Novel fabrication process for carbon fiber composite bipolar plates using sol gel and the double percolation effect for PEMFC

2015 ◽  
Vol 134 ◽  
pp. 44-51 ◽  
Author(s):  
Ha Eun Lee ◽  
Song Hee Han ◽  
Seung A Song ◽  
Seong Su Kim
Keyword(s):  
Carbon Fiber ◽  
Fiber Composite ◽  
Sol Gel ◽  
Fabrication Process ◽  
Bipolar Plates ◽  
Carbon Fiber Composite ◽  
Percolation Effect ◽  
Double Percolation

scholarly journals Investigation of Microwave Absorption Performance of CoFe2O4/NiFe2O4/Carbon Fiber Composite Coated with Polypyrrole in X-Band Frequency

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 809
Author(s):  
Rozhin Sadeghi ◽  
Abbas Sharifi ◽  
Marta Orlowska ◽  
Isabelle Huynen
Keyword(s):  
Carbon Fiber ◽  
Microwave Absorption ◽  
In Situ Polymerization ◽  
Fiber Composite ◽  
Sol Gel ◽  
Interfacial Polarization ◽  
Microwave Absorber ◽  
Carbon Fiber Composite ◽  
Band Frequency ◽  
5 Ghz

The current research reports the preparation of a microwave absorber containing CoFe2O4/NiFe2O4/Carbon fiber (H/S/CF) coated with polypyrrole polymer (PPy@H/S/CF) through sol-gel and in-situ polymerization processes. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM), and a vector network analyzer (VNA) are utilized to evaluate the features of the prepared composite. The microstructure analysis results revealed carbon fibers well decorated with submicron-size particles having hard/soft magnetic phases and thoroughly coated with polymer. The paraffin-based microwave absorber sample filled with 45 wt.% of PPy@H/S/CF has simultaneously both magnetic and dielectric losses in the 8.2–12.4  GHz frequency range. The absorber is used in a Salisbury screen configuration aiming at reducing the radar cross-section of objects. A minimum reflection loss of −55  dB at 10.6 GHz frequency with 5 GHz bandwidth is obtained for the sample with a 2  mm thickness. Different mechanisms, such as interfacial polarization, ferromagnetic resonance, and electron hopping, are the main factors for achieving such an appropriate microwave absorption. These results suggest that the PPy@H/S/CF composite is an ideal candidate for microwave absorption applications requiring high performance and low thickness.

Prestressed Carbon Fiber Composite Overwrapped Gun Tube

2008 ◽  
Author(s):  
Andrew Littlefield ◽  
Edward Hyland ◽  
Jack Keating
Keyword(s):  
Carbon Fiber ◽  
Fiber Composite ◽  
Carbon Fiber Composite

scholarly journals Lightweight Cellulose/Carbon Fiber Composite Foam for Electromagnetic Interference (EMI) Shielding

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1319 ◽  
Author(s):  
Ran Li ◽  
Huiping Lin ◽  
Piao Lan ◽  
Jie Gao ◽  
Yan Huang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Electromagnetic Interference ◽  
Fiber Composite ◽  
Carbon Fiber Composites ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Carbon Fiber Composite ◽  
Foaming Process ◽  
Long Carbon Fibers

Lightweight electromagnetic interference shielding cellulose foam/carbon fiber composites were prepared by blending cellulose foam solution with carbon fibers and then freeze drying. Two kinds of carbon fiber (diameter of 7 μm) with different lengths were used, short carbon fibers (SCF, L/D = 100) and long carbon fibers (LCF, L/D = 300). It was observed that SCFs and LCFs built efficient network structures during the foaming process. Furthermore, the foaming process significantly increased the specific electromagnetic interference shielding effectiveness from 10 to 60 dB. In addition, cellulose/carbon fiber composite foams possessed good mechanical properties and low thermal conductivity of 0.021–0.046 W/(m·K).

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