Article
Chemistry, Multidisciplinary
Takashi Yanagishita, Haruka Itoh, Hideki Masuda
Summary: Ordered alumina through-hole membranes were obtained by a combination of anodization of Al, formation of a TiO2 protective layer, and subsequent etching. These membranes have potential applications in various fields.
Article
Materials Science, Coatings & Films
Min Zhai, A. Locquet, Mi Jung, Deokha Woo, D. S. Citrin
Summary: The ordered nanoporous alumina films were grown on aluminum substrates through a two-step electrochemical anodization process. THz-based techniques allow for nondestructive characterization of the surface morphology of the entire films on the 10-100 mu m length scale, providing information over macroscopic scan areas. The regularity of the surface morphology is not readily ascertained using visible-light optical microscopy.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Electrochemistry
Takashi Yanagishita, Ryotaro Kawato, Hideki Masuda
Summary: Highly ordered anodic porous alumina with a period of 90-160 nm was prepared by anodization using extremely dilute sulfuric acid. The hole period of anodic porous alumina was controllable by changing the anodization voltage. The addition of a small amount of phosphoric acid to the electrolyte improved the uniformity of the oxide film thickness.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Xiao Cheng, Lei Zhao, Zhiwei Zhang, Cheng Deng, Chao Li, Yaohua Du, Jianwei Shi, Mengfu Zhu
Summary: This study utilized the properties of polyacrylonitrile to prepare well-ordered nanofiber membranes, which exhibit excellent air filtration efficiency and low resistance.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Materials Science, Multidisciplinary
Boris Duran, Cesar Saldias, Roberto Villarroel, Samuel A. A. Hevia
Summary: In this study, CuO/Cu2O film supported on nanoporous alumina membranes (NAMs) was synthesized and characterized, and its photocatalytic properties in the removal of the organic pollutant methyl orange (MO) were investigated. Transparent nanostructured membranes were modified with APTS and EDTAD to create a highly functionalized surface with carboxyl groups for complexing with copper cations. The resulting Cu2+-modified membranes were annealed to form a well-ordered nanostructured coating of CuO/Cu2O with photocatalytic properties. The photocatalytic performance of the NAM-CuO/Cu2O nanostructured membranes was tested, showing a 50% removal of MO under continuous light irradiation for 2 hours.
Article
Electrochemistry
Takashi Yanagishita, Takuya Masuda, Hideki Masuda
Summary: Ordered anodic porous WO3 was prepared by anodizing a W substrate with a depression pattern in concentrated phosphoric acid at 120°C and 18V. The behavior of hole formation in depressions was found to be influenced by the depth and diameter of the depressions - shallow depressions formed multiple holes while deep depressions formed only one. Additionally, fine holes were observed to grow around induced holes when depression diameter was small, affecting the growth direction of the induced holes.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Jianhua Zhu, Qian Zhang, Yanjiao Zhao, Ruiyun Zhang, Lifang Liu, Jianyong Yu
Summary: In this study, N-doped porous carbon nanofiber membranes with inter-fiber cross-linked structures were successfully fabricated through eccentric coaxial electrospinning and carbonization processes. The prepared carbon nanofiber membranes showed outstanding electrical conductivity and flexibility. Additionally, NiCo2O4 nanoneedles were in-situ decorated onto the carbon nanofiber membranes to construct hybrid electrodes, which exhibited competitive capacitance and good rate performance. The assembled asymmetric supercapacitors also demonstrated a high energy density. These findings pave a promising way for the application of carbon nanofiber-based electrodes in energy storage systems.
