Fig 1 - uploaded by Huie Zhu
Content may be subject to copyright.
Source publication
Ferroelectric polymers are a family of crystalline polymers with reversible remanent polarization originating from their unique chemical structures and molecular packing. As an important ferroelectric polymer, poly(vinylidene fluoride) (PVDF) and its copolymers have been exploited for various applications, including nonvolatile memories, energy har...
Contexts in source publication
Context 1
... studied, particularly addressing modified polymer structures, crystallization manipulations, and device configurations. Actually, PVDF has a very simple molecular structure, consisting of only carbon, hydrogen and fluorine elements in its molecular structure. Its molecular packing in different forms gives rise to different crystalline structures (Fig. 1a). Polar crystalline phases found in PVDF materials, including the β [12,13] and γ [13][14][15] phases, are the origin of PVDF materials' ferroelectricity. Moreover, they exhibit electroactive properties by which the PVDF molecular chain takes all-trans (TTTT) and trans-rich (TTTG) conformations (Fig. 1b) [16,17]. However, the nonpolar α ...
Context 2
... rise to different crystalline structures (Fig. 1a). Polar crystalline phases found in PVDF materials, including the β [12,13] and γ [13][14][15] phases, are the origin of PVDF materials' ferroelectricity. Moreover, they exhibit electroactive properties by which the PVDF molecular chain takes all-trans (TTTT) and trans-rich (TTTG) conformations (Fig. 1b) [16,17]. However, the nonpolar α phase (Fig. 1a), a monoclinic cell with a rectangular lattice, is the most thermodynamically stable crystalline structure: it has a trans-gauche-trans-gauche (TGTG') chain conformation (Fig. 1b) [13]. Therefore, to improve the application properties, PVDF materials should be pretreated for higher polar ...
Context 3
... 1a). Polar crystalline phases found in PVDF materials, including the β [12,13] and γ [13][14][15] phases, are the origin of PVDF materials' ferroelectricity. Moreover, they exhibit electroactive properties by which the PVDF molecular chain takes all-trans (TTTT) and trans-rich (TTTG) conformations (Fig. 1b) [16,17]. However, the nonpolar α phase (Fig. 1a), a monoclinic cell with a rectangular lattice, is the most thermodynamically stable crystalline structure: it has a trans-gauche-trans-gauche (TGTG') chain conformation (Fig. 1b) [13]. Therefore, to improve the application properties, PVDF materials should be pretreated for higher polar crystal formation. Generally, for bulky ...
Context 4
... electroactive properties by which the PVDF molecular chain takes all-trans (TTTT) and trans-rich (TTTG) conformations (Fig. 1b) [16,17]. However, the nonpolar α phase (Fig. 1a), a monoclinic cell with a rectangular lattice, is the most thermodynamically stable crystalline structure: it has a trans-gauche-trans-gauche (TGTG') chain conformation (Fig. 1b) [13]. Therefore, to improve the application properties, PVDF materials should be pretreated for higher polar crystal formation. Generally, for bulky materials, thermal treatment of oriented samples under high pressure [18,19], mechanical stretching [20][21][22], and/or electric poling [23] are traditional methods to improve polar ...
Similar publications
Poly(vinylidene fluoride) (PVDF)‐based polymers demonstrate great potential for applications in flexible and wearable electronics but show low piezoelectric coefficients (e.g., −d33 < 30 pC N⁻¹). The effective improvement for the piezoelectricity of PVDF is achieved by manipulating its semicrystalline structures. However, there is still a debate ab...
Citations
... Several authors have studied this polymeric material for many applications with different purposes [42]. For example, Mat Nawi et al. [43] used PVDF with polyethylene glycol dissolved in DMAC to improve the process of water treatment. ...
