The utilization of low-grade and abundant thermal sources based on thermoelectric (TE) materials is crucial for the development of a sustainable society. However, high-performance thermoelectric materials with biodegradable, mass-productive, and low-cost features are rarely reported. Here, from the perspective of sustainable development, natural polymer (bacterial cellulose, BC), and "green" solvent (ionic liquids, ILs) are combined to achieve a transparent, flexible, and robust ionogel (BCIGs) by using a facile and versatile modified co-solvent evaporation method. The proposed BCIGs with 95 wt% 1-ethyl-3-methylimidazolium dicyanamide ([EMIm][DCA]) can have high tensile strength (3.05 MPa), skin-like mechanical stretchability (40.99%), and obvious adhesivity. The BCIGs are thermally stable up to 250 °C. They also exhibit a high ionic conductivity (2.88 × 10 −2 S cm −1 ), high ionic thermovoltage (18.04 mV K −1 ), and low thermal conductivity (0.21 W m −1 K −1 ), resulting in the great ionic figure of merit (ZT i ) of 1.33 at room temperature. Through the model of mesoscopic confined ion transportation under a thermal gradient, it is attributed the great thermoelectric properties to the synergistic effect between ion-cellulose interaction and ion-ion interaction. Moreover, a flexible ionic thermoelectric capacitor (ITEC) device is also demonstrated, showing the potential of the BCIGs in wearable energy supply.

Solar-driven seawater desalination is a prospective approach to tackle the problem of freshwater shortage. Establishing a robust, efficient solar−thermal water evaporator with great saltresistance through a facile and scalable fabrication technique is still a challenge. In this study, a floatable and robust monolithic integrated cellulose aerogel-based evaporator (MiCAE) with high performance is fabricated by carefully designing and integrating three functional components, namely, a hydrophilic cellulose−PVA aerogel (CPA), hydrophobic silylated cellulose aerogel (SCA), and multiwalled carbon nanotube (MCNT) coating layer (CPA@ CNT), through the heterogeneous mixing and freeze-drying aerogel fabrication step in situ. Inspired by woods and mushrooms, the incorporation of SCA with mushroom-shaped CPA possessing wood-like structures in MiCAE can realize heat localization and effectively suppress irreversible heat dissipation. Meanwhile, CPA endows the evaporator with the rapid water transportation and great salt excretion capability because of its low-tortuosity porous structure. Thanks to the synergistic effect of the integrated functional structures, in the highly concentrated brine (17.5 wt %), the MiCAE can still realize the combination of high efficiency and obvious salt-resistance behavior. This work offers a facile, efficient salt-resistance solution for seawater desalination.

No abstract

Highly purified protein adsorbents with simultaneous environmental friendliness and high performance are desirable in the biotechnological and biopharmaceutical industries. Herein, the cellulose nanofiber aerogels functionalized with sodium alginate (CNF/SA composite aerogels) featuring aligned 3D porous architecture have been developed via a freeze–drying and Ca2+ cross-linking process. The CNF/SA composite aerogels demonstrated superb underwater structural stability and shape-recovery property originating from the robust aligned porous skeletal structure. Moreover, the resultant CNF/SA composite aerogels with naturally abundant carboxyl groups exhibited unique selectivity toward positive proteins, demonstrating synchronously excellent static (1756 mg g–1) and dynamic (1146 mg g–1) lysozyme adsorption capabilities and high processing flux (21521 L m–2 h–1, gravity driven), which are superior to those of previously reported adsorbents and Sartorius Sartobind commercial membranes. Furthermore, the CNF/SA composite aerogels possessed stable recyclability, easy operation, and good environmental friendliness, demonstrating a bright practical application performance. This work sheds light on a promising direction for developing high-performance protein adsorbents and utilizing sustainable natural biomaterials in bio-separation applications.