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Krutko M, Poling HM, Bryan AE, Sharma M, Singh A, Reza HA, Wikenheiser-Brokamp KA, Takebe T, Helmrath MA, Harris GM, Esfandiari L. Enhanced Piezoelectric Performance of PVDF-TrFE Nanofibers through Annealing for Tissue Engineering Applications. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.16.608345. [PMID: 39229142 PMCID: PMC11370437 DOI: 10.1101/2024.08.16.608345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
This study investigates bioelectric stimulation's role in tissue regeneration by enhancing the piezoelectric properties of tissue-engineered grafts using annealed poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) scaffolds. Annealing at temperatures of 80°C, 100°C, 120°C, and 140°C was assessed for its impact on material properties and physiological utility. Analytical techniques such as Differential Scanning Calorimetry (DSC), Fourier-Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) revealed increased crystallinity with higher annealing temperatures, peaking in β-phase content and crystallinity at 140°C. Scanning Electron Microscopy (SEM) showed that 140°C annealed scaffolds had enhanced lamellar structures, increased porosity, and maximum piezoelectric response. Mechanical tests indicated that 140°C annealing improved elastic modulus, tensile strength, and substrate stiffness, aligning these properties with physiological soft tissues. In vitro assessments in Schwann cells demonstrated favorable responses, with increased cell proliferation, contraction, and extracellular matrix attachment. Additionally, genes linked to extracellular matrix production, vascularization, and calcium signaling were upregulated. The foreign body response in C57BL/6 mice, evaluated through Hematoxylin and Eosin (H&E) and Picrosirius Red staining, showed no differences between scaffold groups, supporting the potential for future functional evaluation of the annealed group in tissue repair.
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Kang DH, Kim NK, Lee W, Kang HW. Geometric feature extraction in nanofiber membrane image based on convolution neural network for surface roughness prediction. Heliyon 2024; 10:e35358. [PMID: 39170369 PMCID: PMC11336630 DOI: 10.1016/j.heliyon.2024.e35358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 08/23/2024] Open
Abstract
As a technique in artificial intelligence, a convolution neural network model has been utilized to extract average surface roughness from the geometric characteristics of a membrane image featuring micro- and nanostructures. For surface roughness measurement, e.g. atomic force microscopy and optical profiler, the previous methods have been performed to analyze a porous membrane surface on an interest of region with a few micrometers of the restricted area according to the depth resolution. However, an image from the scanning electron microscope, combined with the feature extraction process, provides clarity on surface roughness for multiple areas with various depth resolutions. Through image preprocessing, the geometric pattern is elucidated by amplifying the disparity in pixel intensity values between the bright and dark regions of the image. The geometric pattern of the binary image and magnitude spectrum confirmed the classification of the surface roughness of images in a categorical scatter plot. A group of cropped images from an original image is used to predict the logarithmic average surface roughness values. The model predicted 4.80 % MAPE for the test dataset. The method of extracting geometric patterns through a feature map-based CNN, combined with a statistical approach, suggests an indirect surface measurement. The process is achieved through a bundle of predicted output data, which helps reduce the randomness error of the structural characteristics. A novel feature extraction approach of CNN with statistical analysis is a valuable method for revealing hidden physical characteristics in surface geometries from irregular pixel patterns in an array of images.
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Affiliation(s)
- Dong Hee Kang
- Department of Mechanical Engineering, Chonnam National University, 77 Youngbong-ro, Buk-Gu, Gwangju, 61186, Republic of Korea
- Department of Industrial and Systems Engineering, Texas A&M University, College station, TX, 77843, United States
| | - Na Kyong Kim
- Green Energy System Research Center, Korea Automotive Technology Institute, 55 Jingoksandanjungang-ro, Gwangsan-Gu, Gwangju, 62465, Republic of Korea
| | - Wonoh Lee
- Department of Mechanical Engineering, Chonnam National University, 77 Youngbong-ro, Buk-Gu, Gwangju, 61186, Republic of Korea
| | - Hyun Wook Kang
- Department of Mechanical Engineering, Chonnam National University, 77 Youngbong-ro, Buk-Gu, Gwangju, 61186, Republic of Korea
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Mondal A, Faraz M, Singh HH, Khare N. High-performance flexible piezoelectric nanogenerator assisted by a three-phase PVDF/WS 2/rGO nanocomposite. NANOTECHNOLOGY 2024; 35:395401. [PMID: 38949268 DOI: 10.1088/1361-6528/ad5d69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 06/11/2024] [Indexed: 07/02/2024]
Abstract
The emergence of piezoelectric nanogenerators (PENGs) presents a promising alternative to supply energy demands within the realms of portable and miniaturized devices. In this article, the role of 2D transition metal dichalcogenide tungsten sulfide (WS2) and conductive rGO sheets as filler materials inside the polyvinylidene fluoride (PVDF) matrix on piezoelectric performances has been investigated extensively. The strong electrostatic interaction between C-F and C-H monomer bonds of PVDF interacted with the large surface area of the WS2nanosheets, increasing the electroactive polar phases and resulting in enhanced ferroelectricity in the PVDF/WS2nanocomposite. Further, the inclusion of rGO sheets in the PVDF/WS2composite allows mobile charge carriers to move freely through the conductive network provided by the rGO basal planes, which improves the internal polarization of the PVDF/WS2/rGO nanocomposites and increases the electrical performance of the PENGs. The PVDF/WS2/0.3rGO nanocomposite-based PENG exhibits maximum piezoresponses with ∼8.1 times enhancements in the output power density than the bare PVDF-based PENG. The mechanism behind the enhanced piezoresponses in the PVDF/WS2/rGO nanocomposites has been discussed.
