필러 네트워크 구조 제어를 통한 그래핀 기반 고분자 나노 복합재의 전자파 차폐 특성 향상

다국어 초록 (Multilingual Abstract)

Graphene-based polymer nanocomposites offer significant potential for lightweight electrical and electromagnetic applications; however, their performance is strongly influenced by microstructure and filler characteristics. In this study, two distinct graphene-based composite systems were developed to elucidate the impact of processing and filler characteristics on electrical conduction and electromagnetic interference (EMI) shielding performance. First, a non-oxidized graphene flake (NOGF)/polydimethylsiloxane (PDMS) composite was prepared through unidirectional freeze-casting, producing vertically aligned graphene channels. Following the infiltration of PDMS, the resulting composite exhibited significant directional variations in electrical conductivity and EMI shielding. This observation permitted the analysis of alignment-dependent electron transport and electromagnetic wave dissipation behavior. Secondly, two grades of graphene nanoplatelet (GnP) with different lateral sizes were incorporated into polyvinylidene fluoride (PVDF) via solution blending followed by hot pressing to obtain uniform composites. A comprehensive characterization using DSC, XRD, rheology, electrical conductivity, and EMI shielding measurements was employed to ascertain the influence of GnP size on the influenced PVDF crystallization, network development, and conductive pathway formation, which subsequently affected shielding efficiency.
By examining both an aligned porous graphene network and a homogeneous GnP-filled polymer matrix, this work provides integrated insight into how graphene architecture, filler size, and processing route collectively determine the functional properties of graphene-polymer composites, offering design guidelines for high-performance EMI shielding materials.

목차 (Table of Contents)

• 제 I 장 서론 1
• I-1. 전자기 간섭 1
• I-2. 전자기 간섭 차폐 메커니즘 2
• I-3. 전도성 고분자 나노 복합재 7
• I-4. 복합재의 구조 설계 8
• 제 II 장 저함량 비산화 그래핀(NOGF)/폴리디메틸실록산(PDMS) 복합재 기반의 고성능 전자기 간섭 차폐재 10
• II-1. 서론 11
• II-2. 실험 12
• II-2.1. 시약 12
• II-2.2 GO 및 NOGF의 제조 14
• II-2.3 rGO, NOGF 폼 및 PDMS 복합재 제조 15
• II-2.4 분석 및 특성화 17
• II-3. 결과 및 토론 19
• II-4. 결론 45
• 제 III 장 필러 크기에 따른 그래핀 나노 플레이트(GnP)/폴리비닐리덴플루오라이드(PVDF) 복합재의 열적·전기적·유변학적·전자파 차폐 특성 분석 46
• III-1. 서론 47
• III-2. 실험 49
• III-2.1. 시약 49
• III-2.2. GnP/PVDF 복합재의 제조 49
• III-2.3. 분석 및 특성화 49
• III-3. 결과 및 토의 51
• III-4. 결론 70