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Hwang U, Kim BQ, Nam JD, Lee D. Flexible Antireflection Coatings with Enhanced Durability and Antifogging Properties. ACS Appl Mater Interfaces 2024; 16:10714-10721. [PMID: 38377540 DOI: 10.1021/acsami.3c17986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Antireflection coatings (ARCs) enhance optical clarity and improve light transmission by reducing glare and reflections. The application of conventional ARCs in flexible devices, however, is impeded by their lack of durability, particularly under bending deformation. We develop ARCs that withstand delamination and fracture, remaining intact even after 1000 bending cycles with a 5 cm bending radius. We fabricate integrated ARCs (iARCs) on a poly(methyl methacrylate) (PMMA) substrate by inducing free polymers to infiltrate the interstices of a disordered assembly of hollow silica nanochains and nanospheres. The polydispersity of PMMA creates a refractive index gradient, yielding a broadband antireflection capability. The nanochain-based iARCs are superior to the nanosphere-based coatings in both antireflection properties and mechanical durability, owing to the lower packing density and mechanical interlocking of the nanochains, respectively. Additionally, these nanochain iARCs display antifogging properties stemming from their superhydrophilicity. While our demonstrations are based on PMMA as a model substrate, this methodology is potentially extendable to other polymers, enhancing the iARC's applicability across various practical applications, including flexible and wearable devices.
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Affiliation(s)
- Uiseok Hwang
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Polymer Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Baekmin Q Kim
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jae-Do Nam
- Department of Polymer Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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Kumar V, Behera MP, Singamneni S. Polymeric Microfluidic Fuel Cells with Controlled Printed Patterns. 3D Print Addit Manuf 2024; 11:78-93. [PMID: 38434494 PMCID: PMC10908328 DOI: 10.1089/3dp.2022.0280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Since its first appearance almost a couple of decades ago, microfluidic fuel cells (MFFCs) have gained considerable research momentum due to their potential applications in portable devices. The main focus has been on the effective fabrication of microfluidic channels with different materials, where the manufacturing limitations proved to be the main stumbling blocks. Paper-based MFFCs have been reported with some success, where the porosity of the flow channel medium drives the reactants, greatly reducing the need for elaborate external devices and complex manufacturing obstacles, although the longevity of these cells remains questionable. The current article addresses this issue by replacing the paper-based flow channels with 3D-printed substrates of different structural forms to serve as pathways for controlled flow and mixing responses of the reactant liquids without the use of other devices, such as micro pumps and valves. The line-by-line material consolidation mechanics of fused filament fabrication and the porous mesostructural responses of a commercial polymer filament are combined to build the microfluidic fuel channels of varying configurations. Numerical and experimental characterizations proved the cells to perform better than the current paper-based counterparts, apart from better longevity and possible new opportunities for future improvements based on more complex micro-, meso-, and macrostructural advances.
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Affiliation(s)
- Vikash Kumar
- Department of Mechanical Engineering, Additive Manufacturing Research Center, Auckland University of Technology, Auckland, New Zealand
| | - Malaya Prasad Behera
- Department of Mechanical Engineering, Additive Manufacturing Research Center, Auckland University of Technology, Auckland, New Zealand
| | - Sarat Singamneni
- Department of Mechanical Engineering, Additive Manufacturing Research Center, Auckland University of Technology, Auckland, New Zealand
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Hwang U, Nam JD, Lee D. Dual Porosity-Enhanced Antireflection Coatings with Continuous Gradient. ACS Appl Mater Interfaces 2023; 15:40913-40922. [PMID: 37585736 DOI: 10.1021/acsami.3c07254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
The incorporation of porous structures into films and coatings can transform their properties for applications in optics, separation, electronics, and energy generation and storage. Packing nanoparticles (NPs) is a versatile approach for fabricating nanoporous films with a tunable structure and properties. The mechanical fragility of NP packing-based films and coatings, however, significantly impedes their widespread utilization. Although infiltrating a polymer into the interstices of these NP packings has been shown to enhance their mechanical durability, this method completely eliminates the porosity of the structures, compromising their properties and functionality. This study presents a new approach to fabricate highly loaded porous nanocomposite films with a gradient in the refractive index by infiltrating subsaturating amounts of poly(methyl methacrylate) (PMMA) into disordered packings of hollow silica NPs. We demonstrate that dual porosity is a critical feature that enhances their antireflection (AR) and mechanical properties. The hollow cores of NPs prevent a substantial increase in the refractive index of the resulting films. Moreover, the interparticle voids allow for mechanical reinforcement to occur when the NP packings are infiltrated with PMMA, making them even more suitable for AR coatings. The refractive index and gradient across the nanocomposites can be tailored by adjusting the amount of PMMA infiltrated into the NP packing, the shape of hollow NPs, and the annealing time. The nanocomposite coatings with a continuous gradient in refractive index exhibit excellent AR properties and enhanced mechanical durability. Combined with the unique structural tunability afforded by the dual porosity, this approach provides a scalable and effective way to create robust and graded nanoporous structures for various applications.
