Elsevier BV Acta Medica Okayama 2352-4928 51 2026 Optical spectroscopic evaluation on the acquisition of optimal sonication temperature for efficient liquid phase exfoliation of molybdenum disulfide 114910 EN Fatimah Az-Zahra Saravanan binti Abdullah School of Engineering and Physical Sciences, Heriot-Watt University Malaysia Wengnam Lee Foundation Center, Heriot-Watt University Malaysia Patrik Öhberg Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University Boontong Goh Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University of Malaya Wuyi Chong Photonics Research Center, University of Malaya Harith Ahmad Photonics Research Center, University of Malaya Yasuhiko Hayashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Takeshi Nishikawa Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuenkiat Yap Foundation Center, Heriot-Watt University Malaysia This work investigates how the sonication temperature affects the liquid phase exfoliation of MoS₂ using optical and morphological approach in attempt to acquire an optimal temperature for such process at ambient room conditions. In an ultrasonic bath, exfoliation was carried out at six different temperatures. UV-Vis, FTIR, Raman spectroscopy and SEM characterizations reveal that moderate room temperature range yield excellent results producing well-dispersed flakes with strong excitonic properties with mild oxidation. Higher temperatures cause substantial oxidation, deterioration and restacking while lower temperatures led to insufficient exfoliation and fragmented morphologies because of insufficient cavitation energy. The findings highlight the importance of temperature control in producing high quality nanosheets for scalable applications. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0957-4522 36 1 2024 Optical bandgap tuning in SnO2–MoS2 nanocomposites: manipulating the mass of SnO2 and MoS2 using sonochemical solution mixing 6 EN Chinkhai Ong School of Engineering and Physical Sciences, Heriot-Watt University Malaysia Weng Nam Lee Heriot-Watt Global College, Heriot-Watt University Malaysia Yee Seng Tan Sunway Biofunctional Molecules Discovery Centre, School of Medical and Life Sciences, Sunway University Patrik Ohberg School of Engineering and Physical Sciences, Institute of Photonics and Quantum Sciences, Heriot-Watt University Yasuhiko Hayashi Faculty of Environmental, Life, Natural Science and Technology, Okayama University Takeshi Nishikawa Faculty of Environmental, Life, Natural Science and Technology, Okayama University Yuenkiat Yap Heriot-Watt Global College, Heriot-Watt University Malaysia This study investigates controlled optical bandgap tuning through precise adjustment of the SnO2 and MoS2 mass in nanocomposites. A sonochemical solution mixing method, coupled with bath sonication, is employed for the preparation of SnO2–MoS2 nanocomposite. This approach allows for comprehensive characterization using UV–Vis FTIR, XRD, EDX, Raman spectroscopies, and FESEM, providing insights into morphology, chemical, and optical properties. Increasing the SnO2 mass leads to a linear decrease in the optical bandgap energy, from 3.0 to 1.7 eV. Similarly, increasing the MoS2 mass also results in a decrease in the optical bandgap energy, with a limitation of around 2.01 eV. This work demonstrates superior control over optical bandgap by manipulating the SnO2 mass compared to MoS2, highlighting the complexities introduced by MoS2 2D nanosheets during sonication. These findings hold significant value for optoelectronic applications, emphasizing enhanced control of optical bandgap through systematic mass manipulation. No potential conflict of interest relevant to this article was reported.

