hydrogen, [2] solar power plants, [3] photovoltaic cells, [4] photocatalysis, [5] and water desalination, [6] the photothermal materials based solar water evaporation is one of the most promising approaches for harvesting and conversion of solar energy. Solar vapor generation, more specifically, is a surface water evaporation process in which the light is absorbed and converted to heat energy by photothermal materials to generate vapor. Compared with the common water evaporation by solar radiation as heat source which suffers from the drawback of low solar energy conversion efficiency due to the fact that the part solar energy is converted to heat bulk water or is lost to the external environment, solar vapor generation based on photothermal materials has great advantages for its high light-to-heat conversion efficiency due to the fact that solar radiation is only harvested and located at the water-air interface to heat thin air-water surface layer that can effectively minimize the heat loss. [7] Based on the merits mentioned above, up to now, the solar steam generator has been emerged as a kind of efficient device for harvesting solar energy and attracted extensively much more attention in both industrial and academic research throughout the past decades. [8,9] In a given solar steam generation system, the photothermal materials is essential. A desired photothermal material should meet the following criteria: the broadband sunlight absorbability, low thermal conductivity, open porosity for rapid water molecules transportation, and high-energy conversion efficiency. [10,11] Understanding of these complementary roles of these parameters for photothermal material, so far, a number of photothermal materials, including carbon-based materials, [7,8,[12][13][14] metallic nanoparticles, [15][16][17] biomass-based materials, [18,19] and porous polymers, [20,21] etc., have been developed to use as efficient solar steam generators.In general, porous materials with bilayer structure are widely adapted as solar steam generator, in which the top layer consists of carbon materials for light absorption (e.g., graphene, [13] CNTs, [14] graphite, [7] etc.) while the bottom layer is composed by the porous materials (e.g., wood, [18] silica, [10] etc.) for Solar steam generation has been proven to be one of the most efficient approaches for harvesting solar energy for diverse applications such as distillation, desalination, and production of freshwater. Here, the synthesis of monolithic carbon aerogels by facile carbonization of conjugated microporous polymer nanotubes as efficient solar steam generators is reported. The monolithic carbon-aerogel networks consist of randomly aggregated hollow-carbon-nanotubes (HCNTs) with 100-250 nm in diameter and a length of up to several micrometers to form a hierarchically nanoporous network structure. Treatment of the HCNTs aerogels with an ammonium peroxydisulfate/sulfuric acid solution endows their superhydrophilic wettability which is beneficial for rapid transportation of water molecules. ...

Although the rational designed mechanochromic polymer (MCP) materials have evoked major interest and experienced significant progress recently, it is still a great challenge to develop a facile and effective strategy for preparation of reversible broad-spectrum MCPs with a combination of wide-range color switch ability and high sensitivity, which thus make it possible to mimic gorgeous color change as in nature. Herein, we designed and synthesized a novel rhodamine-based mechanochromic elastomer. Our results demonstrated that the elastomer exhibited very promising and unique properties. Three primary fluorescence colors were presented during continuous uniaxial extension and relaxing process, and reversible broad-spectrum fluorescence color change could be achieved consequently. The fluorescence quantum yield of the opened zwitterion of this new mechanophore was as high as 0.67. In addition, the elastomer showed very high sensitivity to stress with a detectable activation strain of ∼0.24, which was much smaller than those reported in the previous literature reports. Meantime, the easy-to-obtain material, facile preparation, and good mechanical property also made it suitable for potential practical applications.

It is becoming more important to detect ultralow concentrations of analytes for biomedical, environmental, and national security applications. Equally important is that new methods should be easy to use, inexpensive, portable, and if possible allow detection by the naked eye. By and large, detection of low concentrations of analytes cannot be achieved directly but requires signal amplification by catalysts, macromolecules, metal surfaces, or supramolecular aggregates. The rapidly progressing field of macromolecular signal amplification has been advanced using conjugated polymers, chirality in polymers, solvating polymers, and polymerization/depolymerization strategies. A new type of aptamer-based hydrogel with specific response to target proteins presented in this report demonstrates an additional category of macromolecular signal amplification. This superaptamer assembly provides the first example of using protein-specific aptamers to create volume-changing hydrogels with amplified response to the target protein. A remarkable aspect of these superaptamer hydrogels is that volume shrinking is visible to the naked eye down to femtomolar concentrations of protein. This extraordinary macromolecular amplification is attributed to a complex interplay between protein-aptamer supramolecular cross-links and the consequential reduction of excluded volume in the hydrogel. Specific recognition is even maintained in biological matrices such as urine and tears. Furthermore, the gels can be dried for long-term storage and regenerated for use without loss of activity. In practice, the ease of this biomarker detection method offers an alternative to traditional analytical techniques that require sophisticated instrumentation and highly trained personnel.

A self-adjusting, blood vessel-mimicking, multilayered tubular structure with two polymers, poly(ε-caprolactone) (PCL) and poly(dl-lactide-co-glycolide) (PLGA), can keep the shape of the scaffold during biodegradation. The inner (PCL) layer of the tube can expand whereas the outer (PLGA) layers will shrink to maintain the stability of the shape and the inner space of the tubular shape both in vitro and in vivo over months. This approach can be generally useful for making scaffolds that require the maintenance of a defined shape, based on FDA-approved materials.