Light or heavy oil and water mixtures can by separated selectively with high efficiency using potato residue coated meshes.

Wearable and stretchable electronics including various conductors and sensors are featured with their lightweight, high flexibility, and easy integration into functional devices or textiles. However, most flexible electronic materials are still unsatisfactory due to their poor recoverability under large strain. Herein, we fabricated a carbon nanotubes (CNTs) and polyurethane (PU) nanofibers composite helical yarn with electrical conductivity, ultrastretchability, and high stretch sensitivity. The synergy of elastic PU molecules and springlike microgeometry enable the helical yarn excellent stretchability, while CNTs are stably winding-locked into the yarn through a simple twisting strategy, making good conductivity. By virtue of the interlaced conductive network of CNTs in microlevel and the helical structure in macrolevel, the CNTs/PU helical yarn achieves good recoverability within 900% and maximum tensile elongation up to 1700%. With these features, it can be used as a superelastic and highly stable conductive wire. Moreover, it also can monitor the human motion as a rapid-response strain sensor by adjusting the content of the CNTs simply. This general and low-cost strategy is of great promise for ultrastretchable wearable electronics and multifunctional devices.

Multi‐wall Sn/SnO2@carbon hollow nanofibers evolved from SnO2 nanofibers are designed and programable synthesized by electrospinning, polypyrrole coating, and annealing reduction. The synthesized hollow nanofibers have a special wire‐in‐double‐wall‐tube structure with larger specific surface area and abundant inner spaces, which can provide effective contacting area of electrolyte with electrode materials and more active sites for redox reaction. It shows excellent cycling stability by virtue of effectively alleviating pulverization of tin‐based electrode materials caused by volume expansion. Even after 2000 cycles, the wire‐in‐double‐wall‐tube Sn/SnO2@carbon nanofibers exhibit a high specific capacity of 986.3 mAh g−1 (1 A g−1) and still maintains 508.2 mAh g−1 at high current density of 5 A g−1. This outstanding electrochemical performance suggests the multi‐wall Sn/SnO2@ carbon hollow nanofibers are great promising for high performance energy storage systems.

Anisotropic interfaces with opposite properties provide numerous unusual physical chemical properties that have played irreplaceable roles in broad domains. Here, we rationally designed an anisotropic Janus membrane with opposite wettability and special interpenetrating interface microstructure, which shows a unidirectional liquid penetration "diode" performance. Liquid is allowed to penetrate from lyophobic to lyophilic direction but is blocked in the reverse direction. Although conventional works suggested the liquid unidirectional penetration is driven by anisotropic wettability in heterogeneous interfaces, here, we theoretically and experimentally reveal that special interpenetrating topology plays another important role in liquid unidirectional penetration. This insight gives a general guide to build a series of Janus membranes for liquid unidirectional penetration with high hydraulic pressure rectification ratio. The liquid diode Janus membrane indicates great promise for liquid manipulation, smart separation membranes, functional textiles, and other fields.

A hybrid membrane with asymmetric microtopology and anisotropic wettability realizes highly efficient fog collection.

No abstract

Oil/water separation is of great importance for the treatment of oily wastewater, including immiscible light/heavy oil-water mixtures, oil-in-water or water-in-oil emulsions. Smart surfaces with responsive wettability have received extensive attention especially for controllable oil/water separation. However, traditional smart membranes with a switchable wettability between superhydrophobicity and superhydrophilicity are limited to certain responsive materials and continuous external stimuli, such as pH, electrical field or light irradiation. Herein, a candle soot coated mesh (CSM) with a larger pore size and a candle soot coated PVDF membrane (CSP) with a smaller pore size with underwater superoleophobicity and underoil superhydrophobicity were successfully fabricated, which can be used for on-demand immiscible oil/water mixtures and surfactants-stabilized oil/water emulsion separation, respectively. Without any continuous external stimulus, the wettability of our membranes could be reversibly switched between underwater superoleophobicity and underoil superhydrophobicity simply by drying and washing alternately, thus achieving effective and switchable oil/water separation with excellent separation efficiency. We believe that such smart materials will be promising candidates for use in the removal of oil pollutants in the future.

No abstract