Structure Tuning and Electrical Properties of Mixed PVDF and Nylon Nanofibers

The paper specifies the electrostatic spinning process of specific polymeric materials, such as polyvinylidene fluoride (PVDF), polyamide-6 (PA6, Nylon-6) and their combination PVDF/PA6. By combining nanofibers from two different materials during the spinning process, new structures with different mechanical, chemical, and physical properties can be created. The materials and their combinations were subjected to several measurements: scanning electron microscopy (SEM) to capture topography; contact angle of the liquid wettability on the sample surface to observe hydrophobicity and hydrophilicity; crystallization events were determined by differential scanning calorimetry (DSC); X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR) to describe properties and their changes at the chemical level. Furthermore, for the electrical properties of the sample, the dielectric characteristics and the piezoelectric coefficient were measured. The advantage of the addition of co-polymers was to control the properties of PVDF samples and understand the reasons for the changed functionality. The innovation point of this work is the complex analysis of PVDF modification caused by mixing with nylon PA6. Here we emphasize that the application of nylon during the spin influences the properties and structure (polarization, crystallization) of PVDF.

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Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

Polymers and Polymer Composites ◽

10.1177/096739110501300811 ◽

2005 ◽

Vol 13 (8) ◽

pp. 839-846 ◽

Cited By ~ 4

Author(s):

Li-Ping Wang ◽

Yun-Pu Wang ◽

Fa-Ai Zhang

Keyword(s):

Polyvinyl Alcohol ◽

Photoelectron Spectroscopy ◽

Thermal Characteristics ◽

Water Soluble ◽

Scanning Calorimetry ◽

Xps Spectra ◽

X Ray ◽

Alcohol Water ◽

Ft Ir ◽

Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

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Fabrication of piezoelectric poly(l-lactic acid)/BaTiO3 fibre by the melt-spinning process

Scientific Reports ◽

10.1038/s41598-020-73261-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Hyun Ju Oh ◽

Do-Kun Kim ◽

Young Chan Choi ◽

Seung-Ju Lim ◽

Jae Bum Jeong ◽

...

Keyword(s):

Phase Transition ◽

Lactic Acid ◽

Crystalline Phase ◽

Melt Spinning ◽

Piezoelectric Properties ◽

Polymeric Materials ◽

Processing Conditions ◽

Post Processing ◽

Scanning Calorimetry ◽

Spinning Process

Abstract Poly(l-lactic acid) (PLLA) based piezoelectric polymers are gradually becoming the substitute for the conventional piezoelectric ceramic and polymeric materials due to their low cost and biodegradable, non-toxic, piezoelectric and non-pyroelectric nature. To improve the piezoelectric properties of melt-spun poly(l-lactic acid) (PLLA)/BaTiO3, we optimized the post-processing conditions to increase the proportion of the β crystalline phase. The α → β phase transition behaviour was determined by two-dimensional wide-angle x-ray diffraction and differential scanning calorimetry. The piezoelectric properties of PLLA/BaTiO3 fibres were characterised in their yarn and textile form through a tapping method. From these results, we confirmed that the crystalline phase transition of PLLA/BaTiO3 fibres was significantly enhanced under the optimised post-processing conditions at a draw ratio of 3 and temperature of 120 °C during the melt-spinning process. The results indicated that PLLA/BaTiO3 fibres could be a one of the material for organic-based piezoelectric sensors for application in textile-based wearable piezoelectric devices.

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Fabrication of silane-grafted graphene oxide and its effect on the structural, thermal, mechanical, and hysteretic behavior of polyurethane

Scientific Reports ◽

10.1038/s41598-020-76153-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Joo Hyung Lee ◽

Seong Hun Kim

Keyword(s):