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Affiliation(s)
- Uiseok Hwang
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Polymer Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jae-Do Nam
- Department of Polymer Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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Kotwa A, Ramiączek P, Bąk-Patyna P, Kowalik R. Parameters of Concrete Modified with Micronized Chalcedonite. Materials (Basel) 2023; 16:ma16093602. [PMID: 37176482 PMCID: PMC10180242 DOI: 10.3390/ma16093602] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
The PN-EN 197-1:2012 standard allows the use of additives as the main component above 5.0% by mass, as well as as a secondary component in an amount less than 5.0% by mass of cement. Proper selection of additives positively affects the rheological characteristics and hardened concrete parameters during longer maturity periods. Additives have already become an integral component of concrete mixes. The aim of the research is to confirm the possibility of using the tested additive in the composition of concrete mixes in an amount of 15% relative to the amount of cement, which would solve the problem of storing and utilizing waste generated during the production of broken chalcedonite aggregates. The planned laboratory tests were carried out for concrete of three classes, C30/37, C35/45, C40/50, according to the PN-EN 206+A1:2016-2 standard, with the addition of chalcedonite dust in a constant amount of 15% relative to cement, and three series without additives as control series. The additive used for concrete mixes was chalcedonite dust with a diameter below 72 μm. It is waste from a broken aggregate mine. The research program included rheological tests of fresh concrete mix, i.e., air content, consistency, bulk density, as well as parameters of hardened concrete mix-compressive strength, absorbability, and capillary uptake. Compressive strength was tested after 7, 14, 28, 56, and 90 days. The laboratory tests aimed to verify whether the addition of 15% chalcedonite dust additive would not worsen the predicted hardened concrete parameters resulting from the designed concrete classes. All three tested series, C30/37, C35/45, and C40/50, with the addition of 15% chalcedonite dust relative to the amount of cement, achieved the assumed strength classes after 28 days of maturation. Concrete mix components were correctly designed. The addition of chalcedonite dust to the concrete mix did not cause a decrease in compressive strength to the extent that the analyzed series did not meet the normative requirements for concrete classes according to the PN-EN 206+A1:2014 standard. The results of absorbability testing indicate water absorption below 5%, while the increase in sample mass in the capillary uptake test gained similar values.
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Affiliation(s)
- Anna Kotwa
- Faculty of Civil Engineering and Architecture, Kielce University of Technology, 25-314 Kielce, Poland
| | - Piotr Ramiączek
- Faculty of Civil Engineering and Architecture, Kielce University of Technology, 25-314 Kielce, Poland
| | - Paulina Bąk-Patyna
- Faculty of Civil Engineering and Architecture, Kielce University of Technology, 25-314 Kielce, Poland
| | - Robert Kowalik
- Faculty of Environmental, Geomatic and Energy Engineering, Kielce University of Technology, 25-314 Kielce, Poland
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Briggs K, Ball R, McCaig I. In-situ measurements of wall moisture in a historic building in response to the installation of an impermeable floor. UCL Open Environ 2022; 4:e046. [PMID: 37228456 PMCID: PMC10171423 DOI: 10.14324/111.444/ucloe.000046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 08/20/2022] [Indexed: 05/27/2023]
Abstract
When impermeable ground bearing slabs are installed in old buildings without a damp-proof course, it is a common belief of conservation practitioners that ground moisture will be 'driven' up adjacent walls by capillary action. However, there is limited evidence to test this hypothesis. An experiment was used to determine if the installation of a vapour-proof barrier above a flagstone floor in a historic building would increase moisture content levels in an adjacent stone rubble wall. This was achieved by undertaking measurements of wall, soil and atmospheric moisture content over a 3-year period. Measurements taken using timber dowels showed that the moisture content within the wall did not vary in response to wall evaporation rates and did not increase following the installation of a vapour-proof barrier above the floor. This indicates that the moisture levels in the rubble wall were not influenced by changes in the vapour-permeability of the floor.
