Nanocomposites including graphene oxide (GO) and conducting polymers (PPy, PANI and PEDOT) were prepared via an in-situ chemical polymerization process, and their characteristic properties depending upon the change of conducting polymer (CP) content were analyzed. A confirmation was made on not only the functional groups formed in GO but also the presence of CP existent in the nanocomposites. The molecular interaction between GO and poly(4-styrene
sulfonic acid) (PSSA) or CP in the nanocomposites was proposed. With the increase of PEDOT content in the GOPSS/PEDOT nanocomposite, the estimated value of ID/IG regarding the Raman analysis of them was decreased and a major change of their Raman spectra characteristic peaks was observed. In the GO-PSS/PEDOT nanocomposite, PEDOT molecules made an exfoliation of GO-PSSA layers and thus they were intercalated among layers. Such a unique molecular morphology induced the highest electrical conductivity for the GO-PSS/PEDOT nanocomposite among three kinds of nanocomposites prepared in this study. It is also noted that the uniform morphology confirmed in this study helped a thermal stability improvement in the nanocomposite due to the presence of GO or GO-PSSA acting as a thermal barrier.
그래핀옥사이드(GO)와 전도성 고분자(PPy, PANI, PEDOT)로 이루어진 나노복합체를 제자리 화학중합을 통하여 제조하였으며, 전도성 고분자의 함량 증가에 따른 특성변화를 분석하였다. GO에 존재하는 반응성 그룹 그리고 GO-poly(4-styrene sulfonic acid)(PSSA) 복합체 및 세 종류 나노복합체에서 고분자의 존재를 확인하였으며, GO와 PSSA 또는 전도성 고분자 사이의 상호작용이 제안되었다. GO-PSS/PEDOT 나노복합체의 경우 PEDOT 함량이 증가함에 따라 라만 스펙트럼의 ID/IG 값이 감소하였으며 특성 피크 위치도 크게 변화하였다. GO-PSS/PEDOT 나노복합체의 경우 PEDOT이 GO-PSSA 층을 박리시켜 그들 분자층 사이로 내부 삽입되어 있는 형태를 취하며 GO 또는 GO-PSSA 분자층이 열차단층으로 작용하게 되어 나노복합체는 GO 또는 GO-PSSA보다 열안정성이 향상되었다. 또한 GO-PSSA와 PEDOT 사이에 형성된 균일한 hybridization 모폴로지를 확인하였으며, GO-PSS/PEDOT 나노복합체의 경우 가장 우수한 전기전도성을 보여 주었다.
Keywords: graphene oxide; in-situ chemical polymerization; conducting polymers; nanocomposites.