From Dynamic Superwettability to Ionic/Molecular Superfluidity.

Life systems present ultralow energy consumption in high-efficiency energy conversion, information transmission, and biosynthesis. The total energy intake of the human body is about 2000 kcal/day to maintain all of our activities, which is comparable to a power of ∼100 W. The energy required for the brain to work is equivalent to ∼20 W, and the rest of the energy (∼80 W) is used for other activities. All in vivo biosyntheses take place only at body temperature, which is much lower than that of in vitro reactions. To achieve these ultralow energy-consumption processes, there should be a kind of ultralow-resistivity matter transport in nanochannels (e.g., ionic and molecular channels), in which the directional collective motion of ions or molecules is a necessary condition rather than traditional Newton diffusion. The directional collective motion of ions and molecules is considered to be ionic/molecular superfluidity. The driving force of ionic/molecular superfluidity formation requires two necessary conditions: (1) Ions or molecules are confined at a certain distance (e.g., approximately twice Debye length (2λD) for ions or twice the van der Waals equilibrium distance (2d0) for molecules). (2) When the attractive potential energy (E0) is stronger than the thermal noise (kBTc), ionic/molecular superfluidity can be formed. The concept of ionic/molecular superfluidity will promote the understanding of energy conversion with ultralow energy consumption in biological systems. The swing of an eel's body generating electricity and cardiac resuscitation denote the conversion from mechanical energy to electrical energy, and mechanical modulation might result in a coherent resonance of ionic motion. The coherent resonance of Ca2+ in myocardium cells can induce a heartbeat, realizing the conversion from the electrical energy to the mechanical energy of a biological system. The macroscopic quantum state of ion channels is considered to be a carrier of neural information, and the environment field might play a significant role in regulating the macroscopic quantum states of various ion channels. In the biological ion channels system, the coupling of ion channels and their released photons might induce an environment wave which in turn regulates the ion oscillations in the channels to a coherent state. The states of decoherence and coherence might correspond to the states of sleep and action. We also demonstrated the decomposition of ATP to ADP released photons with a frequency of ∼34 THz, which could further drive DNA polymerization in the nanocavity of DNA polymerase. The photochemical (mid- and far-IR) reaction might be the driving force in high-efficiency biosynthesis. Quantized syntheses resonantly driven by multiple mid- and far-IR photons could be further designed in a tubular reactor with membranes of different microporous structures to achieve a high-efficiency synthesis with a low energy consumption. Finally, we point out that the Bose-Einstein condensate potentially widely exists. We expect that this Account will provide new ideas for the key problem in life science: how can life systems present ultralow energy consumption in high-efficiency energy conversion, information transmission, and biosynthesis?

Delicate Control on the Shell Structure of Hollow Spheres Enables Tunable Mass Transport in Water Splitting.

In the study of structure-property relationships for rational materials design, hollow multishell structures (HoMSs) have attracted tremendous attention owing to the optimal balance between mass transfer and surface exposure. Considering the shell structure can significantly affect the properties of HoMSs, in this paper, we provide a novel one-step strategy to continually regulate the shell structures of HoMSs. Through a simple phosphorization process, we can effectively modify the shell from solid to bubble-like and even duplicate the shells with a narrow spacing. Benefitting from the structure merits, the fabricated CoP HoMSs with close duplicated shells can promote gas release owing to the unbalanced Laplace pressure, while accelerating liquid transfer for enhanced capillary force. It can provide effective channels for water and gas and thus exhibits a superior electrocatalytic performance in the hydrogen and oxygen evolution reaction.

Increasing the Efficiency of Photocatalytic Reactions via Surface Microenvironment Engineering.

The use of photocatalysis for water purification and environmental protection is of key interest. However, the reaction kinetics can be limited by the restricted accessibility of electron acceptor oxygen and the low adsorption of organic compounds-crucial factors underlying photocatalytic performance. Here we simultaneously alleviate these constraints via reaction interface microenvironment design using superhydrophobic (SHB) TiO2 nanoarrays as a model photocatalyst. The low surface energy and rough surface microstructure features of the SHB nanoarrays give the photocatalytic system long-range hydrophobic force and an air-water-solid triphase reaction interface. This simultaneously changes the adsorption model of organic compounds and the access pathway of oxygen, leading to a markedly enhanced adsorption capacity and higher interfacial oxygen levels. These synergistic qualities result in over 30-fold higher reaction kinetics versus a normal diphase system. In addition, this photocatalytic system is stable via repeated cycling. Our findings highlight the importance of reaction interface microenvironment design and reveal an effective path for the development of efficient photocatalysis systems.

