Article
Materials Science, Textiles
Jackie Y. Cai, Jie Min, Jill McDonnell, Lijing Wang, Robert Knott
Summary: Gamma irradiation was applied to vertically aligned carbon nanotube (CNT) forests to improve the interfacial adhesion and then spun into CNT yarns. The yarns spun from the irradiated forests showed higher tensile strength and lower breaking elongation. Increasing spinning tension improved the strength of both the irradiated and unirradiated yarns, but the irradiated yarns had more significant improvements. The relative improvements in yarn tenacity ranged from 14% to 26% under various spinning tensions.
JOURNAL OF INDUSTRIAL TEXTILES
(2022)
Article
Chemistry, Physical
Jianian Hu, Zhengyuan Liu, Yongyuan You, Haotian Zhang, Xiang Chen, Yi Sun, Jian Zhang, Guoqiang Luo
Summary: This study used ex-situ transmission electron microscopy observations and molecular dynamics simulation methods to investigate the process of forming carbon nanotube forests catalyzed by Fe nanoparticles. The results reveal the rooting path of C in Fe and its motion evolution mechanism. It is found that C reacts with Fe to form Fe3C, and C enters from Fe (110) crystal plane, which transforms Fe (110) crystal plane into Fe3C (013) crystal plane. C then precipitates and grows into carbon nanotubes from Fe3C, creating the parallel relationship between the growth direction of carbon nanotubes and Fe3C (013) crystal plane. Molecular dynamics simulation also confirms the correctness of the experimental results by showing consistent motion paths of C.
COLLOID AND INTERFACE SCIENCE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Fan Liu, Naoto Nishioka, Fumio Ogawa, Toshiyuki Hashida
Summary: This study discusses the growth mechanism of epitaxial PyC layers on CNT surfaces achieved by low-pressure ethylene pyrolysis, distinct from previous studies using higher gas pressures. The average thickness of deposited PyC layers is calculated by analyzing TEM images, and the crystallinity is evaluated by Raman spectroscopy and X-ray diffraction. A two-stage nonlinear behavior in the growth kinetics of PyC layers is found, indicating the influence of surface active sites on the radial growth rate.
DIAMOND AND RELATED MATERIALS
(2022)
Article
Chemistry, Physical
Kai Zhang, Wenbin Gong, Zhuo Li, Weigao Xu, Yagang Yao
Summary: By adding a layer of patterned aluminum to the conventional catalyst, the orientation, density, and arrangement of nanotube segments in CNT forests were improved, resulting in a CNTF with densely-packed, horizontally-aligned surface nanotube segments. Nanoindentation results and coarse-grained simulations indicated that the lateral stretching of nanotube segments played a major role in the superior adhesion performance of the CNTF.
Article
Materials Science, Multidisciplinary
Anna Szabo, Gergo Peter Szekeres, Tamas Gyulavari, Zsejke Reka Toth, Zsuzsanna Papa, Akos Szamosvolgyi, Andras Sapi, Zoltan Konya, Klara Hernadi
Summary: This study used catalytic chemical vapor deposition to synthesize nitrogen-doped carbon nanotube forests on different substrates. It was found that direct injection of a liquid nitrogen precursor promoted the synthesis of bamboo-structured carbon nanotube forests more efficiently. The amount of precursor affected the extent of nitrogen incorporation, and different nitrogen species were identified in the carbon nanotubes. The presence of hydrogen and the temperature also influenced nitrogen incorporation into the carbon nanotubes.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Environmental Sciences
Yu Liu, Lijun Liao, Liping Guo, Zhenzi Li, Xuepeng Wang, Decai Yang, Mingtao Wang, Shijie Wang, Wei Zhou
Summary: Developing photocatalytic technologies with high selectivity for pollutant removal is a significant challenge. In this study, a unique popcorn-stick-like nanocomposite was fabricated and exhibited distinguished photocatalytic activity for simultaneous removal of carbon particles and nitrogen dioxide.
