Study of Microwave Absorbing Properties of Polyaniline/STF Conducting Composites Prepared by <i>in Situ</i> Polymerization

Schettini, Anderson R.A.; Soares, Bluma G.

doi:10.1002/masy.200900106

Cited by 10 publications

(15 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It showed that the best SE and the higher values of reflected power, dielectric constant, dielectric permittivity, and dielectric loss were obtained for higher contents of the conducting composite. The higher value of tanδ was observed for the PAni‐DBSA/STF (=25/75) composition . Best SE value was obtained for larger thicknesses.…”

Section: Selective Overview and Materials Selectionmentioning

confidence: 85%

“…Out of many post‐2010 papers like, results of one interesting publication will now be summarized. Schettini et al studied PAni‐DBSA and PAni‐DBSA/STF samples over X‐band 8.2–12.4 GHz, where PAni = Poly‐aniline, DBSA = Dodecylbenzenesulfonic acid for EM shielding, and RAM applications. It showed that the best SE and the higher values of reflected power, dielectric constant, dielectric permittivity, and dielectric loss were obtained for higher contents of the conducting composite.…”

Section: Selective Overview and Materials Selectionmentioning

confidence: 99%

“…At lower frequencies the materials with a good magnetic conductivity (as well as electric conductivity when dealing with eddy currents) and thicker material may be needed. [7] Out of many post-2010 papers like, [9][10][11][12][13][14][15][16][40][41][42][43][44] results of one interesting publication [43] will now be summarized. Schettini et al [43] studied PAni-DBSA and PAni-DBSA/STF samples over X-band 8.2-12.4 GHz, where PAni ¼ Poly-aniline, DBSA ¼ Dodecylbenzenesulfonic acid for EM shielding, and RAM applications.…”

Section: Sample1mentioning

confidence: 99%

See 2 more Smart Citations

Polymer Composites for Flexible Electromagnetic Shields

Sahu¹,

De²

2018

Macromolecular Symposia

View full text Add to dashboard Cite

Harmful electromagnetic (EM) interference (EMI) to living beings and various sensitive instruments by EM radiations from electronic and electrical gadgets and mobile towers is increasing rapidly. It inflicts illness, and presumably cancerous growth in human cells. EMI is minimized by wrapping the receiver and/or the emitter gaplessly by an efficient EM shielding sheet. Compared to the widely used and classical metallic shields, 2nd generation polymer composite EMI shields are lighter and more flexible. Conventional polymer composites use conducting polymers and metallic/carbon powders that have conducting electrons to reflect EM waves away. A polymeric binder, curing overnight to a soft and flexible sheet, has presently been selected for making the polymeric composites. We test EM shielding by certain non‐metallic composites. We review results for composites with fine metallic fibers (copper and brass turnings, available as waste from mechanical workshops) or conducting forms of cadmium oxide or ferroelectric materials (PbNb2O6 [o‐PN] & BaTiO3 [BT]) or their mixtures (52 samples). Small pieces of these cloth‐like polymeric sheets have been characterized in a Vector Network Analyzer (VNA), by measuring input power (Pin), the reflected power (Prefl), and the transmitted power (Pout), over five frequency bands in 700 MHz to 40 GHz range to find Shielding Effectiveness (SE) = 10 log (Pout/Pin) and Reflection Effectiveness = 10 log (Prefl/Pin). Success of o‐PN, BT, conducting (fired) Cd‐O, metallic turnings and their combinations has been discussed, highlighting some new observations. Composites, developed in this work, include EMI Shielding materials and potential Radar Absorption Materials.

show abstract

Section: Selective Overview and Materials Selectionmentioning

confidence: 85%

Section: Selective Overview and Materials Selectionmentioning

confidence: 99%

Section: Sample1mentioning

confidence: 99%

See 1 more Smart Citation

Polymer Composites for Flexible Electromagnetic Shields

Sahu¹,

De²

2018

Macromolecular Symposia

View full text Add to dashboard Cite

show abstract

“…The attenuation of the electromagnetic radiation is usually evaluated from the scattering (S) parameters obtained from the network analyzer and occurs through three main mechanism: reflection, absorption and multi‐reflection. The transmission power (T) and the reflection power (R) are measured in terms of the incident radiation, according to the following equations:

R = {(true| S_{11} or S_{22} true|)}^{2} . T = {(true| S_{12} or S_{21} true|)}^{2}

