Nanoporous Layer Research Articles

Near-Zero Transmittance Loss, Highly Durable, Flexible, Transparent Electrode with an Ultrathin Ag Nanoporous Structure

Recent advances in state-of-the-art optoelectrical and photovoltaic devices have necessitated further improvements in the efficiency of transparent electrodes by simultaneously minimizing electrical and optical losses, which remain technically challenging to achieve. In this study, we developed a strategy for constructing a highly efficient transparent electrode that retains near-perfect optical transparency at tunable wavelengths in the visible spectral range and has excellent electrical reliability against heavy processing loading. The optoelectrical features were achieved by integrating an ultrathin Ag nanoporous layer and a substoichiometric electron-transferring SiOx film in a multilayered oxide/metal/oxide configuration. Complete sealing of the Ag nanoporous geometry by a subsequently coated SiOx film facilitates near-zero optical transmittance loss (<1%, averaged at 0.7%) over a wide spectral range of 500–700 nm at a near-bulk resistivity of 7.2 × 10–8 Ω m while ensuring extreme durability against chemical corrosion, electrical/thermal degradation, and mechanical deformation. The unexpected performance of such a defective Ag-layered geometry, which has rarely been considered in the design of transparent electrodes, refutes conventional approaches that emphasize the implementation of a completely continuous layered geometry of Ag to optimize the optical and electrical performances. These results provide an alternative solution for maximizing the performance and durability of Ag-based transparent electrodes that can be synthesized on either glass or polymer substrates for various optoelectrical applications, including flexible transparent Joule heaters.

TiO2/HA and Titanate/HA Double-Layer Coatings on Ti6Al4V Surface and Their Influence on In Vitro Cell Growth and Osteogenic Potential.

Hydroxyapatite (HA) layers are appropriate biomaterials for use in the modification of the surface of implants produced inter alia from a Ti6Al4V alloy. The issue that must be solved is to provide implants with appropriate biointegration properties, enabling the permanent link between them and bone tissues, which is not so easy with the HA layer. Our proposition is the use of the intermediate layer ((IL) = TiO2, and titanate layers) to successfully link the HA coating to a metal substrate (Ti6Al4V). The morphology, structure, and chemical composition of Ti6Al4V/IL/HA systems were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectrometry (EDS). We evaluated the apatite-forming ability on the surface of the layer in simulated body fluid. We investigated the effects of the obtained systems on the viability and growth of human MG-63 osteoblast-like cells, mouse L929 fibroblasts, and adipose-derived human mesenchymal stem cells (ADSCs) in vitro, as well as on their osteogenic properties. Based on the obtained results, we can conclude that both investigated systems reflect the physiological environment of bone tissue and create a biocompatible surface supporting cell growth. However, the nanoporous TiO2 intermediate layer with osteogenesis-supportive activity seems most promising for the practical application of Ti6Al4V/TiO2/HA as a system of bone tissue regeneration.

Hierarchical porous metallic glass with strong broadband absorption and photothermal conversion performance for solar steam generation

The development of a strong light absorption absorber with a facile preparation process are crucial for some photothermal conversion applications, such as solar steam generation, photothermal catalysis and detectors. Here, a hierarchical structure based on microporous surface equipped with nanoporous layer is ingeniously designed and fabricated benefiting from the unique thermoplastic forming ability of metallic glasses by using the soluble clusters as template in less than 30 s. The presence of hierarchical porous structures induces multiple reflection of light and excites the plasmonic behavior of surface, achieving over 90% light absorption in the 380–20 µm wavelength range and the broad light incident angle from 0° to 70°, resulting in a remarkable photothermal conversion performance. Compared to conventional and existing absorber, the innovatively designed and fabricated metallic surface offers outstanding advantages in terms of light absorption range, heating rate and maximum temperature rise. Afterwards, the hierarchical porous structures for solar steam generation shows an evaporation efficiency of up to 94.2% and evaporation rate of 1.72 kg m−2 h−1 at 1 kW m−2. The design of unprecedented structure on metallic glass opens up a new strategy for solar energy harvesting, water treatment and other related fields.