Mechanical Properties ◽

Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Testing Machine ◽

Hysteretic Behavior ◽

Hexamethylene Diisocyanate ◽

Scanning Calorimetry ◽

Functionalized Graphene Oxide ◽

X Ray ◽

Ft Ir

Abstract Incorporation of nanofillers into polyurethane (PU) is a promising technique for enhancing its thermal and mechanical properties. Silane grafting has been used as a surface treatment for the functionalization of graphene oxide (GO) with numerous reactive sites dispersed on its basal plane and edge. In this study, amine-grafted GO was prepared using silanization of GO with (3-aminopropyl)triethoxysilane. The functionalized graphene oxide (fGO) was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy. Next, it was introduced in PU fabricated using polycaprolactone diol, castor oil, and hexamethylene diisocyanate. The fGO–PU nanocomposites were in turn characterized by FT-IR, X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and a universal testing machine. The results obtained from these analyses showed changes in structural thermal properties, as well as improved thermal stability and mechanical properties because of the strong interfacial adhesion between the fGO and the PU matrix.

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PVDF Nanoweb Touch Sensors Prepared Using Electro-Spinning Process for Smart Apparels Applications

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.60.52 ◽

2008 ◽

Vol 60 ◽

pp. 52-57 ◽

Cited By ~ 5

Author(s):

Sun Yoon ◽

Arun Anand Prabu ◽

S. Ramasundaram ◽

Kap Jin Kim

Keyword(s):

Polyvinylidene Fluoride ◽

Sensor Applications ◽

Touch Sensor ◽

Multi Walled Carbon Nanotube ◽

Custom Made ◽

Spinning Process ◽

Ft Ir ◽

Set Up ◽

Calculated Amount ◽

Ft Ir Spectroscopy

Polyvinylidene fluoride (PVDF) based electrospun nanoweb fibers with outstanding piezo-, pyro- and ferroelectric behavior are being intensely studied by many researchers, especially for touch-sensor applications. In order to further improve the advantageous characteristics of PVDF nanoweb fibers, we focused our attention on studying the effect of filling PVDF solution with calculated amount of calcium chloride (CaCl2) or multi-walled carbon nanotube (MWCNT), and their electrospun nanoweb fibers were analyzed for the changes in β-crystalline phase, and its associated piezoelectric characteristics using a custom-made sensor set-up developed in our lab. FT-IR spectroscopy was used to confirm the changes in the β-crystalline content with varying content of CaCl2 and MWCNT. SEM data revealed the reducing fiber diameter with increasing CaCl2 content. PVDF nanoweb subjected to pressure showed changes in touch sensing property as analyzed using an oscilloscope integrated with Labview program. Overall, the PVDF nanoweb containing the additives used in our study exhibited greater sensitivity-in-touch for use in smart apparel applications compared to unmodified PVDF nanoweb, and the results are reported in detail here.

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Preparation and properties of polyamide 6 nanocomposites covalently linked with amide functional graphene oxide

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705716684918 ◽

2016 ◽

Vol 31 (2) ◽

pp. 162-180 ◽

Cited By ~ 7

Author(s):

Aidan O’Neill ◽

David Bishop ◽

Brendan Dalton ◽

Edward Archer ◽

Alistair McIlhagger ◽

...

Keyword(s):

Graphene Oxide ◽

Photoelectron Spectroscopy ◽

In Situ Polymerization ◽

Single Layer ◽

Polyamide 6 ◽

Scanning Calorimetry ◽

X Ray ◽

Covalently Linked ◽

Thermal Analysis Techniques ◽

Functional Graphene Oxide

Chemically engineered polyamide 6 (PA6)/graphene oxide (GO) nanocomposites were produced via the functionalization of GO with an amide (CONH2) functional group, in order to produce amide-GO with improved interfacial bonding and dispersion in the host polymer matrix. In situ polymerization of ε-caprolactam was carried out in the presence of amide-GO to create PA6/amide-GO nanocomposites. The nanomaterial (pre- and post-polymerization) and the composites were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and tensile testing. The single-layer nature of GO was attested by TEM. FTIR, XPS, XRD and thermal analysis techniques confirmed the successful amide modification of GO. The expected attachment of PA6 to the surface of GO is demonstrated, along with the reduction of GO during polymerization. Some reduction of GO during the chemical functionalization process was also observed. The thermal stability of the nanocomposites was confirmed, while promotion of α-phase crystallite formation and a molecular weight change of attached PA6 are observed. A linear improvement in stiffness and yield strength was observed as functionalized GO content increased from 0.1 wt% to 0.75 wt%. A levelling off of mechanical properties ensued once the GO content reached 1 wt%, and a decrease was seen at 2 wt%.