Article
Engineering, Environmental
Xianbo Hou, Yiqi Mao, Rubing Zhang, Daining Fang
Summary: The study developed a polyimide (PI) nanofiber cross-linked polyimide aerogel membrane with high flexibility, strong mechanical properties, and efficient heat insulation. Addition of nanofibers significantly enhanced the performance of aerogel, making it a potential material for applications in modern technology, military, and aerospace.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Chemical
Xiaofan Luo, Zhenggong Wang, Shanshan Wu, Wangxi Fang, Jian Jin
Summary: This study successfully prepared a new generation of OSN membranes through metal ion cross-linking, which exhibit excellent stability in various organic solvents and high rejection rates to dyes. Compared to traditional chemical cross-linkers, metal ion cross-linking does not significantly reduce membrane permeability, and also improves membrane compaction resistance.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Lei Xie, Shan Zhou, Jinrong Liu, Beilei Qiu, Tianyi Liu, Qirui Liang, Xiaozhong Zheng, Ben Li, Jie Zeng, Miao Yan, Yanjun He, Xin Zhang, Hui Zeng, Ding Ma, Pu Chen, Kang Liang, Lei Jiang, Yong Wang, Dongyuan Zhao, Biao Kong
Summary: A simple and straightforward soft-templating hydrothermal carbonization approach has been developed to synthesize highly flexible and mechanically robust nanofiber-arrays-based carbonaceous ordered mesoporous nanowires (CMWs). This method shows great versatility in controlling the dimensions of CMWs.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Engineering, Chemical
Malikah Najibah, Ekaterina Tsoy, Hamza Khalid, Yongfang Chen, Qingfeng Li, Chulsung Bae, Jaromir Hnat, Michaela Plevov, Karel Bouzek, Jong Hyun Jang, Hyun S. Park, Dirk Henkensmeier
Summary: The study investigates the reinforcement of anion exchange membranes using polybenzimidazole nanofiber mats filled with the bromomethylated precursor of ultra-stable AEM material mTPN. The optimized PBI/mTPN-50.120 composite membrane shows decreased length swelling, increased tensile strength, and Young's modulus while maintaining high conductivity. In an electrolyser, the membrane demonstrated stable performance over 200 hours of testing.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Chemistry, Analytical
Lu Wang, Lihui Wang, Guijuan Li, Yangyang Zhu, Chang Liu, Lingjun Zeng, Sai Zhong, Li Juan Wang
Summary: The CuPc/PVA PNAs sensors, with well-ordered nanofiber arrays, achieved lower detection limit and shorter response and recovery time for gas monitoring compared to sensors with disordered nanofibers. The sensors showed promising results in real-time monitoring of NO2, with minimal impact from humidity.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Chemistry, Multidisciplinary
Junxi Zhang, Huaping Zhao, Ming Gong, Lide Zhang, Zhijun Yan, Kang Xie, Guangtao Fei, Xiaoguang Zhu, Mingguang Kong, Shuyuan Zhang, Lin Zhang, Yong Lei
Summary: The nonuniformity of the nanochannel geometry in anodic aluminium oxide (AAO) membranes can affect their applications and the reflectance properties of nanostructures. Using depth-profiling transmission electron microscopy, the truncated conical geometry of the entire nanochannels was revealed, and an effective etching method was introduced to remove the nonuniformity.
Article
Biochemistry & Molecular Biology
Javier Garcia, Ruth Gutierrez, Ana S. Gonzalez, Ana I. Jimenez-Ramirez, Yolanda Alvarez, Victor Vega, Heiko Reith, Karin Leistner, Carlos Luna, Kornelius Nielsch, Victor M. Prida
Summary: Tuning and controlling the magnetic properties of nanomaterials is crucial for implementing new technologies. In this study, core/shell Ni@(NiO, Ni(OH)2) nanowire arrays were fabricated using an electrochemical approach, and their magnetic properties were characterized. The results showed surface oxidation-induced magnetic hardening in the nanowires and an increasing exchange bias effect at low temperatures.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Mohamed Shaban
Summary: In this study, different morphologies of nanoarrays were developed using anodic aluminum oxide membranes (AAOMs) and Au-coated AAOMs (AAOM/Au). The nanoarrays showed promising performance in dye removal and pH sensing applications.
Article
Materials Science, Multidisciplinary
Fatih Alarslan, Laura Vittadello, Jonas Klein, Qaiser Ali Khan, Christian Kijatkin, Markus Haase, Helmut Schaefer, Mirco Imlau, Martin Steinhart
Summary: This study presents a method for preparing thin microstructured LiNbO3 layers using environmentally friendly aqueous LiNbO3 precursor solutions and porous polymer stamps, achieving high-throughput generation of microstructured LiNbO3 layers and demonstrating increased second-harmonic generation output by electrodeposition of gold.