…”

Section: Resultsmentioning

confidence: 99%

The Effect of Ionic Liquid on the Development of Polyaniline/Natural Fibers and Biodegradable Conductive Composites Based on Poly(Butylene Adipate‐co‐Terephthalate)

Pontes

Soares

Barra

et al. 2018

Macromolecular Symposia

Self Cite

View full text Add to dashboard Cite

Natural fiber produced from the peach palm trees (PPF) as agricultural waste is used to prepare polyaniline (PAni)‐based hybrid conductive fibers, through the in situ emulsion polymerization of aniline in isopropanol/water medium in the presence of dodecyl benzenesulfonic acid as protonating agent. Polyaniline is uniformly deposited on the fiber surface during the synthesis, as indicated by scanning electron microscopy. The presence of ionic liquid, 1‐butyl‐3‐methyl imidazolium tetrafluoroborate (bmim.BF4) during the PAni synthesis results in conductive fiber with conductivity of around 1.2 × 10−1 S cm−1, which is slightly higher than those obtained for neat PAni samples. The hybrid fibers are compounded with poly(butylene adipate‐co‐terephthalate) (PBAT) in different proportion to develop conductive biodegradable composites. For the same composite composition, those prepared with polyaniline/ionic liquid‐fiber (PAni.IL‐PPF) display higher dielectric constant, higher dielectric low, higher AC electrical conductivity and good electromagnetic interference shielding effectiveness (EMI SE) measured in the X‐band frequency range. In all conducting composites, an absorption dominated EMI shielding mechanism is observed, which make them promising microwave‐absorbing compound.

show abstract

“…Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) was performed on a Bruker spectrometer, model TENSOR 27, in the range of wave numbers from 4000 to 600 cm 21 by accumulating 32 scans at a resolution of 4 cm The electromagnetic interference properties of PU and PU/PPF-PPy composites were measured using an Agilent Technology PNA series network analyzer (N5230C Agilent PNA-L, Santa Clara, CA) and a standard rectangular waveguide in the X-band frequency range (8.2-12.4 GHz), according reported by Schettini and Soares [23] and Schettini, et al [20]. The e 0 and e 00 values were determined through scattering parameters S 11 and S 21 by Agilent 85071 software, in X-band frequency range (8.2 at 12.4 GHz).…”

Section: Characterizationmentioning

confidence: 99%

Electrically conductive composites of polyurethane derived from castor oil with polypyrrole‐coated peach palm fibers

et al. 2015

Self Cite

View full text Add to dashboard Cite

Electrically conducting fibers were prepared through in situ oxidative polymerization of pyrrole (Py) in the presence of peach palm fibers (PPF) using iron (III) chloride hexahydrate (FeCl 3. 6H 2 O) as oxidant. The polypyrrole (PPy) coated PPF displayed a PPy layer on the fibers surface, which was responsible for an electrical conductivity of (2.2 6 0.3) 3 10 21 S cm 21 , similar to the neat PPy. Electrically conductive composites were prepared by dispersing various amounts of PPy-coated PPF in a polyurethane matrix derived from castor oil. The polyurethane/PPy-coated PPF composites (PU/ PPF-PPy) exhibited an electrical conductivity higher than PU/PPy blends with similar filler content. This behavior is attributed to the higher aspect ratio of PPF-PPy when compared with PPy particles, inducing a denser conductive network formation in the PU matrix. Electromagnetic interference shielding effectiveness (EMI SE) value in the X-band (8.2-12.4 GHz) found for PU/PPF-PPy composites containing 25 wt% of PPF-PPy were in the range 212 dB, which corresponds to 93.2% of attenuation, indicating that these composites are promising candidates for EMI shielding applications. POLYM. COMPOS., 00:000-000, 2015.

show abstract

Study of Microwave Absorbing Properties of Polyaniline/STF Conducting Composites Prepared by in Situ Polymerization

Cited by 10 publications

References 20 publications

Polymer Composites for Flexible Electromagnetic Shields

Polymer Composites for Flexible Electromagnetic Shields

The Effect of Ionic Liquid on the Development of Polyaniline/Natural Fibers and Biodegradable Conductive Composites Based on Poly(Butylene Adipate‐co‐Terephthalate)

Electrically conductive composites of polyurethane derived from castor oil with polypyrrole‐coated peach palm fibers

Contact Info

Product

Resources

About