以靜電紡絲法將多層奈米碳管分散於具有氫鍵系統之複合奈米纖維及其特性分析

Abstract

本篇研究利用氧化聚合之方式聚合出具有三點式氫鍵官能基之Poly(3- thiophene-triazole- diaminopyridin) (PTDAP)，並混摻於具有生物官能基的聚苯乙烯尿嘧啶(PVBU)，透過電紡絲之技術噴絲成奈米/微米纖維材料，證實三點式氫鍵作用力之存在不但提升纖維型態和相容性，並在熱性質方面有顯著之提升。 再將多層奈米碳管分散於此氫鍵系統，可置備出形狀完整且無珠狀小球的複合奈米纖維，具有高的比表面積，其直徑可達到500nm。在熱性質方面，三點式氫鍵作用力之存在明顯的提升碳管-高分子複合奈米纖維之熱性質。由拉曼光譜、穿透式電子顯微鏡以及四點碳針可以證實PTDAP中噻吩端(thiophene group) 與多層奈米碳管表面之非共價性π-π作用力(non-covalent π-π interaction)來穩定化碳管表面以及達到分散多層奈米碳管之效果，而三點式氫鍵作用力的存在提升溶液之溶解度，電紡溶液再透過電場的存在下而拉伸，使多層奈米碳管與纖維具有同軸之方向及順向性，進而增加電子之傳導速率，因此在導電性方面有顯著之提升。

In this thesis, the poly(3-thiophene-triazole-diaminopyridin) (PTDAP) possessing triple hydrogen bonding sites were successfully synthesized through chemical oxidative polymerization. Following blending with the biocompatible poly(4-vinylbenzyl uracil) (PVBU), nano/micro nanofibers can be fabricated through electrospinning. These results indicate that the presence of the hydrogen-bonding system may improve the morphology, thermal stability, functionality and compatibility of nanofibers for applying in carbon nanotube dispersion, biomatrix, filter, or battery seperation. In addition, we incorporate the multiwalled carbon nanotubes (MWCNTs) into the PVBU/PTDAP hydrogen-bonding system and successfully fabricated bead-free composite nanofibers with diameter down to 500 nm. Under the hydrogen-bonding system, the thermal stability of the composite nanofibers is improved apparently. Fourier transform Raman (FT-Raman) spectra, transmission electron microscope (TEM) and standard four probe result indicate that the conjugated polymer block such as polythiophenes can form strong non-covalent π–π interactions with multiwalled carbon nanotube walls which prevents MWCNTs from aggregating and dispersion, while the triple hydrogen-bonding interaction between PTDAP and PVBU provide the de-bundled MWCNTs with a good solubility and stability in the organic solvents and host polymer matrices. TEM observation showed the MWCNTs were parallel and oriented along the axes of the nanofibers which increase the conduction of electrons and therefore significantly enhance the conductivity.