Article
Mechanics
Abbasali Abouei Mehrizi, Qiao Liu, Hao Wang
Summary: The extended thin-film region adjacent to the contact line plays a crucial role in heat transfer and wetting dynamics by enhancing heat transfer and influencing contact line morphology. The study focused on advancing contact line morphology induced by water vapor condensation at low rates. Results showed that the morphology of the liquid film in this process differs from nonvolatile cases, with a precursor nanofilm and nanodroplets detected beyond the contact line.
Article
Chemistry, Physical
Deepak Suthar, Himanshu, S. L. Patel, S. Chander, M. D. Kannan, M. S. Dhaka
Summary: This study investigates the impact of hydrogen annealing temperature on the properties of ZnTe films, including their structure, optical transmittance, luminescence, surface morphology, and composition. The results show that annealing significantly affects the crystalline phase, optical transmittance, luminescence properties, surface morphology, and composition of the ZnTe films.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Ian J. Echols, Junyeong Yun, Huaixuan Cao, Ratul Mitra Thakur, Anubhav Sarmah, Zeyi Tan, Richard Littleton, Miladin Radovic, Micah J. Green, Jodie L. Lutkenhaus
Summary: This research reports the functionalization of Ti3C2Tz nanosheets to render them positively charged, enabling the layer-by-layer assembly of Ti3C2Tz-only thin films. These films exhibit significantly higher electrical conductivities and capacitances compared to analogous polymer/MXene LbL films. The LbL assembly method enables adherent coatings on various surfaces and geometries. The potential applications of these MXene-only films include optoelectronics, energy storage devices, catalysis, and sterilization.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Physical
Tefera E. Tesema, Ross McFarland-Porter, Epherem Zerai, John Grey, Terefe G. Habteyes
Summary: This study reveals the self-assembly phenomena in polymer thin films, including the formation of polymer nanoparticles and their assembly patterns in a matrix. It also demonstrates that the structure and scale of polymer self-assembly can be controlled by adjusting the composition of the solution and the speed of spin-coating.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Fushuai Wang, Quanzi Yuan
Summary: In this experiment, uniform, polygonal, and coffee ring patterns were obtained by adjusting the solute concentration of ethanol drops with dissolved ibuprofen. The formation of these patterns involves various hydrodynamic events and can be directly connected from the perspective of fractal geometry. A theoretical model and experiments were conducted to explain the mechanism behind pattern formation. This work presents a unique strategy to connect different patterns under the same physics and provides instructive guidance for practical applications.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Analytical
Bjorn T. H. Borgelink, Erwin J. W. Berenschot, Remco G. P. Sanders, Stefan Schlautmann, Niels R. Tas, Han J. G. E. Gardeniers
Summary: Microfluidic pedestal nozzles with concentric rim at the nozzle exit were fabricated using self-aligned wafer-scale microfabrication methods. The nozzles, made of hydrophilic silicon dioxide, have a nanometrically sharp rim edge that facilitates the geometric contact line pinning of polar liquids. The functionality of the nozzle in increasing macroscopic contact angles was demonstrated through hydrostatic and hydrodynamic measurements.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Thermodynamics
Chieh Wang, Yu-Shiou Chen, Li -Jen Chen
Summary: This study explores and manipulates the deposition morphology of silica/polystyrene suspension droplets on hydrophobic surfaces by controlling the relative humidity. It is found that under higher relative humidity, the deposits of silica suspension droplets become thicker and smaller, while a uniform deposition is observed for polystyrene suspension droplets evaporated at a relative humidity of 15%. The capillary flow velocity inside a shrinking droplet is calculated using a mass conservation model and image analysis, and it is found that the velocity is higher at lower relative humidity.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Mechanics
Xiaolong Zhang, Vadim S. Nikolayev
Summary: This paper presents a theoretical analysis of the liquid film dynamics during the oscillation of a meniscus in a cylindrical capillary, considering factors such as dynamic profile, finite film length, pinned contact line, and contact angle variations. The study also explores the average film thickness as a function of system parameters and compares numerical results with experimental data and quasi-steady approximation. Additionally, the paper discusses the effects of superheating on the oscillating meniscus process and the possibility of contact line recession due to evaporation.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Physical
