scholarly journals 3D Porous Graphene Based Aerogel for Electromagnetic Applications

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hossein Cheraghi Bidsorkhi ◽  
Alessandro Giuseppe D’Aloia ◽  
Alessio Tamburrano ◽  
Giovanni De Bellis ◽  
Andrea Delfini ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Vinylidene Fluoride ◽  
Mechanical Stability ◽  
Electronic Devices ◽  
Cost Effective ◽  
Water Repellent ◽  
Processing Temperature ◽  
Porous Graphene ◽  
Poly Vinylidene Fluoride ◽  
Selection Of

Abstract Lightweight multifunctional electromagnetic (EM) absorbing materials with outstanding thermal properties, chemical resistance and mechanical stability are crucial for space, aerospace and electronic devices and packaging. Therefore, 3D porous graphene aerogels are attracting ever growing interest. In this paper we present a cost effective lightweight 3D porous graphene-based aerogel for EM wave absorption, constituted by a poly vinylidene fluoride (PVDF) polymer matrix filled with graphene nanoplatelets (GNPs) and we show that the thermal, electrical, mechanical properties of the aerogel can be tuned through the proper selection of the processing temperature, controlled either at 65 °C or 85 °C. The produced GNP-filled aerogels are characterized by exceptional EM properties, allowing the production of absorbers with 9.2 GHz and 6.4 GHz qualified bandwidths with reflection coefficients below −10 dB and −20 dB, respectively. Moreover, such aerogels show exceptional thermal conductivities without any appreciable volume change after temperature variations. Finally, depending on the process parameters, it is shown the possibility to obtain water repellent aerogel composites, thus preventing their EM and thermal properties from being affected by environmental humidity and allowing the realization of EM absorber with a stable response.

Flexible Fibrous Piezo-Electric Sensor on Printed Silver Electrode

2014 ◽  
Vol 1685 ◽  
Author(s):  
Ho Yeon Son ◽  
Yoon Sung Nam ◽  
Woo Soo Kim
Keyword(s):  
Vinylidene Fluoride ◽  
Silver Nanowires ◽  
High Sensitivity ◽  
Cost Effective ◽  
Piezoelectric Sensor ◽  
Piezoelectric Sensors ◽  
Mechanical Stimuli ◽  
Aligned Arrays ◽  
Poly Vinylidene Fluoride ◽  
Facile Fabrication

ABSTRACTHere we introduce a facile method to fabricate a flexible piezoelectric sensor using one-dimensional (1-D) piezoelectric poly(vinylidene fluoride) (PVDF) nanofibers directly produced onto flexible printed electrodes by electro-spinning without an additional poling process. The flexible silver electrodes are fabricated on polyethylene terephthalate (PET) using silver nanowires by easy and cost-effective spraying deposition. The electrospun PVDF nanofibers have uniaxially aligned arrays on the electrodes by using a rotating collector. The fabricated PVDF piezoelectric sensors demonstrate the piezoelectric responses with repeated mechanical stimuli with good flexibility and high sensitivity. We expect that the facile fabrication of PVDF piezoelectric sensors on flexible printed electrodes can be usefully exploited to integrate the piezoelectric sensors into flexible and stretchable functional electronic devices.

Fast and simple fabrication of SiO2/poly(vinylidene fluoride) coated cotton fabrics with asymmetric wettability via a facile spray-coating route

2018 ◽  
Vol 89 (6) ◽  
pp. 1013-1026 ◽  
Author(s):  
Rongrong Yu ◽  
Mingwei Tian ◽  
Lijun Qu ◽  
Shifeng Zhu ◽  
Jianhua Ran ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Vinylidene Fluoride ◽  
Spray Coating ◽  
Cotton Fabrics ◽  
Water Repellent ◽  
Water Contact ◽  
Repellent Property ◽  
Poly Vinylidene Fluoride

Cotton fabrics with hydrophilic-to-hydrophobic asymmetric surfaces are attractive as potential utilizable structures for functional garments. The spray-coating route could be deemed as a fast and simple way to achieve asymmetric surfaces. In this paper, SiO2 nanoparticles with size ∼ 205 nm were synthesized via the modified sol-gel method, and then modified with poly(vinylidene fluoride) (PVDF) to form a hydrophobic surface. The SiO2 nanoparticles modified with PVDF were uniformly deposited on the outer surface of cotton fabric aided with the robust air flow force from the sprayer. The morphology and chemical structures were characterized by scanning electron microscopy, mapping, atomic force microscopy, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The results indicated that SiO2 nanoparticles were evenly deposited on the surface of cotton fibers and stable interfacial interaction occurred between SiO2 and PVDF molecular chains. The existence of SiO2 could increase the roughness of the fabric surface, which could enhance the water-repellent property of the coated fabrics. Furthermore, the water-repellent property and thermal insulation properties were evaluated via the water contact angle and thermal conductivity tests, respectively, and the results showed that 20 wt.% SiO2/PVDF fabric achieved a desirable level of contact angle, 136.6°, which was the largest water contact angle among all the samples, and the lowest thermal conductivity of 0.033 W/mK, resulting from the existence of SiO2 nanoparticles. Such a fast and simple spray-coating strategy could be widely introduced into asymmetric fabric modification, and such asymmetric fabrics with reasonable water-repellent and thermal insulating outer surfaces could act as candidates in the field of functional garments.