ENVIRONMENTAL RESEARCH
(2024)
Article
Chemistry, Physical
Minchen Zhou, Jian Qu, Yulong Ji
Summary: This study experimentally investigated water droplet impingement behaviors on carbon nanotube (CNT) array surfaces with varying wettabilities. Different dynamic behaviors of droplet impact were observed and a droplet regime map was developed for different wettabilities. The reduction in post-impact contact angles and enhanced wettability were mainly attributed to self-assembly structures caused by capillary action during spreading.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Seungju Seo, Sanha Kim, Shun Yamamoto, Kehang Cui, Takashi Kodama, Junichiro Shiomi, Taiki Inoue, Shohei Chiashi, Shigeo Maruyama, A. John Hart
Summary: This paper investigates the tailored use of Ar/O-2 plasma etching to modify the surface morphology of multi-walled CNT forests, studying the effects of process parameters on the etching, as well as the influence of different initial characteristics on the etching results. The study also explores the enhancement of alignment and chemical uniformity of the top surface of CNT forests by Ar/O2 plasma.
Article
Nanoscience & Nanotechnology
Beihan Zhao, Vishal Sankar Sivasankar, Swarup Kumar Subudhi, Abhijit Dasgupta, Siddhartha Das
Summary: In this study, we demonstrated the humidity-sensing ability and robustness of syringe-printed single-walled carbon nanotube-graphene oxide (SWCNT-GO) traces on adhesive and flexible PET thin films. The printed traces showed high humidity sensitivity and could be deployed on surfaces with different curvatures. The SWCNT-GO traces exhibited enhanced humidity sensitivity due to the hygroscopic swelling of GO flakes under humid conditions. Furthermore, the traces demonstrated long-term stability and reliable performance even after temperature cycling tests.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Analytical
Pankaj Gupta, Vandna K. Gupta, Artur Huseinov, Connor E. Rahm, Kiera Gazica, Noe T. Alvarez
Summary: The study developed a nonenzymatic glucose sensor using copper nanoparticles and carbon nanotubes microelectrode set, demonstrating excellent sensitivity, low detection limit, and resistance to external interference. The sensor was successfully applied for quantifying glucose in physiological samples, showing great potential for commercial nonenzymatic glucose sensors.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Thermodynamics
JinHyeok Cha, Kei Hasegawa, Jeonyoon Lee, Itai Y. Stein, Asuka Miura, Suguru Noda, Junichiro Shiomi, Shohei Chiashi, Brian L. Wardle, Shigeo Maruyama
Summary: The study demonstrates that thermal diffusivity and conductivity of SWCNT forests increase when the volume fraction exceeds 17%, indicating that some SWCNTs not serving as thermal paths at lower volume fractions start connecting with others. Moreover, the inferred thermal conductivity of individual SWCNTs also enhances with the increase of volume fraction.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Nanoscience & Nanotechnology
Yaniv Cohen, Siva K. Reddy, Assaf Ya'akobovitz
Summary: Effective heat dissipation is crucial for the long-term operation and miniaturization of electronic devices. Graphene foams and carbon nanotube forests, due to their excellent thermal conduction and low thermal interface resistance, show promise in thermal applications such as heat dissipation. By studying the heat transfer characteristics under forced convection, we found that boundary layers significantly affect heat transfer in our samples, reducing heat transfer in the horizontal direction while the vertical direction is dominated by material conduction and exhibits higher heat transfer. This research uncovers the fundamental thermal behavior of graphene foams and carbon nanotube forests, paving the way for their successful integration into cooling devices and other thermal applications.
Article
Nanoscience & Nanotechnology
Denis M. Zhigunov, Daniil A. Shilkin, Natalia G. Kokareva, Vladimir O. Bessonov, Sergey A. Dyakov, Dmitry A. Chermoshentsev, Aram A. Mkrtchyan, Yury G. Gladush, Andrey A. Fedyanin, Albert G. Nasibulin
Summary: It is demonstrated that single-walled carbon nanotube (SWCNT) membranes can enhance visualization and study of individual nanoparticles, showing significant improvement in optical contrast. The high transparency, low reflectance, and thinness of SWCNT membranes offer various potential applications in nanophotonics, bioimaging, and synchrotron radiation studies.
Article
Nanoscience & Nanotechnology
Maofu Geng, Yuhong Tao, Zhenyu Zhang, Yuewen Dai, Juncheng Huang, Fei Liu, Haining Na, Jin Zhu
Summary: By analyzing the transformation of glucose, fructose, and 5-hydroxymethylfurfural in hydrothermal carbonization (HTC) and their adsorption on carbon nanotubes (CNTs), the formation mechanism of a hydroxyl-rich carbon layer on the CNT surface is revealed. The adsorption of furan and aromatic clusters by CNTs through pi-pi interaction during HTC is found to be crucial in improving the utilization rate of carbon sources and the quality of the carbon layer. The use of hydroxyl-rich carbon layer-coated CNTs in a low-acid aqueous system significantly improves cellulose conversion and glucose yield. The HTC route for hydroxylation of CNTs provides guidance for the preparation of functional carbon materials.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Physical
Toshiya Kinoshita, Motoyuki Karita, Norikazu Chikyu, Takayuki Nakano, Yoku Inoue
Summary: The addition of chlorine improved the catalytic activity in the growth process of carbon nanotubes (CNTs), leading to higher growth rate and longer catalyst lifetime. It also affected various structural parameters of CNTs and enhanced their alignment and dry spin capability.
