Su Chen

Fibrous films and fabrics have been extensively employed for solar photothermal interfacial evaporation due to their high specific surface area, flexibility and scalability. However, the inherent planar geometry of fibrous films/fabrics restricts the evaporation area, and vapor/mass diffusion, limiting the evaporation efficiency and inducing salt accumulation. Herein, we propose a strategy of shifting the planar fabrics to photothermal helical microfiber evaporators via microfluidic technology, featuring intrinsic three‐dimensional structure, prominent elasticity and flexibility. The distinctive central cavity in helical gel microfibers enables spatial regulation of light, thermal and water transport, not only expanding evaporation area but also efficiently localizing thermal energy and capturing additional energy. By tuning the helical pitch, the water transport, vapor diffusion and light capture capabilities are synergistically optimized, achieving an evaporation rate of 3.65 kg m ^{− 2} h ^{− 1} under 1 sun irradiation with superior salt resistance. Moreover, the excellent flexibility of the helical microfiber fabric imparts exceptional structural adjustability, allowing to perform solar‐tracking evaporation. Outdoor tests using such solar‐tracking system with enlarged evaporation area deliver a stable evaporation rate of 8.57 kg m ^{− 2} h ^{− 1} under solar intensity of ∼950 W m ^{− 2} , which demonstrates a viable design concept for high‐performance fabric‐based evaporators in sustainable solar interfacial evaporation.

A time-saving approach to gelatin-based hydrogels with versatile properties is highly desirable. Herein, we report the rapid fabrication of new gelatin-containing hydrogels with favorable mechanical properties, biocompatibility and antibacterial capability. Frontal polymerization (FP) of acrylic acid (AA), acrylamide (AM), hydroxypropyl acrylate (HPA) with gelatin methacryloyl (GelMA) enables the rapid formation of multifunctional hydrogels within 7 min, providing a highly efficient route for gelatin-based hydrogel fabrication. The effect of GelMA content on FP features and hydrogel properties was systematically investigated. The resultant hydrogels show attractive collective properties with tensile strength up to 101.3 kPa, elongation at break up to 227.7%, cell viability of 96% after 24 h, and antibacterial activity against S. aureus (92.2%). In addition, the FP of the hydrogels with use of forsythia-derived carbon dots (F-CDs) as bioactive nanofillers is explored, conferring the hydrogels with enhanced mechanical performance and biocompatibility, demonstrating the applicability of this FP strategy upon incorporating functional additives. This work provides a simple and effective approach for the rapid preparation of gelatin-containing hydrogels with versatile functions promising for biomedical applications such as wound healing and tissue engineering.

Methods that allow polymer film to be carried out in a heterogeneous structure and scalable manner are highly desirable in materials science. Herein, a planar frontal polymerization (FP) strategy is presented that enables sustainable and scalable fabrication of heterogeneous films. Gravitational/buoyancy‐oriented assembly of optical microspheres ensures vertically graded photonic heterostructure. Meanwhile, FP eliminates the sustaining energy supply while achieving precise spatial immobilization of the heterostructure. The resultant films demonstrate structure and dimensional effects associated with optical responsiveness. It is shown that the heterogeneous film coupling with high‐crystallinity colloid photonic crystal exhibits high solar reflectance (), enhanced infrared emissivity () and tunable structural colors. Notably, the cooling performance of this colored hybrid coating surpasses that of most state‐of‐the‐art cooling designs with ≈7.0 °C sub‐ambient daytime cooling. Strikingly, this planar FP strategy offers feasibility and convenience for the scalable production of heterogeneous films, ensuring widespread applicability in industrialization for building envelopes.

Methods allowing passive daytime radiative cooling (PDRC) to be carried out in an energy-efficient and scalable way are potentially important for various disciplines. Here, we report a sustainable strategy for scalable-designed and color-regulating PDRC coating based on high-crystallinity photonic metamaterial (crystallinity: 71.5%; enhanced assembly efficiency: 72%), that is derived from the as-prepared 55 wt% solid content poly(methyl methacrylate-butyl acrylate-methacrylic acid) P(MMA-BA-MAA) monodispersed latexes (approaching theoretical limit: 59 wt%). Robust meter-scale PDRC coatings are constructed by various industrial modes onto diverse surfaces, addressing bottlenecks like dull appearance, high cost, low efficiency, and hard construction. Notably, the solar reflectance, long-wave infrared emittance, and calculated theoretical cooling power of the designed PDRC coating, respectively, reach ~ 0.94, ~ 0.97, and ~ 95.5 W m ⁻² under solar radiation, which can achieve an average 5.3 °C sub-ambient daytime temperature drop in the summer in Nanjing. The cooling performance, scale preparation, and cost-effectiveness of the PDRC coating have extended into leading position compared with those of state-of-the-art designs. This work provides promising route to reduce carbon emissions and energy consumption for global sustainability.

