Selective Detection of Toxic C1 Chemicals Using a Hydroxylamine-Based Chemiresistive Sensor Array.

Formaldehyde (FA) is a deleterious C1 pollutant commonly found in the interiors of modern buildings. C1 chemicals are generally more toxic than the corresponding C2 chemicals, but the selective discrimination of C1 and C2 chemicals using simple sensory systems is usually challenging. Here, we report the selective detection of FA vapor using a chemiresistive sensor array composed of modified hydroxylamine salts (MHAs, ArCHONH·HCl) and single-walled carbon nanotubes (SWCNT).

Surface modification enhances the bulk proton conductivity of Prussian blue.

Surface-modified Prussian blue shows 10 times higher bulk proton conductivity (0.018 S cm) than that of unmodified Prussian blue. This enhancement is attributed to the monolayer adsorption of Na[Fe(CN)] on the nanoparticle surface, which reduces the surface resistance.

Amidoamine Oxide Surfactants as Low-Molecular-Weight Hydrogelators: Effect of Methylene Chain Length on Aggregate Structure and Rheological Behavior.

Rheology control is an important issue in many industrial products such as cosmetics and paints. Recently, low-molecular-weight compounds have attracted considerable attention as thickeners/gelators for various solvents; however, there is still a significant need for molecular design guidelines for industrial applications. Amidoamine oxides (AAOs), which are long-chain alkylamine oxides with three amide groups, are surfactants that act as hydrogelators.

Chirality-dependent electrical transport properties of carbon nanotubes obtained by experimental measurement.

Establishing the relationship between the electrical transport properties of single-wall carbon nanotubes (SWCNTs) and their structures is critical for the design of high-performance SWCNT-based electronic and optoelectronic devices. Here, we systematically investigated the effect of the chiral structures of SWCNTs on their electrical transport properties by measuring the performance of thin-film transistors constructed by eleven distinct (n, m) single-chirality SWCNT films. The results show that, even for SWCNTs with the same diameters but different chiral angles, the difference in the on-state current or carrier mobility could reach an order of magnitude.

Atomic force microscopic analysis of the light-harvesting complex 2 from purple photosynthetic bacterium Thermochromatium tepidum.

Structural information on the circular arrangements of repeating pigment-polypeptide subunits in antenna proteins of purple photosynthetic bacteria is a clue to a better understanding of molecular mechanisms for the ring-structure formation and efficient light harvesting of such antennas. Here, we have analyzed the ring structure of light-harvesting complex 2 (LH2) from the thermophilic purple bacterium Thermochromatium tepidum (tepidum-LH2) by atomic force microscopy. The circular arrangement of the tepidum-LH2 subunits was successfully visualized in a lipid bilayer.

Unveiling a new aspect of oxocarbons: open-shell character of 4- and 5-membered oxocarbon derivatives showing near-infrared absorption.

Oxocarbon derivatives consisting of 4- and 5-membered rings, referred to as croconaine and squaraine dyes and regarded as closed-shell molecules, are found to have an intermediate open-shell character from the experimental results of H-NMR, ESR spectroscopy, SQUID magnetometric analysis, and X-ray crystallography. We employed two chalcogenopyrylium moieties with O and S chalcogen atoms as substitutions on oxocarbons. The singlet-triplet energy gaps (Δ ) associated with the degree of diradical nature are smaller for croconaines than for squaraines and smaller for thiopyrylium than for pyrylium groups.

Vapor-Phase Indium Intercalation in van der Waals Nanofibers of Atomically Thin WTe Wires.

One-dimensional (1D) conducting materials are of great interest as potential building blocks for integrated nanocircuits. Ternary 1D transition-metal chalcogenides, consisting of MX wires with intercalated A atoms (M = Mo or W; X = S, Se, or Te; A = alkali or rare metals, .), have attracted much attention due to their 1D metallic behavior, superconductivity, and mechanical flexibility.

Recovery of Pure Methanol from Humid Gas Using Mn-Co Prussian Blue Analogue.

Conventional methanol recovery and purification processes are highly energy-intensive; processes using selective adsorbents that consume low energy are preferable. However, conventional adsorbents have low methanol selectivity under humid conditions. In this study, we develop a selective methanol adsorbent, manganese hexacyanocobaltate (MnHCC), which enables the efficient removal of methanol from waste gas and its subsequent reuse.

