화학적 결함이 제거된 그래핀을 이용한 복합체 개발 및 특성

Abstract

ABSTRACT

Development and properties of a chemical defect-healing graphene composites

Kyeongmin Kim Advisor : Prof. Jaekwan Lee, Ph.D. Department of Carbon materials Graduate School of Chosun University

Aromatic poly-imide (PI) is attractive materials with a wide range of applications in flexible display, aerospace, composite materials, automobile, fiber, because of its excellent thermal and chemical stability. In this work, we report an effective method for fabricating graphene-based multifunctional PI nano composites via in situ polymerization, by the chemical defect-healing of pyridine functionalized reduced graphene oxde (H-Py-RGO). H-Py-RGO was successfully obtained through intramolecular cross-dehydrogenative coupling (ICDC). The thermal stability, mechanical properties and electrical conductivity of the PI/H-Py-RGO nanocomposites were significantly improved compared with those of pristine PI film due to the restoration of the defect sites on the graphene surface, and the resulting high compatibility between the H-Py-RGO and the PI matrix. The modulus and tensile strength of the PI/H-Py-RGO nanocomposites with 1 wt% of added H-Py-RGO were significantly inncreased by about 598% (883.5 MPa) and 535% (39.4 GPa) compared to pristine PI film, respectively. Furthermore, H-Py-RGO 5 wt% loading samples resulted in a 91% reduction in the coefficient of thermal expansion (CTE) of the PI/H-Py-RGO nanocomposite.