Piezoelectric materials such as PVDF and its copolymers have been widely studied in different areas and with promising applications, such as haptic feedback actuators or deformation sensors for aided-mobility scenarios. To develop PVDF-based solutions, different protocols are reported in the literature; however, a toxic and harmful solvent is commonly used (dymethilformamide (DMF)). In the present study, a non-toxic solvent (dymethilsulfoxide (DMSO)) is used to dissolve PVDF powder, while a specific ionic liquid (IL), [PMIM][TFSI], is used to enhance piezoelectric properties. A PVDF/IL thin film is characterized. The physical material characterization is based on optical analysis (to ensure the sample’s homogeneity) and on mechanical linear behaviour (Young’s modulus of 144 MPa and yield stress of 9 MPa). Meanwhile, a chemical analysis focuses on the phase modifications introduced by the addition of IL (𝛽 phase increase to 80% and a degree of crystallinity, 𝜒, of 30%). All the results obtained are in good agreement with the literature, which indicates that the proposed experimental protocol is suitable for producing PVDF-based thin films for biomedical applications.
... Interestingly binder PVDF 1 with a higher amorphous phase (Fig. 2) showed a higher percentage of b phase PVDF compared to PVDF 2. This might be due to the destruction of the crystallographic arrangement of (CH 2 -CF 2 ) in TG TG' conformer (a phase) which is non-polar by the polar arrangement of (CH 2 -CF 2 ) in TTTT conformer (b phase) of the PVDF [31]. Thus the presence of polar chain in a non-polar arrangement leads to the amorphization of PVDF 1 having higher b phase fraction. ...
Poly(vinylidene fluoride) (PVDF) has been widely utilized as a binder material in cathode as well as anode preparation for Li-ion batteries. Recent reports on water-soluble and functional binders have firmly established that even though the binder consists of only a small part of the electrode, it can significantly boost cell performance. However, no previous report has specifically explored the role of PVDF crystallinity on the performance of the LiFePO4 cathode and cell. In the present work, LiFePO4 cathodes with two different binders PVDF 1 (Kynar HSV 900), and PVDF 2 (Solef 5130) have been prepared. The PVDF binder with higher crystallinity showed more viscosity (86.3 Pa.s), higher adhesion strength (11.42 N-cm−1), and minimal electrolyte uptake (11.3%) as compared to the low crystallinity binder (32.8 Pa.s, 1.30 N-cm−1, and 18.88%). Thus, the cell having more crystalline PVDF binder showed a higher initial capacity of ∼146 mAh-g−1 and stable cyclability performance (82% capacity retention after 500 cycles) as compared to the cell with less crystalline binder PVDF (∼136 mAh-g−1 and 64%). The post-mortem analysis performed after 500 cycles of charging and discharging revealed relatively smaller cracks formed in the cathode with higher crystallinity binder, which explains its better cyclability.
Polymer composites exhibit unique mechanical, electrical, and thermal properties which makes them a potential candidate in the realm of nanoscale energy harvesting. The incorporation of various materials, such as ceramics, perovskites, and nanomaterials, into polymer matrices enhances the piezoelectric, pyroelectric, and triboelectric capabilities of the composite for utilization in different nano-generators for energy harvesting. Polymer composites-based nano-generators harvest energy from various sources such as vibrations, human movements, and temperature variations. These polymer composite-based nano-generators also hold significant value for the advancements in self-sustaining electronic devices, wearable sensors, and Internet of Things (IoT) applications. This chapter covers the basic principles and workings of different types of nano-generators including piezoelectric, triboelectric, pyroelectric, and hybridized nano-generators, followed by the polymer composites utilized in the development and performance enhancement of those nano-generators.
The next step in nanotechnology is to establish a methodology to assemble new functional materials based on the knowledge of nanotechnology. This task is undertaken by nanoarchitectonics. In nanoarchitectonics, we architect functional material systems from nanounits such as atoms, molecules, and nanomaterials. In terms of the hierarchy of the structure and the harmonization of the function, the material created by nanoarchitectonics has similar characteristics to the organization of the functional structure in biosystems. Looking at actual biofunctional systems, dynamic properties and interfacial environments are key. In other words, nanoarchitectonics at dynamic interfaces is important for the production of bio-like highly functional materials systems. In this review paper, nanoarchitectonics at dynamic interfaces will be discussed, looking at recent typical examples. In particular, the basic topics of “molecular manipulation, arrangement, and assembly” and “material production” will be discussed in the first two sections. Then, in the following section, “fullerene assembly: from zero-dimensional unit to advanced materials”, we will discuss how various functional structures can be created from the very basic nanounit, the fullerene. The above examples demonstrate the versatile possibilities of architectonics at dynamic interfaces. In the last section, these tendencies will be summarized, and future directions will be discussed.