Article
Chemistry, Multidisciplinary
Wenqian Yao, Jianing Zhang, Jie Ji, He Yang, Binbin Zhou, Xin Chen, Peter Boggild, Peter U. Jepsen, Jilin Tang, Fuyi Wang, Li Zhang, Jiahui Liu, Bin Wu, Jichen Dong, Yunqi Liu
Summary: This study presents a new method for synthesizing large-scale pure single-crystalline graphene monolayers on Cu(111) surface. By selectively etching bottom multilayered graphene, the method ensures high electronic quality and enhances the efficiency of graphene production.
ADVANCED MATERIALS
(2022)
Article
Optics
Anders Lochte Jorgensen, Mads Nibe Larsen, Victor Petrunin, Jakob Kjelstrup-Hansen, Bjarke Jorgensen
Summary: This study demonstrates the possibility of recognizing specific materials from hyperspectral thermal images and successfully distinguishes multiple materials using a logistic regression model. The surface temperature is predicted using a partial least squares (PLS) model, which outperforms conventional thermography with a smaller root mean square error.
Article
Materials Science, Multidisciplinary
Wei Xu, Um Kanta Aryal, Jingnan Wu, Morten Madsen, Jakob Kjelstrup-Hansen, Zhong Cao, Donghong Yu
Summary: By modifying the side chains of DPP molecules with different anthracene groups, it has been found that the charge transport characteristics on organic field-effect transistor devices can be significantly altered.
Article
Chemistry, Physical
Nico Giordano, Suchismita Guha, Beverly Stewart, Jakob Kjelstrup-Hansen, Matti Knaapila
Summary: We have characterized the high-pressure structure and phase behavior of 5,5'-bis(naphth-2-yl)-2,2'-bithiophene (NaT2) using single crystal X-ray diffraction, photoluminescence, and Raman compression measurements. NaT2 maintains its ambient pressure structure on compression but undergoes a subtle second-order phase transition at ca. 3.5 GPa. The newly formed phase at 4.0 GPa is characterized by the formation of a new S...H interaction between thiophene moieties in adjacent molecules and the emergence of a more favorable compression pathway in its long-chain direction. NaT2 also undergoes a reversible band gap closure manifested as a distinct yellow to red color change on compression.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Shuai Yang, Chao Wang, Jing Wu, Hong Yan, Gang Wang, Jianmin Feng, Bo Zhang, Dejun Li, Timonthy J. Booth, Peter Boggild, Gui Yu, Birong Luo
Summary: Engineering interfacial interactions is crucial for manipulating the properties and applications of two-dimensional (2D) materials. In this study, a self-relaxation vapor-liquid-solid (SRVLS) growth method for 2D transition metal dichalcogenides (TMDs) was proposed and investigated. The growth process involves coordination between the precipitation of metal oxides and the capture of chalcogens, resulting in loose interface adhesion and strain relaxation in the as-grown TMD layers. The SRVLS-grown TMDs exhibit significantly reduced adhesion energy compared to traditional vapor-solid (VS) growth, and the growth features allow for curl-free delamination and reverse transfer of TMD layers onto target substrates through water-dissolving the solidified droplets.
APPLIED SURFACE SCIENCE
(2023)
Article
Anatomy & Morphology
Soren Bredmose Simonsen, Zhongtao Ma, Elisabeth Mariegaard, Salvatore De Angelis, Waynah Lou Dacayan, Kristian Speranza Molhave, Christodoulos Chatzichristodoulou
Summary: This study investigates the nanostructure and electrical conductivity of ion beam deposited Pt for operando electron microscopy at elevated temperatures. It reveals that the microstructure of Pt remains stable up to around 800 degrees C and with an applied current density of approximately 100 kA/cm(2). The conductivity increases with temperature due to densification, while changes in the hydrocarbon matrix have less influence. Recommendations are provided for optimizing Pt deposition parameters to maximize stability and minimize electrical resistance.
