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Zhou S, Hu Y, Huang Y, Xu H, Wu D, Wu D, Gao X. Preparation of Polytetrafluoroethylene Superhydrophobic Materials by Femtosecond Laser Processing Technology. Polymers (Basel) 2023; 16:43. [PMID: 38201708 PMCID: PMC10780796 DOI: 10.3390/polym16010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 12/08/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
In recent years, superhydrophobic surfaces have attracted significant attention due to their promising applications, especially in ice prevention, reduction in air resistance, and self-cleaning. This study utilizes femtosecond laser processing technology to prepare different surface microstructures on polytetrafluoroethylene (PTFE) surfaces. Through experiments, it investigates the relationship between the solid-liquid contact ratio and surface hydrophobicity. The shape of water droplets on different microstructure surfaces is simulated using ANSYS, and the relationship between surface microstructures and hydrophobicity is explored in the theoretical model. A superhydrophobic surface with a contact angle of up to 166° was obtained by machining grooves with different spacings in polytetrafluoroethylene sheets with femtosecond laser technology. Due to the micro- and nanostructures on the surface, the oleophobicity of the processed oleophilic PTFE surface is enhanced.
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Affiliation(s)
- Shuangquan Zhou
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (S.Z.); (Y.H.); (Y.H.); (H.X.); (D.W.)
| | - Yayue Hu
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (S.Z.); (Y.H.); (Y.H.); (H.X.); (D.W.)
| | - Yao Huang
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (S.Z.); (Y.H.); (Y.H.); (H.X.); (D.W.)
| | - Hong Xu
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (S.Z.); (Y.H.); (Y.H.); (H.X.); (D.W.)
| | - Daming Wu
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (S.Z.); (Y.H.); (Y.H.); (H.X.); (D.W.)
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Dong Wu
- College of Engineering Science, University of Science and Technology of China, Hefei 230027, China
| | - Xiaolong Gao
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (S.Z.); (Y.H.); (Y.H.); (H.X.); (D.W.)
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Liu H, Zhang Z, Wu C, Su K, Kan X. Biomimetic Superhydrophobic Materials through 3D Printing: Progress and Challenges. MICROMACHINES 2023; 14:1216. [PMID: 37374801 DOI: 10.3390/mi14061216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/02/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023]
Abstract
Superhydrophobicity, a unique natural phenomenon observed in organisms such as lotus leaves and desert beetles, has inspired extensive research on biomimetic materials. Two main superhydrophobic effects have been identified: the "lotus leaf effect" and the "rose petal effect", both showing water contact angles larger than 150°, but with differing contact angle hysteresis values. In recent years, numerous strategies have been developed to fabricate superhydrophobic materials, among which 3D printing has garnered significant attention due to its rapid, low-cost, and precise construction of complex materials in a facile way. In this minireview, we provide a comprehensive overview of biomimetic superhydrophobic materials fabricated through 3D printing, focusing on wetting regimes, fabrication techniques, including printing of diverse micro/nanostructures, post-modification, and bulk material printing, and applications ranging from liquid manipulation and oil/water separation to drag reduction. Additionally, we discuss the challenges and future research directions in this burgeoning field.