Multifunctional nanopore electrode array method for characterizing and manipulating single entities in attoliter-volume enclosures

Structurally regular nanopore arrays fabricated to contain independently controllable annular electrodes represent a new kind of architecture capable of electrochemically addressing small collections of matter—down to the single entity (molecule, particle, and biological cell) level. Furthermore, these nanopore electrode arrays (NEAs) can also be interrogated optically to achieve single entity spectroelectrochemistry. Larger entities such as nanoparticles and single bacterial cells are investigated by dark-field scattering and potential-controlled single-cell luminescence experiments, respectively, while NEA-confined molecules are probed by single molecule luminescence. By carrying out these experiments in arrays of identically constructed nanopores, massively parallel collections of single entities can be investigated simultaneously. The multilayer metal–insulator design of the NEAs enables highly efficient redox cycling experiments with large increases in analytical sensitivity for chemical sensing applications. NEAs may also be augmented with an additional orthogonally designed nanopore layer, such as a structured block copolymer, to achieve hierarchically organized multilayer structures with multiple stimulus-responsive transport control mechanisms. Finally, NEAs constructed with a transparent bottom layer permit optical access to the interior of the nanopore, which can result in the cutoff of far-field mode propagation, effectively trapping radiation in an ultrasmall volume inside the nanopore. The bottom metal layer may be used as both a working electrode and an optical cladding layer, thus, producing bifunctional electrochemical zero-mode waveguide architectures capable of carrying out spectroelectrochemical investigations down to the single molecule level.

Microstructure and mechanical properties of NiTi nanoporous structures fabricated with dealloying process

Dealloying is an emerging material processing technology to fabricate nanoporous functional surface. Systematic characterization of microstructure and mechanical properties for dealloyed surface is a basis for tailoring dealloying parameters. This paper aims to investigate the effect of dealloying treatment on the evolution of microstructures and mechanical properties of NiTi alloy. Firstly, nanoporous layer is fabricated with electrochemical dealloying method to dissolve nickel element selectively from NiTi alloy. Secondly, the microstructures of dealloyed layer are characterized and analyzed with microscopic test methods. The release characteristics of nickel ions from the sample surface before and after dealloying treatment were evaluated using SBF immersion tests. Thirdly, the mechanical properties of NiTi nanoporous structure are evaluated with nanoindentation and micro scratch tests. The results show that both elastic modulus and nanohardness of the NiTi nanoporous layer are over 80% lower than those of the matrix material. The super-elastic property of NiTi alloy is weakened. Meanwhile, the scratching force at the same scratching depth is reduced by over 30% after dealloying process. Instead of severe plastic deformation, irregular brittle fracture occurs along the scratched groove and it demonstrates the plasticity degradation of dealloyed surface. Finally, the weakening mechanism of nanoporous structures fabricated with dealloying treatment is discussed.

3D-Printed Raney-Cu POCS as Promising New Catalysts for Methanol Synthesis

Simultaneous generation and activation of Raney-type periodic open cellular structures (POCS) is a highly promising approach for generating novel structured methanol synthesis catalysts. In detail, we produced stable and highly active POCS from a Cu50Al50 alloy by additive manufacturing via Powder Bed Fusion by Electron Beam (PBF-EB) and activated them via selective leaching of aluminum in a sodium hydroxide/sodium zincate solution. The Raney-type Cu structures possessed catalytic methanol productivities of up to 2.2 gMeOHgnp-Cu h−1 (PBF-EB sticks) and 1.9 gMeOHgnp-Cu h−1 (PBF-EB POCS), respectively. Moreover, it was found that besides the nanoporous layer thickness, an optimum Zn/Cu ratio of 0.3–0.4 can also by adjusted by the leaching conditions.

