Surface Structure, Adsorption, and Thermal Desorption Behaviors of Methaneselenolate Monolayers on Au(111) from Dimethyl Diselenides

To understand the effect of headgroups (i.e., sulfur and selenium) on surface structure, adsorption states, and thermal desorption behaviors of self-assembled monolayers (SAMs) on Au(111), we examined methanethiolate (CH₃–S, MS) and metheneselenolate (CH₃–Se, MSe) monolayers formed from dimethyl disulfide (DMDS) and dimethyl diselenide (DMDSe) molecules by ambient vapor-phase deposition. Scanning tunneling microscopy imaging revealed that DMDS molecules on Au(111) after a 1 h deposition form MS monolayers containing a disordered phase and an ordered row phase with an inter-row spacing of 1.51 nm, whereas DMDSe molecules form long-range-ordered MSe monolayers with a (√3 × 3√3)<i>R</i>30° structure. X-ray photoelectron spectroscopy measurements showed that MS or MSe monolayers chemisorbed on Au(111) were formed via S–S bond cleavage of DMDS or Se–Se bond cleavage of DMDSe. On the other hand, we monitored three main desorption fragments for MS and MSe monolayers using TDS monomers (CH₃S⁺, CH₃Se⁺), parent mass species (CH₃SH⁺, CH₃SeH⁺), and dimers (CH₃S–SCH₃⁺, CH₃Se–SeCH₃⁺). Interestingly, we found that thermal desorption behaviors of MSe monolayers were markedly different from those of MS monolayers. All desorption peaks for MSe monolayers were observed at a higher temperature compared with MS monolayers, suggesting that the adsorption affinity of selenium atoms for the Au(111) surface is stronger than that of sulfur atoms. In addition, the desorption intensity of dimer fragments for MSe monolayers was much lower than for MS monolayers, indicating that selenolate SAMs on Au(111) did not undergo their dimerization efficiently during thermal heating compared with thiolate SAMs. Our results provide new insight into understanding the surface structure and thermal desorption behavior of MSe monolayers on Au(111) surface by comparing those of MS monolayers

Biochemical parameters and the Hb content versus volume correlation map for RBCs of 0.0, 0.1, 0.3, and 0.5% ethanol concentrations

<p>(a) RBC Hb concentration, (b) RBC Hb content, and (c) correlation map between the Hb content and the volume, with the respective volume probability density curves. Each circle indicates an individual RBC measurement. The mean value of each morphological RBC parameter is denoted as a horizontal line with the vertical bar for the standard deviation.</p

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<p>(a–d) 2-D membrane height maps of the representative individual RBCs in the (a) 0.0, (b) 0.1, (c) 0.3, and (d) 0.5% ethanol concentrations. (e–h) 2-D out-of-membrane fluctuation maps of the corresponding four RBCs in (a–d). (i) Dynamic membrane fluctuations for all measured RBCs. The colored circle indicates an individual cell measurement. The mean membrane fluctuation for each ethanol group is denoted as a horizontal line and standard deviation is represented by the vertical bar.</p

The cDOT setup and RBC analysis procedures

<p>(a) Optical setup of the cDOT. GM1-2: galvanometer mirrors, CL: condenser lens, OL: objective lens, M: mirror; (b) Schematic diagram of RBC analysis procedures for retrieving morphological (volume, surface area, and sphericity); biochemical (Hb concentration and Hb content); and biomechanical (membrane fluctuation) parameters.</p

Surface-Fluorinated Proton-Exchange Membrane with High Electrochemical Durability for Direct Methanol Fuel Cells

