본문 바로가기 주메뉴 바로가기
22대 대한민국 국회 국회정보길라잡이 국회의원검색
회원가입 로그인
HOME

정보검색

소장정보 검색

국회도서관 홈으로 정보검색 소장정보 검색
결과 내 검색 동의어 포함
결과 내 검색 동의어 포함

-

목차보기

Title Page

Contents

ABSTRACT 16

Chapter 1. INTRODUCTION 18

1.1. Scope of this study 19

1.2. Background 23

1.2.1. Changing trends in energy systems 23

1.2.2. Strategies to enhance energy efficiency of solar cell 27

1.2.3. Framework in segmented PEMFC system 30

1.2.4. Thermal interface material (TIM) in battery assembly 33

References 36

Chapter 2. All-Cellulose Paper with High Optical Transmittance and Haze Fabricated via Electrophoretic Deposition 44

ABSTRACT 45

2.1. Introduction 46

2.2. Experimental 49

2.2.1. Materials and preparation of CNF/CMC dispersion 49

2.2.2. Preparation of cellulose paper by EPD 49

2.2.3. Characterization 50

2.3. Results and Discussion 52

2.3.1. Materials characterization and EPD set-up 52

2.3.2. Film fabrication and morphology characterization 55

2.3.3. CNF/CMC film thickness control 57

2.3.4. Optical characteristics of CNF/CMC films 59

2.3.5. Mechanical characteristics of CNF/CMC films 65

2.3.6. Water resistance of CNF/CMC films 67

2.4. Conclusions 70

Supporting information 72

References 76

Chapter 3. Low Dielectric Constant and Anisotropic Mechanical Properties of Dispenser-Printed Polyetherimide Films Using Two-Step Thermal Treatment 81

ABSTRACT 82

3.1. Introduction 83

3.2. Experimental 86

3.2.1. PEI ink preparation 86

3.2.2. Fabrication of dispenser-printed PEI films 86

3.2.3. Characterization 87

3.3. Results and discussion 89

3.3.1. Solvent selection and ink viscosity measurement 89

3.3.2. Appropriate ink selection and printing condition optimization 92

3.3.3. Investigation of heating condition 94

3.3.4. Printing PEI films and its thickness control 96

3.3.5. Dielectric and thermal characteristics of PEI films 98

3.3.6. Mechanical characteristics of PEI films 101

3.4. Conclusions 103

Supporting information 104

References 106

Chapter 4. Non-combustible and Thermally Conductive Polytetrafluoroethylene/magnesium hydroxide/expandable graphite Composites 113

ABSTRACT 114

4.1. Introduction 115

4.2. Experimental 119

4.2.1. Materials and composite fabrication methods 119

4.2.2. Characterization 120

4.3. Results and discussion 121

4.3.1. Fabrication process and mechanism of PEM composites 121

4.3.2. Morphologies of materials and composites 124

4.3.3. Thermal stability of materials and PEM composites 126

4.3.4. Flame retardancy of PEM composites 128

4.3.5. Combustion behavior of PEM composites 130

4.4. Conclusions 133

Supporting Information 135

References 140

Chapter 5. Conclusions 144

5.1. Cellulose-based film with high optical transmittance and haze fabricated via electrophoretic deposition 145

5.2. Dispenser-printed polyetherimide film and their characteristics based on printing direction and annealing conditions 146

5.3. Non-combustible and thermally conductive composite films achieved by extremely high loading of flame retardant additives 147

논문요약 149

List of Tables

Table 2.1. Comparison of various transparent and hazy cellulose films with our all-cellulose films. 62

Table 3.1. Dielectric and thermal properties depending on heating time. 100

Table 3.2. Mechanical properties following heating time and printing direction. 102

Table 4.1. Composition of PEM composites. 119

Table 4.2. LOI and UL-94 results of PEM composites. 129

Table 4.3. pHRR, THR, and thermal conductivity of PEM composites. 132

List of Supporting Information Tables

Table S2.1. Optical properties of CNF/CMC3 and CNF/CMC5 films depending on sonication time. 73

Table S2.2. ΦT and ΦH values of CNF/CMC3 and CNF/CMC5 films.[이미지참조] 74

Table S2.3. BoxLucas1 fitting results for the time-dependent water absorption of CNF/CMC3 and CNF/CMC5 films. 75