Operando Liquid Water Saturation in PEFC Catalyst Layers Determined Via Small Angle X-Ray Scattering

Various measurement techniques suitable with the length scale of PEFC components have been explored to address the PEFC water management challenge. For the gas diffusion layer (GDL), technological advances have permitted operando water saturation quantification and elucidation of its mechanism with X-ray tomography with few microns resolution 1-4. Furthermore, sub-voxel information contained in the X-ray tomography data has demonstrated accurate water quantification in the nano-porous microporous layer (MPL)5. However, in the nanoscale regime of the catalyst layer, the quantification of water and the mechanism of the water filling the pores remain nontrivial. Studies involving imaging techniques dedicated to understand the water management in the catalyst layer have been carried out albeit with limited spatial resolution6. Nevertheless, the pore-scale information has remained unresolved.Small angle X-ray scattering (SAXS) technique is proposed as a non-destructive diagnostic tool to investigate the catalyst layer saturation in operating conditions. SAXS is well suited for diagnosing the presence of liquid water during operando experiments because of its sensitivity to electron density contrast, nanoscale observation window, high temporal resolution and adequate spatial resolution to distinguish the components in PEFCs. Herein, SAXS intensity profiles measured at cSAXS, Swiss Light Source, Paul Scherrer Institut, Switzerland, with a recently developed SAXS-compatible operando PEFC (Figure 1 middle and right) are interpreted using representative morphology models and assuming different water filling mechanisms (Figure 1 middle and left). The presentation will provide insights into the wetting phenomena in the catalyst layer of PEFC during operation using a representative morphology modelling approach. This work has been presented in XVIII edition of the International Small-Angle Scattering Conference.(1) Xu, H.; Buhrer, M.; Marone, F.; Schmidt, T. J.; Buchi, F. N.; Eller, J. Effects of Gas Diffusion Layer Substrates on PEFC Water Management: Part I. Operando Liquid Water Saturation and Gas Diffusion Properties. J Electrochem Soc 2021, 168 (7).(2) Eller, J.; Rosen, T.; Marone, F.; Stampanoni, M.; Wokaun, A.; Buchi, F. N. Progress in In Situ X-Ray Tomographic Microscopy of Liquid Water in Gas Diffusion Layers of PEFC. J Electrochem Soc 2011, 158 (8), B963-B970.(3) Mularczyk, A.; Lin, Q. Y.; Niblett, D.; Vasile, A.; Blunt, M. J.; Niasar, V.; Marone, F.; Schmidt, T. J.; Buchi, F. N.; Eller, J. Operando Liquid Pressure Determination in Polymer Electrolyte Fuel Cells. Acs Appl Mater Inter 2021, 13 (29), 34003-34011.(4) Sabharwal, M.; Buchi, F. N.; Nagashima, S.; Marone, F.; Eller, J. Investigation of the transient freeze start behavior of polymer electrolyte fuel cells. J Power Sources 2021, 489.(5) Chen, Y. C.; Berger, A.; De Angelis, S.; Schuler, T.; Bozzetti, M.; Eller, J.; Tileli, V.; Schmidt, T. J.; Buchi, F. N. A Method for Spatial Quantification of Water in Microporous Layers of Polymer Electrolyte Fuel Cells by X-ray Tomographic Microscopy. Acs Appl Mater Inter 2021, 13 (14), 16227-16237.(6) Babu, S. K.; Spernjak, D.; Mukundan, R.; Hussey, D. S.; Jacobson, D. L.; Chung, H. T.; Wu, G.; Steinbach, A. J.; Litster, S.; Borup, R. L.; Zelenay, P. Understanding water management in platinum group metal-free electrodes using neutron imaging. J Power Sources 2020, 472. Figure 1

Effect of Structural Morphology and Material Factors on Radiative Properties of Hybrid Perovskite/Nanoporous GaN Hierarchical Composite Structure

