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Rana A, Yadav A, Gupta G, Rana A. Infrared sensitive mixed phase of V 7O 16 and V 2O 5 thin-films. RSC Adv 2023; 13:15334-15341. [PMID: 37223643 PMCID: PMC10201198 DOI: 10.1039/d3ra00752a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 05/16/2023] [Indexed: 05/25/2023] Open
Abstract
We report an infrared (IR) sensitive mixed phase of V7O16 and V2O5 thin films, grown by cathodic vacuum arc-deposition on glass substrates at relatively low temperatures. We have found that the mixed phase of V7O16 and V2O5 can be stabilized by post-annealing of amorphous VxOy between 300-400 °C, which gets fully converted into V2O5 after annealing at higher temperatures ∼450 °C. The local conversion from VxOy to V2O5 has also been demonstrated by applying different laser powers in Raman spectroscopy measurements. The optical transmission of these films increases as the content of V2O5 increases but the electrical conductivity and the optical bandgap decrease. These results are explained by the role of defects (oxygen vacancies) through the photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements. The IR sensitivity of the mixed phase is explained by the plasmonic absorption by the V7O16 degenerate semiconductor.
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Affiliation(s)
- Anchal Rana
- Centre for Advanced Materials and Devices, School of Engineering and Technology, BML Munjal University Sidhrawali Gurugram-122413 Haryana India
| | - Aditya Yadav
- CSIR-National Physical Laboratory K. S. Krishnan Marg New Delhi 110012 India
| | - Govind Gupta
- CSIR-National Physical Laboratory K. S. Krishnan Marg New Delhi 110012 India
| | - Abhimanyu Rana
- Centre for Advanced Materials and Devices, School of Engineering and Technology, BML Munjal University Sidhrawali Gurugram-122413 Haryana India
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2
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Karna NK, Wohlert J, Hjorth A, Theliander H. Capillary forces exerted by a water bridge on cellulose nanocrystals: the effect of an external electric field. Phys Chem Chem Phys 2023; 25:6326-6332. [PMID: 36779301 DOI: 10.1039/d2cp05563e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Capillary forces play an important role during the dewatering and drying of nanocellulosic materials. Traditional moisture removal techniques, such as heating, have been proved to be deterimental to the properties of these materials and hence, there is a need to develop novel dewatering techniques without affecting the desired properties of materials. It is, therefore, important to explore novel methods for dewatering these high-added-value materials without negatively influencing their properties. In this context, we explore the effect of electric field on the capillary forces developed by a liquid-water bridge between two cellulosic surfaces, which may be formed during the water removal process following its displacement from the interfibrillar spaces. All-atom molecular dynamics (MD) simulations have been used to study the influence of an externally applied electric field on the capillary force exerted by a water bridge. Our results suggest that the equilibrium contact angle of water and the capillary force exerted by the water bridge between two nanocellulosic surfaces depend on the magnitude and direction of the externally applied electric fields. Hence, an external electric field can be applied to manipulate the capillary forces between two particles. The close agreement between the capillary forces measured through MD simulations and those calculated through classical equations indicates that, within the range of the electric field applied in this study, Young-Laplace equations can be safely employed to predict the capillary forces between two particles. The present study provides insights into the use of electric fields for drying of nanocellulosic materials.
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Affiliation(s)
- Nabin Kumar Karna
- Chalmers University of Technology, Chalmersplatsen-4, Sweden. .,Wallenberg Wood Science Center, The Royal Institute of Technology, Chalmers University of Technology and Linköping University, SE-10044 Stockholm, Sweden
| | - Jakob Wohlert
- Wallenberg Wood Science Center, The Royal Institute of Technology, Chalmers University of Technology and Linköping University, SE-10044 Stockholm, Sweden.,KTH Royal Institute of Technology, Stockholm, Sweden
| | - Anna Hjorth
- Chalmers University of Technology, Chalmersplatsen-4, Sweden. .,Wallenberg Wood Science Center, The Royal Institute of Technology, Chalmers University of Technology and Linköping University, SE-10044 Stockholm, Sweden
| | - Hans Theliander
- Chalmers University of Technology, Chalmersplatsen-4, Sweden.