Informa UK Limited Acta Medica Okayama 0003-2719 58 2 2024 Influence of Dilution Upon the Ultraviolet-Visible Peak Absorbance and Optical Bandgap Estimation of Tin(IV) Oxide and Tin(IV) Oxide-Molybdenum(IV) Sulfide Solutions 196 212 EN Chin Khai Ong School of Engineering and Physical Sciences, Heriot-Watt University Malaysia Weng Nam Lee Heriot-Watt Global College, Heriot-Watt University Malaysia Mohammad Khalid Sunway Centre for Electrochemical Energy and Sustainable Technology (SCEEST), School of Engineering and Technology, Sunway University Muhammad Amirul Aizat Mohd Abdah Sunway Centre for Electrochemical Energy and Sustainable Technology (SCEEST), School of Engineering and Technology, Sunway University Patrik Ohberg Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University Ling Hong Lim Heriot-Watt Global College, Heriot-Watt University Malaysia Yasuhiko Hayashi Graduate School of Natural Science and Technology, Faculty of Engineering, Okayama University Takeshi Nishikawa Graduate School of Natural Science and Technology, Faculty of Engineering, Okayama University Yuenkiat Yap Heriot-Watt Global College, Heriot-Watt University Malaysia The study investigated the constraints associated with the dilution technique in determining the optical bandgap of nanoparticle dispersion and modified nanocomposites, utilizing ultraviolet-visible absorbance spectra and Tauc plot analysis. A case study involving SnO2 dispersion and SnO2-MoS2 nanocomposite solutions, prepared through the direct solution mixing method, was conducted to assess the implications of dilution upon the absorbance spectra and bandgap estimation. The results emphasize the considerable impact of the dilution technique on the measured optical bandgap, demonstrating that higher dilution factors lead to shift in bandgap values. Furthermore, the study highlights that dilution can induce variations in the average nanoparticle sizes due to agglomeration, thereby influencing bandgap estimation. In the context of nanocomposites, the interaction between SnO2 nanoparticles and exfoliated MoS2 nanosheets diminishes with increasing dilution, leading to the estimated optical bandgap being primarily attributable to SnO2 nanoparticles alone. These observations underscore the necessity for caution when employing the dilution technique for bandgap estimation in nanoparticles dispersion and nanocomposites, offering valuable insights for researchers and practitioners in the field. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 2633-5409 5 22 2024 Enhanced piezo-response of mixed-cation copper perovskites with Cl/Br halide engineering 8953 8960 EN Amr Elattar Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Christopher Munoz Industrial & Manufacturing Engineering, FAMU-FSU College of Engineering Libor Kobera Institute of Macromolecular Chemistry of the Czech Academy of Sciences Andrii Mahun Institute of Macromolecular Chemistry of the Czech Academy of Sciences Jiri Brus Institute of Macromolecular Chemistry of the Czech Academy of Sciences Mohammed Jasim Uddin Photonics and Energy Research Laboratory (PERL), Department of Mechanical Engineering, The University of Texas Yasuhiko Hayashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Okenwa Okoli Industrial & Manufacturing Engineering, FAMU-FSU College of Engineering Tarik Dickens Industrial & Manufacturing Engineering, FAMU-FSU College of Engineering Halide and cation engineering of organic-inorganic hybrid perovskites has shown a great potential for structural modulation of perovskites and enhancing their optoelectronic properties. Here, we studied the impact of Cl/Br halide engineering on the structural and piezoelectric properties of MA/Cs mixed-cation Cu-perovskite crystals. X-ray diffraction, Raman spectroscopy, and 133Cs solid-state NMR were utilized to find out the nature of the perovskite crystal structure formation. Three distinct crystal structures were obtained depending on the Cl/Br content. High Cl content resulted in the formation of Br-doped (Cs/MA)CuCl3 perovskite with the presence of paramagnetic Cu2+ ions. High Br content led to the formation of Cl-doped (MA/Cs)2CuBr4 perovskite with the presence of diamagnetic Cu+ ions. Equimolar Cl/Br perovskite content gave a novel crystal structure with the formation of well-dispersed diamagnetic domains. Compared to the high Cl/Br containing perovskites, the equimolar Cl/Br perovskite revealed the highest potential for piezoelectric applications with a maximum recordable piezoelectric output voltage of 5.0 V. The results provide an insight into the importance of mixed-halide and mixed-cation engineering for tailoring the perovskite structural properties towards a wide range of efficient optoelectronics. