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Superhydrophobic surfaces have shown versatile applications in waterproofing, self-cleaning, drag reduction, selective absorption, etc. The most convenient and universally applicable approach to forming superhydrophobic surfaces is by coating; however, currently, superhydrophobic, smart coatings with flexibility and multiple functions for wearable sensing electronics are not yet reported. Here, a highly flexible multifunctional smart coating is fabricated by spray-coating multiwalled carbon nanotubes dispersed in a thermoplastic elastomer solution, followed by treatment with ethanol. The coatings not only endow various substrate materials with superhydrophobic surfaces, but can also respond to stretching, bending, and torsion—a property useful for flexible sensor applications. The coatings show superior sensitivity (gauge factor of 5.4–80), high resolution (1° of bending), a fast response time (<8 ms), a stable response over 5000 stretching–relaxing cycles, and wide sensing ranges (stretching: over 76%, bending: 0°–140°, torsion: 0–350 rad m⁻¹). Moreover, multifunctional coatings with thicknesses of only 1 µm can be directly applied to clothing for full-range and real-time detection of human motions, which also show extreme repellency to water, acid, and alkali, which helps the sensors to work under wet and corrosive conditions.

A multifunctional, stretchable smart coating is fabricated by spray-coating multiwalled carbon nanotubes dispersed in a thermoplastic elastomer solution, followed by treatment with ethanol. The coatings are superhydrophobic and piezoresistive, for water repellency and wearable strain-sensor applications. The extreme repellency to water, UV, acid, and alkali characteristics of the coating endow highly sensitive and stable sensing performance under wet/corrosive conditions.

A new water-assisted carbon–sulfur bond-formation strategy is described for direct access to highly valuable (arylsulfonyl)catechols. This scalable transformation is remarkable, as a tandem dearomatization/sulfonylation and hydroxylation process enabled the title compounds to be formed in one pot under catalyst-free conditions. Mechanistic studies revealed that water plays a key role in the synthesis of the catechols. The sulfonylation operates under very mild conditions, shows a broad substrate scope, gives high conversions, and can be carried out on a gram scale. Thus, this method represents a green, efficient method for carbon–sulfur bond formation. The aryl sulfones were also further transformed into molecules that are important for drug discovery.

We describe a catalyst-free method for the direct sulfonylation of 2-methoxyphenols in aqueous media under mild conditions to give (arylsulfonyl)catechols in good to excellent yields. The reaction is environmentally friendly and scalable, and has a broad substrate scope. Some of the synthesized catechol derivatives have been transformed into analogues of COMT inhibitors.

Novel quadruple stimuli-responsive mechanized silica nanoparticles were constructed by installation of supramolecular nanovalves onto the exterior surface of mesoporous silica nanoparticles. The release of cargo molecules is triggered by acid/Zn²⁺/alkali/reduction potential stimuli. This has potential application in the development of drug delivery systems or construction of smart anticorrosion coatings.

Fourth time′s the charm: Mesoporous silica nanoparticles grafted with unique supramolecular nanovalves: The controlled release behaviors can be triggered by quadruple stimuli: acid/alkaline/Zn²⁺/reduction.

A template-mediated process for the preparation of mesoporous carbon shells with high surface area, dual-pore structure, and excellent performance in the adsorption of humic acid is reported. Their synthesis involves templating phenolic resin against wrinkled silica nanospheres, subsequent carbonization under Ar atmosphere, and final release of dual-pore mesoporous carbon shells by etching the silica templates. An additional silica layer was used to protect the phenolic resin from aggregation during carbonization, and its subsequent removal gives the carbon shells a hydrophilic surface, which significantly improves their dispersity in aqueous media. When used as adsorbents for humic acid removal, the as-prepared dual-pore mesoporous carbon shells show superior adsorption performance to activated carbon.

Mesoporous carbon adsorbents: A template-mediated process for the preparation of mesoporous carbon shells with high surface area, dual-pore structure, and excellent performance in the adsorption of humic acid was developed (see figure). The as-prepared dual-pore mesoporous carbon shells show superior adsorption performance to activated carbon in the removal of humic acid from water.

