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Raut SA, Vinx N, Tromont D, Leclère P, Cossement D, Snyders R, Thiry D. Unlocking the Potential of Liquid Plasma Polymer Films: Characterizing Aging Effects and Their Impact on the Wrinkling Phenomenon. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:14633-14640. [PMID: 38970486 DOI: 10.1021/acs.langmuir.4c01552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
Here, we present the study of the intricate dynamics between the physicochemical properties of liquid propanethiol plasma polymer films (PPFs) and the formation of wrinkles in PPF/Al bilayers. The study investigates the effect of liquid PPF aging in the air before top Al layer deposition by magnetron sputtering on the wrinkling phenomenon for 4 days. Thanks to atomic force microscopy, the wrinkle dimensions were found to decrease by approximately 55% in amplitude and 66% in wavelength, correlated with an increase in the viscosity of the PPF over the aging duration (i.e., from less than 107 to 1010 Pa·s). This behavior is not linked to alterations in cross-linking degree as evidenced by time-of-flight secondary ion mass spectrometry experiments but rather to network densification driven by the inherent molecular chain mobility due to the viscous state of the PPF. X-ray photoelectron spectroscopy measurements emphasizing the absence of oxidation of the PPF over the aging duration support this, revealing a unique aging mechanism distinct from other plasma polymer families. Overall, this study offers valuable insights into the design and application of mechanically responsive PPFs involved in bilayer systems, paving the way for advancements in nanotechnology and related fields.
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Affiliation(s)
- Suyog A Raut
- Chimie des Interactions Plasma-Surface (ChIPS), Université de Mons, 20 Place du Parc, B-7000 Mons, Belgium
| | - Nathan Vinx
- Chimie des Interactions Plasma-Surface (ChIPS), Université de Mons, 20 Place du Parc, B-7000 Mons, Belgium
| | - David Tromont
- Chimie des Interactions Plasma-Surface (ChIPS), Université de Mons, 20 Place du Parc, B-7000 Mons, Belgium
| | - Philippe Leclère
- Laboratory for Physics of Nanomaterials and Energy (LPNE), Research Institute for Materials Science and Engineering, Université de Mons (UMONS), 7000 Mons, Belgium
| | - Damien Cossement
- Materia Nova Research Center, Parc Initialis, B-7000 Mons, Belgium
| | - Rony Snyders
- Chimie des Interactions Plasma-Surface (ChIPS), Université de Mons, 20 Place du Parc, B-7000 Mons, Belgium
- Materia Nova Research Center, Parc Initialis, B-7000 Mons, Belgium
| | - Damien Thiry
- Chimie des Interactions Plasma-Surface (ChIPS), Université de Mons, 20 Place du Parc, B-7000 Mons, Belgium
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Li H, Tan P, Rao Y, Bhattacharya S, Wang Z, Kim S, Gangopadhyay S, Shi H, Jankovic M, Huh H, Li Z, Maharjan P, Wells J, Jeong H, Jia Y, Lu N. E-Tattoos: Toward Functional but Imperceptible Interfacing with Human Skin. Chem Rev 2024; 124:3220-3283. [PMID: 38465831 DOI: 10.1021/acs.chemrev.3c00626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
The human body continuously emits physiological and psychological information from head to toe. Wearable electronics capable of noninvasively and accurately digitizing this information without compromising user comfort or mobility have the potential to revolutionize telemedicine, mobile health, and both human-machine or human-metaverse interactions. However, state-of-the-art wearable electronics face limitations regarding wearability and functionality due to the mechanical incompatibility between conventional rigid, planar electronics and soft, curvy human skin surfaces. E-Tattoos, a unique type of wearable electronics, are defined by their ultrathin and skin-soft characteristics, which enable noninvasive and comfortable lamination on human skin surfaces without causing obstruction or even mechanical perception. This review article offers an exhaustive exploration of e-tattoos, accounting for their materials, structures, manufacturing processes, properties, functionalities, applications, and remaining challenges. We begin by summarizing the properties of human skin and their effects on signal transmission across the e-tattoo-skin interface. Following this is a discussion of the materials, structural designs, manufacturing, and skin attachment processes of e-tattoos. We classify e-tattoo functionalities into electrical, mechanical, optical, thermal, and chemical sensing, as well as wound healing and other treatments. After discussing energy harvesting and storage capabilities, we outline strategies for the system integration of wireless e-tattoos. In the end, we offer personal perspectives on the remaining challenges and future opportunities in the field.