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 2046-2069 14 32 2024 Lead-free iron-doped Cs3Bi2Br9 perovskite with tunable properties 23177 23183 EN Thiri Htun Graduate School of Natural Science and Technology, Okayama University Amr Elattar Department of Chemistry, Faculty of Science, Ain Shams University Hytham Elbohy Physics Department, Faculty of Science, Damietta University Kosei Tsutsumi Graduate School of Natural Science and Technology, Okayama University Kazumasa Horigane Research Institute for Interdisciplinary Science, Okayama University Chiyu Nakano Advanced Science Research Center, Okayama University Xiaoyu Gu Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting and Department of Electronic & Electrical Engineering, Southern University of Science and Technology Hiroo Suzuki Graduate School of Natural Science and Technology, Okayama University Takeshi Nishikawa Graduate School of Natural Science and Technology, Okayama University Aung Ko Ko Kyaw Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting and Department of Electronic & Electrical Engineering, Southern University of Science and Technology Yasuhiko Hayashi Graduate School of Natural Science and Technology, Okayama University Perovskite based on cesium bismuth bromide offers a compelling, non-toxic alternative to lead-containing counterparts in optoelectronic applications. However, its widespread usage is hindered by its wide bandgap. This study investigates a significant bandgap tunability achieved by introducing Fe doping into the inorganic, lead-free, non-toxic, and stable Cs3Bi2Br9 perovskite at varying concentrations. The materials were synthesized using a facile method, with the aim of tuning the optoelectronic properties of the perovskite materials. Characterization through techniques such as X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy (EDS), and UV-vis spectroscopy was conducted to elucidate the transformation mechanism of the doping materials. The substitution process results in a significant change in the bandgap energy, transforming from the pristine Cs3Bi2Br9 with a bandgap of 2.54 eV to 1.78 eV upon 70% Fe doping. The addition of 50% Fe in Cs3Bi2Br9 leads to the formation of the orthorhombic structure in Cs2(Bi,Fe)Br5 perovskite, while complete Fe alloying at 100% results in the phase formation of CsFeBr4 perovskite. Our findings on regulation of bandgap energy and crystal structure through B site substitution hold significant promise for applications in optoelectronics. No potential conflict of interest relevant to this article was reported.

Nature Portfolio Acta Medica Okayama 2041-1723 15 1 2024 Photoinduced dynamics during electronic transfer from narrow to wide bandgap layers in one-dimensional heterostructured materials 4600 EN Yuri Saida Graduate School of Science and Technology, University of Tsukuba Thomas Gauthier Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) UMR 6251 Hiroo Suzuki Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Satoshi Ohmura Faculty of Engineering, Hiroshima Institute of Technology Ryo Shikata Graduate School of Science and Technology, University of Tsukuba Yui Iwasaki Graduate School of Science and Technology, University of Tsukuba Godai Noyama Graduate School of Science and Technology, University of Tsukuba Misaki Kishibuchi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yuichiro Tanaka Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Wataru Yajima Graduate School of Science and Technology, University of Tsukuba Nicolas Godin Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) UMR 6251 Gael Privault Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) UMR 6251 Tomoharu Tokunaga Graduate School of Engineering, Nagoya University Shota Ono Institute for Materials Research, Tohoku University Shin-Ya Koshihara School of Science, Tokyo Institute of Technology Kenji Tsuruta Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Yasuhiko Hayashi Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Roman Bertoni Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) UMR 6251 Masaki Hada Institute of Pure and Applied Science and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba Electron transfer is a fundamental energy conversion process widely present in synthetic, industrial, and natural systems. Understanding the electron transfer process is important to exploit the uniqueness of the low-dimensional van der Waals (vdW) heterostructures because interlayer electron transfer produces the function of this class of material. Here, we show the occurrence of an electron transfer process in one-dimensional layer-stacking of carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs). This observation makes use of femtosecond broadband optical spectroscopy, ultrafast time-resolved electron diffraction, and first-principles theoretical calculations. These results reveal that near-ultraviolet photoexcitation induces an electron transfer from the conduction bands of CNT to BNNT layers via electronic decay channels. This physical process subsequently generates radial phonons in the one-dimensional vdW heterostructure material. The gathered insights unveil the fundamentals physics of interfacial interactions in low dimensional vdW heterostructures and their photoinduced dynamics, pushing their limits for photoactive multifunctional applications. No potential conflict of interest relevant to this article was reported.