Ordered-Assembly Conductive Nanowires Array with Tunable Polymeric Structure for Specific Organic Vapor Detection.

An artificial organic vapor sensor based on a finite number of 1D nanowires arrays can provide a strategy to allow classification and identification of different analytes with high efficiency, but fabricating a 1D nanowires array is challenging. Here, a coaxial Ag/polymer nanowires array is prepared as an organic vapor sensor with specific recognition, using a strategy combining superwettability-based nanofabrication and polymeric swelling-induced resistance change. Such organic vapor sensor containing commercial polymers can successfully classify and identify various organic vapors with good separation efficiency. An Ag/polymer nanowires array with synthetic polyethersulfone polymers is also fabricated, through molecular structure modification of the polymers, to distinguish the similar organic vapors of methanol and ethanol. Theoretical simulation results demonstrate introduction of specific molecular interaction between the designed polymers and organic vapors can improve the specific recognition performance of the sensors.

Synthesis of Starch-Based Amphiphilic Fluorescent Nanoparticles and Their Application in Biological Imaging.

Due to the extensive source, good biocompatibility and biodegradability, the starch of carbohydrates has been extensively investigated for application in biological field. Recently, the development of fluorescent organic nanoparticles (FONs) on the basis of aggregation induced emission (AIE) dyes has attracted great research interest. In this article, novel starch-based S-TPEV polymers with AIE property were successfully fabricated by atom transfer radical polymerization (ATRP) of TPEV dye into water-soluble starch for the first time, subsequently, their structure and properties were detailedly investigated by 1H NMR, TEM, UV-vis, FL and FTIR. The characterization results confirmed the successful synthesis of S-TPEV polymers, and the molar fraction of TPEV and C6H10O5 ring in the starch polymers could be respectively calculated as approximate 5.8% and 94.2%. In aqueous solution, the as-prepared S-TPEV polymers will tend to self-assemble into FONs with 100-200 nm diameters, and their fluorescence intensity increased with the increase of the concentration of water in the mixed solution of water and DMSO, indicative of the obvious AIE property. More importantly, owing to their high water dispersity, good fluorescence and excellent biocompatibility, the S-TPEV FONs can be uptaken by HepG2 cells and show promising application in biological imaging field.

Aggregation Induced Emission Fluorogens Based Nanotheranostics for Targeted and Imaging-Guided Chemo-Photothermal Combination Therapy.

Nanotheranostics for biomedical imaging-guided cancer therapy have attracted increasing interest due to their capabilities of both precise tumor diagnosis and high therapeutic efficacy. Among the diverse imaging models, fluorescence imaging have been extensively researched for their high sensitivity, simple operation, and low cost. In this work, aggregation induced emission (AIE) fluorogens based targeted nanotheranostics are facilely fabricated via paclitaxel (PTX) induced assembly of proteins for the first time. Thanks to the unique fluorescence property of AIE fluorogens PhENH2 , the prepared theranostic nanoplatforms can emit bright fluorescence even after being incorporated with the photothermal therapy agent polypyrrole (PPy), which will often decrease or quench the emission of common fluorescence dyes. The target moiety of cyclic arginine-glycine-aspartic acid (cRGD) endows the nanotheranostics with outstanding targeting ability, which can further facilitate the targeted imaging and cancer treatment. As revealed by the in vitro and in vivo experiments, the prepared nanotheranostics human serum albumin-PhENH2 -PPy-PTX-cRGD shows impressive performance in the targeted fluorescence imaging even after intravenous injection for 48 h, and their combined chemo-photothermal therapy is also very effective. These results indicate that AIE fluorogens based nanotheranostics would find a promising prospect in further improved multimodal imaging and imaging guided cancer treatment.

Underwater Thermoresponsive Surface with Switchable Oil-Wettability between Superoleophobicity and Superoleophilicity.

An underwater thermoresponsive surface that can switch between superoleophobicity and superoleophilicity is fabricated with a combination of mixed brushes, containing thermoresponsive poly(N-isopropylacrylamide) and underwater oleophilic heptadecafluorodecyltrimethoxysilane, and nanostructured silicon nanowire arrays. Temperature-induced underwater adhesion switching between low-adhesive superoleophobicity and high-adhesive superoleophobicity is achieved on a pure poly(N-isopropylacrylamide)-modified nanostructured silicon nanowire array.