MICROSCOPY RESEARCH AND TECHNIQUE
(2023)
Article
Chemistry, Analytical
Binbin Zhou, Mattias Rasmussen, Patrick Rebsdorf Whelan, Jie Ji, Abhay Shivayogimath, Peter Boggild, Peter Uhd Jepsen
Summary: We accurately determine the conductivity of graphene on thin-film polymer substrates using reflection-mode air-plasma-based THz time-domain spectroscopy (THz-TDS). The phase uncertainty issue associated with reflection measurements is discussed and our implementation is validated through convincing agreement with graphene electrical properties extracted from more conventional transmission-mode measurements. Both reflection and transmission THz-TDS measurements reveal a strong non-linear and instantaneous conductivity depletion across an ultra-broad bandwidth (1-9 THz) under relatively high incident THz electrical field strengths (up to 1050 kV/cm).
Article
Multidisciplinary Sciences
Peter Boggild
Summary: More than a decade after large-scale graphene synthesis was demonstrated, the commercialization of graphene products is hindered by price and consistency issues. The author addresses the reproducibility problems in the field and proposes solutions to improve the reliability of published results.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Zhongtao Ma, Waynah Lou Dacayan, Christodoulos Chatzichristodoulou, Kristian Speranza Molhave, Francesco Maria Chiabrera, Wenjing Zhang, Soren Bredmose Simonsen
Summary: The combination of electrical impedance spectroscopy (EIS) and environmental transmission electron microscopy (ETEM) is demonstrated by testing a specially designed micro gadolinia-doped ceria (CGO) sample. The EIS-TEM method provides valuable information on the structural and compositional aspects relevant to electrochemical performance. The developed platform is important for understanding nanoscale processes in green energy technologies.
Article
Nanoscience & Nanotechnology
Jie Ji, Yingqiu Zhou, Binbin Zhou, Eva Desgue, Pierre Legagneux, Peter Uhd Jepsen, Peter Boggild
Summary: In this study, the electronic properties and light-induced carrier transport of large-scale PtSe2 films were investigated using terahertz spectroscopy techniques. The results demonstrate that PtSe2 films have a tunable electronic structure and high carrier mobility, and the terahertz methods provide information about the spatial and temporal properties of the films.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Manh-Ha Doan, Shrawan Roy, Yingqiu Zhou, Peter Boggild
Summary: The research suggests that correlated electron-hole pair tunneling can occur at room temperature in a monolithic multilayer WSe2 device with bottom Au contacts. This finding opens up the opportunity for realizing room-temperature superfluidity in vdW materials.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Rolf Erling Robberstad Moller-Nilsen, Silvia Canepa, Eric Jensen, Hongyu Sun, Ivan A. Moreno-Hernandez, Murat Nulati Yesibolati, A. Paul Alivisatos, Kristian S. Molhave
Summary: Liquid phase electron microscopy (LPEM) is important for studying chemical processes in situ, but the interaction between the liquid medium and the electron beam leads to radiolysis and the formation of reactive species that affect the studied processes. Current understanding of LPEM radiolysis is based on simulations using data collected at low electron flux intensities, requiring extrapolation to match the intensities used in LPEM. This study demonstrates a new approach to validate simulations by directly measuring radiolytic products during in situ LPEM.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Cecilie Fynbo, Mathias K. Huss-Hansen, Oier Bikondoa, Chandrasekhar Gangadharappa, Demetrio Antonio da Silva Filho, Satish Patil, Matti Knaapila, Jakob Kjelstrup-Hansen
Summary: This study investigates the influence of deposition method and substrate surface on the morphology and microstructure of n-dialkyl side-chain-substituted thiophene DPP end-capped with phenyl groups (Ph-TDPP-Ph) thin films. Different morphologies were observed between spin-coated and vacuum-deposited thin films, with fiber-like morphology and continuous layer of terraced grains, respectively. After initial film evolution, all deposition methods and substrate types resulted in well-ordered thin films with slight variations in crystallinity and mosaicity. Aging of spin-coated films showed noticeable evolution in morphology and crystalline phases, indicating the possibility of tailoring the thin-film properties of DPP derivatives through film formation process manipulation.
Article
Chemistry, Multidisciplinary
Hjalte Rorbech Ambjorner, Anton Simon Bjornlund, Tobias Georg Bonczyk, Edwin Dollekamp, Lau Morten Kaas, Sofie Colding-Fagerholt, Kristian Speranza Molhave, Christian Danvad Damsgaard, Stig Helveg, Peter Christian Kjaergaard Vesborg
Summary: Graphene is the thinnest imaginable membrane with high impermeability, but leakage pathways at the graphene-substrate interface compromise its impermeability. This study provides a kinetic analysis of interface-mediated leakage and shows that thermal processing can significantly improve the leak rate.