Table S3.1. Density of theoretical and printed PEI under different pressure. 104

Table S4.1. Maximum weight loss rate of MH and PEM composites 136

Table S4.2. Comparison of the flame-retardant performance of various metal hydroxide incorporated composites. 138

List of Figures

Figure 1.1. Schematic illustration of categorized research topics; cellulose film, PEI film, and composite film. 22

Figure 1.2. Total U.S. greenhouse gas emissions by economic sectors and promising solutions. 26

Figure 1.3. Schematic illustration of scattering mechanism by (a) Rayleigh scattering [36] and (b) rough surface layer. 29

Figure 1.4. (a) Mechanism and (b) structure of segmented fuel cell system. 32

Figure 2.1. (a) Zeta potential of CNF dispersion as a function of pH: The inset exhibits the digital image of the anode surface covered with CMC after EPD at... 54

Figure 2.2. (a) Photographs of the dried brass electrode after the EPD process with CNF, (b) CMC, and (c) CNF/CMC mixture. SEM images of (d) CNF, (e)... 56

Figure 2.3. (a) Photographs of the deposited CNF/CMC3 suspension with different deposition time at 3 V. (b) Thickness of CNF/CMC3 films plotted as a... 58

Figure 2.4. (a) The dependency of transmittance and (b) haze of CNF/CMC film on ultrasonic time and ratio of CNF and CMC. (c) Comparison of the optical... 61

Figure 2.5. (a) Photographs of CNF/CMC5_1h film and (b) PET film placed on the printed letters; placed right on the letters and 3 cm separated from the... 64

Figure 2.6. (a) Characterizations of the mechanical properties for CNF/CMC papers with only CMC, CNF/CMC5_1h and CNF/CMC3_1h films, respectively.... 66

Figure 2.7. (a) Digital images of CMC, CNF/CMC3, and CNF/CMC5 films after immersing into water for 10 min. (b) Water contact angles of the CMC,... 69

Figure 3.1. Schematic illustration of the overall process for PEI film fabrication. Inset digital images show the PEI chemical structure, NMP/PEI solution with... 90

Figure 3.2. Viscosities of NMP/PEI10, NMP/PEI20, and NMP/PEI30 inks as a function of shear rate. 91

Figure 3.3. Digital images of (a) NMP/PEI10, (b) NMP/PEI20, and (c) NMP/PEI30 inks while printed under the pneumatic pressures of 0, 50, and 200... 93

Figure 3.4. (a) TGA curves of NMP/PEI10, NMP/PEI20, and NMP/PEI30 inks. (b) FT-IR spectra of PEI films after one-step heat treatment (100 °C for 2... 95

Figure 3.5. Digital images of (a) annealed PEI printed in a complicated pattern, (b) PEI films in different shapes fabricated by two-step heat treatment, and (c)... 97

Figure 3.6. (a) Dielectric constant as a function of frequency and (b) dimensional change of two-step heat-treated PEI films with different annealing... 100

Figure 3.7. As-prepared PEI films along with (a) longitudinal and (b) transversal directions. (c) Tensile strength and (d) modulus of the PEI films at... 102

Figure 4.1. The schematic illustrations of (a) fabrication process of PEM composites and (b) their multifunctionality of heat dissipation and fire suppression. 123

Figure 4.2. FE-SEM images of (a) MH, (b) EG, PTFE (c) before and after (d,e) fibrillation, and (f) the PEM10 composites with different magnification. The... 125

Figure 4.3. (a) TGA and (b) DTG curves of PEM composites in the temperature range of 50-600 ℃. 127

Figure 4.4. Digital images of UL-94 vertical combustion test of PEM5. 129

Figure 4.5. (a) Digital photos of PEM composites during cone calorimetry and the comparison of THR and pHRR of metal hydroxide incorporated flame-... 131

List of Supporting Information Figures

Figure S2.1. (a) Digital images of CNF, CMC, CNF/CMC3, CNF/CMC5 dispersions at pH 8.0 taken right after prepared and (b) taken after 24 h,... 72

Figure S2.2. (a) Enlarged image of CNF deposited electrode showing many cracks. (b) Self-standing CMC film. (c) Flexible CNF/CMC3 film. 72

Figure S2.3. (a) Light transmittance of the CMC film and CNF/CMC3 films, and (b) CNF/CMC5 films in the wavelength range of 400-800 nm. 73

