CuNW 기반 하이브리드 나노필러를 함유한 PDMS 복합체의 신축성 및 전기 전도도 = Stretchability and electrical conductivity of PDMS composites incorporated with CuNW-based hybrid nanofillers

다국어 초록 (Multilingual Abstract)

Over the past few decades, nanocomposites have garnered significant attention in both fundamental research and industrial applications. Generally classified by their matrix and filler types, polymer nanocomposites, fabricated by uniformly dispersing nanoscale fillers within a polymer resin, exhibit markedly ehnanced mechanical strength, wear resistance, and thermal stability. Among these, electrically conductive polymers have emerged as promising candidates for next-generation electronic materials. Specifically, stretchable conductive polymers, which integrate elastic matrices with conductive nanofillers such as graphene, carbon nanotubes (CNTs), and metal nanowires, have seen substantial developmental progress. However, achieving homogeneous dispersion between nanofillers and the polymer matrix remains a critical challenge, as it directly dictates the final performance of the composite. In this study, polydimethylsiloxane (PDMS) was employed as the elastomer matrix, while a hybrid filler system comprising copper nanowires (CuNWs), multi-walled CNTs, and carbon black (CB) was utilized. Isopropyl alcohol (IPA) served as the primary solvent to facilitate the partial dissolution of PDMS and ensure the dispersibility of both CuNWs and MWCNTs. Additionally, silicone oil was incorporated to further enhance the dispersion of the CNTs. The resulting nanocomposites were characterized based on their morphological, mechanical, electrical, and rheological properties. Furthermore, dynamic electrical conductivity and mechanical stability were evaluated through cyclic strain testing. The primary objective of this research was to develop nanocomposites capable of maintaining consistent mechanical and electrical performance under repeated large-scale deformations.
The mechanical analysis revealed that the tensile strength, tensile modulus, and storage modulus of the PDMS/CNT&CuNW composites increased proportionally with CNT loading, which is attributed to the effective reinforcing role of well-dispersed CNTs. Similarly, the PDMS/CB system exhibited enhanced tensile sensitivity, modulus, and elongation at break with increasing CB content. Regarding electrical performance, the hybrid filler system demonstrated superior properties compared to single-filler composites. Specifically, the composition of 3 wt% CNT and 1 wt% CuNW yielded the highest static electrical conductivity (25.75 S/m) and the lowest sheet resistance (5.42 Ω/sq). This optimal ratio also maintained the highest electrical stability after extensive cyclic deformation. In contrast, the PDMS/CB composites reached measurable electrical thresholds only at a CB loading of 10 wt%. Rheological assessments indicated an elastic-dominant behavior in the PDMS/CNT&CuNW system, with tan δ values approaching zero and remaining stable throughout repeated deformation cycles.

목차 (Table of Contents)

• Ⅰ. 서론 1
• 1. 연구배경 및 목표 1
• 2. 나노필러 3
• 1) 탄소나노튜브 3
• 2) 구리 나노와이어 4
• 3. 신축성 전도성 고분자 복합체 5
• Ⅱ. 실험 6
• 1. 시약 및 재료 6
• 2. CuNW의 합성 및 정제 8
• 1) CuNW 합성 8
• 2) CuNW 정제 9
• 3. 나노복합체 분산 및 제조 11
• 1) PDMS/CNT&CuNW 분산 및 제조 11
• 1-1) PDMS/CNT&CuNW 나노복합체 분산 11
• 1-2) 분산 용매 제거 및 나노복합체 경화 12
• 2) PDMS/CB 분산 및 제조 14
• 2-1) PDMS/CB 나노복합체 분산 14
• 2-2) 분산 용매 제거 및 나노복합체 경화 14
• 4. 분석 및 측정 16
• 1) 형태구조 분석 16
• 2) 분산성 분석 16
• 3) 기계적 물성 분석 17
• 4) 전기적 물성 분석 17
• 5) 유변 물성 분석 18
• 6) 반복변형 물성 분석 18
• Ⅲ. 결과 및 고찰 19
• 1. TWCNT 와 CuNW의 모폴로지 19
• 2. 나노복합체의 분산 특성 21
• 1) PDMS/CNT&CuNW 나노복합체 21
• 1-1) PDMS/CNT&CuNW 나노복합체의 모폴로지 21
• 1-2) Silicone oil 분산 효과 27
• 2) PDMS/CB 나노복합체 모폴로지 29
• 3. 나노복합체의 기계적 물성 31
• 1) PDMS/CNT&CuNW 나노복합체의 기계적 물성 31
• 2) PDMS/CB의 기계적 물성 34
• 4. 나노복합체의 전기적 물성 37
• 1) PDMS/CNT&CuNW 나노복합체의 전기적 물성 37
• 2) PDMS/CB 나노복합체의 전기적 물성 40
• 5. PDMS/CNT&CuNW 나노복합체의 유변 물성 42
• 6. PDMS/CNT&CuNW 나노복합체의 반복변형 물성 44
• 1) PDMS/CNT&CuNW 나노복합체의 동적 물성 44
• 2) PDMS/CNT&CuNW 나노복합체의 동적 전기 전도도 51
• Ⅳ. 결론 60
• 참고 문헌 64