Dehumidification is significant for environmental sustainability and human health. Traditional dehumidification methods involve significant energy consumption and have negative impact on the environment. The core challenge is to expose hygroscopic surfaces to the air, and appropriately store the captured water and avoid surface inactivation. Here, a nanostructured moisture‐absorbing gel (N‐MAG) for passive dehumidification, which consists of a hydrophilic nanocellulose network functionalized by hygroscopic lithium chloride, is reported. The interconnected nanocellulose can transfer the captured water to the internal space of the bulky N‐MAG, eliminating water accumulation near the surfaces and hence enabling high‐rate moisture absorption. The N‐MAG can reduce the relative humidity from 96.7% to 28.7% in 6 h, even if the space is over 2 × 104 times of its own volume. The condensed water can be completely confined in the N‐MAG, overcoming the problem of environmental pollution. This research brings a new perspective for sustainable humidity management without energy consumption and with positive environmental footprint.

Dehumidification Dehumidification is significant for environmental sustainability and human health. In article number 2200865, Wenshuai Chen, Guihua Yu, and co‐workers report the development of a nanostructured moisture‐absorbing gel by integration of hygroscopic lithium salt and hydrophilic nanocellulose networks. The gel maintains a large hygroscopic active area for capturing water from air, and thus exhibits super‐moisture‐absorption ability. Even in a space with a volume over 20 000 times of its own, it demonstrates fast dehumidification without energy input and environment pollution.

Multifunctional bionanocomposite foams with 3D interconnected networks showing advantageous mechanical properties, thermal insulation, underwater oleophobicity, and biocompatibility, were made from a chitosan matrix reinforced with nanofibrillated cellulose (NFC). The density of the NFC–chitosan nanocomposite foams can be controlled by varying the NFC/chitosan weight ratio and solid content of the suspension in the fabrication process. The mechanical properties and thermal stability of the nanocomposite foams were significantly improved by increasing the ratio of NFC, and effective thermal insulating performance was exhibited for temperature extremes at 0 °C and 70 °C. Moreover, the NFC–chitosan nanocomposite foams showed a highly efficient oil/water separation capacity even at a severe temperature of 90 °C. In addition, the nanocomposite foams possessed good biocompatibility toward L929 mouse fibroblasts. Therefore, the bionanocomposite foams are available for a number of applications, including as disposable and high‐performance filtration media for water purification, packaging, and biological scaffolds.

This article describes a green approach to the transportation and encapsulation of lauric acid (LA), a natural food-grade phase change material (PCM), in polystyrene (PS) hollow fibers. By simply tuning the temperature, the obtained LAPS composite fibers achieved an unprecedented thermal energy storage capacity up to 81.6% of pristine LA. This capacity was higher than the reported values in the literature which were generally less than 50%. The thermally triggered nanocapillary transportation and encapsulation of LA did not alter the size and morphology of PS hollow fibers. Furthermore, the LA was contained inside PS hollow fibers, leaving the interfiber space and surface free of LA. Direct SEM observation, IR spectra, Raman spectra, XRD diffractograms, and simultaneous TGA–DSC thermograms of LAPS composite fibers proved that the amount of encapsulated LA declined with the elevation of temperature. The distribution of LA in PS hollow fibers was found to be homogeneous across the membrane by TGA and SEM. Further, the LAPS composite fibers demonstrated a robust cycling stability and reusability without notable deterioration of thermal storage capacity during 100 continuous heating–cooling cycles. Also, the composite fibers showed excellent structural stability without any fiber rupture or LA leakage during prolonged and repeated heating–cooling cycles.

To fabricate robust nanofibrillated cellulose (NFC) hydro/aerogels, benign solution/solvent exchange treatment was developed by adding five different water miscible solutions/solvents into a NFC aqueous suspension. The NFC self-aggregated and formed self-standing gels during the solution/solvent exchange treatment. After a further exchange of solution/solvent inside the gels with water by a thorough water washing followed by freeze-drying, NFC hydrogels and aerogels were obtained. The NaOH-hydrogel demonstrated a decent rheology with a storage modulus of 36.4 kPa and a satisfactory mechanical property with a compressive modulus of 37.6 kPa. On the contrary, the acetone-hydrogel was weak due to disaggregation. The NFC aerogels were lightweight and had a characteristic porous structure. The packing density and structure varied among aerogels with different solution/solvent treatments. The NaOH-aerogel had a 2D sheet-like structure with densely packed micrometer-sized pores uniformly distributed within the aerogel network, which demonstrated a high compressive strength. However, the structures of other aerogels were loose, leading to a low compressive strength. These NFC aerogels demonstrated high thermal stability and superior performance for efficient thermal insulation. We believe our work can stimulate interest in the development of NFC hydro/aerogels with multiple structures, properties, and functions for a variety of applications.