Diverse Hierarchical Meso/Nanoporous Pt Film Electrocatalysts Prepared via Hydrogen Adsorption-Assisted Dynamic Soft Templating.

In this study, we present an innovative approach for creating hierarchical meso/nanoporous Pt films using dynamic soft templating. The fabrication process, called dynamic soft templating, involves Pt electrodeposition within a specialized bicontinuous microemulsion (BME) system characterized by a sophisticated three-dimensional network comprising water and oil phases, surfactants, and cosurfactants. Pt electrodeposition exclusively occurs in the water phase of the BME.

Phase Diagrams of Anthracene Derivatives in Pyridinium Ionic Liquids.

Crystal engineering for single crystallization of π-conjugated molecules has attracted much attention because of their electronic, photonic, and mechanical properties. However, reproducibility is a problem in conventional printing techniques because control of solvent evaporation is difficult. We investigated the phase diagrams of two anthracene derivatives in synthesized ionic liquids for non-volatile crystal engineering to determine the critical points for nucleation and crystal growth.

Chemical Recycling and Physical Tuning of Necklace-Shaped Polydimethylsiloxanes Bearing Anthracene Dimer Units.

The problem of plastic waste in the environment calls for the development of new polymeric materials designed specifically for easy recycling at the end of their life cycle. Herein, a green polymer system comprising a series of necklace-shaped polydimethylsiloxanes bearing anthracene dimer units is developed. The polymers have low environmental impact and are easily recycled.

Electrochemistry in bicontinuous microemulsions derived from two immiscible electrolyte solutions for a membrane-free redox flow battery.

Hypotheses: Bicontinuous microemulsions (BMEs) have attracted attention as unique heterogeneous mixture for electrochemistry. An interface between two immiscible electrolyte solutions (ITIES) is an electrochemical system that straddles the interface between a saline and an organic solvent with a lipophilic electrolyte. Although most BMEs have been reported with nonpolar oils, such as toluene and fatty acids, it should be possible to construct a sponge-like three-dimensionally expanded ITIES comprising a BME phase.

Single Crystallization of CsPbBr Perovskite from Supersaturated Organic Solutions Optimized Through Solubility Studies.

We demonstrate the fabrication of millimeter-sized single crystals of 0D-CsPbBr grown in a supersaturated solution consisting of organic solvents without HBr (aq). One of the precursors, CsBr, was dissolved in ethylene glycol (EG) mixed with dimethyl sulfoxide, which is a good solvent for the other precursor, PbBr. At a solvent ratio of 20 vol % EG, the solubility of cesium bromide decreased and the title compound, CsPbBr, was selectively formed, whereas, with an EG ratio of 80 vol %, 3D-CsPbBr was formed.

Infusion of Variable Chemical Structure to Tune Stacking among Metal-Organic Layers in 2D Nano MOFs.

Invited for the cover of this issue is the group of Biplab Manna at the University of Kumamoto. The image depicts various kinds of stacking between the metal-organic layers of MOFs. Read the full text of the article at 10.

Infusion of Variable Chemical Structure to Tune Stacking among Metal-Organic Layers in 2D Nano MOF.

Thickness of two-dimensional (2D) metal-organic frameworks (MOFs) govern their intriguing functionalities. Primarily this thickness is controlled by the stacking between the metal-organic layers (MOL). It is observed that until now such modulating factors for stacking efficiency of MOL are not well studied.

Preparation of double-layered nanosheets containing pH-responsive polymer networks in the interlayers and their conversion into single-layered nanosheets through the cleavage of cross-linking points.

Double-layered nanosheets containing pH-cleavable polymer networks between two niobate layers were prepared by copolymerization of -isopropylacrylamide and an acid-degradable crosslinker surface-initiated atom transfer radical polymerization on the surface of hydrated interlayers (interlayer I) of KNbO·3HO and subsequent exfoliation by the introduction of tetra--butylammonium (TBA) ions into anhydrous interlayers (interlayer II). Moreover, the double-layered nanosheets were converted into single-layered nanosheets by the cleavage of cross-linking points in polymer networks by lowering pH. Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TG) results showed that polymer networks were present, and nanosheets with a thickness of 10.

Lipophilic probe behavior in microemulsions evaluated by fluorescence correlation spectroscopy.

We evaluated the dispersion and diffusion of fluorescent-labeled lipophilic vitamin E (VE) in microemulsions (MEs) including water-in-oil (W/O) type ME, oil-in-water (O/W) type ME, and bicontinuous ME (BME), using fluorescence correlation spectroscopy (FCS). We prepared a fluorescent ATTO 488 or BODIPY group labeled VE (VE-ATTO or VE-BODIPY). VE-ATTO possesses lipophilic and hydrophilic parts, while VE-BODIPY consists solely of the lipophilic part.

Preparation of water-dispersible Janus nanosheets from KNbO·3HO and their behaviour as a two-dimensional surfactant on air-water and water-toluene interfaces.

