Cross-Linked Sulfonated Poly(arylene ether sulfone) Membranes Formed by <i>in Situ</i> Casting and Click Reaction for Applications in Fuel Cells

Sulfonated poly­(arylene ether sulfone) membranes with cross-linked structures (C-SPAES) were simply prepared by simultaneously casting and heating the polymer solutions composed of sulfonated poly­(arylene ether sulfone) with azidomethyl side groups (SPAES-N₃), cross-linkers such as 1,4-diethynylbenzene and 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt tetrahydrate, and a click reaction catalyst such as CuBr and <i>N</i>,<i>N</i>,<i>N</i>′,<i>N</i>″,<i>N</i>″-pentamethyldiethylenetriamine in <i>N</i>,<i>N</i>-dimethylacetamide, where SPAES-N₃ were prepared by the substitution of sulfonated PAES (SPAES) through chloromethylation followed by azidation reaction. C-SPAES membranes obtained using the optimum amount of the cross-linkers showed much improved chemical and physical stabilities and mechanical strength compared with linear SPAES membrane. Since the cross-linked structures were formed by the cross-linker having sulfonic acid groups, C-SPAES membranes showed higher ion exchange capacity and proton conductivity than the linear SPAES membrane. Although the C-SPAES membrane can absorb more water than the linear SPAES membrane, less volume expansion was observed due to their physically stable cross-linked structures

Additional file 1 of Direct comparison of diagnostic and clinical values between Tc-99 m DPD and Tc-99 m PYP scintigraphy in patients with cardiac amyloidosis

Supplementary Material

Three-Dimensional Surface Treatment of MoS₂ Using BCl₃ Plasma-Derived Radicals

The realization of next-generation gate-all-around field-effect transistors (FETs) using two-dimensional transition metal dichalcogenide (TMDC) semiconductors necessitates the exploration of a three-dimensional (3D) and damage-free surface treatment method to achieve uniform atomic layer-deposition (ALD) of a high-k dielectric film on the inert surface of a TMDC channel. This study developed a BCl3 plasma-derived radical treatment for MoS2 to functionalize MoS2 surfaces for the subsequent ALD of an ultrathin Al2O3 film. Microstructural verification demonstrated a complete coverage of an approximately 2 nm-thick Al2O3 film on a planar MoS2 surface, and the applicability of the technique to 3D structures was confirmed using a suspended MoS2 channel floating from the substrate. Density functional theory calculations supported by optical emission spectroscopy and X-ray photoelectron spectroscopy measurements revealed that BCl radicals, predominantly generated by the BCl3 plasma, adsorbed on MoS2 and facilitated the uniform nucleation of ultrathin ALD–Al2O3 films. Raman and photoluminescence measurements of monolayer MoS2 and electrical measurements of a bottom-gated FET confirmed negligible damage caused by the BCl3 plasma-derived radical treatment. Finally, the successful operation of a top-gated FET with an ultrathin ALD–Al2O3 (∼5 nm) gate dielectric film was demonstrated, indicating the effectiveness of the pretreatment

Cross-Linked Sulfonated Poly(arylene ether sulfone) Containing a Flexible and Hydrophobic Bishydroxy Perfluoropolyether Cross-Linker for High-Performance Proton Exchange Membrane

Here we show a simple and effective cross-linking method to prepare a high performance cross-linked sulfonated poly­(arylene ether sulfone) (C-SPAES) membrane using bishydroxy perfluoropolyether (PFPE) as a cross-linker for fuel cell applications. The C-SPAES membrane shows much improved physicochemical stability due to the cross-linked structure and reasonably high proton conductivity compared to the non-cross-linked SPAES membrane due to the incorporation of flexible PFPE and the effective phase-separated morphology between the hydrocarbon and perfluorinated moieties forming well-connected networks. Under intermediate-temperature and low humidity conditions (90 °C, 50% RH, and 150 kPa), the membrane electrode assembly employing the C-SPAES membrane reveals an outstanding cell performance (1.17 W cm^–2 at 0.65 V) ascribed to its reasonably high proton conductivity and enhanced interfacial compatibility between the perfluorinated moieties in the electrode and C-SPAES membrane. Furthermore, a hydration–dehydration cycling test result at 90 °C reveals that the C-SPAES membrane has notable durability against rigorous operating conditions