Stable cross-linked fluorescent polymeric nanoparticles for cell imaging.

Aggregation-induced emission (AIE) dye-based cross-linked fluorescent polymeric nanoparticles (FPNs) are facilely prepared via a two-step polymerization process including emulsion polymerization and subsequent anhydride cross-linking. Then, a variety of characterization methods are carried out to determine the performance of the FPNs, which show high dispersibility and strong fluorescence in an aqueous solution due to the hydrophilic carboxyl groups on the surfaces and the AIE components as the cores. Biocompatibility evaluation and cell imaging results suggest that these FPNs are biocompatible for cell imaging. More importantly, this cross-linking strategy is proven to overcome the issue of critical micelle concentration and opens the opportunity to develop more robust fluorescent bioprobes.

Ionic Liquid-Enhanced Assembly of Nanomaterials for Highly Stable Flexible Transparent Electrodes.

The controlled assembly of nanomaterials has demonstrated significant potential in advancing technological devices. However, achieving highly efficient and low-loss assembly technique for nanomaterials, enabling the creation of hierarchical structures with distinctive functionalities, remains a formidable challenge. Here, we present a method for nanomaterial assembly enhanced by ionic liquids, which enables the fabrication of highly stable, flexible, and transparent electrodes featuring an organized layered structure. The utilization of hydrophobic and nonvolatile ionic liquids facilitates the production of stable interfaces with water, effectively preventing the sedimentation of 1D/2D nanomaterials assembled at the interface. Furthermore, the interfacially assembled nanomaterial monolayer exhibits an alternate self-climbing behavior, enabling layer-by-layer transfer and the formation of a well-ordered MXene-wrapped silver nanowire network film. The resulting composite film not only demonstrates exceptional photoelectric performance with a sheet resistance of 9.4 Ω sq-1 and 93% transmittance, but also showcases remarkable environmental stability and mechanical flexibility. Particularly noteworthy is its application in transparent electromagnetic interference shielding materials and triboelectric nanogenerator devices. This research introduces an innovative approach to manufacture and tailor functional devices based on ordered nanomaterials.

2D Graphene Oxide Membrane Nanoreactors for Rapid Directional Flow Ring-Opening Reactions with Dominant Same-Configuration Products.

Nanoconfinement within enzymes can increase reaction rate and improve selectivity under mild conditions. However, it remains a great challenge to achieve chemical reactions imitating enzymes with directional molecular motion, short reaction time, ≈100% conversion, and chiral conversion in artificial nanoconfined systems. Here, directional flow ring-opening reactions of styrene oxide and alcohols are demonstrated with ≈100% conversion in <120 s at 22 °C using graphene oxide membrane nanoreactors. Dominant products have the same configuration as chiral styrene oxide in confined reactions, which is dramatically opposed to bulk reactions. The unique chiral conversion mechanism is caused by spatial confinement, limiting the inversion of benzylic chiral carbon. Moreover, the enantiomeric excess of same-configuration products increased with higher alkyl charge in confined reactions. This work provides a new route to achieve rapid flow ring-opening reactions with specific chiral conversion within 2D nanoconfined channels, and insights into the impact of nanoconfinement on ring-opening reaction mechanisms.

Efficient Flow Synthesis of Aspirin within 2D Sub-Nanoconfined Laminar Annealed Graphene Oxide Membranes.

The aim of this work is to develop an environmentally friendly, safe, and simple route for realizing efficient preparation of aspirin. Here, inspired by enzyme synthesis in vivo, the aspirin synthesis has been realized by sub-nanoconfined esterification with directional flow and ≈100% conversion in an unprecedented reaction time of <6.36 s at 23 °C. Such flow esterification reaction is catalyzed by thermally transformed graphene oxide (GO) membranes with tailored physicochemical properties, which can be obtained simply through a mild annealing method. A possible mechanism is revealed by density functional theory calculation, indicating that the synergistic effect of spatial confinement and surface electronic structure can significantly improve the catalytic performance. By restricting reactants within 2D sub-nano space created by GO-based laminar flow-reactors, the present strategy provides a new route to achieve rapid flow synthesis of aspirin with nearly complete conversion.

Recent advances in organic mechanofluorochromic materials.

Mechanofluorochromic materials, which are dependent on changes in physical molecular packing modes, have attracted considerable interest over the past ten years. In this review, recent progress in the area of pure organic mechanofluorochromism is summarized, and majority of the reported organic mechanofluorochromic systems are discussed, along with their derived structure-property relationships. The existence of a structural relationship between aggregation-induced emission compounds and mechanofluorochromism is recognized based on our recent results, which considered aggregation-induced emission compounds as a well of mechanofluorochromic materials. The established structure-property relationship will guide researchers in identifying and synthesizing more mechanofluorochromic materials.

