Ultrafast molecular sieving through functionalized graphene membranes

Anticorrosion Coating with Heterogeneous Assembly of Nanofillers Modulated by a Magnetic Field

An anticorrosive coating with randomly distributed passive barriers and regionally enriched active corrosion inhibitors is developed by integrating mica nanosheets (MNSs) and magnetic-responsive core-shell mesoporous nanoparticles with 2-mercaptobenzothiazole (Fe₃O₄@mSiO₂/MBT) under magnetic field incubation. The bottom enriched Fe₃O₄@mSiO₂/MBT rapidly releases the MBT to form a passivation layer on corrosion sites, enhancing the corrosion inhibition efficiency by 30.36% compared with the control (NP_0.7EP-R). The impedance modulus |Z|_0.01 Hz of the sample (NP_0.7/MNS_0.5/EP) increases by five orders of magnitude compared with that of its control (NP_0.7/MNS₀EP) after 30 days of corrosion immersion. NP_0.7/MNS_0.5/EP exhibited the lowest corrosion rate (3.984 × 10^-5 mm/year) as compared to the other samples. Notably, the coating in a fractured state still maintains superior corrosion inhibition even after 40 day salt spray testing. The differentiated distribution of nanofillers was well confirmed by optical microscopy and SEM-EDS, and the synergistic effect of the active/passive integrated anticorrosive coating with merits of both comprehensive protection and fast responsiveness was systematically explored.

Photoresponsive Solid Nanochannels Membranes: Design and Applications

Light stimuli have notable advantages over other environmental stimuli, such as more precise spatial and temporal regulation, and the ability to serve as an energy source to power the system. In nature, photoresponsive nanochannels are important components of organisms, with examples including the rhodopsin channels in optic nerve cells and photoresponsive protein channels in the photosynthesis system of plants. Inspired by biological channels, scientists have constructed various photoresponsive, smart solid-state nanochannels membranes for a range of applications. In this review, the methods and applications of photosensitive nanochannels membranes are summarized. The authors believe that this review will inspire researchers to further develop multifunctional artificial nanochannels for applications in the fields of biosensors, stimuli-responsive smart devices, and nanofluidic devices, among others.

Tailoring CO2-Activated Ion Nanochannels Using Macrocyclic Pillararenes

Gas-responsive nanochannels have great relevance for applications in many fields. Inspired by CO₂-sensitive ion channels, herein we present an approach for designing solid-state nanochannels that allow controlled regulation of ion transport in response to alternate CO₂/N₂ stimuli. The pillar[5]arene (P5N) bearing diethylamine groups can convert into the water-soluble host P5C, containing cationic tertiary ammonium salt groups after absorbing CO₂. Subsequently, the nanochannel walls are tailored using P5N-based host-guest chemistry. The ion transport rate of K⁺ in the P5N nanochannels under CO₂ was 1.66 × 10^-4 mol h^-1 m^-2, whereas that under N₂ was 7.98 × 10^-4 mol h^-1 m^-2. Notably, there was no significant change to the ion current after eight cycles, which may indicate the stability and repeatability of CO₂-activated ion nanochannels. It is speculated that the difference in ion conductance resulted from the change in wettability and surface charge within the nanochannels in response to the gas stimuli. Achieving CO₂-activated ion transport in solid-state nanochannels opens new avenues for biomimetic nanopore systems and advanced separation processes.

Superior to graphene: super-anticorrosive natural mica nanosheets

Graphene has been generally considered to be the most ideal anticorrosive material based on its extraordinary impermeability, but tends in practical applications to promote metal corrosion because of its inherently high electrical conductivity. Mica nanosheets (MNSs), in contrast, display excellent electrical insulation properties, as well as excellent temperature stability and chemical durability, and show tremendous potential for protecting metals, and hence are a promising substitute for graphene. To date, however, there have been no reports about MNS-based anticorrosive coatings, since it is much more difficult to exfoliate high-quality MNSs than other layered materials. In this work, high-concentration (4.3 mg ml-1) ultrathin MNS (1-5 layers) dispersions were synthesized based on a facile and efficient hydrothermal exfoliation approach. Epoxy (EP) coatings were filled with the as-obtained MNSs to enhance the anticorrosion performance of the coatings, and their corrosion behaviors were studied systemically through a series of measurements. With the addition of only 0.4 wt% MNSs, the corrosion rate was observed to be reduced 6500 fold, and the coating impedance increased by four orders of magnitude compared with the blank EP coating. We believe that this method opens a novel avenue for developing high-performance anticorrosive coatings to replace graphene materials for metal protection.

High rejection performance ultrafiltration membrane with ultrathin dense layer fabricated by the movement and dissolution of metal–organic frameworks

Ultrafiltration membranes have potential to solve the problems of water pollution and shortage.