Ice accumulation causes various problems in our daily life for human society. The daunting challenges in ice prevention and removal call for novel efficient antiicing strategies. Recently, photothermal materials have gained attention for creating icephobic surfaces owing to their merits of energy conservation and environmental friendliness. However, it is always challenging to get an ideal photothermal material which is cheap, easily fabricating, and highly photothermally efficient. Here, we demonstrate a low-cost, high-efficiency superhydrophobic photothermal surface, uniquely based on inexpensive commonly seen candle soot. It consists of three components: candle soot, silica shell, and polydimethylsiloxane (PDMS) brushes. The candle soot provides hierarchical nano/microstructures and photothermal ability, the silica shell strengthens the hierarchical candle soot, and the grafted low-surface-energy PDMS brushes endow the surface with superhydrophobicity. Upon illumination under 1 sun, the surface temperature can increase by 53 °C, so that no ice can form at an environmental temperature as low as −50 °C and it can also rapidly melt the accumulated frost and ice in 300 s. The superhydrophobicity enables the melted water to slide away immediately, leaving a clean and dry surface. The surface can also self-clean, which further enhances its effectiveness by removing dust and other contaminants which absorb and scatter sunlight. In addition, after oxygen plasma treatment, the surface can restore superhydrophobicity with sunlight illumination. The presented icephobic surface shows great potential and broad impacts owing to its inexpensive component materials, simplicity, ecofriendliness, and high energy efficiency.

Highlights d SARS-CoV-2 genome sequencing and phylogenetic analyses identify 35 recurrent mutations d Association with 117 clinical phenotypes reveals potentially important mutations d D500-532 in Nsp1 coding region correlates with lower viral load and serum IFN-b d Viral isolates with D500-532 mutation induce lower IFN-I response in the infected cells

Crosslinked polymers and gels are important in soft robotics, solar vapor generation, energy storage, drug delivery, catalysis, and biosensing. However, their attractive mass transport and volume‐changing abilities are diffusion‐limited, requiring miniaturization to avoid slow response. Typical approaches to improving diffusion in hydrogels sacrifice mechanical properties by increasing porosity or limit the total volumetric flux by directionally confining the pores. Despite tremendous efforts, simultaneous enhancement of diffusion and mechanical properties remains a long‐standing challenge hindering broader practical applications of hydrogels. In this work, cononsolvency photopolymerization is developed as a universal approach to overcome this swelling–mechanical property trade‐off. The as‐synthesized poly(N‐isopropylacrylamide) hydrogel, as an exemplary system, presents a unique open porous network with continuous microchannels, leading to record‐high volumetric (de)swelling speeds, almost an order of magnitude higher than reported previously. This swelling enhancement comes with a simultaneous improvement in Young's modulus and toughness over conventional hydrogels fabricated in pure solvents. The resulting fast mass transport enables in‐air operation of the hydrogel via rapid water replenishment and ultrafast actuation. The method is compatible with 3D printing. The generalizability is demonstrated by extending the technique to poly(N‐tertbutylacrylamide‐co‐polyacrylamide) and polyacrylamide hydrogels, non‐temperature‐responsive polymer systems, validating the present hypothesis that cononsolvency is a generic phenomenon driven by competitive adsorption.

Nitroxides have great potential as magnetic resonance imaging (MRI) contrast agents for tumor detection. Polyacetylenes(PAs) containing 2,2,6,6-tetramethyl-piperidine oxyl (TEMPO) and poly(ethylene glycol) were synthesized via metathesis polymerization of the corresponding substituted acetylenes to be used for targeted bimodal MRI /optical imaging of tumors. The poly(ethylene glycol) in the polyacetylenes enables covalent conjugation of carboxyl fluorescein and folic acid (FA) with hydroxyl groups to develop targeted multifunctional organic radical contrast agents (ORCAs). In vitro studies confirm the excellent binding specificity and subsequent enhanced cellular internalization of the targeted ORCAs (PA-TEMPO-FI-FA) without cytotoxicity. In vivo T1-weighted MRI demonstrates the active tumor targeting ability of PA-TEMPO-FI-FA to generate specific contrast enhancement in mice bearing HeLa tumors. Moreover, longitudinal optical imaging displays high tumor accumulation after 1 h post-injection of PA-TEMPO-FI-FA. These results indicate that multifunctional ORCAs may provide a tumor-targeted delivery platform for further molecular imaging guided cancer therapy.

As the soaring demand for energy storage continues to grow, batteries that can cope with extreme conditions are highly desired. Yet, existing battery materials are limited by weak mechanical properties and freeze‐vulnerability, prohibiting safe energy storage in devices that are exposed to low temperature and unusual mechanical impacts. Herein, a fabrication method harnessing the synergistic effect of co‐nonsolvency and “salting‐out” that can produce poly(vinyl alcohol) hydrogel electrolytes with unique open‐cell porous structures, composed of strongly aggregated polymer chains, and containing disrupted hydrogen bonds among free water molecules, is introduced. The hydrogel electrolyte simultaneously combines high strength (tensile strength 15.6 MPa), freeze‐tolerance (< −77 °C), high mass transport (10× lower overpotential), and dendrite and parasitic reactions suppression for stable performance (30 000 cycles). The high generality of this method is further demonstrated with poly(N‐isopropylacrylamide) and poly(N‐tertbutylacrylamide‐co‐acrylamide) hydrogels. This work takes a further step toward flexible battery development for harsh environments.