PVDF forms β- and γ-phases in the presence of alkylammonium salts. We investigated crystal polymorphism obtained by various crystallization processes using FT-IR in PVDF added with two different alkylammonium salts. The fractions of crystalline phase changed with crystallization processes and ionic salts, which is attributed to the different crystallization mechanisms depending on the strengths of the ion-dipole interactions between alkylammonium salts and PVDF chains.
The development of off-stoichiometry thiol-ene-epoxy (OSTE+) based functional polymer has paramount importance for smart photonic sensors integrated lab-on-chip device applications. A modest attempt has been made to develop a semiconducting...
Poly(vinylidene fluoride) (PVDF) is one of the most extensively used polymers for superhydrophobic coatings because of its low surface free energy and inertness to various chemicals. Based on general rules, not only a low surface free energy but also high surface roughness is required for preparing artificial superhydrophobic surfaces. Therefore, enhancement of the hydrophobicity of PVDF coatings is commonly conducted through a two-stage method: incorporation of micro/nanoparticles into the PVDF matrix and postcoating with low-surface-energy materials. In our previous work, a nonsolvent-induced crystallization method was applied to obtain PVDF nanostructure assemblies with different surface morphologies through the selection of various nonsolvents. In this work, we investigated how morphologies influenced the surface wettability of PVDF nanostructure assembly coatings. The coatings consisting of nanoparticles exhibited highly improved hydrophobicity compared with that of the flat drop-coating PVDF surface. As the portion of nanoparticles increased, the roughness of the surfaces increased, as did the water contact angle (WCA). In the case of surfaces composed of nanoparticles (60–250 nm in diameter), superhydrophobic and oleophilic properties were achieved with a high air-pocket fraction, as described by the Cassie–Baxter model. These results provide valuable insight into PVDF surface design, especially for superhydrophobic coatings. © 2022, The Author(s), under exclusive licence to The Society of Polymer Science, Japan.
A facile and room temperature approach to synthesize pure TiO 2 and different variants of nirogen and cobalt co-doped TiO 2 (CoN-TiO 2 ) catalysts is reported in this study. The successful synthesis and crystalline phase analysis was carried out via X-ray diffraction (XRD) which confirmed anatase phase with tetragonal structure. The spherical morphology, uniform size distribution in the range of 20-40 nm and presence of dopants in final product were validated by scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS). Diffused reflectance spectroscopy (DRS) is deployed for study of optical properties. A reduction in band gap from 3.2 eV for pure TiO 2 nanoparticles to 2.34 eV for the 7 wt.%. doped CoN-TiO 2 was observed. The photocatlytic activity of pure TiO 2 , and CoN-TiO 2 nanoparticles was studied against methyl orange.The photocatlytic activity of CoN-TiO 2 was almost double as compared to undoped TiO 2 which proves these catalysts to be very efficient and potential candidate for the wastewater treatment at industrial level.
Aqueous zinc ion batteries are regarded as ideal candidates for stationary energy storage systems due to their low cost and high safety. However, zinc can readily grow into dendrites, leading to limited cycling performance and quick failure of the batteries. Herein, we propose a novel strategy to mitigate this dendrite problem, in which selectively-polarized ferroelectric polymer material (poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))) is employed as a surface protective layer on zinc anodes. Such a polarized ferroelectric polymer layer could enable a locally-concentrated zinc ion distribution along the coated surface and thus enable the horizontal growth of zinc plates. As a result, symmetrical zinc batteries using such anodes exhibits long cycling lifespan at 0.2 mA cm⁻², 0.2 mAh cm⁻² for 2000 hours, and a high rate performance up to 15 mA cm⁻². Also, the full cell (including Zn-MnO2 battery and zinc ion capacitor) based on this anode has been demonstrated. This work provides a novel strategy to protect the zinc anode and even other metal anodes exploiting polymer ferroelectricity.
This article is protected by copyright. All rights reserved