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Affiliation(s)
- Haishuo Liu
- School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China
| | - Zipeng Zhang
- College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Chenyu Wu
- Qingdao Institute for Theoretical and Computational Sciences, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao 266237, China
| | - Kang Su
- School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China
| | - Xiaonan Kan
- College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
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Xu YS, Li ZZ, Fan H, Liu YF, Xia H, Juodkazis S, Chen QD, Wang L. Optical near fields for ablation of periodic structures. OPTICS LETTERS 2023; 48:2841-2844. [PMID: 37262224 DOI: 10.1364/ol.487323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/23/2023] [Indexed: 06/03/2023]
Abstract
The formation mechanism of laser-induced periodic surface structures (LIPSS) has been a key to high-resolution sub-diffraction lithography or high-efficiency large-area nanotexturing. We show the evolution of LIPSS formation from a nanohole seed structure to high-spatial-frequency LIPSS by using a tightly focused and rectangular-shaped laser beam with different shape-polarization orientations. Formation of LIPSS based on light intensity distribution without invoking any long-range electromagnetic modes achieved quantitative match between modeling and experiment. Our results clearly show the entire step-like and deterministic process of LIPSS evolution based on experimental data and numerical simulations, revealing the dominant structural near-field enhancement on the ripple formation. A rectangular-shaped beam with an aspect ratio of 7:3 was used to break the symmetry of a circularly shaped focus. By azimuthally rotating the orientation of the focal spot and the polarization, it is possible to visualize the far-field effect for the initial seed structure formation and the competition between the far and near fields in the subsequent structure evolution.
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Xu YS, Li ZZ, Wang ZH, Xia H, Liu YF, Juodkazis S, Chen QD, Wang L. Nanoscale control of non-reciprocal ripple writing. OPTICS EXPRESS 2023; 31:14796-14807. [PMID: 37157336 DOI: 10.1364/oe.487107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Femtosecond laser-induced deep-subwavelength structures have attracted much attention as a nanoscale surface texturization technique. A better understanding of the formation conditions and period control is required. Herein, we report a method of non-reciprocal writing via a tailored optical far-field exposure, where the period of ripples varies along different scanning directions, and achieve a continuous manipulation of the period from 47 to 112 nm (±4 nm) for a 100-nm-thick indium tin oxide (ITO) on glass. A full electromagnetic model was developed to demonstrate the redistributed localized near-field at different stages of ablation with nanoscale precision. It explains the formation of ripples and the asymmetry of the focal spot determines the non-reciprocity of ripple writing. Combined with beam shaping techniques, we achieved non-reciprocal writing (regarding scanning direction) using an aperture-shaped beam. The non-reciprocal writing is expected to open new paths for precise and controllable nanoscale surface texturing.
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Maggiore E, Corsaro C, Fazio E, Mirza I, Ripamonti F, Tommasini M, Ossi PM. Laser-Treated Steel Surfaces Gliding on Snow at Different Temperatures. MATERIALS (BASEL, SWITZERLAND) 2023; 16:3100. [PMID: 37109937 PMCID: PMC10146630 DOI: 10.3390/ma16083100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 06/19/2023]
Abstract
With the goal of substituting a hard metallic material for the soft Ultra High Molecular Weight Polyethylene (UHMWPE) presently used to make the bases of skis for alpine skiing, we used two non-thermodynamic equilibrium surface treatments with ultra-short (7-8 ps) laser pulses to modify the surface of square plates (50 × 50 mm2) made of austenitic stainless steel AISI 301H. By irradiating with linearly polarized pulses, we obtained Laser Induced Periodic Surface Structures (LIPSS). By laser machining, we produced a laser engraving on the surface. Both treatments produce a surface pattern parallel to one side of the sample. For both treatments, we measured with a dedicated snow tribometer the friction coefficient µ on compacted snow at different temperatures (-10 °C; -5 °C; -3 °C) for a gliding speed range between 1 and 6.1 ms-1. We compared the obtained µ values with those of untreated AISI 301H plates and of stone grinded, waxed UHMWPE plates. At the highest temperature (-3 °C), near the snow melting point, untreated AISI 301H shows the largest µ value (0.09), much higher than that of UHMWPE (0.04). Laser treatments on AISI 301H gave lower µ values approaching UHMWPE. We studied how the surface pattern disposition, with respect to the gliding direction of the sample on snow, affects the µ trend. For LIPSS with pattern, orientation perpendicular to the gliding direction on snow µ (0.05) is comparable with that of UHMWPE. We performed field tests on snow at high temperature (from -0.5 to 0 °C) using full-size skis equipped with bases made of the same materials used for the laboratory tests. We observed a moderate difference in performance between the untreated and the LIPSS treated bases; both performed worse than UHMWPE. Waxing improved the performance of all bases, especially LIPSS treated.