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Affiliation(s)
- Arun Mondal
- Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Mohd Faraz
- Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Huidrom Hemojit Singh
- Department of Physics, Gauhati University, Gopinath Bordoloi Nagar, Jalukbari, Guwahati, Assam 781014, India
| | - Neeraj Khare
- Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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Siddique A, Nawaz H, Razzaque S, Tabasum A, Gong H, Razzaq H, Umar M. PVDF-Based Piezo-Catalytic Membranes-A Net-Zero Emission Approach towards Textile Wastewater Purification. Polymers (Basel) 2024; 16:699. [PMID: 38475382 DOI: 10.3390/polym16050699] [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: 12/31/2023] [Revised: 02/05/2024] [Accepted: 02/14/2024] [Indexed: 03/14/2024] Open
Abstract
Among the various water purification techniques, advancements in membrane technology, with better fabrication and analysis, are receiving the most research attention. The piezo-catalytic degradation of water pollutants is an emerging area of research in water purification technology. This review article focuses on piezoelectric polyvinylidene difluoride (PVDF) polymer-based membranes and their nanocomposites for textile wastewater remediation. At the beginning of this article, the classification of piezoelectric materials is discussed. Among the various membrane-forming polymers, PVDF is a piezoelectric polymer discussed in detail due to its exceptional piezoelectric properties. Polyvinylidene difluoride can show excellent piezoelectric properties in the beta phase. Therefore, various methods of β-phase enhancement within the PVDF polymer and various factors that have a critical impact on its piezo-catalytic activity are briefly explained. This review article also highlights the major aspects of piezoelectric membranes in the context of dye degradation and a net-zero approach. The β-phase of the PVDF piezoelectric material generates an electron-hole pair through external vibrations. The possibility of piezo-catalytic dye degradation via mechanical vibrations and the subsequent capture of the resulting CO2 and H2 gases open up the possibility of achieving the net-zero goal.
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Affiliation(s)
- Amna Siddique
- Department of Chemistry, University of Wah, Quaid Avenue, Wah 47040, Pakistan
| | - Hifza Nawaz
- Department of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Shumaila Razzaque
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka44/52, 01-224 Warsaw, Poland
| | - Anila Tabasum
- Department of Chemistry, University of Wah, Quaid Avenue, Wah 47040, Pakistan
| | - Hugh Gong
- Department of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Humaira Razzaq
- Department of Chemistry, University of Wah, Quaid Avenue, Wah 47040, Pakistan
| | - Muhammad Umar
- Department of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK
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Han P, Tofangchi A, Carr D, Zhang S, Hsu K. Enhancing the Piezoelectric Properties of 3D Printed PVDF Using Concurrent Torsional Shear Strain. Polymers (Basel) 2023; 15:4204. [PMID: 37959883 PMCID: PMC10647440 DOI: 10.3390/polym15214204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/07/2023] [Accepted: 10/24/2023] [Indexed: 11/15/2023] Open
Abstract
Extrusion-based polymer 3D printing induces shear strains within the material, influencing its rheological and mechanical properties. In materials like polyvinylidene difluoride (PVDF), these strains stretch polymer chains, leading to increased crystallinity and improved piezoelectric properties. This study demonstrates a 400% enhancement in the piezoelectric property of extrusion-printed PVDF by introducing additional shear strains during the printing process. The continuous torsional shear strains, imposed via a rotating extrusion nozzle, results in additional crystalline β-phases, directly impacting the piezoelectric behavior of the printed parts. The effect of the nozzle's rotational speed on the amount of β-phase formation is characterized using FTIR. This research introduces a new direction in the development of polymer and composite 3D printing, where in-process shear strains are used to control the alignment of polymer chains and/or in-fill phases and the overall properties of printed parts.