The encapsulation of hybrid perovskite in nanoporous GaN is a promising strategy to reduce perovskite degradation and improve photoelectric performance. Exploitation of the intrinsic light-matter interaction in such a composite structure greatly benefits improving device optimization. Herein, we report the perovskite synthesis, structural design, and radiative properties of perovskite/nanoporous GaN hierarchical composites using spectroscopic ellipsometry (SE) experiments as well as electromagnetic simulations. First-principles calculations reveal the relationship between electronic interband transitions and the dielectric function of perovskite measured by SE. We use the finite-difference time-domain (FDTD) and finite-element method (FEM) simulations to analyze the spectral radiation properties for the hierarchical composite structure in terms of both morphology dependence and material factors. The optical absorption peaks in the near-infrared–visible region are collectively determined by the nanopore size, layer thickness, and incident angle of light. Also, the optical absorption distribution patterns are related to variables of the halogen, metal elements, and temperature. This work is integrated with the development of perovskite-based applications for solar functional batteries, light-emitting diodes (LED), and optoelectronic detectors.

4.1: Invited Paper: Analysis of Color Conversion in III‐Nitride Micro‐LEDs with Embedded Nanostructures

We report in this conference the modeling analysis of absorption and color conversion characteristics of III‐nitride micro‐LED arrays embedded with nanostructures. While nanoporous GaN layers in the micro‐LED pixels have been reported to function as the color‐converting element by incorporating quantum dot‐based nanophosphor inside the porous cavity, our computational study reveals that extraction efficiencies of both excitation (blue) and down‐conversion (red) light from the nanophosphor‐coupled LED structure decrease dramatically with porosity and the thickness of embeded down‐conversion layer s. The cross‐talk of down‐conversion light between adjacent micro‐LED pixels is also found to be substantially higher compared to the excitation light cross‐talk due to the location of the phosphors in the pore cavities and the resultant strong scattering by the surrounding nanopores. Studying and attempting to overcome those color‐conversion challenges of the nanoporous GaN based micro‐LEDs could pave the way of developing full‐color miro‐LED display panels that simultaneously preserve the high‐resolution and efficiency performances of micro‐LED display devices.

Ultrasound effects on titanium dioxide compact layer and its application of dye-sensitized solar cell

Herein, the influence of ultrasound on the compact layer of titanium dioxide was studied. An anodization technique formed a titanium dioxide layer on the Ti substrate. The lactic acid electrolyte contained dimethyl sulfoxide and ammonium fluoride, and the condition of the experiment was 20 volts for 30 min. The results proved the important role of sound vibration in the growth of titanium dioxide nanotubes (TiO2-NTs). In the absence of ultrasound, it was found that nanoporous oxide (TiO2-NPO) was formed with an aggregation of titanium dioxide particles. The XRD analysis proved that the phase of TiO2-NPO and TiO2-NTs is anatase, with estimated crystal sizes of 34.07 nm and 14.33 nm (101). FE-SEM images confirmed the growth of nanotube structures and the nanoporous compact oxide layer on the titanium surface. The EDS spectra showed the atomic ratio of elements for the Ti and O was 1:2 and 1:1 in sequences of 41.07 % and 58.93 %. A dye-sensitized solar cell has been fabricated from the TiO2-NPO and TiO2-NTs photoanodes. The graphene nanoplate was used as counter electrodes to evaluate power conversion. The findings showed for TiO2-NTs η = 0.492 and Jsc = 2.416 mA/cm2 under 100 mW/cm2 sunlight simulation.

Building a Highly Stable Ultrathin Nanoporous Layer Assisted by Glucose for Desalination

