QHB) and a supramolecular system based on the lignosulphonate (LS)-functionalized cellulose nanofibrils (CNF) (LS@CNF) hybrids. The cationic QHB was synthesized by a one-step process from hyperbranched polyamide and quaternary ammonium salt. Meanwhile, the functional LS@CNF hybrids act as a well-dispersed and rigid cross-linked domain in CS matrix. Owing to the interconnected hyperbranched and enhanced supramolecular network, the toughness and tensile strength of the CS/QHB/LS@CNF film simultaneously increased to 19.1 MJ/m3 and 50.4 MPa, 170.2 % and 72.6 % higher than the pristine CS film. Additionally, the functional QHB/LS@CNF hybrids endow the films with superior antibacterial activity, water resistance, UV shielding, and thermal stability. This bioinspired strategy provides a novel and sustainable method for the production of multifunctional CS films.