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Affiliation(s)
- Hongbian Li
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Philip Tan
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Yifan Rao
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Sarnab Bhattacharya
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Zheliang Wang
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Sangjun Kim
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Susmita Gangopadhyay
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Hongyang Shi
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Matija Jankovic
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Heeyong Huh
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Zhengjie Li
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Pukar Maharjan
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jonathan Wells
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Hyoyoung Jeong
- Department of Electrical and Computer Engineering, University of California Davis, Davis, California 95616, United States
| | - Yaoyao Jia
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Nanshu Lu
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712, United States
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
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Loh JYY, Zeineddine A, Shayegannia M, McNeil R, McRae L, Kherani NP. A one-step, tunable method of selective reactive sputter deposition as a wrinkling approach for silver/polydimethylsiloxane for electrically conductive pliable surfaces. MICROSYSTEMS & NANOENGINEERING 2022; 8:89. [PMID: 35957954 PMCID: PMC9360048 DOI: 10.1038/s41378-022-00420-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/25/2022] [Accepted: 06/08/2022] [Indexed: 05/31/2023]
Abstract
The wrinkle period and morphology of a metal thin film on an elastic substrate is typically controlled by modifying the substrate before carrying out additional metal deposition steps. Herein, we show that a simultaneously selective and reactive sputtering plasma that modifies the surface of a polydimethylsiloxane (PDMS) substrate while not reacting with the metal during the deposition process decreases the wrinkle wavelength and induces additional wrinkling components and features such as ripples or folds. The selective reaction of the nitrogen plasma with PDMS functionalizes the siloxane surface into silicon oxynitride. This hardens the immediate surface of PDMS, with a quadratic increase in the Young's modulus as a function of the sputtering flow ratio. The increase in the critical strain mismatch and the corresponding presence of folds in the nitrogen-modified wrinkled silver film form a suitable plasmonic platform for surface-enhanced Raman spectroscopy (SERS), yielding an enhancement factor of 4.8 × 105 for detecting lipids. This enhancement is linked to the emergence of electromagnetic hotspots from surface plasmon polariton coupling between the folds/wrinkles, which in turn enables the detection of low concentrations of organics using SERS. Furthermore, when strained, the nitrogen-modified wrinkles enhance electrical conductivity by a factor of 12 compared with unmodified films. Finally, the optical properties of the substrate can be tuned by altering the N2 content. The simple addition of nonreactive nitrogen to silver sputtering enables simultaneous PDMS hardening and growth of the silver film and together provide a new avenue for tuning wrinkling parameters and enhancing the electrical conductivity of pliable surfaces.
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Affiliation(s)
- Joel Y. Y. Loh
- Department of Electrical and Computing Engineering, University of Toronto, Toronto, ON M5S 3G4 Canada
| | - Ali Zeineddine
- Department of Electrical and Computing Engineering, University of Toronto, Toronto, ON M5S 3G4 Canada
| | - Moein Shayegannia
- Department of Electrical and Computing Engineering, University of Toronto, Toronto, ON M5S 3G4 Canada
| | - Robyn McNeil
- Department of Material Science and Engineering, University of Toronto, Toronto, ON M5S 3E4 Canada
| | - Liam McRae
- Department of Electrical and Computing Engineering, University of Toronto, Toronto, ON M5S 3G4 Canada
| | - Nazir P. Kherani
- Department of Electrical and Computing Engineering, University of Toronto, Toronto, ON M5S 3G4 Canada
- Department of Material Science and Engineering, University of Toronto, Toronto, ON M5S 3E4 Canada
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Wawryk MM, Turpin GA, Tabor RF. Surface defects on wrinkled PDMS induce droplet anisotropy. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128317] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Zhang Q, Peng B, Chu M, Wen P, Wang S, Xu J. Curved Film Microstructure Arrays Fabricated via Mechanical Stretching. MICROMACHINES 2021; 12:1281. [PMID: 34832694 PMCID: PMC8617774 DOI: 10.3390/mi12111281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 10/10/2021] [Accepted: 10/16/2021] [Indexed: 12/21/2022]
Abstract
We report on curved film microstructure arrays fabricated through polydimethylsiloxane (PDMS) film buckling induced by mechanical stretching. In the process of the microstructure preparation, a PDMA film is glued on a bidirectionally prestretched PDMS sheet that has a square distributed hole array on its surface. After releasing the prestrain, the film microstructure array is created spontaneously. The fabricated microstructures possess a spherical surface and demonstrate very good uniformity. The film microstructure arrays can serve as microlens arrays with a focal length of 1010 μm. The microstructure formation mechanism is investigated via theoretical analysis and numerical simulation. The simulation results agree well with the experimental results. The prestrain applied by mechanical stretching during the fabrication has an important effect on the shape of the resulting film microstructures. The microstructure geometry can be easily tuned through controlling the applied prestrain.