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Affiliation(s)
- Kevin Briggs
- Department of Architecture and Civil Engineering, University of Bath, Bath, BA2 7AY, UK
| | - Richard Ball
- Department of Architecture and Civil Engineering, University of Bath, Bath, BA2 7AY, UK
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Stępień P, Spychał E, Skowera K. A Comparative Study on Hygric Properties and Compressive Strength of Ceramic Bricks. Materials (Basel) 2022; 15:7820. [PMID: 36363412 PMCID: PMC9657362 DOI: 10.3390/ma15217820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/31/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
This article analyzes the results of capillary rise, compressive strength and water absorption tests on solid ceramic bricks from existing structures and demolition materials taken from 11 different structures. In addition (for more extensive interpretation and evaluation of porosity), tests were performed for the selected series of bricks using a mercury porosimeter (MIP) and a micro computed tomography (micro-CT). Contemporary bricks (2 series) were also evaluated for comparison purposes. The conducted tests indicate that bricks obtained from different sources are characterized by "individual" relation of compressive strength and porosity, and "individual" relation of water absorption coefficient and porosity. In addition, on the basis of the results obtained in the study, compared with the literature data, it can be deduced that ceramic bricks with a water absorption coefficient of less than 50 g/m2s0.5 are characterized by a compressive strength of more than 80 MPa. As the research shows, the properties of bricks even from a single building can differ one from another, which can result in varying durability even within a single building. When choosing a material during the renovation or restoration of facilities, it is important to perform tests on the physical and mechanical properties of the original material, which will be reused.
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Chanut J, Wang Y, Gougeon RD, Bellat JP, Karbowiak T. Unraveling the Complex Interfacial Properties of Cork-Based Materials in Their Use as Wine Stoppers. ACS Appl Mater Interfaces 2022; 14:42602-42612. [PMID: 36074384 DOI: 10.1021/acsami.2c07299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
This study investigates the surface and interfacial properties of the different components of a system composed of an agglomerated cork stopper in a glass bottleneck. Each constituting element has carefully been examined to unveil its underlying complexity. First, there was no effect of supercritical CO2 pretreatment or particle size on the surface properties of cork particles. The wettability of the binder was also evaluated, showing that the binder can spread relatively well on the surface of cork particles. Second, capillary rise measurements carried out on three different agglomerated corks indicate that the formulation of the agglomerates has no effect on its surface properties. The binder represents only a small fraction of the total stopper volume and is therefore not the major contributor to the surface tension. Third, the two coating agents studied display different behaviors. The first one, composed of a paraffin emulsion, exhibits poorer wettability than the second one, composed of a paraffin and silicone emulsion. However, once the coating agent has solidified on the surface of the stopper, both coatings display similar adhesion with the glass of the bottleneck. Starting with fundamental considerations, and then progressing to a more applicative aspect, has led to a better understanding of the properties of cork-based materials in their use as wine stoppers.