Although nanoporous membranes are of great interest in desalination, it is still challenging to construct highly permeable nanoporous membranes with excellent rejections for an efficient desalination process. In this work, highly permeable nanoporous membranes were built from renewable resources, assisted by the versatile functions of glucose and dopamine, with coupling reactive groups via interfacial reaction with 1,3,5-benzenetricarbonyl trichloride (TMC). The small molecules (0.66 nm) of glucose, which have high hydrophilicity, can diffuse into the membrane for an effective reaction to ensure structural integration. Our novel ultrathin (∼44 nm) nanofiltration (NF) membrane exhibits ultra-high Na 2 SO 4 flux and excellent rejection of Na 2 SO 4 (66.5 L∙m −2 ∙h −1 , 97.3%) and MgSO 4 (63.0 L∙m −2 ∙h −1 , 92.1%) under a pressure of 5 bar (1 bar = 10 5 Pa) which is much superior to the performance of natural-product NF membranes. The membrane demonstrates excellent long-term stability, as well as tremendous acid-base and alkali-base stability and high anti-pollution capacity. The designed membrane materials and architecture open a new door to biopolymer-based separation membranes beyond existing membrane materials.

Nanoporous anodic alumina layers obtained from novel deep eutectic solvent formulations

ABSTRACT The possible fabrication of porous anodic oxide films on aluminium in ionic liquids based on choline dihydrogen citrate eutectic mixtures both with oxalic acid and isopropyl alcohol and ethylene glycol, has been investigated. The anodisation has been carried out in either potentiostatic or galvanostatic regime, at temperatures of 45–80°C, for different process durations. Quite compact, uniform anodic alumina layers have been obtained. Based on AFM and SEM investigations, pore diameters between 50 and 80 nm and interpore distances in the range of 160–200 nm have been estimated, with values influenced by the electrolyte type and anodisation conditions. The highest anodisation rate of about 0.4 µm min−1 has been determined by applying operation temperatures of 60°C. The recorded EIS spectra showed a pure capacitive behaviour and high anodic oxide resistances of 106–107 Ω cm2 order.

Cascade scaffold of porous carbon-coated carbon derivates from a bimetallic zeolitic imidazolate framework for use as an efficient sulfur host in high-performance Li-S batteries

Currently, there is increasing concern about meeting energy demands, and a lithium-sulfur (Li-S) battery is a promising candidate for use in next-generation energy storage systems. However, some problems still limit the practical implementation of Li-S batteries. Herein, we present a conductive cascade scaffold developed by depositing a porous carbon over a nanoporous carbon layer derived from bimetallic zeolitic imidazolate (BMZIF) as an efficient sulfur host for use in Li-S batteries. Due to the increased conductivity, abundant active sites and large surface area of this prepared material, the assembled Li-S batterie exhibits excellent rate and long cycling performances. Results show an outstanding reversible cycling capacity above 1004.1 mAh/g at 0.2 C for over 100 cycles. This work is designed to effectively address the problems of sulfur electrodes and proposes a new scheme of hosting sulfur in Li-S batteries.

Performance improvement of InGaN-based multiple quantum wells embedded nanoporous n-GaN layers

InGaN-based multiple quantum wells (MQWs) embedded nanoporous (NP) GaN layers were fabricated by metal-organic chemical vapor deposition (MOCVD) and followed by electrochemical (EC) etching in oxalic, HF or HNO3 electrolytes. The oxalic-etching and HF-etching do not lead to enhanced luminescence of MQWs, which should be contributed to the damage of InGaN/GaN stacking layers. For the HNO3-etching, the photoluminescence (PL) strength of MQW layer is increased by a factor of 0.52 compared with the as-grown sample, which should be contributed to stress relaxation, light scattering and reflection of quasi vertical nanopore array, and amplify spontaneous emission by resonant cavity. If the nanopore walls in NP-GaN layer are smoothed by the annealing in NH3 atmosphere, the light extraction efficiency of MQWs can be further improved. The study provides a useful method for improving the light extraction efficiency of GaN-based light emitting devices.