A new piezochromic fluorescence and aggregation-induced emission compound containing tetraphenylethylene and triphenylamine moieties with morphology-alterable property.

A novel piezochromic fluorescent (PCF) compound with aggregation-induced emission (AIE) effect and morphology-alterable emission property was developed. The amorphous and crystalline aggregates were obtained, and their spectroscopic properties and morphological structures were reversibly and repeatedly exhibited upon pressing (fuming) or annealing. The piezochromic fluorescent nature was generated through crystalline-amorphous phase transformation. It was proposed that AIE compounds existing a twisted propeller-shaped conformation will exhibit PCF activity. The common relationship betweeen AIE and PCF established will guide researchers in identifying and synthesizing more piezochromic fluorescent materials.

Comparison of responsive behaviors of two cinnamic acid derivatives containing carbazolyl triphenylethylene.

Two cinnamic acid derivatives (CPA and CPC) containing carbazolyl triphenylethylene moiety have been synthesized and characterized. The two derivatives possessed aggregation-induced emission property. They exhibited different and interesting responsive behaviors to solvents, water and metal ions. Considering the structural differences between the two derivatives resulting in different interactions between their molecules and the various media was proposed as a possible explanation for these observations. The intermolecular interactions of CPC were much stronger than those of CPA, which promoted molecular association through intermolecular hydrogen bonding to form multimers. It was found that CPC and CPA exhibited high sensitivity to K(+) and Mn(2+), respectively. It is suggested that the derivatives have potential technological applications in chemosensor fields.

Synthesis and characterization of triphenylethylene derivatives with aggregation-induced emission characteristics.

New aggregation-induced emission (AIE) compounds derived from triphenylethylene were synthesized. The thermal, photophysical, electrochemical and aggregation-induced emissive properties were investigated. All the compounds had strong blue light emission capability and good thermal stability. Their maximum fluorescence emission wavelengths were between 443 to 461 nm in solid states, while their glass transition temperatures ranged from 86 to 129 °C. The decomposition temperatures of the synthesized compounds were in the range of 432-534 °C. The synthesized compounds possessed aggregation-induced emission properties, namely exhibited enhanced fluorescence emission in aggregated states. The highest occupied molecular orbital (HOMO) energy levels estimated from the oxidation potentials were between 5.61 and 5.66 eV and the lowest unoccupied molecular orbital/highest occupied molecular orbital (LUMO/HOMO) energy gap values were found to be in the range of 3.18-3.22 eV. The compounds 4-(4-(2,2-bis(4-(naphthalen-1-yl)phenyl)vinyl)phenyl) dibenzothiophene [(BN)(2)Bt] and 4-(4-(2,2-di(biphenyl-4-yl)vinyl)phenyl) dibenzothiophene [(BB)(2)Bt] exhibited vibronic fine-structure photoluminescence spectra when the water fraction was less than 70%.

Synthesis and properties of diphenylcarbazole triphenylethylene derivatives with aggregation-induced emission, blue light emission and high thermal stability.

New aggregation-induced emission materials derived from diphenylcarbazole triphenylethylene were prepared. The thermal, photophysical, electrochemical and aggregation-induced emissive properties were investigated. All the compounds had strong blue light emission capability and excellent thermal stability. Their maximum fluorescence emission wavelengths were between 450 to 460 nm in TLC plates, while their glass transition temperatures ranged from 162.2 to 182.4 °C. The decomposition temperatures of the synthesized compounds were all well over 500 °C. The synthesized compounds possessed aggregation-induced emission (AIE) properties, which exhibited enhanced fluorescence emissions in aggregation states or in solid states. The HOMO energy levels estimated from the oxidation potentials were found in the range from 5.49 to5.52 eV. The lowest unoccupied molecular orbital/highest occupied molecular orbital (LUMO/HOMO) energy gaps (ΔEg) for the compounds were estimated from the onset absorption wavelengths of UV absorption spectra and ranged from 3.04 to 3.20 eV.

Decoupling hydrogen production from water oxidation by integrating a triphase interfacial bioelectrochemical cascade reaction.

