Low contents of graphite improving general properties of poly(vinylidene fluoride)

Tienne, Lucas Galhardo Pimenta; Abreu, Thiago Brito de; Gondim, Fernanda Fabbri; Cruz, Bárbara de Salles Macena da; Martins, Gustavo Reis; Simão, Renata Antoun; Marques, Maria de Fátima Vieira

doi:10.1016/j.polymertesting.2020.106790

Cited by 8 publications

(3 citation statements)

References 49 publications

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“…Graphite was selected as a viscosity-modifying additive to both enhance mechanical properties as well as achieve a shear-thinning photopolymer formulation capable of being processed at room temperature. [42][43][44] While low concentrations of graphite (0-28 wt% of resin) were found to only moderately change the rheological behavior, 30 wt% displayed a distinct change with regards to both shear stress and viscosity, indicating good shear thinning behavior. Qualitatively, the appearance of the ink was distinctly different at this stage, with a transition taking place from a liquid resin to a more toothpaste-like ink capable of maintaining its shape after mixing with a spatula.…”

Section: Rheological Characterizationsmentioning

confidence: 99%

4D Aliphatic photopolymer polycarbonates as direct ink writing of biodegradable, conductive graphite‐composite materials

et al. 2021

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Photopolymers are one of the fastest growing 3D printing material classes, despite the lack of diversity in performance or composition. A simple addition of graphite nanopowder is explored for tailoring aliphatic polycarbonate performance and enhancing advanced material properties, targeting the mechanical performance of the norbornene-containing poly(norbornene trimethyl carbonate) using poly(trimethyl propane allyl ether carbonate) for thermoset formation using thiol-ene photochemistry. A 30 wt% graphite-composite photopolymer ink displays shear thinning behavior suitable for pneumatic direct ink write (DIW) printing, along with enhanced elastic modulus (15-542 MPa) and an increase in ultimate strength (2-22 MPa for the composite ink) without significant variation in the glass transition temperature. The composites are further demonstrated as 4D materials including shape memory, conductivity, and recyclability, with this work serving as a guide for designing DIW inks from photopolymer resins.

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Section: Rheological Characterizationsmentioning

confidence: 99%

4D Aliphatic photopolymer polycarbonates as direct ink writing of biodegradable, conductive graphite‐composite materials

et al. 2021

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“…To date, various techniques have been proposed to enhance the electroactive β‐phase content including but not limited to mechanical stretching, [ 13 ] electrical poling, [ 14 ] solution casting, [ 15 ] filler incorporation, [ 16 ] spin coating, [ 17 ] and electrospinning. [ 18 ] Among them, the in situ electrical poling process during electrospinning and the enhancement of the β‐phase through the incorporation of high piezoelectric coefficient materials, such as barium titanate (BT), [ 19 ] or conductive carbon‐based filles, such as graphite nano‐sheet (GNS) [ 20 ] into P(VDF‐TrFE) matrix have been shown to significantly improve the piezoelectric performance of PENGs. In order to further improve the device performances, layer‐by‐layer structures of electrospun fiber mats were studied.…”

Section: Introductionmentioning

confidence: 99%

Giant Energy Harvesting via Maxwell Displacement Current Enhancement Using Metal Sheet Interspaced Hetero‐Layer Structured Piezo‐Composite Nanofiber Device

Mahanty,

Ghosh,

Prasad

et al. 2023

Adv Funct Materials

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The limited performance of piezoelectric nanogenerators (PENGs) has hindered their practical applications in self‐powered electronics. To address these limitations, this study presents a new design of a PENG that incorporates hetero‐layer structured piezo‐composite nanofibers with interspaced metal sheets. The hetero‐layer structure consists of alternating layers of ferroelectric barium titanate (BT) nanoparticles interfaced with poly(vinylidene fluoride‐co‐trifluoroethylene) (P(VDF‐TrFE)) composite nanofibers (P(VDF‐TrFE)/BT), and conductive graphite nano‐sheets (GNS)‐embedded P(VDF‐TrFE) composite nanofibers (P(VDF‐TrFE)/GNS) mats. The inclusion of interspaced metal sheets in the device configuration enhances the stress concentration effect, thereby effectively distributing the applied mechanical vibrations. Simultaneously, the P(VDF‐TrFE)/BT composite nanofibers improve the piezoelectric coefficient (187.86 pC N−1), while the P(VDF‐TrFE)/GNS composite nanofibers reduce the internal impedance of the device. These combined enhancements result in an increased Maxwell displacement current and power output. Consequently, the hetero‐layer structured PENG exhibits an impressive open circuit voltage (Voc) output of 350 V, a short circuit current (Isc) output of 6 µA, and a power output of 3.62 W m−2. Moreover, the developed PENG demonstrates extraordinary energy harvesting performance under harsh vibrations caused by human musculoskeletal movements, as well as subtle vibrations from heart pulses, emotional changes, and speech recognition. Additionally, the PENG shows its potential use in wearable self‐powered wireless e‐health systems.

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“…This paper focus on the preparation of new membranes based on PS which are widely used as a polymer for commercial ultra-filtration and microfiltration membranes. PS as a thermoplastic polymer has been used as a support material for nano-filtration and reverse osmosis membranes, because it has high thermal (150-170 o C) and chemical stability, mechanical strength and microorganism resistance [30][31][32][33]. Additives such as PEG, PVP and ZnO NPs were separately used with PS to produce composite membranes.…”

Section: Introductionmentioning

confidence: 99%

Assessment of green biodiesel production based on Egyptian waste cooking oil using different porous membranes

et al. 2021

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In this study, green biodiesel was produced from Egyptian waste cooking oil by trans-esterification reaction using membrane technology. The produced biodiesel was characterized by physicochemical properties, FTIR, and gas chromatography/mass spectrometry (GC/MS). It was found that it meets the specifications of the American standard test method (ASTM) D6751. Because glycerol was the only impurity that was difficult to separate from the prepared biodiesel by regular methods, polysulfone (PS) membrane and three hybrid membranes were prepared using the phase inversion method for the glycerol purification process. The hybrid membranes were prepared by mixing PS with different weight ratios of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP), and zinc oxide nanoparticles (ZnO NPs). The structure and surface morphology of the resulted membranes were characterized by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA). The purification efficiency of these membranes was satisfied by highperformance liquid chromatography (HPLC) and weight loss ratio. The HPLC chromatogram showed that the membrane of the PS/ZnO NPs provided the highest separation rate of the biodiesel by-product glycerol compared to the other ones.

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Low contents of graphite improving general properties of poly(vinylidene fluoride)

Cited by 8 publications

References 49 publications

4D Aliphatic photopolymer polycarbonates as direct ink writing of biodegradable, conductive graphite‐composite materials

4D Aliphatic photopolymer polycarbonates as direct ink writing of biodegradable, conductive graphite‐composite materials

Giant Energy Harvesting via Maxwell Displacement Current Enhancement Using Metal Sheet Interspaced Hetero‐Layer Structured Piezo‐Composite Nanofiber Device

Assessment of green biodiesel production based on Egyptian waste cooking oil using different porous membranes

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