ADVANCED ENGINEERING MATERIALS
(2022)
Article
Chemistry, Physical
Jannis Thien, Jascha Bahlmann, Andreas Alexander, Kevin Ruwisch, Jari Rodewald, Tobias Pohlmann, Martin Hoppe, Fatih Alarslan, Martin Steinhart, Baki Altuncevahir, Padraic Shafer, Carola Meyer, Florian Bertram, Joachim Wollschlaeger, Karsten Kuepper
Summary: This study presents the magnetic properties and cation ordering of ultrathin Co-rich cobalt ferrite films. The electronic structure and distribution of cations in the films were examined using various characterization techniques. The results show a partially inverse spinel structure and an increased amount of Co3+ cations in the low-spin state for one of the films.
Article
Polymer Science
Marianna Spyridakou, Kostas Tsimenidis, Manos Gkikas, Martin Steinhart, Robert Graf, George Floudas
Summary: This study investigates the self-assembly and dynamics of PBLG and its copolymer with PIB both in bulk and under nanometer confinement. The results reveal that confinement accelerates the segmental process and partially destabilizes the secondary structure.
Article
Multidisciplinary Sciences
Yupeng Chen, Zhongpeng Zhu, Martin Steinhart, Stanislav N. Gorb
Summary: This article discusses the concept of bio-inspired wet adhesion, reviews associated challenges, and discusses future directions. It also proposes a model for wet adhesion management.
Article
Chemistry, Multidisciplinary
Jonas Klein, Fatih Alarslan, Martin Steinhart, Markus Haase
Summary: This report describes the post-modification of mesoporous antimony-doped tin oxide (ATO) nanoparticle layers with a redox-active cerium compound. The switching of the Ce3+/Ce4+ couple on the conductive nanoparticle scaffold is demonstrated using a non-intercalating electrolyte. Nanoparticle layers doped with 15% Sb exhibit the highest storage capacity, and show promising performance as charge storage layers in an electrochromic device.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jonas Klein, Michael Philippi, Fatih Alarslan, Tim Jaehnichen, Dirk Enke, Martin Steinhart, Markus Haase
Summary: High-temperature treatment, specifically through postsynthesis calcination, is crucial for maximizing the potential of functional nanomaterials. However, this step often hinders the preparation of colloidal solutions due to agglomeration. In this study, researchers successfully obtained stable colloidal solutions of calcined n-conductive antimony doped tin oxide (ATO) and titanium dioxide (TiO2) nanoparticles without using sacrificial materials. This was achieved by reducing the contact between nanoparticles through aerogel assembly. The resulting aggregates in solution, although slightly sintered, were remarkably small, with sizes below 30 nm.
Article
Chemistry, Multidisciplinary
Sebastian Stater, Felix A. Wenzel, Hannes Welz, Klaus Kreger, Jurgen Kohler, Hans-Werner Schmidt, Richard Hildner
Summary: Funneling excitation energy toward lower energy excited states is a key concept in photosynthesis, often realized with at most two types of pigment molecules. However, current synthetic approaches rely on Fo''rster-type energy-transfer cascades along chemically different molecules. Here, we demonstrate a novel concept where an excited-state energy gradient is achieved along micrometer-long supramolecular nanofibers based on a single component, the conjugated polymer poly(3-hexylthiophene), P3HT. This gradient is attributed to defect fractionation during nanofiber growth and provides guidelines for designing supramolecular structures with intrinsic energy gradients for nanophotonic applications.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Biochemistry & Molecular Biology
Gririraj Manoharan, Petra Boesel, Jannis Thien, Michael Holtmannspoetter, Laura Meingast, Mercedes Schmidt, Henning Eickmeier, Markus Haase, Janina Maultzsch, Martin Steinhart, Joachim Wollschlaeger, Matteo Palma, Carola Meyer
Summary: In this study, we propose a method to functionalize silanized single-walled carbon nanotubes (SWNTs) using copper-free click chemistry for the assembly of inorganic and biological nanohybrids. Silanization and strain-promoted azide-alkyne cycloaddition reactions (SPACC) were employed for SWNT functionalization. The functionalized SWNTs were successfully immobilized onto patterned substrates through dielectrophoresis (DEP). The strategy demonstrated general applicability for the functionalization of SWNTs with metal nanoparticles, fluorescent dyes, and biomolecules.