Figure S2.4. (a) Optical microscope images of CMC, (b) CNF/CMC3_1h, and (c)CNF/CMC5_1h films, respectively. 74

Figure S2.5. Water absorption and thickness change of CNF/CMC3 film as a function of immersion time. 75

Figure S4.1. (a) MH, EG, and PTFE mixed powder after mixing and (b) dough-like structure of materials after manual pressing. 135

Figure S4.2. (a) agglomerated sphere-shaped and (b) flexible film shaped PEM10 composites. 135

Figure S4.3. (a) TGA and (b) DTG of PTFE, MH, and EG in the range of 50-600 ℃ measured under nitrogen atmosphere. 136

Figure S4.4. Heat release rate of (a) PEM5, (b) PEM10, (c) PEM15, and (d) PEM 20 measured during cone calorimeter test. 137

초록보기

 기술의 진보와 인구의 증가는 필연적으로 더 많은 에너지를 요구하게 되었으며 이는 최종적으로 화석 연료 소비량의 증가를 유발하여 심각한 환경오염 문제를 초래하게 되었다. 인류의 지속가능성을 위해 친환경 에너지원의 사용 및 개선된 성능의 에너지 시스템 개발 등 다양한 연구가 수행되고 있으며, 본 연구 역시 이러한 연구들과 기조를 함께하여 유망 차세대 에너지 시스템인 태양광전지, 연료전지, 그리고 배터리의 성능 및 안정성을 향상시킬 수 있는 기능성 고분자 기반 필름과 이의 제조 공정 개발에 관한 내용을 소개한다.

가장 먼저 2장에서는 태양광전지의 성능 향상에 기여할 수 있는 셀룰로오스 나노피브릴 (CNF)로 구성된 투명필름을 소개한다. CNF 분산액과 카르복시메틸화 셀룰로오스 분산액을 일정 비율에 맞게 혼합하여 초음파 처리 진행, 균일한 분산액을 제조하고 해당 분산액에 전기영동법을 진행하여 전극에 흡착시킴으로써 필름 제조에 성공하였다. 이 투명필름은 높은 빛 투과도와 산란도를 동시에 보유하고 있어 더욱 많은 빛 입자가 활성층에 도달하도록 유도하는 빛 거동 제어층 (light management layer)의 역할을 수행함으로써 태양광 전지의 효율 향상에 기여할 수 있을 것으로 기대된다. 또한, 우수한 기계적 물성, 유연성, 수분 저항성 등을 보유하는 것을 확인하여 그 활용도가 매우 높을 것으로 기대된다.

3장에서는 연료전지의 제조 공정의 간소화 및 비용 절감을 위해 디스펜서 프린팅 공정을 통한 폴리이써이미드(polyetherimide, PEI) 필름의 제조에 관한 내용을 포함한다. PEI 용액을 디스펜서 프린터를 통해 직접 프린팅 한 후 정교하게 설계된 두단계 열처리 공정을 진행하였고, 그 결과 마스크 없이 간편하게 희망하는 구조를 갖는 PEI 필름의 제조에 성공하였다. 또한 해당 PEI 필름은 프린팅 방향, 열처리 조건 등에 따라 독특한 전기적, 기계적 물성을 보유함을 확인하였으며 이는 추후 고분자의 열처리에 따른 화학적 거동의 분석에 크게 도움을 줄 수 있을 것으로 기대된다.

마지막 4장은 최근 가장 큰 이슈가 되고 있는 전기자동차 배터리에 적용됨으로써 배터리의 열 및 화재 안정성을 향상시키는 필름과 이의 제조에 관한 내용을 포함한다. 폴리테트라플루오르에틸렌 섬유를 바인더로 사용함으로써 95 wt%의 난연재를 함유하는 복합소재 필름의 제조에 성공하였으며, 해당 필름은 우수한 열 전도도뿐만 아니라 불연의 성질을 보유함을 확인하였다. 이와 같은 시스템을 활용한다면 해당 문제를 해결함에 크게 기여할 수 있을 것으로 사료된다.

추천서가 (다양한 추천 자료를 만나보세요)

권호기사보기

권호기사 목록 테이블로 기사명, 저자명, 페이지, 원문, 기사목차 순으로 되어있습니다.
기사명 저자명 페이지 원문 기사목차