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3
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Haq EU, Zhang Y, O'Dowd N, Liu N, Leesment S, Becker C, Rossi EM, Sebastiani M, Tofail SAM, Silien C. Quantitative surface free energy with micro-colloid probe pairs. RSC Adv 2023; 13:2718-2726. [PMID: 36741155 PMCID: PMC9847652 DOI: 10.1039/d2ra05508b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 12/15/2022] [Indexed: 01/20/2023] Open
Abstract
Measurement of the surface free energy (SFE) of a material allows the prediction of its adhesion properties. Materials can have microscale or sub-microscale surface inhomogeneities, engineered or random, which affect the surface macroscopic behaviour. However, quantitative characterization of the SFE at such length scales remains challenging in view of the variety of instruments and techniques available, the poor knowledge of critical variables and parameters during measurements and the need for appropriate contact models to derive the SFE from the measurements. Failure to characterize adhesion correctly may result in defective components or lengthy process optimization costing billions to industry. Conversely, for planar and homogeneous surfaces, contact angle (CA) measurements are standardized and allow for calculating the SFE using for example the Owen-Wendt model, relying only on the properties of the probing liquids. As such, we assessed and report here a method to correlate quantitative measurements of force-distance curves made with an atomic force microscope (AFM) and with silica and polystyrene (PS) colloidal probe pairs, with quantitative CA measurements and CA-derived SFE values. We measured five surfaces (mica, highly oriented pyrolytic graphite, thermally grown silica on silicon, silicon, and silicon with a super-hydrophobic coating), ranging from hydrophilic to super-hydrophobic, and found an excellent classification of the AFM measurements when these are represented by a set of principal components (PCs), and when both silica and PS colloidal probes are considered together. A regression of the PCs onto the CA measurements allows recovery of the SFE at the length scale of the colloidal probes, which is here ca. 1 micron. We found that once the PC-regression model is built, test sets of only ten AFM force-distance curves are sufficient to predict the local SFE with the calibrated silica and PS colloidal probes.
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Affiliation(s)
- Ehtsham-Ul Haq
- Department of Physics and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Yongliang Zhang
- Department of Physics and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Noel O'Dowd
- School of Engineering and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Ning Liu
- Department of Physics and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Stanislav Leesment
- Spectrum Instruments Ltd. Stewart House, National Technological Park Limerick Ireland
| | - Claude Becker
- Funcoats SA Technoport 4B, Rue du Commerce Foetz Luxembourg
| | - Edoardo M Rossi
- Engineering Department, Roma Tre University Via della Vasca Navale 79 Rome 00146 Italy
| | - Marco Sebastiani
- Engineering Department, Roma Tre University Via della Vasca Navale 79 Rome 00146 Italy
| | - Syed A M Tofail
- Department of Physics and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
| | - Christophe Silien
- Department of Physics and Bernal Institute, University of Limerick Limerick V94 T9PX Ireland
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4
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Shyam S, Misra S, Mitra SK. A UNIVERSAL CAPILLARY-DEFLECTION BASED ADHESION MEASUREMENT TECHNIQUE. J Colloid Interface Sci 2022; 630:322-333. [DOI: 10.1016/j.jcis.2022.09.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/22/2022] [Accepted: 09/26/2022] [Indexed: 10/06/2022]
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5
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Graphene overcoats for ultra-high storage density magnetic media. Nat Commun 2021; 12:2854. [PMID: 34001870 PMCID: PMC8129078 DOI: 10.1038/s41467-021-22687-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 03/17/2021] [Indexed: 02/03/2023] Open
Abstract
Hard disk drives (HDDs) are used as secondary storage in digital electronic devices owing to low cost and large data storage capacity. Due to the exponentially increasing amount of data, there is a need to increase areal storage densities beyond ~1 Tb/in2. This requires the thickness of carbon overcoats (COCs) to be <2 nm. However, friction, wear, corrosion, and thermal stability are critical concerns below 2 nm, limiting current technology, and restricting COC integration with heat assisted magnetic recording technology (HAMR). Here we show that graphene-based overcoats can overcome all these limitations, and achieve two-fold reduction in friction and provide better corrosion and wear resistance than state-of-the-art COCs, while withstanding HAMR conditions. Thus, we expect that graphene overcoats may enable the development of 4-10 Tb/in2 areal density HDDs when employing suitable recording technologies, such as HAMR and HAMR+bit patterned media.
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6
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Suzuki I, Kubo S, Sepehri-Amin H, Takahashi YK. Dependence of the Growth Mode in Epitaxial FePt Films on Surface Free Energy. ACS APPLIED MATERIALS & INTERFACES 2021; 13:16620-16627. [PMID: 33787207 DOI: 10.1021/acsami.0c22510] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Epitaxial thin films of L10-ordered FePt alloys are one of the most important materials in magnetic recording and spintronics applications due to their large perpendicular magnetic anisotropy (PMA). The key to the production of these required superior properties lies in the control of the growth mode of the films. Further, it is necessary to distinguish between the effect of lattice mismatch and surface free energy on the growth mode because of their strong correlation. In this study, the effect of surface free energy on the growth mode of FePt epitaxial films was investigated using MgO, NiO, and MgON surfaces with almost the same lattice constant to exclude the effect of lattice mismatch. It was found that the growth mode can be tuned from a three-dimensional (3D) island mode on MgO to a more two-dimensional (2D)-like mode on MgON and NiO. Contact angle measurements revealed that MgON and NiO show larger surface free energy than MgO, indicating that the difference in the growth mode is due to their larger surface free energy. In addition, MgON was found to induce not only a flat surface as FePt grown on SrTiO3 (STO), which has a small lattice mismatch, but also a larger PMA than that of STO/FePt. As larger lattice mismatch is favored to induce a higher PMA into the FePt films, MgO substrates are exclusively used, but 3D island growth is indispensable. This work demonstrates that tuning the surface free energy enables us to achieve a large PMA and flat film surface in FePt epitaxial films on MgO. The results also indicate that modifying the surface free energy is pertinent for the flexible functional design of thin films.