American Chemical Society Acta Medica Okayama 2470-1343 2022 Characteristics of Vertical Ga2O3 Schottky Junctions with the Interfacial Hexagonal Boron Nitride Film 26021 26028 EN Venkata Krishna Rao Rama Graduate School of Natural Science and Technology, Okayama University Ajinkya K. Ranade Department of Physical Science and Engineering, Nagoya Institute of Technology Pradeep Desai Department of Physical Science and Engineering, Nagoya Institute of Technology Bhagyashri Todankar Department of Physical Science and Engineering, Nagoya Institute of Technology Golap Kalita Department of Physical Science and Engineering, Nagoya Institute of Technology Hiroo Suzuki Graduate School of Natural Science and Technology Masaki Tanemura Department of Physical Science and Engineering, Nagoya Institute of Technology Yasuhiko Hayashi We present the device properties of a nickel (Ni)- gallium oxide (Ga2O3) Schottky junction with an interfacial hexagonal boron nitride (hBN) layer. A vertical Schottky junction with the configuration Ni/hBN/Ga2O3/In was created using a chemical vapor-deposited hBN film on a Ga(2)O(3 )substrate. The current-voltage characteristics of the Schottky junction were investigated with and without the hBN interfacial layer. We observed that the turn-on voltage for the forward current of the Schottky junction was significantly enhanced with the hBN interfacial film. Furthermore, the Schottky junction was analyzed under the illumination of deep ultraviolet light (254 nm), obtaining a photoresponsivity of 95.11 mA/W under an applied bias voltage (-7.2 V). The hBN interfacial layer for the Ga2O3-based Schottky junction can serve as a barrier layer to control the turn-on voltage and optimize the device properties for deep-UV photosensor applications. Furthermore, the demonstrated vertical heterojunction with an hBN layer has the potential to be significant for temperature management at the junction interface to develop reliable Ga2O3-based Schottky junction devices. No potential conflict of interest relevant to this article was reported.

Springer Nature Acta Medica Okayama 1226-4601 24 1 2021 Synthesis and characterization of conductive flexible cellulose carbon nanohorn sheets for human tissue applications 18 EN Karthik Paneer Selvam Graduate School of Natural Science and Technology, Okayama University Taichi Nagahata Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Kosuke Kato Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Mayuko Koreishi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Takeshi Nishikawa Graduate School of Natural Science and Technology, Okayama University Ayano Satoh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yasuhiko Hayashi Graduate School of Natural Science and Technology, Okayama University Background<br> Conductive sheets of cellulose and carbon nanomaterials and its human skin applications are an interesting research aspect as they have potential for applications for skin compatibility. Hence it is needed to explore the effects and shed light on these applications.<br> Method<br> To fabricate wearable, portable, flexible, lightweight, inexpensive, and biocompatible composite materials, carbon nanohorns (CNHs) and hydroxyethylcellulose (HEC) were used as precursors to prepare CNH-HEC (Cnh-cel) composite sheets. Cnh-cel sheets were prepared with different loading concentrations of CNHs (10, 20 50,100mg) in 200mg cellulose. To fabricate the bio-compatible sheets, a pristine composite of CNHs and HEC was prepared without any pretreatment of the materials.<br> Results<br> The obtained sheets possess a conductivity of 1.83x10(-10)S/m and bio-compatible with human skin. Analysis for skin-compatibility was performed for Cnh-cel sheets by h-CLAT in vitro skin sensitization tests to evaluate the activation of THP-1 cells. It was found that THP-1 cells were not activated by Cnh-cel; hence Cnh-cel is a safe biomaterial for human skin. It was also found that the composite allowed only a maximum loading of 100mg to retain the consistent geometry of free-standing sheets of <100<mu>m thickness. Since CNHs have a unique arrangement of aggregates (dahlia structure), the composite is homogeneous, as verified by transmission electron microscopy (TEM) and, scanning electron microscopy (SEM), and other functional properties investigated by Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), conductivity measurement, tensile strength measurement, and skin sensitization.<br> Conclusion<br> It can be concluded that cellulose and CNHs sheets are conductive and compatible to human skin applications. No potential conflict of interest relevant to this article was reported.