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Affiliation(s)
- Ettore Maggiore
- Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Politecnico di Milano, 20133 Milano, Italy; (E.M.); (M.T.)
| | - Carmelo Corsaro
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università degli Studi di Messina, 98166 Messina, Italy; (C.C.); (E.F.)
| | - Enza Fazio
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università degli Studi di Messina, 98166 Messina, Italy; (C.C.); (E.F.)
| | - Inam Mirza
- HiLASE Center, Institute of Physics of the Czech Academy of Sciences (CAS), 252 41 Dolní Břežany, Czech Republic;
| | | | - Matteo Tommasini
- Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Politecnico di Milano, 20133 Milano, Italy; (E.M.); (M.T.)
| | - Paolo M. Ossi
- Dipartimento di Energia, Politecnico di Milano, 20133 Milano, Italy
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Physicochemical Modifications on Thin Films of Poly(Ethylene Terephthalate) and Its Nanocomposite with Expanded Graphite Nanostructured by Ultraviolet and Infrared Femtosecond Laser Irradiation. Polymers (Basel) 2022; 14:polym14235243. [PMID: 36501637 PMCID: PMC9737047 DOI: 10.3390/polym14235243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
In this work, the formation of laser-induced periodic surface structures (LIPSS) on the surfaces of thin films of poly(ethylene terephthalate) (PET) and PET reinforced with expanded graphite (EG) was studied. Laser irradiation was carried out by ultraviolet (265 nm) and near-infrared (795 nm) femtosecond laser pulses, and LIPSS were formed in both materials. In all cases, LIPSS had a period close to the irradiation wavelength and were formed parallel to the polarization of the laser beam, although, in the case of UV irradiation, differences in the formation range were observed due to the different thermal properties of the neat polymer in comparison to the composite. To monitor the modification of the physicochemical properties of the surfaces after irradiation as a function of the laser wavelength and of the presence of the filler, different techniques were used. Contact angle measurements were carried out using different reference liquids to measure the wettability and the solid surface free energies. The initially hydrophilic surfaces became more hydrophilic after ultraviolet irradiation, while they evolved to become hydrophobic under near-infrared laser irradiation. The values of the surface free energy components showed changes after nanostructuring, mainly in the polar component. Additionally, for UV-irradiated surfaces, adhesion, determined by the colloidal probe technique, increased, while, for NIR irradiation, adhesion decreased. Finally, nanomechanical properties were measured by the PeakForce Quantitative Nanomechanical Mapping method, obtaining maps of elastic modulus, adhesion, and deformation. The results showed an increase in the elastic modulus in the PET/EG, confirming the reinforcing action of the EG in the polymer matrix. Additionally, an increase in the elastic modulus was observed after LIPSS formation.
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Advances in the Fabrication and Characterization of Superhydrophobic Surfaces Inspired by the Lotus Leaf. Biomimetics (Basel) 2022; 7:biomimetics7040196. [PMID: 36412724 PMCID: PMC9680393 DOI: 10.3390/biomimetics7040196] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/12/2022] Open
Abstract
Nature has proven to be a valuable resource in inspiring the development of novel technologies. The field of biomimetics emerged centuries ago as scientists sought to understand the fundamental science behind the extraordinary properties of organisms in nature and applied the new science to mimic a desired property using various materials. Through evolution, living organisms have developed specialized surface coatings and chemistries with extraordinary properties such as the superhydrophobicity, which has been exploited to maintain structural integrity and for survival in harsh environments. The Lotus leaf is one of many examples which has inspired the fabrication of superhydrophobic surfaces. In this review, the fundamental science, supported by rigorous derivations from a thermodynamic perspective, is presented to explain the origin of superhydrophobicity. Based on theory, the interplay between surface morphology and chemistry is shown to influence surface wetting properties of materials. Various fabrication techniques to create superhydrophobic surfaces are also presented along with the corresponding advantages and/or disadvantages. Recent advances in the characterization techniques used to quantify the superhydrophobicity of surfaces is presented with respect to accuracy and sensitivity of the measurements. Challenges associated with the fabrication and characterization of superhydrophobic surfaces are also discussed.