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Radiation-Induced Graft Immobilization (RIGI): Covalent Binding of Non-Vinyl Compounds on Polymer Membranes

Polymers ◽

10.3390/polym13111849 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1849

Author(s):

Martin Schmidt ◽

Stefan Zahn ◽

Florian Gehlhaar ◽

Andrea Prager ◽

Jan Griebel ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Polyvinylidene Fluoride ◽

Covalent Binding ◽

Polymer Surface ◽

Experimental Studies ◽

Polymeric Materials ◽

Covalent Attachment ◽

Minor Role ◽

Water Radiolysis ◽

Radiation Induced

Radiation-induced graft immobilization (RIGI) is a novel method for the covalent binding of substances on polymeric materials without the use of additional chemicals. In contrast to the well-known radiation-induced graft polymerization (RIGP), RIGI can use non-vinyl compounds such as small and large functional molecules, hydrophilic polymers, or even enzymes. In a one-step electron-beam-based process, immobilization can be performed in a clean, fast, and continuous operation mode, as required for industrial applications. This study proposes a reaction mechanism using polyvinylidene fluoride (PVDF) and two small model molecules, glycine and taurine, in aqueous solution. Covalent coupling of single molecules is achieved by radical recombination and alkene addition reactions, with water radiolysis playing a crucial role in the formation of reactive solute species. Hydroxyl radicals contribute mainly to the immobilization, while solvated electrons and hydrogen radicals play a minor role. Release of fluoride is mainly induced by direct ionization of the polymer and supported by water. Hydrophobic chains attached to cations appear to enhance the covalent attachment of solutes to the polymer surface. Computational work is complemented by experimental studies, including X-ray photoelectron spectroscopy (XPS) and fluoride high-performance ion chromatography (HPIC).

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Effect of Polythiophene Content on Thermomechanical Properties of Electroconductive Composites

Molecules ◽

10.3390/molecules26092476 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2476

Author(s):

Katarzyna Bednarczyk ◽

Tomasz Kukulski ◽

Ryszard Fryczkowski ◽

Ewa Schab-Balcerzak ◽

Marcin Libera

Keyword(s):

Organic Solar Cells ◽

Polyamide 6 ◽

Thermomechanical Properties ◽

Scanning Calorimetry ◽

Good Thermal Stability ◽

Mechanical And Electrical Properties ◽

Ft Ir ◽

Conductive Properties ◽

The Impact ◽

Properties Of Composites

The thermal, mechanical and electrical properties of polymeric composites combined using polythiophene (PT) dopped by FeCl3 and polyamide 6 (PA), in the aspect of conductive constructive elements for organic solar cells, depend on the molecular structure and morphology of materials as well as the method of preparing the species. This study was focused on disclosing the impact of the polythiophene content on properties of electrospun fibers. The elements for investigation were prepared using electrospinning applying two substrates. The study revealed the impact of the substrate on the conductive properties of composites. In this study composites exhibited good thermal stability, with T5 values in the range of 230–268 °C that increased with increasing PT content. The prepared composites exhibited comparable PA Tg values, which indicates their suitability for processing. Instrumental analysis of polymers and composites was carried out using Fourier Transform Infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM).

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Grafting of TiO2 on PMMA Film and Reusability in Photodegradation of Organic Dye

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.99.17 ◽

2016 ◽

Vol 99 ◽

pp. 17-21

Author(s):

Rachan Klaysri ◽

Sopita Wichaidit ◽

Piyasan Praserthdam ◽

Okorn Mekasuwandumrong

Keyword(s):

Photoelectron Spectroscopy ◽

Surface Composition ◽

Bulk Composition ◽

Pmma Film ◽

Glass Temperature ◽

Scanning Calorimetry ◽

X Ray ◽

H Nmr ◽

Ft Ir ◽

Novel Method

Grafting TiO2 on PMMA was studied by atom-transfer radical-polymerization (ATRP). Each step in grafting process was monitored by fourier transform infrared spectroscopy (FT-IR), 1H NMR and 13C NMR spectra. The glass temperature of grafted-PMMA film was determined by using differential scanning calorimetry (DSC). The morphology and bulk composition were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The surface composition was characterized by X-ray photoelectron spectroscopy (XPS). As results, a novel method of grafting TiO2 on PMMA was successfully grafted and confirmed in various techniques. The photocatlytic activity was evaluated under UV and visible light irradiation. The reusability of TiO2-g-PMMA films was studied in details.