Huiying Liu, LingXu Wang, Zhibiao Ma, Xiaodong Guo, Bingdong Yao, Yangyang Wang, Yan Liu, Fengqing Zhang, Luyi Zhu
Summary: Epitaxial growth of BiFe0.95Mn0.05O3 (BFMO) thin films on single crystal substrates with different orientations was achieved by sol-gel and layer-by-layer rapid thermal annealing methods. The structure and aging behavior of the films were analyzed using various test techniques.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Christopher Salmean, Huihe Qiu
Summary: This study investigates the enhancement of flow boiling by manipulating wettability patterns and contact-line pinning. Two main principles for enhancing boiling heat transfer are identified: the interaction between the local contact angle and the bubble's tilt influences the ease of bubble departure from superhydrophobic patches, and ring-shaped superhydrophobic patches can trap droplets inside the forming bubbles, supplementing the heat transfer coefficient and critical heat flux. By applying these principles, the heat transfer coefficient and critical heat flux of heterogeneous surfaces were improved by 62% and 24%, respectively. A general model to estimate the ease of bubble departure using geometric arguments is established and validated.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Mechanics
Anna Zigelman, Peter Breitman, Amir D. Gat
Summary: Hydraulic fracturing and natural geological phenomena involve the propagation of thin viscous films within elastic media. The contact line paradox, where stress diverges as the film thickness tends to zero, is resolved by considering a precursor film. This study examines the impact of a pre-wetting layer on the rate of viscous flow propagation and finds that the peeling front propagation scales with time to the power of 1/9 and 1/3 for thin and thick pre-wetting layers, respectively. The results contribute to the understanding of the contact line paradox and the role of the pre-wetting layer in resolving it.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Nanoscience & Nanotechnology
Taoufik Slimani Tlemcani, Clement Mauduit, Micka Bah, Meiling Zhang, Matthew Charles, Romain Gwoziecki, Arnaud Yvon, Daniel Alquier
Summary: This study investigates the formation of Au-free Ohmic contacts on p-type GaN using a bilayer Ni/Al-doped ZnO (AZO) thin film. The results show that the contact resistance can be significantly reduced using a suitable thermal process, reaching the lowest value of 1.85 x 10-4 ohm·cm2 for a sample with a 5 nm Ni layer annealed at 500 degrees C in air for 5 min.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Christopher Salmean, Huihe Qiu
Summary: Flow boiling is a promising method for cooling sensitive components. In this study, the researchers discovered that using nanostructures can control the coalescence and flow interactions of bubbles, leading to enhanced heat transfer efficiency.
Article
Multidisciplinary Sciences
Hossein Zargartalebi, S. Hossein Hejazi, Amir Sanati-Nezhad
Summary: The authors introduce a passive protocol to suppress the coffee-ring effect and form uniform films at micro- and nanoscales by combining superhydrophilic substrate with a neutral-wetting low-roughness mold. This method has broad applications in fabricating ordered coatings, producing nanofilters, and creating functionalized nanosensors.
NATURE COMMUNICATIONS
(2022)
Article
Mechanics
T-S Lin, J. A. Dijksman, L. Kondic
Summary: In this study, the flow of completely wetting fluid in a funnel is explored with a focus on contact line instabilities. The convergent nature of the flow leads to thickening of the film, influencing its stability properties. By combining physical experiments, asymptotic modelling, self-similar analysis, and numerical simulations, the study provides insight into the development of contact line instability and emerging length scales.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Analytical
Robert Nissler, Larissa Kurth, Han Li, Alexander Spreinat, Ilyas Kuhlemann, Benjamin S. Flavel, Sebastian Kruss
Summary: Semiconducting single-wall carbon nanotubes (SWCNTs) emit near-infrared (NIR) fluorescence, with the emission wavelength determined by their chirality. Functionalizing SWCNTs with DNA can tailor the fluorescence for biosensors, with chirality-pure sensors showing higher brightness, stability, and selectivity for analytes.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Han Li, Georgy Gordeev, Dimitrios Toroz, Devis Di Tommaso, Stephanie Reich, Benjamin S. Flavel