Water electrolysis to produce H2 is a promising strategy for generating a renewable fuel. However, the sluggish-kinetics and low value-added anodic oxygen evolution reaction (OER) restricts the overall energy conversion efficiency. Herein we report a strategy of boosting H2 production at low voltages by replacing OER with a bioelectrochemical cascade reaction at a triphase bioanode. In the presence of oxygen, oxidase enzymes can convert biomass into valuable products, and concurrently generate H2O2 that can be further electrooxidized at the bioanode. Benefiting from the efficient oxidase kinetics at an oxygen-rich triphase bioanode and the more favorable thermodynamics of H2O2 oxidation than that of OER, the cell voltage and energy consumption are reduced by ~0.70 V and ~36%, respectively, relative to regular water electrolysis. This leads to an efficient H2 production at the cathode and valuable product generation at the bioanode. Integration of a bioelectrochemical cascade into the water splitting process provides an energy-efficient and promising pathway for achieving a renewable fuel.

Aggregation-Induced Emission Molecule Microwire-Based Specific Organic Vapor Detector through Structural Modification.

An optical organic vapor sensor array based on colorimetric or fluorescence changes quantified by spectroscopy provides an efficient method for realizing rapid identification and detection of organic vapor, but improving the sensitivity of the optical organic vapor sensor is challenging. Here, AIE/polymer (AIE, ggregation-induced emission) composites into microwires arrays are fabricated as organic vapor sensors with specific recognition and high sensitivity for different vapors using the capillary-bridge-mediated assembly method. Such organic vapor sensor successfully detects organic vapor relying on a swelling-induced fluorescence change of the AIE/polymer composites, combating the unique property of AIE molecules and vapor absorption-induced polymer swelling. A series of AIE/polymer composites into microwires arrays with four different groups on the AIE molecule and four different side chains on the polymer is fabricated to detect four different organic vapors. The mechanism for improved sensitivity of the AIE/polymer composites microwires arrays sensors is the same because of the similar polarity between the group of AIE molecules and the vapor molecules. Molecular design of the side chains of the polymer and the groups of AIE molecules based on the polarity of the targeted vapor molecule can enhance the sensitivity of the sensors to the subparts per million level.

Quantum-confined superfluid reactions.

A helium atom superfluid was originally discovered by Kapitsa and Allen. Biological channels in such a fluid allow ultrafast molecule and ion transport, defined as a quantum-confined superfluid (QSF). In the process of enzymatic biosynthesis, unique performances can be achieved with high flux, 100% selectivity and low reaction activation energy at room temperature, under atmospheric pressure in an aqueous environment. Such reactions are considered as QSF reactions. In this perspective, we introduce the concept of QSF reactions in artificial systems. Through designing the channel size at the van der Waals equilibrium distance (r 0) for molecules or the Debye length (λ D) for ions, and arranging the reactants orderly in the channel to satisfy symmetry-matching principles, QSF reactions in artificial systems can be realized with high flux, 100% selectivity and low reaction activation energy. Several types of QSF-like molecular reactions are summarized, including quantum-confined polymerizations, quasi-superfluid-based reactions and superfluid-based molecular reactions, followed by the discussion of QSF ion redox reactions. We envision in the future that chemical engineering, based on multi-step QSF reactions, and a tubular reactor with continuous nanochannel membranes taking advantage of high flux, high selectivity and low energy consumption, will replace the traditional tower reactor, and bring revolutionary technology to both chemistry and chemical engineering.

Wettability and Applications of Nanochannels.

Wettability in nanochannels is of great importance for understanding many challenging problems in interface chemistry and fluid mechanics, and presents versatile applications including mass transport, catalysis, chemical reaction, nanofabrication, batteries, and separation. Recently, both molecular dynamic simulations and experimental measurements have been employed to study wettability in nanochannels. Here, wettability in three types of nanochannels comprising 1D nanochannels, 2D nanochannels, and 3D nanochannels is summarized both theoretically and experimentally. The proposed concept of "quantum-confined superfluid" for ultrafast mass transport in nanochannels is first introduced, and the mostly studied 1D nanochannels are reviewed from molecular simulation to water wettability, followed by reversible switching of water wettability via external stimuli (temperature and voltage). Liquid transport and two confinement strategies in nanochannels of melt wetting and liquid wetting are also included. Then, molecular simulation, water wettability, liquid transport, and confinement in nanochannels are introduced for 2D nanochannels and 3D nanochannels, respectively. Based on the wettability in nanochannels, broad applications of various nanochannels are presented. Finally, the perspective for future challenges in the wettability and applications of nanochannels is discussed.