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Affiliation(s)
- Julie Chanut
- Univ. Bourgogne Franche-Comté, Institut Agro Dijon, PAM UMR 02 102, 1 Esplanade Erasme, 21000 Dijon, France
- Univ. Bourgogne Franche-Comté, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, 9 Avenue Alain Savary, 21078 Dijon, France
| | - Yiqian Wang
- Univ. Bourgogne Franche-Comté, Institut Agro Dijon, PAM UMR 02 102, 1 Esplanade Erasme, 21000 Dijon, France
| | - Régis D Gougeon
- Univ. Bourgogne Franche-Comté, Institut Agro Dijon, PAM UMR 02 102, 1 Esplanade Erasme, 21000 Dijon, France
- Univ. Bourgogne Franche-Comté, Institut Universitaire de la Vigne et du Vin, 1 Rue Claude Ladrey, 21000 Dijon, France
| | - Jean-Pierre Bellat
- Univ. Bourgogne Franche-Comté, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, 9 Avenue Alain Savary, 21078 Dijon, France
| | - Thomas Karbowiak
- Univ. Bourgogne Franche-Comté, Institut Agro Dijon, PAM UMR 02 102, 1 Esplanade Erasme, 21000 Dijon, France
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Abstract
In view of the COVID-19 pandemic, most countries in the world have mandated the use of face masks to limit the spread of this dangerous disease. The billions of face masks that are produced around the world to date generate millions of tonnes of plastic waste that is thrown into the environment. The present work aims to valorise single-use masks or surgical masks in mortar. In this work, the effect of substituting 1–5% of the volume of the mortar with pieces of masks of 2 cm2 section and 4 cm2 section is explored. Mechanically, an increase in compressive strength of between 10 and 20% is noted, as well as an improvement in flexural strength of 19–30%. Physically, the thermal resistance of the mortars formulated from waste mask improved by up to 23%, and there was a clear improvement in the acoustic reflection coefficient for all frequencies. The capillary rise test conducted on the mortar samples shows that the amount of the absorbed water increases. However, although in most cases the presence of mask pieces increases the sorptivity of the mortar, this is not associated with a higher capillary rise. The results found are encouraging, allowing on the one hand to improve the physical and mechanical characteristics of the mortar and on the other hand to solve a dangerous environmental problem.
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Affiliation(s)
- Lassaad Ajam
- Institut Supérieur des Technologies de l’Environnement de l’Urbanisme et du Bâtiment, Université de Carthage, 2 Rue de l’Artisanat Charguia 2, 2035 Tunis, Tunisia
- Ecole Nationale d’Ingénieurs de Tunis, LR-03-ES05 Laboratoire de Génie Civil, Université de Tunis El Manar, 1002 Tunis, Tunisia
| | - Abderraouf Trabelsi
- Ecole Nationale d’Ingénieurs de Tunis, LR-03-ES05 Laboratoire de Génie Civil, Université de Tunis El Manar, 1002 Tunis, Tunisia
- Département génie civil, Académie Militaire, Fondouk Jadid, Tunisia
| | - Zied Kammoun
- Institut Supérieur des Technologies de l’Environnement de l’Urbanisme et du Bâtiment, Université de Carthage, 2 Rue de l’Artisanat Charguia 2, 2035 Tunis, Tunisia
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Zhou H, Zhao WZ. [Soil physical characteristics of shallow vadose zone and modeling its effects on upward capillary rise of groundwater in an arid-desert area.]. Ying Yong Sheng Tai Xue Bao 2019; 30:2999-3009. [PMID: 31529875 DOI: 10.13287/j.1001-9332.201909.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Two typical soil profiles of sand dune (mixed sandy loam with sandy soil; uniform sandy soil) were selected from the arid region on the edge of the Badain Jaran desert to analyze soil physical characteristics. The effects of soil physical characteristics on capillary rise were monitored and simulated. The relationship between two typical soil profiles of sand dune and capillary rise were investigated to reveal the interactive processes among groundwater, capillary water, and soil water. Results showed that capillary rise was mainly affected by soil bulk density and soil clay content in the arid-desert area. The capillary rise could reach to 152 cm above shallow layer in the profile of mixed sandy loam with sandy soils, and 120 cm in the profile of sandy soil, respectively. Soil water distribution driven by the capillary rise was more uniform in the profile of sandy soil. Soil water content showed a diminishing trend from the groundwater to the maximum distance of capillary rise. In contrast, soil water distribution was markedly varied in the profile of mixed sandy loam with sandy soil. The process of capillary movement could be well simulated with Hydrus-3D model. Soil structure above the groundwater was the critical factor, which could affect the capillary rise and soil water distribution. However, the effects of soil in-season evaporation and plant root uptake on capillary rise movement need to be explored in further studies.