Summary: This study examines the effect of filling on the separation results of SWCNTs, using rate-zonal centrifugation to obtain different filled SWCNTs and analyzing the extent of endohedral filling using absorption and Raman spectroscopy. Results show a preference for less-filled or empty species. Molecular dynamics simulations are used to explain the difficulty in directly measuring partial water filling.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Christian Rust, Han Li, Georgy Gordeev, Manuel Spari, Markus Guttmann, Qihao Jin, Stephanie Reich, Benjamin S. Flavel
Summary: Single wall carbon nanotubes (SWCNTs) dispersed by negatively charged sodium deoxycholate (DOC) or positively charged cetrimonium bromide (CTAB) can assemble into aligned films on polycarbonate membranes using slow flow dead-end filtration. The alignment was studied using various microscopic and spectroscopic techniques, revealing factors influencing the alignment such as membrane fouling and interaction potential between the membrane surface and nanotubes. Successful control and measurement of SWCNT film formation were achieved using a custom microfluidic setup.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Robert Nissler, Andrea T. Mueller, Frederike Dohrman, Larissa Kurth, Han Li, Eric G. Cosio, Benjamin S. Flavel, Juan Pablo Giraldo, Axel Mithofer, Sebastian Kruss
Summary: The study developed molecular sensors based on near-infrared fluorescent single-wall carbon nanotubes for imaging plant polyphenols, providing a new tool for studying plant immune defense. These sensors can real-time report changes in total polyphenol level after herbivore or pathogen challenge in crop plants.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Finn L. Sebastian, Nicolas F. Zorn, Simon Settele, Sebastian Lindenthal, Felix J. Berger, Christoph Bendel, Han Li, Benjamin S. Flavel, Jana Zaumseil
Summary: Researchers have proposed a direct quantification protocol based on a linear correlation that can accurately assess the defect density on the lattice of single-wall carbon nanotubes (SWCNTs) and determine the oscillator strengths of different defect types.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Qing Gao, Jun Yan, Lu Wan, Cuili Zhang, Zhixi Wen, Xin Zhou, Han Li, Feng Li, Jingwei Chen, Jianxin Guo, Dengyuan Song, Benjamin S. Flavel, Jianhui Chen
Summary: A breakthrough in graphene-oxide/silicon heterojunction solar cells is achieved by combining edge-oxidized graphene and a charge transfer dopant, resulting in a high-quality passivating contact scheme. A high-power conversion efficiency and large area solar cell is reported using this scalable solution-based processing technique, showing potential for low-cost carbon/silicon heterojunction photovoltaic devices.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Maksiem Erkens, Dmitry Levshov, Wim Wenseleers, Han Li, Benjamin S. Flavel, Jeffrey A. Fagan, Valentin N. Popov, Marina Avramenko, Salome Forel, Emmanuel Flahaut, Sofie Cambre
Summary: The study investigates the synergetic effects in double-wall carbon nanotube (DWCNT) samples through absorption, fluorescence excitation, and resonant Raman scattering spectroscopy. The chirality-dependent shifts of the vibrational frequencies and transition energies of the inner and outer DWCNT walls are determined. The combined analysis of PLE and RRS results provides insights into the energy transfer within DWCNT structures and the specific combinations present in the samples.
Article
Chemistry, Physical
Han Li, Christopher M. Sims, Rui Kang, Frank Biedermann, Jeffrey A. Fagan, Benjamin S. Flavel
Summary: In this study, highly purified (>80%) left- and right-handed (6,5) single-wall carbon nanotubes (SWCNTs) were separated using aqueous two-phase extraction (ATPE), with limited experimental steps. The optimized surfactant conditions were determined, and analytical ultracentrifugation (AUC) and near-infrared photoluminescence (PL) measurements were used to examine the required conditions for surfactant wrapping and partition coefficient change (PCCCs). This study provides valuable insights into the underlying mechanisms behind surfactant-assisted SWCNT separations and promotes the future use of SWCNT enantiomers in fundamental studies and applications.
Article
Chemistry, Physical
Qing Gao, Jun Yan, Han Li, Jingwei Chen, Xueliang Yang, Yuhua Bai, Xuning Zhang, Bingbing Chen, Jianxin Guo, Weiyuan Duan, Kaixin Han, Feng Li, Jianming Wang, Dengyuan Song, Shufang Wang, Benjamin S. Flavel, Jianhui Chen
Summary: This study demonstrates that commercially available SWCNT soots, combined with organic passivation technology, can serve as an efficient rear contact and alternative to ALD-Al2O3/PECVD-SiNx/laser treatment in conventional PERC solar cells, achieving a power conversion efficiency of over 23%. This approach is simple, scalable, and eliminates the issue of high interfacial recombination caused by metal-semiconductor contact in PERC technology.
