Microtubular PEDOT-Coated Bricks for Atmospheric Water Harvesting

Biomimetic Network and Microstructure for Multifunctional Recyclable Ramie Fiber-Reinforced Composites: High-Hydrophobic, Wave-Transparent, and Heat-Conducting

Ramie fiber yarn (PRF), characterized by its superior microwave transmittance (MWT), is a novel material that can effectively substitute traditional glass fiber (D-GF) in the fabrication of composites for communication equipment shells. However, the super hydrophilicity and inadequate thermal conductivity (λ) of PRF hinder its overall performance and safety in use. To date, no effective strategy has been developed to prepare multifunctional PRF-reinforced composites, including high hydrophobicity, MWT, and λ. Herein, by integrating the template method with vacuum-assisted spraying technology, a mosquito-eye-like honeycomb network was constructed on the surface of PRF fabric. This network, composed of nacre-like brick-and-mortar microstructures as its fundamental units, achieves both mesoscopic and microscopic order. The biomimetic network and microstructure enable the PRF fabric to transition from superhydrophilic to high-hydrophobic, significantly reducing water absorption in PRF-reinforced composites to levels similar to D-GF-reinforced composites. Furthermore, the biomimetic structures are incorporated into the composite interface via the fabric surface, resulting in MWT and λ values of up to 98% and 1.0582 W/mK, respectively. Importantly, PRF-reinforced composite waste can be fully transformed to multifunctional particles, thereby enabling closed-loop recycling and reuse. This biomimetic network and microstructure offer an efficient and versatile surface modification strategy for multifunctional composites.

Porous Spindle-Knot Fiber by Fiber-Microfluidic Phase Separation for Water Collection and Nanopatterning

Porous spindle-knot structures have been found in many creatures, such as spider silk and the root of the soybean plant, which show interesting functions such as droplet collection or biotransformation. However, continuous fabrication of precisely controlled porous spindle-knots presents a big challenge, particularly in striking a balance among good structural controllability, low-cost, and functions. Here, we propose a concept of a fiber-microfluidics phase separation (FMF-PS) strategy to address the above challenge. This FMF-PS combines the advantages of a microchannel regulated Rayleigh instability of polymer solution coated onto a fiber with the nonsolvent-induced phase separation of the polymer solution, which enables continuous and cost-effective production of porous spindle-knot fiber (PSKF) with well-controlled size and porous structures. The critical factors controlling the geometry and the porous structures of the spindle-knot by FMF-PS have been systematically investigated. For applications, the PSKF exhibited faster water droplet nucleation, growth, and maximum water collection capability, compared to the control samples, as revealed by in situ water collection growth curves. Furthermore, high-level fabrics of the PSKFs, including a two-dimensional network and three-dimensional architecture, have been demonstrated for both large-scale water collection and art performance. Finally, the PSKF is demonstrated as a programmable building block for surface nanopatterning.

Neonatal rat ventricular myocytes interfacing conductive polymers and carbon nanotubes

Carbon nanotubes (CNTs) have become promising advanced materials and a new tool to specifically interact with electroresponsive cells. Likewise, conductive polymers (CP) appear promising electroactive biomaterial for proliferation of cells. Herein, we have investigated CNT blends with two different conductive polymers, polypyrrole/CNT (PPy/CNT) and PEDOT/CNT to evaluate the growth, survival, and beating behavior of neonatal rat ventricular myocytes (NRVM). The combination of CP/CNT not only shows excellent biocompatibility on NRVM, after 2 weeks of culture, but also exerts functional effects on networks of cardiomyocytes. NRVMs cultured on CNT-based substrates exhibited improved cellular function, i.e., homogeneous, non-arrhythmogenic, and more frequent spontaneous beating; particularly PEDOT/CNT substrates, which yielded to higher beating amplitudes, thus suggesting a more mature cardiac phenotype. Furthermore, cells presented enhanced structure: aligned sarcomeres, organized and abundant Connexin 43 (Cx43). Finally, no signs of induced hypertrophy were observed. In conclusion, the combination of CNT with CP produces high viability and promotes cardiac functionality, suggesting great potential to generate scaffolding supports for cardiac tissue engineering.

Hygroscopic and Photothermal All-Polymer Foams for Efficient Atmospheric Water Harvesting, Passive Humidity Management, and Protective Packaging

Environmental humidity and thermal control are of primary importance for fighting global warming, growing energy consumption, and greenhouse gas emissions. Sorption-based atmospheric water harvesting is an emerging technology with great potential in clean water production and passive cooling applications. However, sorption-based humidity management and their hybrid applications are limited due to the lack of energywise designs of hygroscopic materials and devices. Herein, all polymeric 3D foams are developed and evaluated as hygroscopic and photothermal materials. The gas-foaming method generates closed-cell structures with interconnected hydrophilic networks and wrinkled surfaces, expanding hygroscopic, photothermal, and evaporating areas of the 3D foams. These unique advantages lead to efficient water vapor sorption in a wide broad relative humidity (RH) range of 50-90% and efficient water release in a wide solar intensity (0.4-1 sun) and temperature range (27-80 °C). The reversible moisture sorption/release in 50 adsorption/desorption cycles highlights the excellent durability of the 3D foams compared to conventional inorganic desiccants. The 3D foams disclose passive and efficient apparent temperature regulation in warm and humid environments. Moreover, the use of the 3D foams as loose fill for fruit preservation and packaging is demonstrated for the first time by taking the merit of the 3D foams' moisture-absorbing, quick-drying, cushioning, and thermal-insulating properties. This work presents an integrated design of polymeric desiccants and scaffolds, not merely delivering stable water adsorption/desorption but also discovering innovative hybrid applications in humidity management and protective packaging.