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Laser-enhanced electrodeposition preparation technology of superhydrophobic micro-nano structure coating. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.130507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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He JG, Zhao GL, Dai SJ, Li M, Zou GS, Wang JJ, Liu Y, Yu JQ, Xu LF, Li JQ, Fan LW, Huang M. Fabrication of Metallic Superhydrophobic Surfaces with Tunable Condensate Self-Removal Capability and Excellent Anti-Frosting Performance. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3655. [PMID: 36296847 PMCID: PMC9611512 DOI: 10.3390/nano12203655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/08/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
Laser fabrication of metallic superhydrophobic surfaces (SHSs) for anti-frosting has recently attracted considerable attention. Effective anti-frosting SHSs require the efficient removal of condensed microdroplets through self-propelled droplet jumping, which is strongly influenced by the surface morphology. However, detailed analyses of the condensate self-removal capability of laser-structured surfaces are limited, and guidelines for laser processing parameter control for fabricating rationally structured SHSs for anti-frosting have not yet been established. Herein, a series of nanostructured copper-zinc alloy SHSs are facilely constructed through ultrafast laser processing. The surface morphology can be properly tuned by adjusting the laser processing parameters. The relationship between the surface morphologies and condensate self-removal capability is investigated, and a guideline for laser processing parameterization for fabricating optimal anti-frosting SHSs is established. After 120 min of the frosting test, the optimized surface exhibits less than 70% frost coverage because the remarkably enhanced condensate self-removal capability reduces the water accumulation amount and frost propagation speed (<1 μm/s). Additionally, the material adaptability of the proposed technique is validated by extending this methodology to other metals and metal alloys. This study provides valuable and instructive insights into the design and optimization of metallic anti-frosting SHSs by ultrafast laser processing.
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Affiliation(s)
- Jian-Guo He
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- School of Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Computational Optical Imaging Technology, Chinese Academy of Sciences, Beijing 100094, China
| | - Guan-Lei Zhao
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
- State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Shou-Jun Dai
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- Key Laboratory of Computational Optical Imaging Technology, Chinese Academy of Sciences, Beijing 100094, China
| | - Ming Li
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics of CAS, Xi’an 710119, China
| | - Gui-Sheng Zou
- State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Jian-Jun Wang
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yang Liu
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- Key Laboratory of Computational Optical Imaging Technology, Chinese Academy of Sciences, Beijing 100094, China
| | - Jia-Qi Yu
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- Key Laboratory of Computational Optical Imaging Technology, Chinese Academy of Sciences, Beijing 100094, China
| | - Liang-Fei Xu
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Jian-Qiu Li
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Lian-Wen Fan
- Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China
| | - Min Huang
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China
- Key Laboratory of Computational Optical Imaging Technology, Chinese Academy of Sciences, Beijing 100094, China
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Xu Y, Shen Y, Tao J, Jiang J, Liu W, Chen H, Liu S, Li H, Jiang B, Xie X. Role of Molecular Chains Arrangement and Surface Energy State in the Low Ice Adhesion on Poly(tetrafluoroethylene). J Phys Chem Lett 2022; 13:6117-6122. [PMID: 35759359 DOI: 10.1021/acs.jpclett.2c01331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The relation between polymer molecular chains arrangement and ice adhesion was studied at the molecular scale, and the energy states of water molecules on the poly(tetrafluoroethylene) surface were analyzed to explain the energy essence of ice adhesion. The ice adhesion on crystalline poly(tetrafluoroethylene) displayed a clear anisotropy phenomenon. Further research proved that the energy states of water molecules along the vertical direction of the molecular chains fluctuated regularly, and the water molecules in gaps between molecular chains were in the energy troughs, leading to the formation of energy traps. Water molecules needed more energy from outside to escape the energy traps, causing additional resistance to the ice movement and obvious increase of ice adhesion. Therefore, ice adhesion was closely related to the distribution of energy traps in the direction of ice removing, which mainly depended on the possibility of molecular chains perpendicularly arranged in the direction of ice removing.