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Assessing the performance of electrospun nanofabrics as potential interlayer reinforcement materials for fiber-reinforced polymers

Composites and Advanced Materials ◽

10.1177/26349833211002519 ◽

2021 ◽

Vol 30 ◽

pp. 263498332110025

Author(s):

Katerina Loizou ◽

Angelos Evangelou ◽

Orestes Marangos ◽

Loukas Koutsokeras ◽

Iouliana Chrysafi ◽

...

Keyword(s):

Polyvinylidene Fluoride ◽

Mechanical Response ◽

Mechanical Performance ◽

Polyamide 6 ◽

Processing Parameters ◽

Fiber Reinforced Polymers ◽

Fiber Reinforced ◽

Scanning Calorimetry ◽

Multiwalled Carbon ◽

Reinforced Polymers

Multiscale-reinforced polymers offer enhanced functionality due to the three different scales that are incorporated; microfiber, nanofiber, and nanoparticle. This work aims to investigate the applicability of different polymer-based nanofabrics, fabricated via electrospinning as reinforcement interlayers for multilayer-fiber-reinforced polymer composites. Three different polymers are examined; polyamide 6, polyacrylonitrile, and polyvinylidene fluoride, both plain and doped with multiwalled carbon nanotubes (MWCNTs). The effect of nanotube concentration on the properties of the resulting nanofabrics is also examined. Nine different nanofabric systems are prepared. The stress–strain behavior of the different nanofabric systems, which are eventually used as reinforcement interlayers, is investigated to assess the enhancement of the mechanical properties and to evaluate their potential as interlayer reinforcements. Scanning electron microscopy is employed to visualize the morphology and microstructure of the electrospun nanofabrics. The thermal behavior of the nanofabrics is investigated via differential scanning calorimetry to elucidate the glass and melting point of the nanofabrics, which can be used to identify optimum processing parameters at composite level. Introduction of MWCNTs appears to augment the mechanical response of the polymer nanofabrics. Examination of the mechanical performance of these interlayer reinforcements after heat treatment above the glass transition temperature reveals that morphological and microstructural changes can promote further enhancement of the mechanical response.

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Structural, Thermal and Electrical Properties of Doped Poly(3,4 ethylenedioxythiophene)

Chemistry & Chemical Technology ◽

10.23939/chcht10.04.395 ◽

2016 ◽

Vol 10 (4) ◽

pp. 395-400 ◽

Cited By ~ 1

Author(s):

Deepali Kelkar ◽

◽

Ashish Chourasia ◽

◽

Keyword(s):

Crystal Structure ◽

Electrical Properties ◽

Xrd Analysis ◽

Structure Modification ◽

Camphorsulfonic Acid ◽

Thermal And Electrical Properties ◽

Ft Ir

Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically synthesized, undoped and then re-doped using FeCl3 as well as camphorsulfonic acid (CSA). FT-IR results confirm the nature of the synthesized and doped samples. XRD analysis indicates crystal structure modification after doping and was also used to calculate crystallinity of samples. Crystallinity increases after FeCl3 doping, whereas it reduces due to CSA doping. TGA-DTA results show reduction in Tg value for FeCl3 doped sample while it increases for CSA doped samples compared to that of undoped PEDOT. Reduction in Tg indicates plasticizing effect of FeCl3 whereas increase in Tg show anti-plasticizing effect of CSA in PEDOT. Conductivity value () increases by two orders of magnitude after doping. Log vs. 1/T graph show metallic nature of undoped PEDOT above 308 K, however both doped samples show semiconducting nature from 301 to 383 K.

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