Freshwater crisis has emerged as a global problem, which has significant negative impact on human production and life. Thus, material design and fabrication are extremely necessary for high salt tolerance and highly efficient evaporation in freshwater production. In this work, polyzwitterionic hydrogel is designed by an in situ frontal curing‐3D printing strategy, which greatly saves times and energy, while ensuring high fidelity and integrity of the printed structure. The polyzwitterionic hydrogel has anti‐polyelectrolyte effect and boosted hydration, showing a higher intermediate water/free water ratio and lower evaporation enthalpy. Meanwhile, the macro‐channels formed by 3D printing and inherent microchannels in hydrogels are synergistically enhancing the water transport performance. As a consequence, the hydrogel exhibits a high evaporation rate of 4.02 kg·m ⁻² ·h ⁻¹ in 15 wt.% NaCl solution with excellent salt tolerance. This work provides an in situ frontal curing‐3D printing strategy for the preparation of highly efficient and salt‐tolerant polyzwitterionic hydrogel evaporator, which would guide the development of advanced hydrogel evaporator in a facile fashion.

The application of solar interfacial evaporation technology in clean water production has garnered increasing attention in recent years, with thin-film evaporation being considered one of the most efficacious strategies to address the growing demand for high evaporation rates at moderate temperatures. This investigation presents the design of a Janus nanofiber film based on a self-pumping effect, comprising a hydrophobic layer (TPU) and a hydrophilic layer (PVA-(ε-PL)@MXene). This structure creates a self-pumping effect that promotes unidirectional transfer of liquids, effectively increasing water transfer efficiency and evaporation, achieving a maximum evaporation rate of 1.56 kg m^-2 h^-1 while maintaining 1.52 kg m^-2 h^-1 after multiple cycles. This Janus nanofiber film exhibits high performance in the 200-2500 nm range, demonstrating strong light absorption with an absorption efficiency of 87.69%, and rapidly increasing from room temperature to 57.8 °C in 3 min under 1 kW m^-2. Furthermore, TPU/PVA-(ε-PL)@MXene exhibited substantial antimicrobial activity against E. coli (89.77%) and S. aureus (53.96%), attributed to the inhibitory effect of ε-PL on the biosynthesis of proteins and enzymatic biomolecules.

3D printing has gained immense recognition owing to its fascinating ability for rapid prototyping and customization. However, the current methods usually require post‐processing (direct ink writing) or continuous energy input (stereolithography) for polymer gel curing. The former lowers the fidelity and integrity of the printed layers, whereas the latter suffers from high energy consumption. To address these issues, a frontal polymerization (FP)–3D printing–in situ‐curing method is developed to construct printable and polymerizable inks for acrylate‐based monomers and soft organogel materials. Once initiated, no external energy supply is required, which allows for real‐time conversion of monomers into polymers within seconds. Thus, the energy requirements are reduced by several orders of magnitude. More importantly, the printed structure is closely bonded, effectively avoiding the collapse and deformation of soft materials. The as‐printed organogel is used as an evaporator and achieves a high water‐evaporation rate of 3.77 kg m ⁻²  h ⁻¹ . This FP–3D printing–in situ‐curing strategy is an alternative, energy‐saving method for fabricating soft materials, enabling high fidelity and integrity of printed patterns with wide applicability.

Graphene carbonene fiber (GCF) supercapacitors are promising for portable/wearable electronics but suffer from fabrication‐induced restacking and uneven hybridization between graphene sheets and hybrid active materials, degrading electrochemical performance and hindering practical applications. Here, an innovative microfluidic‐spinning‐chemistry (MSC) method is proposed for the in situ construction of the nickel molybdate/porous GCF (NiMoO ₄ /PGCF) hybrid, which manifests a large specific surface area, high electrical conductivity, and abundant redox activity, facilitating ion diffusion, and ensuring energy storage and supply. As a result, the NiMoO ₄ /PGCFs express an exceptional areal capacitance of 3597.7 mF cm ⁻² in a three‐electrode system. Additionally, this flexible solid‐state NiMoO ₄ /PGCF supercapacitor presents large areal capacitance (1006.8 mF cm ⁻² ), ultrahigh energy density (218.5 µWh cm ⁻² ), and long‐term cycling stability (90.2% capacitive retention at 1 mA cm ⁻² after 20 000 cycles), which is capable of powering a toy windmill without extra recharging by other power sources. Furthermore, a demonstration of a supercapacitive controller using the solid‐state NiMoO ₄ /PGCF is presented, which could couple with a triode to manage the takeoff of gliding unmanned aircraft. This provides high‐efficiency start/stop control and safety redundancy for gliding unmanned aircraft, while also paving the way for the innovation of next‐generation gliding unmanned aircraft energy management and control systems.