Enhancement of the Dielectric Constant and Thermal Properties of α-Poly(vinylidene fluoride)/Zeolite Nanocomposites

2010 ◽  
Vol 114 (34) ◽  
pp. 14446-14452 ◽  
Author(s):  
Ana Catarina Lopes ◽  
Marco P. Silva ◽  
Renato Gonçalves ◽  
Manuel F. R. Pereira ◽  
Gabriela Botelho ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Thermal Properties ◽  
Vinylidene Fluoride ◽  
Poly Vinylidene Fluoride

Design and Synthesis of a Superhydrophobic PVDF-Based Composite

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Hyunho Choi ◽  
Kyungjun Lee ◽  
John Reeks ◽  
Hong Liang
Keyword(s):  
Phase Separation ◽  
Chemical Treatment ◽  
Vinylidene Fluoride ◽  
Cost Effective ◽  
Simple Approach ◽  
Material Surface ◽  
Engineering Applications ◽  
Design And Synthesis ◽  
Material Surfaces ◽  
Poly Vinylidene Fluoride

The ability to design, control, and synthesize a material surface with superhydrophobicity is of great interests in many engineering applications. Here, we report a cost-effective process to fabricate poly(vinylidene fluoride) (PVDF)/zirconium(IV) oxide (ZrO2) composites with superhydrophobicity. This is achieved by combining an antisolvent that induces phase separation, i.e., the precipitation of PVDF from the solution through a spray-on method on various liquids. The material surfaces possess wrinkled micron-sized beads which displayed superhydrophobicity in water without any chemical treatment. The process developed in this research presented a fast and simple approach in making hydrophobic surfaces.

scholarly journals Enhanced thermal properties of poly(vinylidene fluoride) composites with ultrathin nanosheets of MXene

RSC Advances ◽  
2017 ◽  
Vol 7 (33) ◽  
pp. 20494-20501 ◽  
Author(s):  
Yong Cao ◽  
Qihuang Deng ◽  
Zhiduo Liu ◽  
Dianyu Shen ◽  
Ting Wang ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Vinylidene Fluoride ◽  
Ultrathin Nanosheets ◽  
Poly Vinylidene Fluoride

We report a facile method to delaminate MXenes and prepare poly(vinylidene fluoride)/MXene composites with excellent thermal properties.

Investigation of electrical and thermal properties of poly (vinylidene fluoride)/strontium hexaferrite polymer composites

2020 ◽  
Vol 31 (24) ◽  
pp. 22687-22698
Author(s):  
Deeptimayee Khatua ◽  
Minakshi Padhy ◽  
Rajesh K. Singh ◽  
R. N. P. Choudhary ◽  
P. Ganga Raju Achary
Keyword(s):  
Thermal Properties ◽  
Polymer Composites ◽  
Vinylidene Fluoride ◽  
Strontium Hexaferrite ◽  
Poly Vinylidene Fluoride

The improved interfacial polarization in a poly(vinylidene fluoride-co-chlorotrifluoroethylene) composite with hyperbranched polyethylene-graft-poly(methyl methacrylate) modified boron nitride nanosheets

2020 ◽  
Vol 8 (37) ◽  
pp. 12819-12828
Author(s):  
Huijian Ye ◽  
Wenqing Liu ◽  
Xuanhe Zhang ◽  
Lixin Xu
Keyword(s):  
Boron Nitride ◽  
Methyl Methacrylate ◽  
Power Density ◽  
Vinylidene Fluoride ◽  
Electronic Devices ◽  
Interfacial Polarization ◽  
Large Power ◽  
Poly Methyl Methacrylate ◽  
Boron Nitride Nanosheets ◽  
Poly Vinylidene Fluoride

Polymer capacitors are promising candidates for the miniaturization and integration of electronic devices due to their flexibility and large power density.

Enhanced ferroelectricity and energy storage in poly(vinylidene fluoride)–clay nanocomposite films via nanofiller surface charge modulation

RSC Advances ◽  
2015 ◽  
Vol 5 (104) ◽  
pp. 85884-85888 ◽  
Author(s):  
Y. Wang ◽  
J. Li ◽  
Y. Deng
Keyword(s):  
Energy Storage ◽  
Composite Film ◽  
Vinylidene Fluoride ◽  
Electronic Devices ◽  
Nanocomposite Films ◽  
Simultaneous Increase ◽  
Organic Electronic Devices ◽  
Organic Electronic ◽  
Poly Vinylidene Fluoride ◽  
Charge Modulation

Simultaneous increase in ferroelectricity and energy storage was achieved in pvdf/mmt composite film indicating a good candidate for all-organic electronic devices.

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