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Affiliation(s)
- Yangjiangshan Xu
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Yizhou Shen
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Jie Tao
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Jiawei Jiang
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Weilan Liu
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
- Institute of Advanced Materials, Nanjing Tech University, 30 Puzhu South Road, Nanjing 210009, People's Republic of China
| | - Haifeng Chen
- Department of Materials Chemistry, Qiuzhen School, Huzhou University, 759# East Second Road, Huzhou 313000, People's Republic of China
| | - Senyun Liu
- Key Laboratory of Icing and Anti/De-icing, China Aerodynamics Research and Development Center, 6 Erhuan South Road, Mianyang 621000, People's Republic of China
| | - Huaguan Li
- Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing Institute of Technology, Nanjing 211167, People's Republic of China
| | - Biao Jiang
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
| | - Xinyu Xie
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People's Republic of China
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Femtosecond Laser-Ablated Copper Surface as a Substrate for a MoS 2-Based Hydrogen Evolution Reaction Electrocatalyst. MATERIALS 2022; 15:ma15113926. [PMID: 35683217 PMCID: PMC9182345 DOI: 10.3390/ma15113926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/19/2022] [Accepted: 05/30/2022] [Indexed: 12/02/2022]
Abstract
One of the methods to improve the performance of a heterogeneous electrocatalyst is the dispersion of a catalytic material on a suitable substrate. In this study, femtosecond laser ablation was used to prepare very rough but also ordered copper surfaces consisting of vertical, parallel ridges. Then, a molybdenum sulfide coating was electrochemically deposited onto these surfaces. It was observed by profilometry that the average roughness of the surface after coating with MoS2 had decreased, but the developed surface area still remained significantly larger than the projected surface area. The electrodes were then used as an electrocatalyst for the hydrogen evolution reaction in acidic media. These were highly efficient, reaching 10 mA cm−2 of HER current at a −181 mV overpotential and a Tafel slope of ~39 mV dec−1. Additionally, scanning electrochemical microscopy was used to observe whether hydrogen evolution would preferentially occur in certain spots, for example, on the peaks, but the obtained results suggest that the entire surface is active. Finally, the electrochemical impedance spectroscopy data showed the difference in the double-layer capacitance between the ablated and non-ablated surfaces (up to five times larger) as well as the parameters that describe the improved catalytic activity of fs-Cu/MoS2 electrodes.
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Comparison of Metrics for Shape Quality Evaluation of Textures Produced by Laser Structuring by Remelting (Waveshape). MICROMACHINES 2022; 13:mi13040618. [PMID: 35457922 PMCID: PMC9030285 DOI: 10.3390/mi13040618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 12/10/2022]
Abstract
The study is focused on investigating approaches for assessing the texture shape deviation obtained by laser structuring by remelting (Waveshape). A number of metrics such as Fourier spectrum harmonic ratio, cross-correlation coefficient (reverse value), and spectral entropy are investigated in terms of surface-texture shape deviation estimation. The metrics are compared with each other by testing two hypotheses: determination of target-like shape of texture (closest to harmonic shape) and determination of texture presence on the cross-section. Spectral entropy has the best statistical indicators for both hypotheses (Matthews correlation coefficient is equal to 0.70 and 0.77, respectively). The reverse cross-correlation coefficient proved to be close in terms of statistical indicators (Matthews correlation coefficient is equal to 0.58 and 0.75 for the first and second hypothesis), but is able to estimate the shape similarity of regular texture independent on its type. The provided metrics of shape assessment are not limited to the texturing process, so the presented results can be used in a broad range of scientific fields.