Random disulfonated poly(arylene ether sulfone)−silica nanocomposite (FSPAES-SiO2) membranes were physicochemically tuned via surface fluorination. Surface fluorination for 30 min converted about 20% of the C−H bonds on the membrane surface into C−F bonds showing hydrophobicity and electronegativity at the same time. The membranes with hydrophobic surface properties showed high dimensional stability and low methanol permeability when hydrated for direct methanol fuel cell applications. In particular, the surface enrichment of fluorine atoms led to anisotropic swelling behavior, associated with a stable electrode interface formation. Interestingly, in spite of the use of a random copolymer as a polymer matrix, the low surface free energy of the C−F bonds induced a well-defined continuous ionic channel structure, similar to those of multiblock copolymers. In addition to the morphological transition, fluorine atoms with high electron-withdrawing capability promoted the dissociation of sulfonic acid (−SO3H) groups. Consequently, FSPAES-SiO2 membranes exhibited improved proton conductivity. Thus, FSPAES-SiO2 membranes exhibited significantly improved single-cell performances (about 200%) at a constant voltage of 0.4 V in comparison with those of Nafion 117 and nonfluorinated membranes. Surprisingly, their good electrochemical performances were maintained with very low nonrecovery loss over the time period of 1400 h and interfacial resistances 380% times lower than those of conventional membrane−electrode assemblies comprising the control hydrocarbon membrane and a Nafion binder for the electrodes

Reconstructed 3-D RI distributions of RBCs.

<p>(a–d) Cross-sectional images of 3-D RI tomograms of RBCs (along the <i>x</i>–<i>y</i>, the <i>x</i>–<i>z</i>, and the <i>z</i>–<i>y</i> planes) exposed to diluted blood solutions of (a) 0.0, (b) 0.1, (c) 0.3, and (d) 0.5% ethanol concentrations; (e–h) 3-D rendered RI isosurfaces (<i>n</i> > 1.355) of the four representative RBCs in (a–d).</p

Morphological parameters for RBCs exposed to 0.0, 0.1, 0.3, and 0.5% ethanol concentrations

<p>(a) Volume, (b) Surface area, and (c) Sphericity. Each circle indicates individual RBC measurements. Each circle indicates measurements of an individual RBCl measurements. The mean value of each morphological RBC parameters is denoted as the horizontal line with the vertical bar for the standard deviation.</p

Highly Efficient Flexible Perovskite Light-Emitting Diodes Using the Modified PEDOT:PSS Hole Transport Layer and Polymer–Silver Nanowire Composite Electrode

Metal halide perovskites have been actively studied as promising materials in optoelectronic devices because of their superior optical and electrical properties and have also shown considerable potential for flexible devices because of their good mechanical properties. However, the large hole injection barrier and exciton quenching between the perovskite emitter and poly­(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) can lead to the reduction in device efficiency. Here, a nonconductive fluorosurfactant, Zonyl FS-300 (Zonyl), is introduced into the PEDOT:PSS hole transport layer, which reduces the hole injection barrier and exciton quenching at the PEDOT:PSS/perovskite interface. Moreover, a flexible perovskite light-emitting diode with a polymer–silver nanowire composite electrode is demonstrated, showing a maximum current efficiency (CEmax) of 17.90 cd A–1, and this is maintained even after 1000 cycles of bending with a 2.5 mm bending radius

Quantitative Phase Imaging and Artificial Intelligence: A Review

Recent advances in quantitative phase imaging (QPI) and artificial intelligence (AI) have opened up the possibility of an exciting frontier. The fast and label-free nature of QPI enables the rapid generation of large-scale and uniform-quality imaging data in two, three, and four dimensions. Subsequently, the AI-assisted interrogation of QPI data using data-driven machine learning techniques results in a variety of biomedical applications. Also, machine learning enhances QPI itself. Herein, we review the synergy between QPI and machine learning with a particular focus on deep learning. Further, we provide practical guidelines and perspectives for further development

Highly Efficient Flexible Perovskite Light-Emitting Diodes Using the Modified PEDOT:PSS Hole Transport Layer and Polymer–Silver Nanowire Composite Electrode

Metal halide perovskites have been actively studied as promising materials in optoelectronic devices because of their superior optical and electrical properties and have also shown considerable potential for flexible devices because of their good mechanical properties. However, the large hole injection barrier and exciton quenching between the perovskite emitter and poly­(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) can lead to the reduction in device efficiency. Here, a nonconductive fluorosurfactant, Zonyl FS-300 (Zonyl), is introduced into the PEDOT:PSS hole transport layer, which reduces the hole injection barrier and exciton quenching at the PEDOT:PSS/perovskite interface. Moreover, a flexible perovskite light-emitting diode with a polymer–silver nanowire composite electrode is demonstrated, showing a maximum current efficiency (CEmax) of 17.90 cd A–1, and this is maintained even after 1000 cycles of bending with a 2.5 mm bending radius