Limits...
Highly Omnidirectional and Frequency Controllable Carbon/Polyaniline-based 2D and 3D Monopole Antenna.

Shin KY, Kim M, Lee JS, Jang J - Sci Rep (2015)

Bottom Line: Solvated C/PANI was synthesized by low-temperature interfacial polymerization, during which strong π-π interactions between graphene and the quinoid rings of PANI resulted in an expanded PANI conformation with enhanced crystallinity and improved mechanical and electrical properties.These antennas attained high peak gain (3.60 dBi), high directivity (3.91 dBi) and radiation efficiency (92.12%) relative to 2D monopole antenna.These improvements were attributed the high packing density and aspect ratios of C/PANI fibers and the removal of the flexible substrate.

View Article: PubMed Central - PubMed

Affiliation: World Class University program of Chemical Convergence for Energy &Environment, School of Chemical and Biological Engineering, Seoul National University, 151-742, Korea.

ABSTRACT
Highly omnidirectional and frequency controllable carbon/polyaniline (C/PANI)-based, two- (2D) and three-dimensional (3D) monopole antennas were fabricated using screen-printing and a one-step, dimensionally confined hydrothermal strategy, respectively. Solvated C/PANI was synthesized by low-temperature interfacial polymerization, during which strong π-π interactions between graphene and the quinoid rings of PANI resulted in an expanded PANI conformation with enhanced crystallinity and improved mechanical and electrical properties. Compared to antennas composed of pristine carbon or PANI-based 2D monopole structures, 2D monopole antennas composed of this enhanced hybrid material were highly efficient and amenable to high-frequency, omnidirectional electromagnetic waves. The mean frequency of C/PANI fiber-based 3D monopole antennas could be controlled by simply cutting and stretching the antenna. These antennas attained high peak gain (3.60 dBi), high directivity (3.91 dBi) and radiation efficiency (92.12%) relative to 2D monopole antenna. These improvements were attributed the high packing density and aspect ratios of C/PANI fibers and the removal of the flexible substrate. This approach offers a valuable and promising tool for producing highly omnidirectional and frequency-controllable, carbon-based monopole antennas for use in wireless networking communications on industrial, scientific, and medical (ISM) bands.

No MeSH data available.


Related in: MedlinePlus

(a) Typical stress-strain curves under tensile loading, (b) electrical-resistance changes upon repeated bending, (c) dielectric constants and (d) XRD diffractograms are shown for carbon, PANI, and C/PANI thin films. Mechanical measurements were performed at a strain rate of 1 mm s−1. Loss factors were obtained by differentiation of the permittivity values. Powdered samples were used in XRD analyses.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4559896&req=5

f2: (a) Typical stress-strain curves under tensile loading, (b) electrical-resistance changes upon repeated bending, (c) dielectric constants and (d) XRD diffractograms are shown for carbon, PANI, and C/PANI thin films. Mechanical measurements were performed at a strain rate of 1 mm s−1. Loss factors were obtained by differentiation of the permittivity values. Powdered samples were used in XRD analyses.

Mentions: Representative stress−strain curves of the synthesized thin films, obtained using UTM, are shown in Fig. 2a. The carbon and PANI thin films had tensile strengths of 264 and 208 MPa and moduli of 7.13 and 4.33 GPa, respectively. Significant improvements in tensile strength and modulus were observed with the C/PANI thin film, which exhibited a tensile strength of 315 MPa and a modulus of 10.05 GPa (Table 1). Compared to carbon and PANI thin films, the elongation at break was higher for the C/PANI thin film (ca. 6.31%). The work of extension to toughness was assumed to be ca. 8.74 MJ m−3 for the C/PANI thin film, which is slightly higher than that of pristine PANI thin films (ca. 6.93 MJ m-3). These results suggest that strong interactions between the graphene sheets and PANI enhanced the mechanical strength of the C/PANI thin films.


Highly Omnidirectional and Frequency Controllable Carbon/Polyaniline-based 2D and 3D Monopole Antenna.

Shin KY, Kim M, Lee JS, Jang J - Sci Rep (2015)

(a) Typical stress-strain curves under tensile loading, (b) electrical-resistance changes upon repeated bending, (c) dielectric constants and (d) XRD diffractograms are shown for carbon, PANI, and C/PANI thin films. Mechanical measurements were performed at a strain rate of 1 mm s−1. Loss factors were obtained by differentiation of the permittivity values. Powdered samples were used in XRD analyses.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4559896&req=5

f2: (a) Typical stress-strain curves under tensile loading, (b) electrical-resistance changes upon repeated bending, (c) dielectric constants and (d) XRD diffractograms are shown for carbon, PANI, and C/PANI thin films. Mechanical measurements were performed at a strain rate of 1 mm s−1. Loss factors were obtained by differentiation of the permittivity values. Powdered samples were used in XRD analyses.
Mentions: Representative stress−strain curves of the synthesized thin films, obtained using UTM, are shown in Fig. 2a. The carbon and PANI thin films had tensile strengths of 264 and 208 MPa and moduli of 7.13 and 4.33 GPa, respectively. Significant improvements in tensile strength and modulus were observed with the C/PANI thin film, which exhibited a tensile strength of 315 MPa and a modulus of 10.05 GPa (Table 1). Compared to carbon and PANI thin films, the elongation at break was higher for the C/PANI thin film (ca. 6.31%). The work of extension to toughness was assumed to be ca. 8.74 MJ m−3 for the C/PANI thin film, which is slightly higher than that of pristine PANI thin films (ca. 6.93 MJ m-3). These results suggest that strong interactions between the graphene sheets and PANI enhanced the mechanical strength of the C/PANI thin films.

Bottom Line: Solvated C/PANI was synthesized by low-temperature interfacial polymerization, during which strong π-π interactions between graphene and the quinoid rings of PANI resulted in an expanded PANI conformation with enhanced crystallinity and improved mechanical and electrical properties.These antennas attained high peak gain (3.60 dBi), high directivity (3.91 dBi) and radiation efficiency (92.12%) relative to 2D monopole antenna.These improvements were attributed the high packing density and aspect ratios of C/PANI fibers and the removal of the flexible substrate.

View Article: PubMed Central - PubMed

Affiliation: World Class University program of Chemical Convergence for Energy &Environment, School of Chemical and Biological Engineering, Seoul National University, 151-742, Korea.

ABSTRACT
Highly omnidirectional and frequency controllable carbon/polyaniline (C/PANI)-based, two- (2D) and three-dimensional (3D) monopole antennas were fabricated using screen-printing and a one-step, dimensionally confined hydrothermal strategy, respectively. Solvated C/PANI was synthesized by low-temperature interfacial polymerization, during which strong π-π interactions between graphene and the quinoid rings of PANI resulted in an expanded PANI conformation with enhanced crystallinity and improved mechanical and electrical properties. Compared to antennas composed of pristine carbon or PANI-based 2D monopole structures, 2D monopole antennas composed of this enhanced hybrid material were highly efficient and amenable to high-frequency, omnidirectional electromagnetic waves. The mean frequency of C/PANI fiber-based 3D monopole antennas could be controlled by simply cutting and stretching the antenna. These antennas attained high peak gain (3.60 dBi), high directivity (3.91 dBi) and radiation efficiency (92.12%) relative to 2D monopole antenna. These improvements were attributed the high packing density and aspect ratios of C/PANI fibers and the removal of the flexible substrate. This approach offers a valuable and promising tool for producing highly omnidirectional and frequency-controllable, carbon-based monopole antennas for use in wireless networking communications on industrial, scientific, and medical (ISM) bands.

No MeSH data available.


Related in: MedlinePlus