Article
Chemistry, Multidisciplinary
Christian Rust, Pavel Shapturenka, Manuel Spari, Qihao Jin, Han Li, Andreas Bacher, Markus Guttmann, Ming Zheng, Tehseen Adel, Angela R. Hight Walker, Jeffrey A. Fagan, Benjamin S. Flavel
Summary: Dead-end filtration is an effective method for preparing aligned thin films of single-wall carbon nanotubes. This study focuses on the role of SWCNT length and diameter in the alignment process. Films were prepared from length-sorted fractions of small and large diameter SWCNTs, and the alignment was characterized using various microscopy and spectroscopy techniques. The findings suggest a law that relates the length of a carbon nanotube to its diameter and zeta potential.
Article
Chemistry, Multidisciplinary
Xin Zhou, Lu Wan, Han Li, Xueliang Yang, Jingwei Chen, Kunpeng Ge, Jun Yan, Cuili Zhang, Qing Gao, Xuning Zhang, Jianxin Guo, Feng Li, Jianming Wang, Dengyuan Song, Shufang Wang, Benjamin S. Flavel, Jianhui Chen
Summary: By using metal-assisted chemical etching (MACE) and a vacuum-free organic passivation layer, a low reflectance black silicon structure with long minority carrier lifetimes can be formed. This provides a feasible technical scheme for the multiple carrier generation through the inverse Auger effect.
Article
Chemistry, Multidisciplinary
Christian Rust, Elias Schill, Oisin Garrity, Manuel Spari, Han Li, Andreas Bacher, Markus Guttmann, Stephanie Reich, Benjamin S. S. Flavel
Summary: Dead-end filtration is a simple method to align single wall carbon nanotubes in large area films with a high 2D order parameter. In this study, three different radially symmetrical patterns were created and two of them showed an approximate S-2D value of 0.85. The aligned films were transferred to a flexible printed circuit board for electrical measurements.
Article
Materials Science, Multidisciplinary
Nicolas Frederic Zorn, Simon Settele, Shen Zhao, Sebastian Lindenthal, Abdurrahman Ali El Yumin, Tim Wedl, Han Li, Benjamin Scott Flavel, Alexander Hoegele, Jana Zaumseil
Summary: Semiconducting single-walled carbon nanotubes (SWCNTs) have outstanding electrical and optical properties, making them highly suitable for optoelectronic devices. However, the luminescence spectra of SWCNT thin films on commonly used substrates are often compromised by broadening of the main excitonic emission and unwanted low-energy sidebands. Surface passivation with a low dielectric constant polymer enhances the emission properties of SWCNTs and enables the fabrication of high-performance light-emitting field-effect transistors. Passivation with this polymer is proposed as a standard treatment for substrates used in spectroscopic investigations and optoelectronic devices with SWCNTs and other low-dimensional emitters.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Chen Ma, C. Alexander Schrage, Juliana Gretz, Anas Akhtar, Linda Sistemich, Lena Schnitzler, Han Li, Kristina Tschulik, Benjamin S. Flavel, Sebastian Kruss
Summary: Small perturbations in material structures can significantly affect their properties. By modifying single wall carbon nanotubes (SWCNTs) with quantum defects using diazonium salts, the photophysics of the nanotubes can be determined. The presence of multiple chiralities in SWCNT samples complicates the identification of defect-related emission features. This study shows that quantum defects do not affect aqueous two-phase extraction of different SWCNT chiralities, indicating a low number of defects. The results demonstrate the importance of stochasticity in the optical properties of SWCNTs and highlight the discrepancy between ensemble and single particle experiments/properties of nanomaterials.
Article
Chemistry, Multidisciplinary
Salome Forel, Han Li, Stein van Bezouw, Jochen Campo, Laura Wieland, Wim Wenseleers, Benjamin S. Flavel, Sofie Cambre
Summary: The research reveals that the stacking of dye molecules inside semiconducting chirality-sorted SWCNTs with diameters ranging from 1.15 to 1.5 nm affects their optical properties, and different SWCNT diameters and chiralities also result in changes in the absorption wavelength of the dye molecules.