KNbO·3HO-based Janus nanosheets with water dispersibility and surface activity were prepared sequential regioselective surface modification. To provide individual Janus nanosheets with these two properties, phenylphosphonic acid and phosphoric acid were utilized for surface modification at interlayers I and II of KNbO·3HO, respectively, and the resulting product was exfoliated into single-layered nanosheets by ultrasonication in water. The resulting aqueous dispersion of the Janus nanosheets showed lower surface tension than pure water, confirming that the Janus nanosheets had surface activity.

Multimotion of Marangoni Propulsion Ships Controlled by Two-Wavelength Near-Infrared Light.

Multimode motion of Marangoni propulsion ships on a water surface as per a near-infrared, two-wavelength selective response is achieved for the first time. The ships are rhombus- or propeller-shaped polyacrylamide or siloxane resin-based gels in which NdO and YbO nanoparticles are incorporated separately for photothermal conversion at 808 and 980 nm, respectively. The rhombus geometry is for straight locomotion, and the propeller geometry is for rotation.

Lipophilic Vitamin E Diffusion through Bicontinuous Microemulsions.

We studied the diffusion properties of lipophilic vitamin E (VE) through bicontinuous microemulsions (BME) using both electrochemical and fluorescence correlation spectroscopy (FCS) measurements. We investigated the effect of different composition ratios of micro-water and micro-oil phases in BMEs (W/O). When we employed the BME with a lower W/O value of 40/60 (oil-rich BME) as an electrolyte solution, we obtained a larger current response from VE at a fluorinated nanocarbon film electrode.

Stand-Alone Semi-Solid-State Electrochemical Systems Based on Bicontinuous Microemulsion Gel Films.

Bicontinuous microemulsion (BME)-based hydrogel films were integrated with screen-printed electrodes (SPEs) comprising working, counter, and reference electrodes to form stand-alone, semi-solid-state electrochemical systems that do not require an outer electrolyte solution. The gel network of the BME hydrogel only exists in the microaqueous phase and retains the structure of the entire BME gel. Following gelation, a microaqueous phase with sufficient ionic strength ensured effective ionic conductivity, even in thin gel films.

Monomolecular covalent honeycomb nanosheets produced by surface-mediated polycondensation between 1,3,5-triamino benzene and benzene-1,3,5-tricarbox aldehyde on Au(111).

Fabrication of a two-dimensional covalent network of honeycomb nanosheets comprising small 1,3,5-triamino benzene and benzene-1,3,5-tricarboxaldehyde aromatic building blocks was conducted on Au(111) in a pH-controlled aqueous solution. scanning tunneling microscopy revealed a large defect-free and homogeneous honeycomb π-conjugated nanosheet at the Au(111)/liquid interface. An electrochemical potential dependence indicated that the nanosheets were the result of thermodynamic self-assembly based not only on the reaction equilibrium but also on the adsorption (partition) equilibrium, which was controlled by the building block surface coverage as a function of electrode potential.

Study of Gases Permeation in Necklace-Shaped Dimethylsiloxane Polymers Bearing POSS Cages.

The transport of small gases (H, CO, N, O) through a series of novel membranes based on necklace-shaped inorganic polymers (DMS@POSS), in which a polyhedral oligomeric silsesquioxane (POSS) cage unit and soft chains of oligo-dimethyl siloxane (DMS) were alternately connected, was investigated. The influence of the DMS chain length and crosslinking density of the DMS@POSS on membrane properties were studied. The membranes revealed characteristic structure-property relation towards both glass transition and gases transport.

Two-wavelength infrared responsive hydrogel actuators containing rare-earth photothermal conversion particles.

Two-wavelength infrared responsive soft actuators composed of rare-earth-oxide particles composited in a thermoresponsive hydrogel have been constructed. Because NdO and YbO particles possess independent narrow infrared adsorption at 808 and 980 nm, respectively, the vicinity of the particles in the gel can be individually heated by irradiation at each adsorption wavelength, inducing a local volume phase transition. The wavelength-selective volume phase transition can be controlled based on the combination of the particles incorporated in the gels and the wavelength of the irradiation laser at the optimized water temperature.

Inorganic Janus nanosheets bearing two types of covalently bound organophosphonate groups via regioselective surface modification of KNbO·3HO.

Janus nanosheets were prepared from K4Nb6O17·3H2O by modifying surfaces of their two distinct interlayers in a regioselective and sequential manner and subsequent exfoliation. The surface properties of nanosheets were investigated by phase atomic force microscopy imaging and two types of surfaces were discriminated, indicating that Janus nanosheets were successfully prepared.

Quasi-Phase Diagrams at Air/Oil Interfaces and Bulk Oil Phases for Crystallization of Small-Molecular Semiconductors by Adjusting Gibbs Adsorption.

The temperature and concentration dependencies of the crystallization of two small-molecular semiconductors were clarified by constructing quasi-phase diagrams at air/oil interfaces and in bulk oil phases. A quinoidal quaterthiophene derivative with four alkyl chains (QQT(CN)4) in 1,1,2,2-tetrachroloethane (TCE) and a thienoacene derivative with two alkyl chains (C8-BTBT) in o-dichlorobenzene were used. The apparent crystal nucleation temperature (T) and dissolution temperature (T) of the molecules were determined based on optical microscopy examination in closed glass capillaries and open dishes during slow cooling and heating processes, respectively.