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Li C, Jiang L, Hu J, Xu C, Li Z, Liu W, Zhao X, Zhao B. Superhydrophilic-Superhydrophobic Multifunctional Janus Foam Fabrication Using a Spatially Shaped Femtosecond Laser for Fog Collection and Detection. ACS APPLIED MATERIALS & INTERFACES 2022; 14:9873-9881. [PMID: 35142217 DOI: 10.1021/acsami.1c24284] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Fog collection is an effective method for addressing water shortages in arid areas. By constructing a Janus structure with asymmetric wettability on its two sides, flexible and efficient fog capture can be achieved. However, in situ detection and fog collection on a Janus surface are still challenging tasks. Herein, a novel method for producing a superhydrophilic-superhydrophobic Janus fog collector is proposed; the method utilizes a combined process in which a spatially shaped femtosecond laser treatment (superhydrophilic) is applied to one side of a copper foam and a chemical replacement reaction (superhydrophobic) is applied to the other side of the copper foam. Two configurations of the Janus structure were designed to study different water transport behaviors. Furthermore, the Au micro-nanoparticle prepared adhered to the Janus structure, indicating the effectiveness of surface-enhanced Raman spectroscopy detection. The Janus foam shows excellent sensitivity and stability on testing the fog mixed with rhodamine 6G. This surface allows for the simultaneous collection and detection of fog, which can provide insights into the preparation of Janus multifunction structures and how such structures can play a key role in the subsequent purification and usage of water resources.
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Affiliation(s)
- Chen Li
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Lan Jiang
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
- Beijing Institute of Technology Chongqing Innovation Center, Chongqing 401120, P. R. China
| | - Jie Hu
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Chenyang Xu
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Zihao Li
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Wei Liu
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Xiaoming Zhao
- Tianjin Navigation Instruments Research Institute, Tianjin 300131, P. R. China
| | - Bingquan Zhao
- Tianjin Navigation Instruments Research Institute, Tianjin 300131, P. R. China
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Zhang Z, Xu C, Liu W, Wang K, Rao Y, Jiang C, Li D, Zhang Y, Jiang X, Chen X, Xu C. Ultrasonic assisted rapid preparation of superhydrophobic stainless steel surface and its application in oil/water separation. ULTRASONICS SONOCHEMISTRY 2021; 81:105848. [PMID: 34847449 PMCID: PMC8637139 DOI: 10.1016/j.ultsonch.2021.105848] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/17/2021] [Accepted: 11/24/2021] [Indexed: 06/13/2023]
Abstract
The preparation of superhydrophobic (SH) surface on stainless steel by chemical etching method is challenging due to the good corrosion resistance of the material. In this work, SH surface with water contact angle (WCA) as high as 163.21° was accomplished on 304 stainless steel surface by a rapid ultrasonic-assisted chemical etching method within 7 min and a low-cost fluorine-free modification treatment. The mechanism of ultrasonic field on the etching process was explored by detecting the cavitation and oscillation energy in the reactor. It is the first time to found that the ultrasonic cavitation effect enhanced the etching process by both chemical and physical facilitation resulting in hierarchical lamellar micro-structures, "mountain-like" micro-structure clusters and "coral-reef-like" nano-scale structures on the surface. With the ultrasonic power increasing, the ultrasonic cavitation effect not only enhanced the superhydrophobicity of sample surface, but also improved the uniformity of surface wettability. The samples also showed excellent performance of oil/water separation for various organics (all separation efficiencies up to 96%) and remarkable mechanical stability.