American Institute of Physics Acta Medica Okayama 0003-6951 117 10 2020 Super-chiral vibrational spectroscopy with metasurfaces for high-sensitive identification of alanine enantiomers 101103 EN Takumi Iida Department of Electrical and Electronic Engineering, Okayama University Atsushi Ishikawa Department of Electrical and Electronic Engineering, Okayama University Takuo Tanaka Metamaterials Laboratory, RIKEN Cluster for Pioneering Research Atsuya Muranaka Advanced Elements Chemistry Laboratory, RIKEN Cluster for Pioneering Research Masanobu Uchiyama Advanced Elements Chemistry Laboratory, RIKEN Cluster for Pioneering Research Yasuhiko Hayashi Department of Electrical and Electronic Engineering, Okayama University Kenji Tsuruta Department of Electrical and Electronic Engineering, Okayama University Chiral nature of an enantiomer can be characterized by circular dichroism (CD) spectroscopy, but such a technique usually suffers from weak signal even with a sophisticated optical instrument. Recent demonstrations of plasmonic metasurfaces showed that chiroptical interaction of molecules can be engineered, thereby greatly simplifying a measurement system with high sensing capability. Here, by exploiting super-chiral field in a metasurface, we experimentally demonstrate high-sensitive vibrational CD spectroscopy of alanine enantiomers, the smallest chiral amino acid. Under linearly polarized excitation, the metasurface consisting of an array of staggered Au nano-rods selectively produces the left- and right-handed super-chiral fields at 1600 cm�|1, which spectrally overlaps with the functional group vibrations of alanine. In the Fourier-transform infrared spectrometer measurements, the mirror symmetric CD spectra of D- and L-alanine are clearly observed depending on the handedness of the metasurface, realizing the reliable identification of small chiral molecules. The corresponding numerical simulations reveal the underlying resonant chiroptical interaction of plasmonic modes of the metasurface and vibrational modes of alanine. Our approach demonstrates a high-sensitive vibrational CD spectroscopic technique, opening up a reliable chiral sensing platform for advanced infrared inspection technologies. No potential conflict of interest relevant to this article was reported.

Nature Acta Medica Okayama 2045-2322 10 1 2020 Whitish daytime radiative cooling using diffuse reflection of non-resonant silica nanoshells 6486 EN Takahiro Suichi Department of Electrical and Electronic Engineering, Okayama University Atsushi Ishikawa Department of Electrical and Electronic Engineering, Okayama University Takuo Tanaka Metamaterials Laboratory, RIKEN Cluster for Pioneering Research Yasuhiko Hayashi Department of Electrical and Electronic Engineering, Okayama University Kenji Tsuruta Department of Electrical and Electronic Engineering, Okayama University Daytime radiative cooling offers efficient passive cooling of objects by tailoring their spectral responses, holding great promise for green photonics applications. A specular reflector has been utilized in cooling devices to minimize sunlight absorption, but such a glaring surface is visually less appealing, thus undesirable for public use. Here, by exploiting strong diffuse reflection of silica nanoshells in a polymer matrix, daytime radiative cooling below the ambient temperature is experimentally demonstrated, while showing whitish color under sunlight. The cooling device consists of a poly(methyl methacrylate) layer with randomly distributed silica nanoshells and a polydimethylsiloxane (PDMS) layer on an Ag mirror. The non-resonant nanoshells exhibit uniform diffuse reflection over the solar spectrum, while fully transparent for a selective thermal radiation from the underneath PDMS layer. In the temperature measurement under the sunlight irradiation, the device shows 2.3 degrees C cooler than the ambient, which is comparable to or even better than the conventional device without the nanoshells. Our approach provides a simple yet powerful nanophotonic structure for realizing a scalable and practical daytime radiative cooling device without a glaring reflective surface. No potential conflict of interest relevant to this article was reported.