Article
Engineering, Electrical & Electronic
Cunzhi Sun, Cheng Xiang, Rongdun Hong, Feng Zhang, Timothy J. Booth, Peter Boggild, Manh-Ha Doan
Summary: This study demonstrates a method using fluorinated bilayer graphene as a barrier to prevent strong Fermi level pinning at metal/2D material interfaces, which enhances the tunability of Schottky barrier height and has potential applications in electronics and optoelectronics.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
Yiping Yin, Zhe Wang, Hua Zou
Summary: This study presents a novel method for preparing dimpled polymer-silica nanocomposite particles using interfacial swelling-based seeded polymerization. The optimized conditions allow for a relatively high percentage of dimpled particles to be achieved.
Article
Chemistry, Physical
Brenden D. Hoehn, Elizabeth A. Kellstedt, Marc A. Hillmyer
Summary: Porous materials with nanometer-scale pores have important applications as nanoporous membranes. In this study, ABA triblock copolymers were used as precursors to produce nanoporous polymeric membranes (NPMs) in thin film form by degrading the end blocks. Polycyclooctene (PCOE) NPMs with tunable pore sizes were successfully prepared using solvent casting technique. Oxygen plasma etching was employed to improve the surface porosity and hydrophilicity of the membranes. This study provides a straightforward method to produce tough NPMs with high porosity and hydrophilic surface properties.
Article
Chemistry, Physical
Vladislav S. Petrovskii, Stepan I. Zholudev, Igor I. Potemkin
Summary: This article investigates the behavior of linear and ring polypeptide chains in aqueous solution and explores the properties of the complexes formed by these chains with oppositely charged surfactants. The results demonstrate that the complexes of linear supercharged unfolded polypeptides and the corresponding surfactants exhibit impressive adhesive properties.
Article
Chemistry, Physical
Merve Cevik, Serkan Dikici
Summary: Cardiovascular diseases are a leading cause of death globally, and vascular grafts are a promising treatment option. This study focuses on tissue-engineered vascular grafts (TEVGs) using decellularized parsley stems as a potential biomaterial. The decellularized parsley stems showed suitable properties for TEVGs, providing a suitable environment for human endothelial cells to form a pseudo endothelium. This study showcases the potential of using parsley stems for TEVGs.
Article
Chemistry, Physical
Gustavo A. Vasquez-Montoya, Tadej Emersic, Noe Atzin, Antonio Tavera-Vazquez, Ali Mozaffari, Rui Zhang, Orlando Guzman, Alexey Snezhko, Paul F. Nealey, Juan J. de Pablo
Summary: The optical properties of liquid crystals are typically controlled by electric fields. In this study, we investigate the effects of microfluidic flows and acoustic fields on the molecular orientation and optical response of nematic liquid crystals. We identify several previously unknown structures and explain them through calculations and simulations. These findings hold promise for the development of new systems combining sound, flow, and confinement.
Article
Chemistry, Physical
Xinjun Wu, Xin Guan, Shushu Chen, Jiangpeng Jia, Chongyi Chen, Jiawei Zhang, Chuanzhuang Zhao
Summary: This research presents a novel shape memory hydrogel with a remodelable permanent shape and programmable cold-induced shape recovery behavior. The hydrogel is prepared using specific treatment methods to achieve shape fixation by heating and shape recovery by cooling. Additionally, deformable devices can be obtained by assembling hydrogel blocks with different concentrations.
Article
Chemistry, Physical
Rebecca Hengsbach, Gerhard Fink, Ulrich Simon
Summary: This study examines the properties of DNA functionalized pNipmam microgels and pure pNipmam microgels at different concentrations of sodium chloride and in PBS solutions using temperature dependent H-1-NMR measurements. The results show that DNA modification affects the volume phase transition temperature and the addition of salt and PBS further enhances this effect.
Article
Chemistry, Physical
Ningyi Li, Junhong Li, Lijingting Qing, Shicheng Ma, Yao Li, Baohui Li
Summary: This paper investigates the self-assembly behavior of colloids with competing interactions under spherical confinement and finds that different ordered structures can be formed under different sized spherical confinements. Moreover, more perforated structures are formed in smaller spheres.