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Affiliation(s)
- Hong Zhou
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences/Linze Inland River Basin Research Station, Chinese Ecosystem Research Network/Key Laboratory of Inland River Basin Ecohydrology, Chinese Academy of Sciences Lanzhou 730000, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Zhi Zhao
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences/Linze Inland River Basin Research Station, Chinese Ecosystem Research Network/Key Laboratory of Inland River Basin Ecohydrology, Chinese Academy of Sciences Lanzhou 730000, China
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Abstract
Effective, long-range, and self-propelled water elevation and transport are important in industrial, medical, and agricultural applications. Although research has grown rapidly, existing methods for water film elevation are still limited. Scaling up for practical applications in an energy-efficient way remains a challenge. Inspired by the continuous water cross-boundary transport on the peristome surface of Nepenthes alata, here we demonstrate the use of peristome-mimetic structures for controlled water elevation by bending biomimetic plates into tubes. The fabricated structures have unique advantages beyond those of natural pitcher plants: bulk water diode transport behavior is achieved with a high-speed passing state (several centimeters per second on a milliliter scale) and a gating state as a result of the synergistic effect between peristome-mimetic structures and tube curvature without external energy input. Significantly, on further bending the peristome-mimetic tube into a "candy cane"-shaped pipe, a self-siphon with liquid diode behavior is achieved. Such a transport mechanism should inspire the design of next generation water transport devices.
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Hor JL, Jiang Y, Ring DJ, Riggleman RA, Turner KT, Lee D. Nanoporous Polymer-Infiltrated Nanoparticle Films with Uniform or Graded Porosity via Undersaturated Capillary Rise Infiltration. ACS Nano 2017; 11:3229-3236. [PMID: 28221754 DOI: 10.1021/acsnano.7b00298] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this work, we present the fabrication of nanoporous polymer-infiltrated nanoparticle films (PINFs) with either uniform or graded porosity based on undersaturated capillary rise infiltration (UCaRI) and study the processing-structure-property relationship of these nanoporous PINFs. The UCaRI process involves first generating a bilayer film of a randomly packed nanoparticle layer atop a polymer layer, such that the volume of the polymer is less than the void volume in the nanoparticle packing. Subsequently, the bilayer film is annealed above the glass transition temperature of the polymer to induce polymer infiltration into the voids of the nanoparticle packing. Using in situ spectroscopic ellipsometry and molecular dynamics simulations, we observe that the polymer transport occurs in two stages: capillarity-induced infiltration, followed by gradual spreading, likely via surface diffusion. By varying the annealing time, UCaRI enables the generation of graded or uniform nanoporous PINFs. We also show that these nanoporous PINFs have tunable optical and mechanical properties, which can be tailored simply by changing the nanoparticle to polymer layer thickness ratio in the initial bilayer. The UCaRI approach is versatile and widely applicable to various polymers, which allows generation of nanoporous PINFs for multiple applications.
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Affiliation(s)
- Jyo Lyn Hor
- Department of Chemical and Biomolecular Engineering and ‡Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Yijie Jiang
- Department of Chemical and Biomolecular Engineering and ‡Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - David J Ring
- Department of Chemical and Biomolecular Engineering and ‡Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Robert A Riggleman
- Department of Chemical and Biomolecular Engineering and ‡Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Kevin T Turner
- Department of Chemical and Biomolecular Engineering and ‡Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering and ‡Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
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Acquarelli C, Paliotta L, Tamburrano A, De Bellis G, Sarto MS. Electro-Mechanical Properties of Multilayer Graphene-Based Polymeric Composite Obtained through a Capillary Rise Method. Sensors (Basel) 2016; 16:E1780. [PMID: 27792153 PMCID: PMC5134439 DOI: 10.3390/s16111780] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/15/2016] [Accepted: 10/20/2016] [Indexed: 11/16/2022]
Abstract
A new sensor made of a vinyl-ester polymer composite filled with multilayer graphene nanoplatelets (MLG) is produced through an innovative capillary rise method for application in strain sensing and structural health monitoring. The new sensor is characterized by high stability of the piezoresistive response under quasi-static consecutive loading/unloading cycles and monotonic tests. This is due to the peculiarity of the fabrication process that ensures a smooth and clean surface of the sensor, without the presence of filler agglomerates acting as micro- or macro-sized defects in the composite.
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Affiliation(s)
- Chiara Acquarelli
- Department of Astronautical, Electrical and Energy Engineering of Sapienza University of Rome (DIAEE), Via Eudossiana 18, Rome 00185, Italy.
- Research Center for Nanotechnology Applied to Engineering of Sapienza University (CNIS), Rome 00185, Italy.
| | - Licia Paliotta
- Department of Astronautical, Electrical and Energy Engineering of Sapienza University of Rome (DIAEE), Via Eudossiana 18, Rome 00185, Italy.