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Affiliation(s)
- Pu Han
- Ira A Fulton Schools of Engineering, Arizona State University, Tempe, AZ 85212, USA;
| | - Alireza Tofangchi
- J. B. Speed School of Engineering, University of Louisville, Louisville, KY 40208, USA
| | - Derek Carr
- J. B. Speed School of Engineering, University of Louisville, Louisville, KY 40208, USA
| | - Sihan Zhang
- J. B. Speed School of Engineering, University of Louisville, Louisville, KY 40208, USA
| | - Keng Hsu
- Ira A Fulton Schools of Engineering, Arizona State University, Tempe, AZ 85212, USA;
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Solvent Evaporation Rate as a Tool for Tuning the Performance of a Solid Polymer Electrolyte Gas Sensor. Polymers (Basel) 2022; 14:polym14214758. [DOI: 10.3390/polym14214758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Solid polymer electrolytes show their potential to partially replace conventional electrolytes in electrochemical devices. The solvent evaporation rate represents one of many options for modifying the electrode–electrolyte interface by affecting the structural and electrical properties of polymer electrolytes used in batteries. This paper evaluates the effect of solvent evaporation during the preparation of solid polymer electrolytes on the overall performance of an amperometric gas sensor. A mixture of the polymer host, solvent and an ionic liquid was thermally treated under different evaporation rates to prepare four polymer electrolytes. A carbon nanotube-based working electrode deposited by spray-coating the polymer electrolyte layer allowed the preparation of the electrode–electrolyte interface with different morphologies, which were then investigated using scanning electron microscopy and Raman spectroscopy. All prepared sensors were exposed to nitrogen dioxide concentration of 0–10 ppm, and the current responses and their fluctuations were analyzed. Electrochemical impedance spectroscopy was used to describe the sensor with an equivalent electric circuit. Experimental results showed that a higher solvent evaporation rate leads to lower sensor sensitivity, affects associated parameters (such as the detection/quantification limit) and increases the limit of the maximum current flowing through the sensor, while the other properties (hysteresis, repeatability, response time, recovery time) change insignificantly.
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Ekbote GS, Khalifa M, Mahendran A, Anandhan S. Cationic surfactant assisted enhancement of dielectric and piezoelectric properties of PVDF nanofibers for energy harvesting application. SOFT MATTER 2021; 17:2215-2222. [PMID: 33464271 DOI: 10.1039/d0sm01943g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Poly(vinylidene fluoride) (PVDF) is among the most versatile polymers due to its wide range of properties, including dielectric, piezoelectric and ferroelectric properties. However, more frequently than not a range of processing routes and/or additives have been used to enhance such properties. In this study, PVDF nanofibers were electrospun from PVDF solution that contained tetra-n-butyl ammonium chloride (TBAC) at different loadings (1, 2, 3, and 5 wt%). The effect of TBAC on the morphology, crystallinity, and polymorphism of PVDF was studied using various characterization techniques. Addition of TBAC significantly improved the electroactive β-phase of PVDF. The highest β-phase content of 89% was attained at a TBAC loading of 3 wt%. Consequently, the dielectric and piezoelectric properties of the PVDF nanofibers improved significantly. A nanogenerator fabricated using 3 wt% TBAC/PVDF nanofibers exhibited the maximum voltage output of 17.2 V (under 5 N force) and the maximum power density of ∼1.4 μW cm-2 (under 3 N force). Improved dielectric and piezoelectric properties of PVDF upon the addition of a small amount of TBAC could be useful for researchers in upbringing the material for flexible electronic devices.
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Affiliation(s)
- Govind S Ekbote
- Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Srinivas Nagar, Mangaluru 575025, India.
| | - Mohammed Khalifa
- Kompetenzzentrum Holz GmbH, W3C, A-9300 St. Veit/Glan, Klagenfurter Strasse 87-89, Linz, Austria
| | - Arunjunairaj Mahendran
- Kompetenzzentrum Holz GmbH, W3C, A-9300 St. Veit/Glan, Klagenfurter Strasse 87-89, Linz, Austria
| | - S Anandhan
- Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Srinivas Nagar, Mangaluru 575025, India.
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Son S, Liu Y, Chae D, Lee H. Cross-Linked Porous Polymeric Coating without a Metal-Reflective Layer for Sub-Ambient Radiative Cooling. ACS APPLIED MATERIALS & INTERFACES 2020; 12:57832-57839. [PMID: 33345542 DOI: 10.1021/acsami.0c14792] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Passive daytime radiative cooling provides cooling without energy input. This method is eco-friendly, which is beneficial, considering the increasing problems of global warming and urban heat islands. A poly(vinylidene fluoride) (PVDF) and polyurethane acrylate (PUA) matte white coating was prepared via photo-initiated free-radical polymerization. The porous polymeric coating without a metal-reflective layer exhibited an average emissivity of 0.9333 in the atmospheric window and an average solar reflectance of 0.9336 in the direct AM1.5 solar spectrum (888 W m-2 in the 0.3-2.5 μm region). The radiative cooling power of the fabricated radiative cooler with a thickness of 518 μm was 94.2 W m-2. Furthermore, the radiative cooler demonstrated radiative cooling performance during both daytime and nighttime in Seoul, Korea, and Chiang Mai, Thailand. The PVDF/PUA matte white coating without a silver reflector can prevent solar absorption caused by the oxidation of silver and reduce the light pollution caused by the metallic film because of the antiglare surface of the matte coating.
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Affiliation(s)
- Soomin Son
- Department of Materials and Science Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Yuting Liu
- Department of Materials and Science Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Dongwoo Chae
- Department of Materials and Science Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Heon Lee
- Department of Materials and Science Engineering, Korea University, Seoul 02841, Republic of Korea
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