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Theoretical and Numerical Approaches for Determining the Reflection and Transmission Coefficients of OPEFB-PCL Composites at X-Band Frequencies.

Ahmad AF, Abbas Z, Obaiys SJ, Ibrahim N, Hashim M, Khaleel H - PLoS ONE (2015)

Bottom Line: In contrast to the effective medium theory, which states that polymer-based composites with a high dielectric constant can be obtained by doping a filler with a high dielectric constant into a host material with a low dielectric constant, this paper demonstrates that the use of a low filler percentage (12.2%OPEFB) and a high matrix percentage (87.8%PCL) provides excellent results for the dielectric constant and loss factor, whereas 63.8% filler material with 36.2% host material results in lower values for both the dielectric constant and loss factor.The comparative approach indicates that the mean relative error of FEM is smaller than that of NRW in terms of the corresponding S21 magnitude.The present calculation of the matrix/filler percentages endorses the exact amounts of substrate utilized in various physics applications.

View Article: PubMed Central - PubMed

Affiliation: Institute for Mathematical Research, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia.

ABSTRACT
Bio-composites of oil palm empty fruit bunch (OPEFB) fibres and polycaprolactones (PCL) with a thickness of 1 mm were prepared and characterized. The composites produced from these materials are low in density, inexpensive, environmentally friendly, and possess good dielectric characteristics. The magnitudes of the reflection and transmission coefficients of OPEFB fibre-reinforced PCL composites with different percentages of filler were measured using a rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in the X-band frequency range. In contrast to the effective medium theory, which states that polymer-based composites with a high dielectric constant can be obtained by doping a filler with a high dielectric constant into a host material with a low dielectric constant, this paper demonstrates that the use of a low filler percentage (12.2%OPEFB) and a high matrix percentage (87.8%PCL) provides excellent results for the dielectric constant and loss factor, whereas 63.8% filler material with 36.2% host material results in lower values for both the dielectric constant and loss factor. The open-ended probe technique (OEC), connected with the Agilent vector network analyzer (VNA), is used to determine the dielectric properties of the materials under investigation. The comparative approach indicates that the mean relative error of FEM is smaller than that of NRW in terms of the corresponding S21 magnitude. The present calculation of the matrix/filler percentages endorses the exact amounts of substrate utilized in various physics applications.

No MeSH data available.


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The Substrate preparation.
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pone.0140505.g003: The Substrate preparation.

Mentions: OPEFB fibre in this work was soaked in distilled water for 24 hours and then heated at about 80°C. This process was repeated twice. The filtered fibre was washed by acetone and then dried again in an oven to remove the wax layer of fibre. A grinded machine was used to grind fibre chains into small powder molecules and then sieved to sizes of 200μm. The compound of OPEFB-PCL was carried out in a Thermo Haake blending machine at 80°C with 50 rpm rotor speed for 20 minutes. The substrate of 1mm thickness was prepared by placing 10 g of the blend into a mold of 10×8cm2 dimensions. After that, OPEFB-PCL composites were preheated for 10 minutes with upper and lower plate. To reduce the void, a breathing time of one minute was allowed for bubble sand releasing. Finally, hot and cold pressed step of 110 kg/cm2 each was carried out for another 10 minutes each to obtain the required substrate. Fig 3 bellow illustrates the process of the substrate preparation.


Theoretical and Numerical Approaches for Determining the Reflection and Transmission Coefficients of OPEFB-PCL Composites at X-Band Frequencies.

Ahmad AF, Abbas Z, Obaiys SJ, Ibrahim N, Hashim M, Khaleel H - PLoS ONE (2015)

The Substrate preparation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608678&req=5

pone.0140505.g003: The Substrate preparation.
Mentions: OPEFB fibre in this work was soaked in distilled water for 24 hours and then heated at about 80°C. This process was repeated twice. The filtered fibre was washed by acetone and then dried again in an oven to remove the wax layer of fibre. A grinded machine was used to grind fibre chains into small powder molecules and then sieved to sizes of 200μm. The compound of OPEFB-PCL was carried out in a Thermo Haake blending machine at 80°C with 50 rpm rotor speed for 20 minutes. The substrate of 1mm thickness was prepared by placing 10 g of the blend into a mold of 10×8cm2 dimensions. After that, OPEFB-PCL composites were preheated for 10 minutes with upper and lower plate. To reduce the void, a breathing time of one minute was allowed for bubble sand releasing. Finally, hot and cold pressed step of 110 kg/cm2 each was carried out for another 10 minutes each to obtain the required substrate. Fig 3 bellow illustrates the process of the substrate preparation.

Bottom Line: In contrast to the effective medium theory, which states that polymer-based composites with a high dielectric constant can be obtained by doping a filler with a high dielectric constant into a host material with a low dielectric constant, this paper demonstrates that the use of a low filler percentage (12.2%OPEFB) and a high matrix percentage (87.8%PCL) provides excellent results for the dielectric constant and loss factor, whereas 63.8% filler material with 36.2% host material results in lower values for both the dielectric constant and loss factor.The comparative approach indicates that the mean relative error of FEM is smaller than that of NRW in terms of the corresponding S21 magnitude.The present calculation of the matrix/filler percentages endorses the exact amounts of substrate utilized in various physics applications.

View Article: PubMed Central - PubMed

Affiliation: Institute for Mathematical Research, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia.

ABSTRACT
Bio-composites of oil palm empty fruit bunch (OPEFB) fibres and polycaprolactones (PCL) with a thickness of 1 mm were prepared and characterized. The composites produced from these materials are low in density, inexpensive, environmentally friendly, and possess good dielectric characteristics. The magnitudes of the reflection and transmission coefficients of OPEFB fibre-reinforced PCL composites with different percentages of filler were measured using a rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in the X-band frequency range. In contrast to the effective medium theory, which states that polymer-based composites with a high dielectric constant can be obtained by doping a filler with a high dielectric constant into a host material with a low dielectric constant, this paper demonstrates that the use of a low filler percentage (12.2%OPEFB) and a high matrix percentage (87.8%PCL) provides excellent results for the dielectric constant and loss factor, whereas 63.8% filler material with 36.2% host material results in lower values for both the dielectric constant and loss factor. The open-ended probe technique (OEC), connected with the Agilent vector network analyzer (VNA), is used to determine the dielectric properties of the materials under investigation. The comparative approach indicates that the mean relative error of FEM is smaller than that of NRW in terms of the corresponding S21 magnitude. The present calculation of the matrix/filler percentages endorses the exact amounts of substrate utilized in various physics applications.

No MeSH data available.


Related in: MedlinePlus