Smart surfaces with controllable wettability have attracted substantial interest owing to the potential use of these materials for the separation of oil from oily water caused by frequent oil-spill accidents. Because there are few separation materials on the market that are capable of switching between hydrophobicity and hydrophilicity, this work reports an efficient and low-cost method to fabricate a photoresponsive membrane through the sulfur(VI) fluoride exchange reaction (SuFEx) between poly(4-vinylphenol sulfofluoridate) and (E)-1-(4-(tert-butoxy)phenyl)-2-(4-(trifluoromethoxy)phenyl)diazene. The resulting material displays switchable wettability between hydrophobic and hydrophilic states when subjected to ultraviolet or visible irradiation. This membrane can be recycled (greater than five times) and features superior efficiency (up to 97.9 %) for the separation of oils that have both higher and lower densities than water. This work is the first proof-of-concept application of SuFEx to fabricate functional materials for environmental remediation.

An intelligent polymer with switchable wettability was synthesized through a click reaction (sulfur(VI) fluoride exchange reaction) between silylated compounds containing an azobenzene structure and fluorinated polymer (poly(4-vinylphenol sulfofluoridate)). The azobenzene derivative on the surface of the polymer provides it with photoswitchable wettability between hydrophobicity and hydrophilicity by adjusting UV or visible light irradiation.

With the Minamata Convention coming into force this year, there is a growing requirement for low-cost sorbents for mercury pollution. Thus, a polysulfide was prepared by the co-polymerization of sulfur and canola oil. As sulfur is a byproduct of the petroleum industry and used cooking oils are suitable starting materials, the resulting sorbent can be prepared entirely from waste. This high-sulfur rubber was effective in trapping diverse forms of mercury including mercury metal, inorganic mercury, and organomercury compounds. More information can be found in the Full Paper by J. M. Chalker et al. (DOI: 10.1002/chem.201702871).

Bionic condensate microdrop self-propelling (CMDSP) surfaces are attracting increased attention as novel, low-adhesivity superhydrophobic surfaces due to their value in fundamental research and technological innovation, e.g., for enhancing heat transfer, energy-effective antifreezing, and electrostatic energy harvesting. Here, the focus is on recent progress in bionic CMDSP surfaces. Metal-based CMDSP surfaces, which are the most promising in their respective fields, are highlighted for use in future applications. The selected topics are divided into four sections: biological prototypes, mechanism and construction rules, fabrication, and applications of metal-based CMDSP surfaces. Finally, the challenges and future development trends in bionic CMDSP surfaces are envisioned, especially the utilization of potential bionic inspiration in the design of more advanced CMDSP surfaces.

Biological inspirations, mechanisms, and construction rules of emerging bionic condensate microdrop self-propelling (CMDSP) surfaces are presented, and fabrication methods and technological innovations of metal-based CMDSP surfaces, involving heat transfer enhancement, energy-effective antifreezing, and electrostatic energy harvesting, are highlighted. Finally, their challenges and development trends are envisaged, especially the design of more advanced bionic CMDSP surfaces.

Existing Janus filters cannot separate oil from emulsions stabilized by nonionic surfactants. Reported herein are universal Janus filters that separate oil from emulsions stabilized by not only ionic but also nonionic surfactants. To prepare such a filter, poly(dimethyl siloxane) (PDMS) is grafted onto one side of a fabric. The other side is then grafted with a copolymer polysoap bearing pendant oligo(ethylene glycol) monolaurate (EL) chains. Upon contact with an emulsion, the grafted polysoap competes with free surfactants, ionic or nonionic, for adsorption onto the emulsified droplets, drawing them to the surfaces of the fabric fibers, and causes them to coalesce locally. The coalesced oil then migrates to the PDMS-coated side of the fabric and selectively permeates it. These novel filters possess enhanced versatility and showcase a new application for polysoaps.

Janus fabric filter: A surfactant was grafted onto one side of a cotton fabric, and silicone was grafted onto the other. The surfactant draws emulsified oil droplets to the surface of the fabric fibers and causes them to coalesce. The coalesced oil globules then selectively permeate the silicone-coated hydrophobic side.

An efficient and green synthetic method for the preparation of N,N-disubstituted tetramethylpyrazinium radical cations was developed, which does not require any solvent or strong alkylating agents. The investigation by UV/Vis and electron paramagnetic resonance (EPR) spectroscopy proved the stability of the prepared radical cation. Moreover, it was shown for the first time that the prepared N,N-disubstituted tetramethylpyrazine can act as a powerful metal-free catalyst for the selective oxidative homocoupling of amines to the corresponding imines under solvent-free conditions. Furthermore, oxygen or even air can be employed as an efficient oxidative reagent.