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Affiliation(s)
- Ippei Suzuki
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan
| | - Shoichi Kubo
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Meguro, Tokyo 152-8552, Japan
| | - Hosein Sepehri-Amin
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan
| | - Yukiko K Takahashi
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan
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7
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Al-Gharabli S, Al-Omari B, Kujawski W, Kujawa J. How Can the Desert Beetle and Biowaste Inspire Hybrid Separation Materials for Water Desalination? ACS APPLIED MATERIALS & INTERFACES 2021; 13:11268-11283. [PMID: 33645982 PMCID: PMC8031369 DOI: 10.1021/acsami.0c21649] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Highly effective, hybrid separation materials for water purification were generated following a bioinspired system available in nature. The desert beetle was the inspiration for the generation of separation materials. Using the hydrophobic poly(vinylidene fluoride) (PVDF) membrane as the basis, the membrane was first activated and then furnished with silane-based linkers, and the covalent anchoring of chitosan was successfully accomplished. The obtained surface architecture was a copy of the desert beetle's armor possessing a hydrophobic matrix with hydrophilic domains. The modification was done in the presence or the lack of catalyst (N,N-diisopropylethylamine) that made it possible to tune easily wettability, roughness, and material as well as adhesive features. The membrane morphology and surface chemistry were studied by applying a series of analytical techniques. As a result of chitosan attachment, substantial improvement in transport and separation was reported. Pristine PVDF was characterized by a water flux of 5.28 kg m-2 h-1 and an activation energy of 48.16 kJ mol-1. The water flux and activation energy for a hybrid membrane with chitosan were equal to 15.55 kg m-2 h-1 and 33.98 kJ mol-1, respectively. The hybrid materials possessed enhanced stability and water resistance that were maintained after 10 cycles of membrane distillation tests.
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Affiliation(s)
- Samer Al-Gharabli
- Pharmaceutical
and Chemical Engineering Department, German
Jordanian University, Amman 11180, Jordan
| | - Bana Al-Omari
- Pharmaceutical
and Chemical Engineering Department, German
Jordanian University, Amman 11180, Jordan
| | - Wojciech Kujawski
- Faculty
of Chemistry, Nicolaus Copernicus University
in Toruń, 7 Gagarina
Street, Toruń 87-100, Poland
| | - Joanna Kujawa
- Faculty
of Chemistry, Nicolaus Copernicus University
in Toruń, 7 Gagarina
Street, Toruń 87-100, Poland
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8
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Zirconium dioxide membranes decorated by silanes based-modifiers for membrane distillation – Material chemistry approach. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2019.117597] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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Daniel D, Lay CL, Sng A, Jun Lee CJ, Jin Neo DC, Ling XY, Tomczak N. Mapping micrometer-scale wetting properties of superhydrophobic surfaces. Proc Natl Acad Sci U S A 2019; 116:25008-25012. [PMID: 31772014 PMCID: PMC6911201 DOI: 10.1073/pnas.1916772116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
There is a huge interest in developing superrepellent surfaces for antifouling and heat-transfer applications. To characterize the wetting properties of such surfaces, the most common approach is to place a millimetric-sized droplet and measure its contact angles. The adhesion and friction forces can then be inferred indirectly using Furmidge's relation. While easy to implement, contact angle measurements are semiquantitative and cannot resolve wetting variations on a surface. Here, we attach a micrometric-sized droplet to an atomic force microscope cantilever to directly measure adhesion and friction forces with nanonewton force resolutions. We spatially map the micrometer-scale wetting properties of superhydrophobic surfaces and observe the time-resolved pinning-depinning dynamics as the droplet detaches from or moves across the surface.