Outstanding Robust Photo- and Thermo-Electric Applications with Stabilized n-Doped Carbon Nanotubes by Parylene Coating.

Stabilization techniques for n-doped carbon nanotubes (CNTs) are essential for the practical use of CNT devices. However, none of the reported n-dopants have sufficient robustness in a practical environment. Herein, we report a highly stable technique for fabricating n-doped CNT films.

H-NMR Karplus Analysis of Molecular Conformations of Glycerol under Different Solvent Conditions: A Consistent Rotational Isomerism in the Backbone Governed by Glycerol/Water Interactions.

Glycerol is a symmetrical, small biomolecule with high flexibility in molecular conformations. Using a H-NMR spectroscopic Karplus analysis in our way, we analyzed a rotational isomerism in the glycero backbone which generates three kinds of staggered conformers, namely gt (-), gg (-), and tg (-), at each of -1,2 and -2,3 positions. The Karplus analysis has disclosed that the three rotamers are consistently equilibrated in water keeping the relation of 'gt:gg:tg = 50:30:20 (%)' at a wide range of concentrations (5 mM~540 mM).

Photo-and Heat-Induced Dismantlable Adhesion Interfaces Prepared by Layer-by-Layer Deposition.

The development of a dismantlable adhesion technology that allows switching between bonding and debonding states using external stimuli is important for realizing renewable and sustainable material cycles. Controlling the adhesion interface is an effective approach to manipulate the adhesion strength; however, research on dismantlable systems focusing on the interface has not been proceeded. Recently, we demonstrated a novel dismantlable system based on a stimuli-responsive molecular layer comprising cleavable anthracene dimers, which strengthen the initial adhesive force by forming chemical bonds between the substrate and adhesive and can be dismantled when required via stimulation-induced bond breaking.

Size distributions of cellulose nanocrystals in dispersions using the centrifugal sedimentation method.

Nanocellulose is a remarkable biomaterial. It is a plastic alternative with significance from the viewpoint of carbon offset and neutrality. To efficiently develop nanocellulose-based functional materials, it is imperative to evaluate their dispersion states.

Coenzyme corona formation on carbon nanotubes leads to disruption of the redox balance in metabolic reactions.

Carbon nanotubes (CNTs) have adverse impacts on metabolism in biological systems. The impacts should be associated with interactions of the CNTs with coenzymes, such as nicotinamide adenine dinucleotide (NAD), because most metabolic processes are governed by coenzyme-dependent reactions. This study demonstrates that NAD molecules adsorb onto the CNT surface, leading to the formation of interfacial NAD layers-in other words, a coenzyme corona (coenzyme-based biomolecular corona).

Cryopreservation of tissues by slow-freezing using an emerging zwitterionic cryoprotectant.

Cryopreservation of tissues is a tough challenge. Cryopreservation is categorized into slow-freezing and vitrification, and vitrification has recently been recognized as a suitable method for tissue cryopreservation. On the contrary, some researchers have reported that slow-freezing also has potential for tissue cryopreservation.

Desorption of Ammonia Adsorbed on Prussian Blue Analogs by Washing with Saturated Ammonium Hydrogen Carbonate Solution.

Prussian blue analogs (PBAs) have been reported as promising ammonia (NH) adsorbents with a high capacity compared to activated carbon, zeolite, and ion exchange resins. The adsorbed NH was desorbed by heating and washing with water or acid. Recently, we demonstrated that desorption was also possible by washing with a saturated ammonium hydrogen carbonate solution (sat.

Fluoridated Apatite Coating on Human Dentin via Laser-Assisted Pseudo-Biomineralization with the Aid of a Light-Absorbing Molecule.

A simple, area-specific coating technique for fluoridated apatite (FAp) on teeth would be useful in dental applications. Recently, we achieved area-specific FAp coating on a human dentin substrate within 30 min by a laser-assisted biomimetic (LAB) process; pulsed Nd:YAG laser irradiation in a fluoride-containing supersaturated calcium phosphate solution (FCP solution). The LAB-processed, FAp-coated dentin substrate exhibited antibacterial activity against a major oral bacterium, .