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Affiliation(s)
| | - Bei Peng
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China; (Q.Z.); (M.C.); (P.W.); (S.W.); (J.X.)
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Tunable Optical Diffusers Based on the UV/Ozone-Assisted Self-Wrinkling of Thermal-Cured Polymer Films. SENSORS 2021; 21:s21175820. [PMID: 34502713 PMCID: PMC8434521 DOI: 10.3390/s21175820] [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: 07/13/2021] [Revised: 08/18/2021] [Accepted: 08/26/2021] [Indexed: 12/02/2022]
Abstract
Tunable optical diffusers have attracted attention because of the rapid development of next generation stretchable optoelectronics and optomechanics applications. Flexible wrinkle structures have the potential to change the light path and tune the diffusion capability, which is beneficial to fabricate optical diffusers. The generation of wrinkles usually depends on an external stimulus, thus resulting in complicated fabricating equipment and processes. In this study, a facile and low-cost method is proposed to fabricate wrinkle structures by the self-wrinkling of thermal-cured polymer for tunable optical diffusers. The uncured polydimethylsiloxane (PDMS) precursors were exposed to UV/ozone to obtain hard silica layers and then crosslinked via heating to induce the wrinkle patterns. The wrinkle structures were demonstrated as strain-dependent tunable optical diffusers and the optical diffusion of transmitted light via the deformable wrinkle structures was studied and adjusted. The incident light isotropically diffused through the sample at the initial state. When the wrinkle structures deformed, it showed a more pronounced isotropic optical diffusion with uniaxial tensile strain. The optical diffusion is anisotropical with a further increase in uniaxial tensile strain. The proposed method of fabricating wrinkles by UV/ozone-assisted self-wrinkling of thermal-cured polymer films is simple and cost-effective, and the obtained structures have potential applications in tunable optical diffusers.
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Qi H, Wang S, Li C, Zhao Y, Xu B, Jiang X, Fang Y, Wang A, Shen H, Du Z. High performance blue quantum light-emitting diodes by attaching diffraction wrinkle patterns. NANOSCALE 2021; 13:8498-8505. [PMID: 33899873 DOI: 10.1039/d1nr00082a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Highly efficient blue quantum-dot light-emitting diodes (QLEDs) are still challenging to use in displays and solid-state lighting. Enhancing light outcoupling is one of the most effective methods to improve the performance of blue QLEDs. Here, a strategy for a spectrally independent boost in light outcoupling of blue QLEDs is demonstrated by quasi-periodic wrinkles, which are successfully used as a diffraction grating for extracting trapped light at the substrate/air interface. The quasi-periodic wrinkles can be adjusted from nano-scale to micron-scale under the condition of a constant aspect ratio, and the optimized wrinkle device shows a maximum luminance of 11 769 cd m-2 and a peak EQE of 15.41%. The enhancement of EQE is 49.5% higher compared to that of the reference device. Furthermore, simulation and calculation also indicate that external micron-scattering wrinkle patterns are an attractive option for boosting the performances of blue QLEDs.
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Affiliation(s)
- Hui Qi
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Shujie Wang
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Chenguang Li
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Yaolong Zhao
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Bo Xu
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Xiaohong Jiang
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Yan Fang
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Aqiang Wang
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Huaibin Shen
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
| | - Zuliang Du
- Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology, School of Materials and Engineering, Collaborative Innovation Centre of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, China.