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Affiliation(s)
- Zongbo Zhang
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China.
| | - Chunling Xu
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Wengang Liu
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Kai Wang
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Yunlong Rao
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Chen Jiang
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Dawei Li
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Yu Zhang
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Xin Jiang
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Xintong Chen
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Changbin Xu
- College of Mechanical and Electrical Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
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15
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Laser ablation of silicon with THz bursts of femtosecond pulses. Sci Rep 2021; 11:13321. [PMID: 34172786 PMCID: PMC8233330 DOI: 10.1038/s41598-021-92645-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/02/2021] [Indexed: 02/06/2023] Open
Abstract
In this work, we performed an experimental investigation supported by a theoretical analysis, to improve knowledge on the laser ablation of silicon with THz bursts of femtosecond laser pulses. Laser ablated craters have been created using 200 fs pulses at a wavelength of 1030 nm on silicon samples systematically varying the burst features and comparing to the normal pulse mode (NPM). Using bursts in general allowed reducing the thermal load to the material, however, at the expense of the ablation rate. The higher the number of pulses in the bursts and the lower the intra-burst frequency, the lower is the specific ablation rate. However, bursts at 2 THz led to a higher specific ablation rate compared to NPM, in a narrow window of parameters. Theoretical investigations based on the numerical solution of the density-dependent two temperature model revealed that lower lattice temperatures are reached with more pulses and lower intra-burst frequencies, thus supporting the experimental evidence of the lower thermal load in burst mode (BM). This is ascribed to the weaker transient drop of reflectivity, which suggests that with bursts less energy is transferred from the laser to the material. This also explains the trends of the specific ablation rates. Moreover, we found that two-photon absorption plays a fundamental role during BM processing in the THz frequency range.
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16
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A Review of Fabrication Methods, Properties and Applications of Superhydrophobic Metals. Processes (Basel) 2021. [DOI: 10.3390/pr9040666] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Hydrophobicity and superhydrophobicity with self-cleaning properties are well-known characteristics of several natural surfaces, such as the leaves of the sacred lotus plant (Nelumbo nucifera). To achieve a superhydrophobic state, micro- and nanometer scale topography should be realized on a low surface energy material, or a low surface energy coating should be deposited on top of the micro-nano topography if the material is inherently hydrophilic. Tailoring the surface chemistry and topography to control the wetting properties between extreme wetting states enables a palette of functionalities, such as self-cleaning, antifogging, anti-biofouling etc. A variety of surface topographies have been realized in polymers, ceramics, and metals. Metallic surfaces are particularly important in several engineering applications (e.g., naval, aircrafts, buildings, automobile) and their transformation to superhydrophobic can provide additional functionalities, such as corrosion protection, drag reduction, and anti-icing properties. This review paper focuses on the recent advances on superhydrophobic metals and alloys which can be applicable in real life applications and aims to provide an overview of the most promising methods to achieve sustainable superhydrophobicity.
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17
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Improving the Laser Texture Strategy to Get Superhydrophobic Aluminum Alloy Surfaces. COATINGS 2021. [DOI: 10.3390/coatings11030369] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Changing the wetting properties of surfaces is attracting great interest in many fields, in particular to achieve a surface with a superhydrophobic behavior. Laser machining is an emerging technique to functionalize materials with high precision and flexibility without any chemical treatment. However, when it is necessary to treat large area surfaces laser-based methods are still too slow to be exploited in industrial productions. In this work, we show that by improving the laser texture strategy it is possible to reduce the laser processing time to produce superhydrophobic aluminum alloy surfaces. Three different surface texture geometries were micromachined; namely, square, circular and triangular lattice grooves. We found that if the spacing between the grooves is narrow, i.e., when the percentage of the textured surface is high, the volume of air trapped inside the micromachined structures plays an important role in the wetting behavior. Meanwhile, when the groove spacing approaches the droplet dimensions, the texture geometry has a preponderant influence. Based on these findings an appropriate choice of the laser texture strategy allowed the fabrication of superhydrophobic aluminum alloy surfaces with a 10% reduction of processing time.
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