Mechanical and Thermal ON-OFF Switching of the Vapochromic Behavior of a Luminescent Polymorphic Pt(II) Complex.

Vapochromic materials that exhibit color/luminescence changes induced by vapor exposure have attracted considerable attention. Herein, we report the grinding- and heating-induced ON-OFF switching of the vapochromic behavior of [Pt(ppyCl)(Clacac)] (; ppyCl = 2-(3-chlorophenyl)-4-chloropyridinato, Clacac = 3-chloroacetylacetonato). formed yellow and orange polymorphs ( and ), and could be converted to , which showed a very similar crystal structure but with a broadened X-ray diffraction pattern compared with that of .

Length-Controllable Gold-Coated Silver Nanowire Probes for High AFM-TERS Scattering Activity.

Tip-enhanced Raman scattering (TERS) microscopy is an advanced technique for investigation at the nanoscale that provides topographic and chemical information simultaneously. The TERS probe plays a crucial role in the microscopic performance. In the recent past, the development of silver nanowire (AgNW) based TERS probes solved the main tip fabrication issues, such as low mechanical strength and reproducibility.

Isotropic Anhydrous Superprotonic Conductivity Cooperated with Installed Imidazolium Molecular Motions in a 3D Hydrogen-Bonded Phosphate Network.

Utilizing molecular motion is essential for the use of anhydrous superprotonic molecular proton conductors (σ beyond 10  S cm ) as electrolytes in hydrogen fuel cells. However, molecular motion contributing to the improvement of intrinsic proton conduction has been limited and little clarified in relation to the proton conduction mechanism, limiting the development of material design guidelines. Here, a salt with a three-dimensional (3D) hydrogen-bonded (H-bonded) phosphate network with imidazolium cations installed inside was studied, whose components are known to exhibit molecular motions that contribute to proton conduction.

Investigation of Morphological, Optical, and Dielectric Properties of RF Sputtered WO Thin Films for Optoelectronic Applications.

Tungsten oxide (WO) thin films were synthesized through the RF magnetron sputtering method by varying the sputtering power from 30 W to 80 W. Different investigations have been conducted to evaluate the variation in different morphological, optical, and dielectric properties with the sputtering power and prove the possibility of using WO in optoelectronic applications. An Energy Dispersive X-ray (EDX), stylus profilometer, and atomic force microscope (AFM) have been used to investigate the dependency of morphological properties on sputtering power.

High Immobilization Efficiency of Basic Protein within Heparin-Immobilized Calcium Phosphate Nanoparticles.

Previously, we achieved one-pot fabrication of heparin-immobilized calcium phosphate (CaP) nanoparticles with high dispersibility by a precipitation process in a highly supersaturated reaction solution. In this study, we revealed that the heparin-immobilized CaP nanoparticles have a greater co-immobilizing capacity for basic proteins than for acidic proteins. In this process, heparin acted as not only a particle-dispersing agent but also as an immobilizing agent for basic proteins; it remarkably (approximately three-fold) improved the immobilization efficiency of cytochrome C (a model basic protein) within the CaP nanoparticles.

Room-Temperature Ring-Opening Polymerization of δ-Valerolactone and ϵ-Caprolactone Caused by Uptake into Porous Pillar[5]arene Crystals.

Confined space provides a reaction platform with altered reaction rate and selectivity compared with a homogeneous solution. In this work, porous phenolic pillar[5]arene crystals were used as a reaction space to promote and perturb equilibrium between lactones and their corresponding polyesters. Immersion of porous pillar[5]arene crystals in liquid lactones induced ring-opening polymerization of δ-valerolactone and ϵ-caprolactone at room temperature because the phenolic hydroxy groups have catalytic activity via hydrogen bonds and the pillar[5]arene cavities prefer linear guests.

Determination of the critical chain length for macromolecular crystallization using structurally flexible polyketones.

Critical chain length that divides small molecule crystallization from macromolecular crystallization is an important index in macro-organic chemistry to predict chain-length dependent properties of oligomers and polymers. However, extensive research on crystallization behavior of individual oligomers has been inhibited by difficulties in their synthesis and crystallization. Here, we report on the determination of critical chain length of macromolecular crystallization for structurally flexible polyketones consisting of 3,3-dimethylpentane-2,4-dione.