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Evaluation of grain boundaries as percolation pathways in quartz-rich continental crust using Atomic Force Microscopy. Sci Rep 2021; 11:9831. [PMID: 33972600 PMCID: PMC8111022 DOI: 10.1038/s41598-021-89250-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 04/19/2021] [Indexed: 11/08/2022] Open
Abstract
Hydrous fluids play a vital role in the chemical and rheological evolution of ductile, quartz-bearing continental crust, where fluid percolation pathways are controlled by grain boundary domains. In this study, widths of grain boundary domains in seven quartzite samples metamorphosed under varying crustal conditions were investigated using Atomic Force Microscopy (AFM) which allows comparatively easy, high magnification imaging and precise width measurements. It is observed that dynamic recrystallization at higher metamorphic grades is much more efficient at reducing grain boundary widths than at lower temperature conditions. The concept of force-distance spectroscopy, applied to geological samples for the first time, allows qualitative estimation of variations in the strength of grain boundary domains. The strength of grain boundary domains is inferred to be higher in the high grade quartzites, which is supported by Kernel Average Misorientation (KAM) studies using Electron Backscatter Diffraction (EBSD). The results of the study show that quartzites deformed and metamorphosed at higher grades have narrower channels without pores and an abundance of periodically arranged bridges oriented at right angles to the length of the boundary. We conclude that grain boundary domains in quartz-rich rocks are more resistant to fluid percolation in the granulite rather than the greenschist facies.
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Kim ES, Kim SH, Lee SJ, Lee JH, Byeon M, Suh DH, Choi WJ. Facile fabrication of micro/nano-structured wrinkles by controlling elastic properties of polydimethylsiloxane substrates. POLYMER 2021. [DOI: 10.1016/j.polymer.2020.123087] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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10
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Su Y, Zhang E, Wang Y, Li Q, Chen M, Dong M. Tunable hierarchical wrinkling surface via microscale patterned vertical deformation. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Varughese SM, Bhandaru N. Durability of submerged hydrophobic surfaces. SOFT MATTER 2020; 16:1692-1701. [PMID: 31967169 DOI: 10.1039/c9sm01942a] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Hydrophobic and superhydrophobic surfaces have gained wide popularity due to their potential in various areas such as in self-cleaning and anti-fouling materials, drag reduction and microfluidics. However, for all practical applications, the long term durability of these surfaces is extremely important, yet not often investigated. Of particular interest is the long term durability of soft hydrophobic surfaces that remain submerged underwater for a prolonged duration. In this article, we explore how the chemical durability of flat and patterned crosslinked PDMS surfaces (polydimethylsiloxane, a preferred material for microfabrication) change as a function of time when submerged in acidic, basic and neutral media for different durations over a prolonged period of time. Based on contact angle measurements, atomic force microscopy, confocal microscopy and SEM analysis of the surfaces, we checked if there is any change in the morphology of the surface due to deposition or etching. We created a biomimetic positive replica of a lotus leaf that exhibited super-hydrophobicity and Cassie state of wetting with a static water contact angle (θ) > 150°, and compared the degradation with a negative replica of lotus leaf (θ ∼ 127°), a grating patterned surface that exhibited Wenzel state of wetting (θ ∼ 110°) and a flat crosslinked PDMS surface (θ ∼ 105°). The positive replica maintained reasonable hydrophobicity (θ > 90°) for up to a month, but lost its super-hydrophobic property. The surface hydrophobicity degraded the most in the case of basic solution due to deposition.
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Affiliation(s)
- Sharon Mariam Varughese
- Department of Chemical Engineering, Birla Institute of Technology and Science Pilani, Hyderabad Campus, 500 078, Telangana, India.
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12
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Wu H, Yu S, Xu Z, Cao B, Peng X, Zhang Z, Chai G, Liu A. Theoretical and Experimental Study of Reversible and Stable Wetting States of a Hierarchically Wrinkled Surface Tuned by Mechanical Strain. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:6870-6877. [PMID: 31042869 DOI: 10.1021/acs.langmuir.9b00599] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The wetting behavior of hierarchically wrinkled surfaces has attracted great interest because of its broad application in flexible electronic, microfluidic chip, and biomedicine. However, theoretical studies concerning the relationship between the apparent contact angle and mechanical strain applied on the soft and flexible surface with a hierarchically wrinkled structure are still limited. We established a theoretical framework to describe and understand how prestrain and applied dynamic strain reversibly tune the wettability of the hierarchically wrinkled surface. More specifically, a direct relationship between the mechanical strain and contact angle was built through reversible tuning of the amplitude and the wavelength of the wrinkled structures caused by mechanical strain, which allowed for more precise adjustment of surface wettability. To verify the accuracy of the theoretical relationship between the contact angle and mechanical strain, a soft surface with a hierarchically wrinkled structure was prepared by combining wrinkled microstructures and strip ones. The results showed that the experimental contact angles were in agreement with the theoretical ones within a limited error range. This will be helpful for further investigation on the wettability of hierarchically wrinkled surfaces.