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Affiliation(s)
- Dan Daniel
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, Singapore 138634;
| | - Chee Leng Lay
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, Singapore 138634
| | - Anqi Sng
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, Singapore 138634
| | - Coryl Jing Jun Lee
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, Singapore 138634
| | - Darren Chi Jin Neo
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, Singapore 138634
| | - Xing Yi Ling
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Nikodem Tomczak
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Innovis, Singapore 138634
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10
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Adsorption performance of 5A molecular sieve zeolite in water vapor–binary gas environment: Experimental and modeling evaluation. J IND ENG CHEM 2018. [DOI: 10.1016/j.jiec.2018.03.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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11
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Kakekhani A, Roling LT, Kulkarni A, Latimer AA, Abroshan H, Schumann J, AlJama H, Siahrostami S, Ismail-Beigi S, Abild-Pedersen F, Nørskov JK. Nature of Lone-Pair–Surface Bonds and Their Scaling Relations. Inorg Chem 2018; 57:7222-7238. [DOI: 10.1021/acs.inorgchem.8b00902] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Arvin Kakekhani
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Luke T. Roling
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Ambarish Kulkarni
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Allegra A. Latimer
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Hadi Abroshan
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Julia Schumann
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Hassan AlJama
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Samira Siahrostami
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Sohrab Ismail-Beigi
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, United States
| | - Frank Abild-Pedersen
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jens K. Nørskov
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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12
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Liu J, Lai CY, Zhang YY, Chiesa M, Pantelides ST. Water wettability of graphene: interplay between the interfacial water structure and the electronic structure. RSC Adv 2018; 8:16918-16926. [PMID: 35540542 PMCID: PMC9080294 DOI: 10.1039/c8ra03509a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 04/28/2018] [Indexed: 12/14/2022] Open
Abstract
Wetting phenomena are ubiquitous and impact a wide range of applications. Simulations so far have largely relied on classical potentials. Here, we report the development of an approach that combines density-functional theory (DFT)-based calculations with classical wetting theory that allows practical but sufficiently accurate determination of the water contact angle (WCA). As a benchmark, we apply the approach to the graphene and graphite surfaces that recently received considerable attention. The results agree with and elucidate the experimental data. For metal-supported graphene where electronic interactions play a major role, we demonstrate that doping of graphene by the metal substrate significantly alters the wettability. In addition to theory, we report new experimental measurements of the WCA and the force of adhesion that corroborate the theoretical results. We demonstrate a correlation between the force of adhesion and WCA, and the use of the atomic force microscope (AFM) technique as an alternative measure for wettability at the nanoscale. The present work not only provides a detailed understanding of the wettability of graphene, including the role of electrons, but also sets the stage for studying the wettability alteration mechanism when sufficiently accurate force fields may not be available.
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Affiliation(s)
- Jian Liu
- Department of Physics and Astronomy, Vanderbilt University Tennessee 37235 USA
| | - Chia-Yun Lai
- Laboratory for Energy and Nano-Sciences, Khalifa University of Science and Technology Abu Dhabi United Arab Emirates
| | - Yu-Yang Zhang
- Department of Physics and Astronomy, Vanderbilt University Tennessee 37235 USA
| | - Matteo Chiesa
- Laboratory for Energy and Nano-Sciences, Khalifa University of Science and Technology Abu Dhabi United Arab Emirates
| | - Sokrates T Pantelides
- Department of Physics and Astronomy, Vanderbilt University Tennessee 37235 USA
- Department of Electrical Engineering and Computer Science, Vanderbilt University Tennessee 37235 USA
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Prakash S, Ghosh S, Patra A, Annamalai M, Motapothula MR, Sarkar S, Tan SJR, Zhunan J, Loh KP, Venkatesan T. Intrinsic hydrophilic nature of epitaxial thin-film of rare-earth oxide grown by pulsed laser deposition. NANOSCALE 2018; 10:3356-3361. [PMID: 29388649 DOI: 10.1039/c7nr06642b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Herein, we report a systematic study of water contact angle (WCA) of rare-earth oxide thin-films. These ultra-smooth and epitaxial thin-films were grown using pulsed laser deposition and then characterized using X-Ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), and atomic force microscopy (AFM). Through both the traditional sessile drop and the novel f-d method, we found that the films were intrinsically hydrophilic (WCA < 10°) just after being removed from the growth chamber, but their WCAs evolved with an exposure to the atmosphere with time to reach their eventual saturation values near 90° (but always stay 'technically' hydrophilic). X-Ray photoelectron spectroscopy analysis was used to further investigate qualitatively the nature of hydrocarbon contamination on the freshly prepared as well as the environmentally exposed REO thin-film samples as a function of the exposure time after they were removed from the deposition chamber. A clear correlation between the carbon coverage of the surface and the increase in WCA was observed for all of the rare-earth films, indicating the extrinsic nature of the surface wetting properties of these films and having no relation to the electronic configuration of the rare-earth atoms as proposed by Azimi et al.
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Affiliation(s)
- Saurav Prakash
- NUSNNI-NanoCore, National University of Singapore, 117411, Singapore.
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