Negative Photoconductance in Heavily Doped Si Nanowire Field-Effect Transistors

We report the first observation of negative photoconductance (NPC) in n- and p-doped Si nanowire field-effect transistors (FETs) and demonstrate the strong influence of doping concentrations on the nonconventional optical switching of the devices. Furthermore, we show that the NPC of Si nanowire FETs is dependent on the wavelength of visible light due to the phonon-assisted excitation to multiple conduction bands with different band gap energies that would be a distinct optoelectronic property of indirect band gap semiconductor. We attribute the main driving force of NPC in Si nanowire FETs to the photogenerated hot electrons trapping by dopants ions and interfacial states. Finally, comparing back- and top-gate modulation, we derive the mechanisms of the transition between negative and positive photoconductance regimes in nanowire devices. The transition is decided by the competition between the light-induced interfacial trapping and the recombination of mobile carriers, which is dependent on the light intensity and the doping concentration

Plasma Processing for Crystallization and Densification of Atomic Layer Deposition BaTiO₃ Thin Films

High-<i>k</i>, low leakage thin films are crucial components for dynamic random access memory (DRAM) capacitors with high storage density and a long storage lifetime. In this work, we demonstrate a method to increase the dielectric constant and decrease the leakage current density of atomic layer deposited BaTiO₃ thin films at low process temperature (250 °C) using postdeposition remote oxygen plasma treatment. The dielectric constant increased from 51 (as-deposited) to 122 (plasma-treated), and the leakage current density decreased by 1 order of magnitude. We ascribe such improvements to the crystallization and densification of the film induced by high-energy ion bombardments on the film surface during the plasma treatment. Plasma-induced crystallization presented in this work may have an immediate impact on fabricating and manufacturing DRAM capacitors due to its simplicity and compatibility with industrial standard thin film processes

Cross-Linked Graphene Oxide Membrane Functionalized with Self-Cross-Linkable and Bactericidal Cardanol for Oil/Water Separation

A cross-linked graphene oxide (GO) membrane was fabricated by a simple vacuum filtration, which was followed by a thermal treatment to functionalize GO with renewable cardanol (cardanol-GO). The cardanol-GO was fabricated through reactions between epoxy groups on the GO surface and phenolic moieties of cardanol with the participation of a catalyst. The prepared cardanol-GO membrane was then heated to form a cross-linked structure by reactions between the double bonds of cardanol. The cross-linked GO membrane exhibited outstanding dimensional stability and oil/water separation efficiency. Furthermore, the cross-linked cardanol-GO membrane was proved to contain a marked antibacterial property against Escherichia coli that originates from the cardanol moieties

Plasma-Enhanced Atomic Layer Deposition of SiN–AlN Composites for Ultra Low Wet Etch Rates in Hydrofluoric Acid

The continued scaling in transistors and memory elements has necessitated the development of atomic layer deposited (ALD) of hydrofluoric acid (HF) etch resistant and electrically insulating films for sidewall spacer processing. Silicon nitride (SiN) has been the prototypical material for this need and extensive work has been conducted into realizing sufficiently lower wet etch rates (WERs) as well as leakage currents to meet industry needs. In this work, we report on the development of plasma-enhanced atomic layer deposition (PEALD) composites of SiN and AlN to minimize WER and leakage current density. In particular, the role of aluminum and the optimum amount of Al contained in the composite structures have been explored. Films with near zero WER in dilute HF and leakage currents density similar to pure PEALD SiN films could be simultaneously realized through composites which incorporate ≥13 at. % Al, with a maximum thermal budget of 350 °C

Optimal timing of treatment at relapse after autologous stem cell transplantation in patients with multiple : A study of the Korean Multiple Myeloma Working Party (KMM-1909)

Clinical data of stem cell transplantatio

Preparation and Analysis of Bicyclic Polystyrene

Bicyclic polystyrene was prepared by combining atom transfer radical polymerization and click chemistry. The bicyclic polymer was separated from concurrently produced acyclic (branched) polymers through fractional precipitation, and its purity was quantified by two-dimensional liquid chromatography analysis. The structure of bicyclic polymer was characterized by SEC, MALDI–TOF MS, ¹H NMR, and FT-IR