The Study of Electromagnetic Shielding for Multiwall Carbon Nanotube Composites

by Chang, Chia-Ming

Abstract (Summary)
The shielding effectiveness (SE) of the novel multiwall carbon nanotube (MWCNT) plastic composites is studied for the purpose of the electromagnetic interference (EMI) protection and the electromagnetic susceptibility (EMS) improvement in the application of the optical transmitter and receiver modules. The experimental results showed that the liquid crystal polymer (LCP) based MWCNT composites can exhibit a high SE of 38 dB ~ 45 dB within the frequency range of 1 GHz ~ 3 GHz. The shielding capability was demonstrated by examining the electromagnetic susceptibility performance of the optical transmitter and receiver modules, which were packaged by the MWCNT-LCP composites. The EMS performance was evaluated by eye diagram and bit-error-rate test in a 2.5 Gbps lightwave transmission system. The results showed that the MWCNT-LCP composite packaged modules with more weight percentage of the MWCNTs can exhibit a higher SE, and hence showed effective EMS performance, a better mask margin, and a lower power penalty. A novel polyimide (PI) plastic consisting of finely ionic liquid (IL) dispersed MWCNTs was also demonstrated to have high SE under a lower MWCNT loading. The experimental results showed that the IL dispersed MWCNT-PI composite can exhibit a high SE of 40 dB ~ 46 dB within the frequency range of 1 GHz ~ 3 GHz. By comparison, the composite fabricated by non-dispersed process required a higher loading of MWCNTs than the dispersed one. To understand the detailed intermolecular forces among MWCNTs, the dispersion mechanism of the MWCNTs is studied qualitatively. The aggregation of MWCNTs is from van der Waals forces among MWCNTs, and it can be dispersed by using IL dispersant. This is due to the predominant cation-
Bibliographical Information:

Advisor:Ken-Huang Lin; Mei-Ying Chang; Tsong-Sheng Lay; Jiang-Jen Lin; Tzong-Lin Wu; Hung-Chun Chang; Way-Seen Wang; Wood-Hi Cheng; Wern-Shiarng Jou

School:National Sun Yat-Sen University

School Location:China - Taiwan

Source Type:Master's Thesis

Keywords:carbon nanotube shielding effectiveness emi ems


Date of Publication:02/12/2008

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