The long-living pyrazine radical cations derived from N,N-disubstituted tetramethylpyrazines were used for the first time as a catalyst for the selective oxidative homocoupling of amines to the corresponding imines under solvent-free conditions by using oxygen (from air) as the terminal oxidant.

Several examples of nucleophilic substitution reactions of compounds that have good leaving groups have been previously reported, but the direct use of simple alcohols still remains a challenge because of the poor leaving ability of the hydroxy group. Herein, an efficient and highly chemoselective method for the S-benzylation of a wide range of aromatic and aliphatic thiols has been accomplished in the presence of catalytic amounts (0.1–0.2 mol-%) of indium(III) triflate. Our approach is atom efficient (water is the only byproduct) and suitable to obtain the corresponding unsymmetrical thioethers in excellent yields (up to 99 %). The low loading of catalyst that are needed to obtain extraordinarily high chemoselectivities and the generality of the reaction make this approach unique.

We have developed a highly efficient method for the chemoselective nucleophilic substitution of tertiary and secondary benzylic alcohols with aliphatic and aromatic thiols in the presence of catalytic amounts of indium(III) triflate under mild conditions. A broad range of unsymmetrical sulfides were synthesized in excellent isolated yields (89–99 %) by using this approach.

A series of anion-functionalized pillararenes were prepared and applied in the capture of SO₂ through incorporating an anion with different basicity into pillararenes. A high SO₂ absorption capacity up to 15.9 mmol g⁻¹ and excellent reversibility were achieved by tuning the basicity of the anion and the size of the cavity. Spectroscopic investigations and DFT calculations indicated that high SO₂ capacity originated from multiple sites interaction between SO₂ and the anion, where SO₂ chemical absorption was significant strengthened by the cavity, because the anion was confined in the window of the cavity and the window was electron-deficient. Interestingly, a phase transition occurred during absorption and desorption process. The method proposed in this work provided an efficient strategy for improving gas absorption through a simple functionalization of the supermolecule, which was also very important for some other fields such as polymers and materials.

Catch me! A series of anion-functionalized pillararenes were prepared and applied in the capture of SO₂, which exhibited high SO₂ capacity and excellent reversibility, where SO₂ chemical absorption was strenghened significantly by the cavity.

Recyclable materials for simultaneous detection and uptake of ammonia (NH₃) are of great interest due to the hazardous nature of NH₃. The structural versatility and porous nature of metal–organic frameworks (MOFs) make them ideal candidates for NH₃ capture. Herein, the synthesis of a water-stable and porous 3-dimensional Cu^II-based MOF (SION-10) displaying a ship-in-a-bottle structure is reported; the pores of the host SION-10 framework accommodate mononuclear Cu^II-complexes. SION-10 spontaneously uptakes NH₃ as a result of two concurrent mechanisms: chemisorption due to the presence of active Cu^II sites and physisorption (bulk permanent porosity). The color of the material changes from green to blue upon NH₃ capture, with the shifts of the UV/Vis absorption bands clearly seen at NH₃ concentrations as low as 300 ppm. SION-10 can be recovered upon immersion of SION-10⊃NH₃ in water and can be further reused for NH₃ capture for at least three cycles.

Response to Ammonia: A water stable and porous ship-in-a-bottle structure (SION-10), spontaneously uptakes NH₃ and displays high sensitivity toward this hazardous gas. The SION-10⊃NH₃ can be easily regenerated and recycled for at least three times.

Hypergolic ionic liquids (HILs) are a family of promising green fuels among the liquid propellants. As compared to previous studies and mainly focusing on structural innovations and ignition improvement of anions, here a new strategy of introducing energetic nitrato group into the cationic framework is proposed and is aimed at providing additional oxygen in the fuel molecule to enhance the combustion performance of HILs. These newly developed nitrato-functionalized HILs exhibit improved physical properties and combustion behavior including higher density, larger combustion flames, and longer combustion duration. More information can be found in the Full Paper by Q. Zhang et al. (DOI: 10.1002/chem.201701804).