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Affiliation(s)
- Huaping Wu
- Key Laboratory of E&M, Ministry of Education & Zhejiang Province , Zhejiang University of Technology , Hangzhou 310014 , China
| | - Sihang Yu
- Key Laboratory of E&M, Ministry of Education & Zhejiang Province , Zhejiang University of Technology , Hangzhou 310014 , China
| | - Zhenxiong Xu
- Key Laboratory of E&M, Ministry of Education & Zhejiang Province , Zhejiang University of Technology , Hangzhou 310014 , China
| | - Binbin Cao
- Key Laboratory of E&M, Ministry of Education & Zhejiang Province , Zhejiang University of Technology , Hangzhou 310014 , China
| | - Xiang Peng
- Key Laboratory of E&M, Ministry of Education & Zhejiang Province , Zhejiang University of Technology , Hangzhou 310014 , China
| | - Zheng Zhang
- Key Laboratory of E&M, Ministry of Education & Zhejiang Province , Zhejiang University of Technology , Hangzhou 310014 , China
| | - Guozhong Chai
- Key Laboratory of E&M, Ministry of Education & Zhejiang Province , Zhejiang University of Technology , Hangzhou 310014 , China
| | - Aiping Liu
- Center for Optoelectronics Materials and Devices , Zhejiang Sci-Tech University , Hangzhou 310018 , China
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Parihar V, Bandyopadhyay S, Das S, Mukherjee R, Chakraborty S, Dasgupta S. Tailored topography: a novel fabrication technique using an elasticity gradient. SOFT MATTER 2018; 14:7034-7044. [PMID: 30109884 DOI: 10.1039/c8sm01054d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A facile methodology to create a wrinkled surface with a tailored topography is presented herein. The dependency of the elasticity of poly(dimethyl)siloxane (PDMS) on the curing temperature has been exploited to obtain a substrate with an elasticity gradient. The temperature gradient across the length of PDMS is created by a novel set-up consisting of a metal and insulator connected to a heater and the highest usable (no degradation of PDMS) temperature gradient is used. The time-dependent temperature distributions along the substrate are measured and the underlying physics of the dependence of the PDMS elasticity on the curing temperature is addressed. The PDMS substrate with the elasticity gradient is first stretched and subsequently oxidized by oxygen plasma. Upon relaxation, an ordered wrinkled surface with continuously varying wavelength and amplitude along the length of PDMS is obtained. The extent of hydrophobicity recovery of this plasma oxidized PDMS with varying elasticity has been studied. The change in the wavelength and amplitude of the regular patterns on the substrate can be controlled by varying operational parameters like applied pre-strain, plasma power and the heater temperature. It has been found that the spatial distributions of the topography and the hydrophobicity collectively decide the resultant wettability of the substrate. Such surfaces with gradients in the substructure dimensions demonstrate different wetting characteristics that may lead to a wide gamut of applications including droplet movement, cell adhesion and proliferation, diffraction grating etc.
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Affiliation(s)
- Vartika Parihar
- Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India.
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14
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Guo W, Reese CM, Xiong L, Logan PK, Thompson BJ, Stafford CM, Ievlev AV, Lokitz BS, Ovchinnikova OS, Patton DL. Buckling Instabilities in Polymer Brush Surfaces via Postpolymerization Modification. Macromolecules 2017; 50:8670-8677. [PMID: 29503464 PMCID: PMC5831323 DOI: 10.1021/acs.macromol.7b01888] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We report a simple route to engineer ultrathin polymer brush surfaces with wrinkled morphologies using post-polymerization modification (PPM), where the length scale of the buckled features can be tuned from hundreds of nanometers to one micrometer using PPM reaction time. We show that partial crosslinking of the outer layer of the polymer brush under poor solvent conditions is critical to obtain wrinkled morphologies upon swelling. Characterization of the PPM kinetics and swelling behavior via ellipsometry and the through-thickness composition profile via time-of-flight secondary ion mass spectroscopy (ToF-SIMS) provided keys insight into parameters influencing the buckling behavior.
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Affiliation(s)
- Wei Guo
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406
| | - Cassandra M. Reese
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406
| | - Li Xiong
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406
| | - Phillip K. Logan
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406
| | - Brittany J. Thompson
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406
| | - Christopher M. Stafford
- Materials Science and Engineering Division, Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - Anton V. Ievlev
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN
| | - Bradley S. Lokitz
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN
| | - Olga S. Ovchinnikova
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN
| | - Derek L. Patton
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406
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