Improving the photoelectrochemical performance of porous anodic SnO x films by adjusting electrosynthesis conditions

A comprehensive characterization of photoelectrochemical (PEC) properties of the nanoporous tin oxide (SnOx) films of different thicknesses and complex internal morphology is presented. Nanoporous SnOx layers were obtained by one-step anodic oxidation (anodization) of Sn foil in 1 M NaOH. Semiconducting films with a uniform diameter of ca. 50 nm were grown if the potential of 4 V was applied during anodization, and the layers with different thicknesses were synthesized by changing the duration of the process. Switching the potential between 2 and 4 V allows the formation of anodic films with segments of different channel diameters. The optimal anodizing duration for layers with uniform channels was found to be 50 minutes, which corresponds to the thickness of SnOx film of slightly above 6 μm. In the case of layers with segments of different channel diameters, the segment arrangement was found to be crucial for optimal PEC performance. Layers with the segment of narrower channels being in the contact with the current collector were found to exhibit enhanced photoelectrochemical performance compared to their counterparts with an opposite segment arrangement. This was mainly attributed to the favorable band arrangement facilitating the transfer of the photogenerated electrons to the external circuit as well as enhanced adhesion of the anodic SnOx layer to the current collector. Highlights Nanoporous SnOx films were synthesized electrochemically. Layers with various morphologies were studied as photoanodes. The optimal thickness of anodic SnOx was found to be 6 μm. Enhanced PEC performance was observed for multisegment anodic films. The segment arrangement is crucial for optimal PEC performance.

A microstructural study on the alkali-treated titanium subjected to induction heating

Alkali-treated titanium and its alloys (with or without heat treatment) have been paid more attention in the biomaterial field for the formation of a nanoporous layer that can induce apatite deposition and improve bone-implant integration. In this work, a hierarchical micro-nano structure was fabricated by alkali treatment and subsequent induction heating at different temperatures. The surface morphology, phase composition, microstructure, and elemental binding state were investigated using scanning electron microscopy (SEM), X-ray diffractometer (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. As the induction heating temperature increases, the porous structure of the outmost sodium titanate layer is maintained with increased anatase TiO2 and decreased wetting angle from 21.8° to 11.8°. At a relatively high temperature (700 °C), the composite layer is composed of a porous sodium titanate layer with a thickness of around 1 μm and a titanium oxide layer of about 2 μm thickness with nanopores. Importantly, the amorphous structure with the oxygen vacancy that exists on the sample surface is conducive to apatite deposition. The assessment of the in-vitro bioactivity performed in 1.5 simulated body fluid shows that the ability to induce apatite deposition increases with the increasing induction heating temperature from 500 to 700 °C. These results are helpful to understand the microstructure of the alkali and induction heating treated titanium that may be responsible for its bioactivity.

Improved strength and heat transfer of W/Cu joints via surface nano-activation of W

Joining of tungsten (W) and copper (Cu) is of significance in fusion reactors. In this research, a novel method for enhancing direct alloying of W/Cu using nanoporous structures, but without using interlayer metals, is presented. The method mainly includes three steps: firstly, a pure-metal nanoporous layer was prepared on the surface of the W foil via anodizing and deoxidized annealing in H2 atmosphere; secondly, a layer of copper was electrodeposited on the nanoporous W and then annealed at the temperature close to TmCu (980°C); finally, the W/electroplated Cu layer/Cu joints were obtained by diffusion bonding in H2 atmosphere. The Owen-Wendt method was used to measure the surface energy of W. The test results showed that surface nano-activation of W can significantly promote the direct alloying and improve the tensile strength of W/Cu joints. The high-resolution transmission electron microscopy observation results showed that the diffusion distance between W and Cu reaches 32 nm (vs. 22 nm in our previous work). The maximum average tensile strength for W/Cu joints with nano-activation reached approximately 128 MPa, which is approximately 110% higher than that of W/Cu joints without nano-activation. Surface nano-activation can also enhance the thermal diffusivity of W/Cu joints at high temperatures. This nano-activation can promote direct alloying between W and Cu because it enables an increase in the amount of W crystal surfaces with high surface energy.