Cohelical Crossover Network by Supramolecular Polymerization of a 4,6-Acetalized β-1,3-Glucan Macromer.

Natural polysaccharides represent a renewable resource whose effective utilization is of increasing importance. Chemical modification is a powerful tool to transform them into processable materials but usually sacrifices the original structures and properties of value. Here we introduce a chemical modification of Curdlan, a β-1,3-glucan, via 4,6-acetalization.

Direct Analysis of Lipophilic Antioxidants of Olive Oils Using Bicontinuous Microemulsions.

Quantitative analyses of olive oil for lipophilic antioxidants, such as α-tocopherol and phenolics, by simple electrochemical measurements were conducted in a bicontinuous microemulsion (BME), which was bicontinuously composed of saline and toluene microphases with a surfactant system. Lipophilic antioxidants in oils were directly monitored in BME solutions using a lipophilic, fluorinated nanocarbon-film electrode (F-ECR). The combination of a well-balanced BME and extremely biased electrodes, such as strongly hydrophilic indium/tin oxide and strongly lipophilic (hydrophobic) F-ECR, allowed individual monitoring of hydrophilic and lipophilic antioxidants in the same BME solution without any required extraction.

Simultaneous electrochemical analysis of hydrophilic and lipophilic antioxidants in bicontinuous microemulsion.

Qualitative and quantitative analyses of hydrophilic and lipophilic antioxidants, such as polyphenols, by simple electrochemical measurements were conducted in a bicontinuous microemulsion (BME), in which water and oil phases coexisted bicontinuously on a microscopic scale. Hydrophilic and lipophilic antioxidants were individually monitored in the same BME solution using a hydrophilic indium tin oxide (ITO) electrode and a lipophilic fluorinated nanocarbon film electrode (F-ECR), respectively. The combination of well-balanced BME and extremely biased electrodes, such as ITO and F-ECR, in terms of hydrophilic-lipophilic balance allowed us to achieve individual monitoring of hydrophilic and lipophilic antioxidants in the same BME solution without extraction.

Thermodynamic self-assembly of two-dimensional pi-conjugated metal-porphyrin covalent organic frameworks by "on-site" equilibrium polymerization.

Two-dimensional pi-conjugated metal-porphyrin covalent organic frameworks were produced in aqueous solution on an iodine-modified Au(111) surface by "on-site" azomethine coupling of Fe(III)-5,10,15,20-tetrakis(4-aminophenyl)porphyrin (FeTAPP) with terephthal dicarboxaldehyde and investigated in detail using in-situ scanning tunneling microscopy. Mixed covalent organic porphyrin frameworks consisting of FeTAPP and metal-free TAPP (H2TAPP) were prepared through simultaneous adsorption in a mixed solution as well as partial replacement of FeTAPP by H2TAPP in an as-prepared metal-porphyrin framework. In the mixed framework, the relative distribution of FeTAPP to H2TAPP was not random and revealed a preference for homo-connection rather than heteroconnection.

Construction and characterization of molecular nonwoven fabrics consisting of cross-linked poly(γ-methyl-L-glutamate).

Molecular nonwoven fabrics in the form of ultrathin layer-by-layer (LbL) helical polymer films with covalent cross-linking were assembled on substrates by an alternate ester-amide exchange reaction between poly(γ-methyl L-glutamate) (PMLG) and cross-linking agent ethylene diamine or 4,4'-diamino azobenzene. The regular growth of helical monolayers without excessive adsorption and the formation of amide bonds were confirmed by ultraviolet-visible (UV-vis) spectrophotometry, quartz crystal microbalance (QCM), ellipsometry, and infrared reflection-absorption spectroscopy (IR-RAS) measurements. Nanostructures with high uniformity and ultrathin films with few defects formed by helical rod segments of PMLG were characterized by atomic force microscopy (AFM) and Kelvin probe force microscopy (KFM).

Electrochemical elucidation of structural changes in physical organo bicontinuous microemulsion gel systems.

The structural changes in a bicontinuous microemulsion gel system in a sol-gel state were elucidated via determination of the apparent diffusion coefficients, which were estimated electrochemically. The temperature dependence of D(app) in the micro oil phase or the saline phase revealed complementary hysteresis, which occurred as a result of formation of a gel network and subsequent mesoscopic phase separation.

In situ STM investigation of aromatic poly(azomethine) arrays constructed by "on-site" equilibrium polymerization.

Two-dimensional (2D) arrays of π-conjugated aromatic polymers produced by surface-selective Schiff base coupling reactions between an aromatic diamine and an aromatic dialdehyde were investigated in detail using in situ scanning tunneling microscopy. Surface-selective coupling was achieved for almost all diamine/dialdehyde combinations attempted, although several combinations did not proceed even in homogeneous aqueous alkaline solution. Most of the combinations of an aromatic diamine and a dialdehyde, except the combinations of 4,4'-azodianiline with mono/bithiophenedicarboxaldehyde, formed highly ordered π-conjugated polymer arrays on an iodine-modified Au(111) surface in aqueous solution at a suitable pH.