- Research Center for Nanotechnology Applied to Engineering of Sapienza University (CNIS), Rome 00185, Italy.
| | - Alessio Tamburrano
- Department of Astronautical, Electrical and Energy Engineering of Sapienza University of Rome (DIAEE), Via Eudossiana 18, Rome 00185, Italy.
- Research Center for Nanotechnology Applied to Engineering of Sapienza University (CNIS), Rome 00185, Italy.
| | - Giovanni De Bellis
- Department of Astronautical, Electrical and Energy Engineering of Sapienza University of Rome (DIAEE), Via Eudossiana 18, Rome 00185, Italy.
- Research Center for Nanotechnology Applied to Engineering of Sapienza University (CNIS), Rome 00185, Italy.
| | - Maria Sabrina Sarto
- Department of Astronautical, Electrical and Energy Engineering of Sapienza University of Rome (DIAEE), Via Eudossiana 18, Rome 00185, Italy.
- Research Center for Nanotechnology Applied to Engineering of Sapienza University (CNIS), Rome 00185, Italy.
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Alimov MM, Kornev KG. Meniscus on a shaped fibre: singularities and hodograph formulation. Proc Math Phys Eng Sci 2014; 470:20140113. [PMID: 25104910 DOI: 10.1098/rspa.2014.0113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 05/01/2014] [Indexed: 11/12/2022] Open
Abstract
Using the method of matched asymptotic expansions, the problem of the capillary rise of a meniscus on the complex-shaped fibres was reduced to a nonlinear problem of determination of a minimal surface. This surface has to satisfy a special boundary condition at infinity. The proposed formulation allows one to interpret the meniscus problem as a problem of flow of a fictitious non-Newtonian fluid through a porous medium. As an example, the shape of a meniscus on a fibre of an oval cross section was analysed employing Chaplygin's hodograph transformation. It was discovered that the contact line may form singularities even if the fibre has a smooth profile: this statement was illustrated with an oval fibre profile having infinite curvature at two endpoints.
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Affiliation(s)
- Mars M Alimov
- Lobachevsky Institute of mathematics, Kazan Federal University , Kazan, Russia
| | - Konstantin G Kornev
- Department of Materials Science and Engineering , Clemson University , Clemson, SC, 29634-0971, USA
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Lehnert MS, Monaenkova D, Andrukh T, Beard CE, Adler PH, Kornev KG. Hydrophobic-hydrophilic dichotomy of the butterfly proboscis. J R Soc Interface 2013; 10:20130336. [PMID: 23760299 PMCID: PMC4043169 DOI: 10.1098/rsif.2013.0336] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 05/20/2013] [Indexed: 11/12/2022] Open
Abstract
Mouthparts of fluid-feeding insects have unique material properties with no human-engineered analogue: the feeding devices acquire sticky and viscous liquids while remaining clean. We discovered that the external surface of the butterfly proboscis has a sharp boundary separating a hydrophilic drinking region and a hydrophobic non-drinking region. The structural arrangement of the proboscis provides the basis for the wetting dichotomy. Theoretical and experimental analyses show that fluid uptake is associated with enlargement of hydrophilic cuticular structures, the legulae, which link the two halves of the proboscis together. We also show that an elliptical proboscis produces a higher external meniscus than does a cylindrical proboscis of the same circumference. Fluid uptake is additionally facilitated in sap-feeding butterflies that have a proboscis with enlarged chemosensory structures forming a brush near the tip. This structural modification of the proboscis enables sap feeders to exploit films of liquid more efficiently. Structural changes along the proboscis, including increased legular width and presence of a brush-like tip, occur in a wide range of species, suggesting that a wetting dichotomy is widespread in the Lepidoptera.
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Affiliation(s)
- Matthew S. Lehnert
- School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC 29634, USA
- Department of Biological Sciences, Kent State University, North Canton, OH 44720, USA
| | - Daria Monaenkova
- Department of Materials Science & Engineering, Clemson University, Clemson, SC 29634, USA
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Taras Andrukh
- Department of Materials Science & Engineering, Clemson University, Clemson, SC 29634, USA
| | - Charles E. Beard
- School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC 29634, USA
| | - Peter H. Adler
- School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC 29634, USA
| | - Konstantin G. Kornev
- Department of Materials Science & Engineering, Clemson University, Clemson, SC 29634, USA
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