Nature Acta Medica Okayama 2045-2322 10 1 2020 Controlling Electronic States of Few-walled Carbon Nanotube Yarn via Joule-annealing and p-type Doping Towards Large Thermoelectric Power Factor 7307 EN May Thu Zar Myint Graduate School of Natural Science and Technology, Okayama University Takeshi Nishikawa Graduate School of Natural Science and Technology, Okayama University Kazuki Omoto Graduate School of Natural Science and Technology, Okayama University Hirotaka Inoue Graduate School of Natural Science and Technology, Okayama University Yoshifumi Yamashita Graduate School of Natural Science and Technology, Okayama University Aung Ko Ko Kyaw Department of Electrical and Electronic Engineering, Southern University of Science and Technology Yasuhiko Hayashi Graduate School of Natural Science and Technology, Okayama University Flexible, light-weight and robust thermoelectric (TE) materials have attracted much attention to convert waste heat from low-grade heat sources, such as human body, to electricity. Carbon nanotube (CNT) yarn is one of the potential TE materials owing to its narrow band-gap energy, high charge carrier mobility, and excellent mechanical property, which is conducive for flexible and wearable devices. Herein, we propose a way to improve the power factor of CNT yarns fabricated from few-walled carbon nanotubes (FWCNTs) by two-step method; Joule-annealing in the vacuum followed by doping with p-type dopants, 2,3,5,6-tetrafluo-7,7,8,8-tetracyanoquinodimethane (F4TCNQ). Numerical calculations and experimental results explain that Joule-annealing and doping modulate the electronic states (Fermi energy level) of FWCNTs, resulting in extremely large thermoelectric power factor of 2250 mu Wm(-1) K-2 at a measurement temperature of 423K. Joule-annealing removes amorphous carbon on the surface of the CNT yarn, which facilitates doping in the subsequent step, and leads to higher Seebeck coefficient due to the transformation from (semi) metallic to semiconductor behavior. Doping also significantly increases the electrical conductivity due to the effective charge transfers between CNT yarn and F4TCNQ upon the removal of amorphous carbon after Joule-annealing. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 2053-1591 7 5 2020 Synthesis of solvent-free conductive and flexible cellulose-carbon nanohorn sheets and their application as a water vapor sensor 056402 EN Karthik Paneer Selvam Graduate School of Natural Science and Technology, Okayama University Tomohiro Nakagawa Graduate School of Natural Science and Technology, Okayama University Tatsuki Marui Graduate School of Natural Science and Technology, Okayama University Hirotaka Inoue Graduate School of Natural Science and Technology, Okayama University Takeshi Nishikawa Graduate School of Natural Science and Technology, Okayama University Yasuhiko Hayashi Graduate School of Natural Science and Technology, Okayama University Carbon nanohorns (CNHs) are mixed with cellulose to make freestanding thin-film conductive sheets. CNHs, at different ratios (5, 10, 25, 50 wt%), form composites with cellulose (hydroxyethylcellulose). Freestanding cellulose-carbon nanohorn (CCN) sheets were fabricated using a 100 mu m-thick metal bar coater. Surfactants or any other chemical treatments to tailor the surface properties of CNHs were avoided to obtain composite sheets from pristine CNHs and cellulose. Utilizing the hygroscopic property of hydroxyethylcellulose and the electrical conductivity of CNHs paved a path to perform this experiment. The synthesis technique is simple, and the fabrication and drying of the sheets were effortless. As the loading concentration of CNH increased, the resistance, flexibility, and strength of the CCN composite sheets decreased. The maximum loading concentration possible to obtain a freestanding CCN sheet is 50 wt%. The resistance of the maximum loading concentration of CNH was 53 k omega. The response of the CCN sheets to water vapor was 4 s and recover time was 13 s, and it is feasible to obtain a response for different concentrations of water vapor. High-resolution transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, resistance measurement, tensile strength measurement, and thermogravimetric analysis were used to investigate the mechanical, morphological, electrical, and chemical properties of the CCN sheets. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1420-3049 25 5 2020 Systematic Investigations of Annealing and Functionalization of Carbon Nanotube Yarns 1144 EN Maik Scholz Leibniz Institute for Solid State and Material Research Dresden, Helmholtzstr. 20 Yasuhiko Hayashi Graduate School of Natural Science and Technology, Okayama University Victoria Eckert Leibniz Institute for Solid State and Material Research Dresden, Helmholtzstr. 20 Vyacheslav Khavrus Leibniz Institute for Solid State and Material Research Dresden, Helmholtzstr. 20 Albrecht Leonhardt Leibniz Institute for Solid State and Material Research Dresden, Helmholtzstr. 20 Bernd Büchner Leibniz Institute for Solid State and Material Research Dresden, Helmholtzstr. 20 Michael Mertig Institute for Physical Chemistry, Technische Universität Dresden Silke Hampel Leibniz Institute for Solid State and Material Research Dresden, Helmholtzstr. 20 Carbon nanotube yarns (CNY) are a novel carbonaceous material and have received a great deal of interest since the beginning of the 21st century. CNY are of particular interest due to their useful heat conducting, electrical conducting, and mechanical properties. The electrical conductivity of carbon nanotube yarns can also be influenced by functionalization and annealing. A systematical study of this post synthetic treatment will assist in understanding what factors influences the conductivity of these materials. In this investigation, it is shown that the electrical conductivity can be increased by a factor of 2 and 5.5 through functionalization with acids and high temperature annealing respectively. The scale of the enhancement is dependent on the reducing of intertube space in case of functionalization. For annealing, not only is the highly graphitic structure of the carbon nanotubes (CNT) important, but it is also shown to influence the residual amorphous carbon in the structure. The promising results of this study can help to utilize CNY as a replacement for common materials in the field of electrical wiring. No potential conflict of interest relevant to this article was reported.

Nature Publishing Group Acta Medica Okayama 2041-1723 10 2019 Ultrafast isomerization-induced cooperative motions to higher molecular orientation in smectic liquid-crystalline azobenzene molecules 4159 EN Masaki Hada Graduate School of Natural Science and Technology, Okayama University Daisuke Yamaguchi Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo Tadahiko Ishikawa School of Science,Tokyo Institute of Technology Takayoshi Sawa Graduate School of Natural Science and Technology, Okayama University Kenji Tsuruta Graduate School of Natural Science and Technology, Okayama University Ken Ishikawa School of Materials and Chemical Technology, Tokyo Institute of Technology Shin-Ya Koshihara School of Science,Tokyo Institute of Technology Yasuhiko Hayashi Graduate School of Natural Science and Technology, Okayama University Takashi Kato Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo The photoisomerization of molecules is widely used to control the structure of soft matter in both natural and synthetic systems. However, the structural dynamics of the molecules during isomerization and their subsequent response are difficult to elucidate due to their complex and ultrafast nature. Herein, we describe the ultrafast formation of higherorientation of liquid-crystalline (LC) azobenzene molecules via linearly polarized ultraviolet light (UV) using ultrafast time-resolved electron diffraction. The ultrafast orientation is caused by the trans-to-cis isomerization of the azobenzene molecules. Our observations are consistent with simplified molecular dynamics calculations that revealed that the molecules are aligned with the laser polarization axis by their cooperative motion after photoisomerization. This insight advances the fundamental chemistry of photoresponsive molecules in soft matter as well as their ultrafast photomechanical applications. No potential conflict of interest relevant to this article was reported.