Article
Polymer Science
Niko Nagengast, Christian Bay, Frank Doepper, Hans-Werner Schmidt, Christian Neuber
Summary: Polymers have advantageous characteristics and additive manufacturing technologies have introduced versatile production processes. However, the increasing demand for polymer products leads to resource and energy consumption, resulting in waste accumulation. Therefore, appropriate product and material design is essential to close the loop of economically driven product systems.
Article
Multidisciplinary Sciences
Chien-Hua Tu, Martin Steinhart, Ruediger Berger, Michael Kappl, Hans-Juergen Butt, George Floudas
Summary: By confining semicrystalline polymers within nanoscopic cylindrical pores, they can flow at temperatures below the melting point with intermediate viscosity between the melt and crystal states. This unexpected enhancement in flow, while preserving the polymer crystallites, is important for designing polymer processing conditions applicable at low temperatures, such as for cold drawn polymers like polytetrafluoroethylene, self-healing materials, and nanoconfined donor/acceptor polymers used in organic electronics.
Article
Chemistry, Physical
Yun Dong, Martin Steinhart, Hans-Juergen Butt, George Floudas
Summary: The conductivity of ionic liquids (ILs) in nanopores is crucial for their application in energy materials. However, the impact of confinement on ion mobility is still not well understood. A study on ILs with the same cation and different anions revealed differences in self-assembly, thermodynamics, and ionic conductivity between bulk and confined states, suggesting the influence of confinement on IL behavior.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Materials Science, Multidisciplinary
Fatih Alarslan, Hanna Huebner, Jonas Klein, Karsten Kuepper, Joachim Wollschlaeger, Markus Haase, Markus Gallei, Martin Steinhart
Summary: The wettability of surfaces is crucial for various applications including antifouling, antifogging, anti-icing, and self-cleaning. Solvent-free high-temperature capillary stamping of stimuli-responsive polymers allows the generation of switchable surfaces with different water contact angles (WCAs). Potential problems associated with polymer solution deposition are overcome.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Joshua Piaskowski, Georg Haberfehlner, Theresa Bartschmid, Gerald Kothleitner, Martin Steinhart, Gilles R. Bourret
Summary: Bimetallic AuRh_Au nanorod dimers with a thin lossy Rh segment in the gap region were synthesized using OWL. The E-field enhancement at the Rh segment and the coupling between the Au NR antennas were investigated using EELS, electromagnetic simulations, and SERS. Simple design rules for maximizing the E-field at a given wavelength within and on the Rh were provided. These bimetallic NR dimers are versatile platforms for studying plasmonic coupling in heterostructures and have potential applications in plasmonic catalysis.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Nadine Rassmann, Melina Weber, Roman E. J. Glass, Klaus Kreger, Nicolas Helfricht, Hans-Werner Schmidt, Georg Papastavrou
Summary: This study investigates the controlled electrochemical deposition of hydrogel films on ultraflat gold electrodes by studying the deposition of fibrillar networks. The resulting hydrogel film, formed through self-assembly of supramolecular fibrillar structures, was characterized in terms of its thickness. The film thickness was controlled by adjusting gelator concentration, applied potential, and gelation time. This research has potential applications in the field of biomedicine.
Article
Chemistry, Physical
Leiming Guo, Martin Steinhart
Summary: In this study, we explored the potential of using block copolymer (BCP) polystyrene-block-poly (2-vinylpyridine) (PS-b-P2VP) stamps for the generation of topographic surface patterns. We demonstrated the fabrication of additive surface patterns using PS-b-P2VP breath figure (BF) arrays and the fabrication of subtractive surface patterns using PS-b-P2VP stamps penetrated by spongy mesopore systems. These findings provide new possibilities for controlling surface properties and achieving graphoepitaxy.
APPLIED SURFACE SCIENCE
(2023)