Electrical Detection of Gaseous Pollutants Using Nanoporous-Based Gas Sensors

The advanced in situ detection of gaseous pollutants, such as NOx or SOx, is of great interest in many applications, such as the automotive and coal industries. We will discuss the continued advancement of our low power sensors for these pollutants, leveraging the previous successful development of impedance spectroscopy-based sensors for the detection of gaseous I2.1-3 The sensors, composed of Pt interdigitated electrodes (IDEs) with a nanoporous adsorbent layer, can be tuned to selectively adsorb gases of interest through judicious material selection, and the electrical response directly correlated to gas concentration. The current work is focused on exploring these nanoporous phases (metal-organic frameworks (MOFs), zeolites, etc.) for the real-time detection of NOx. The sensors have been successfully demonstrated for detection of trace NO2 (0.5 – 5 ppm),4 and experimental results, collected at relatively low temperature (25-50°C), will be discussed. Other recent work exploring the direct growth of crystalline MOF membranes, through the chemical functionalization of the surface of interdigitated electrodes will also be discussed.5 Direct growth of thin MOF films on surface functionalized IDEs has been shown to result in increased sensor sensitivity and a faster response time. Lastly, we will present initial results for the use of the sensors in the selective detection of NO2 in complex environments (e.g. presence of H2O, CO2, etc.).6 Acknowledgements Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government. References Small, L.J and Nenoff, T.M., ACS Appl. Mater. Interfaces, 2017, 9 (51), 44649.Small, L.J.; Krumhansl, J.L.; Rademacher, D.X.; Nenoff, T.M. Meso. Mater., 2019, 280, 82.Small, L.J.; Hill, R. C.; Krumhansl, J. L.; Schindelholz, M. E.; Chen, Z.; Chapman, K.W.; Zhang, X.; Yang, S.; Schroder, M.; Nenoff, T.M., ACS Applied Materials and Interfaces, 2019, 11 (31), 27982.Small, L.J.; Henkelis, S.E; Rademacher, D.X.; Schindelholz, M. E.; Krumhansl, J. L.; Vogel, D.J.; Nenoff, T.M, Advanced Functional Materials, 2020, 30 (50), 2006598.Henkelis, S.E; Percival, S.J.; Small, L.J; Rademacher, D.X.; Nenoff, T.M, Membranes, 2021, 11 (3), 176.Percival, S.J.; Henkelis, S.E; Li, M.; Schindelholz, M.E.; Krumhansl, J. L.; Small, L.J.; Lobo, R.F.; Nenoff, T.M., I Eng. Chem. Res., 2021, 60 (40), 14371.

Highly Water-Repellent and Anti-Reflective Glass Based on a Hierarchical Nanoporous Layer

Optically anti-reflective and water-repellent glass is required for solar cell covers to improve power-generation efficiency due to transparency improvement and dirt removal. Research has been conducted in recent years on technologies that do not use fluorine materials. In this study, we focused on the anti-reflective properties and microstructure of hierarchical nanoporous layer (HNL) glass and used it as a substrate. As a result, we have achieved both strong anti-reflectivity and high water repellency on HNL glass by coating polydimethylsiloxane (PDMS) using baking and thermal chemical vapor deposition (CVD). The surfaces showed a significantly higher sliding velocity of water droplets than the PDMS-treated material on the flat glass plate. They also showed such water repellency that the droplets bounced off the surface.

CO2 Permeation through Nanoporous graphene: a theoretical study

This work is part of a systematic study on the energy barriers for the permeation of several molecules, like He, H2, CO, CO2, H2O, NH3, CH4 etc, through nanoporous single layer graphene, having pores with different shape, size, and type. In the present work, we focus on the permeation of CO2 through graphene pores which are constructed when neighboring carbon atoms of the graphene layer are removed from the structure, and nitrogen atoms have replaced the carbon atoms in the boundary of the pore. The energy barriers for each different pore are calculated using 2 different ReaxFF potentials along a path which the molecule would ideally follow in order to pass from the one side of the membrane to the other through the pore. Using the calculated values of the energy barriers, we estimate permeances by employing the kinetic theory of gasses. We give estimates for the preferable sizes and structures of the pores for permeability and demonstrate the ability of nanoporous graphene for CO2 separation.