Ultra-broadband EMI shielding with heat dissipation of carbon nanotubes-boron nitride-thermoplastic polyurethane composite thin film fabricated by surface modification and layer-by-layer deposition = 표면 개질 및 층별 증착에 의해 제작된 탄소나노튜브-질화붕소-열가소성 폴리우레탄 복합박막의 초광대역 전자기파 차폐와 열 방출

다국어 초록 (Multilingual Abstract)

Electromagnetic interference (EMI) shielding material is the most effective solution to protect electronic devices and human health from the harmful effect of electromagnetic radiation. The study of EMI shielding materials is intensifying in the constantly developing picture of the fourth industrial revolution. A huge demand for compact and multi-functional devices requires the integration of new functions into EMI shielding materials. Multifunctional EMI shielding materials perform multiple functions beyond their main function EMI shielding in a system due to their specific properties.
The miniaturization and integration of electronic devices have led to an increased accumulation of heat, which can disrupt normal functioning. Their functionalities are also severely affected when they are exposed to the abundant electromagnetic interference (EMI) resulting from the rapid development of fifth-generation telecommunication technology extended to mmWaves and sixth-generation telecommunication frequencies up to 110 GHz. Therefore, it is urgent to develop composite materials with excellent EMI shielding effectiveness and heat dissipation abilities. Herein, I fabricated an all-in-one thin film composite using carbon nanotubes (CNT), boron nitride (BN), and thermoplastic polyurethane (TPU) through a layer-by-layer casting method to create a composite supported by hydrogen bonding with impressive EMI shielding and heat dissipation properties. The high electrical conductivity of the CNT-BN-TPU composite resulted in the highest EMI shielding effectiveness, ranging from 90.66 dB in Ka-band to 79.8 dB in W-band, at a thickness of 100 µm, with absorption efficiency of 83.07% at 34 GHz and 80.85% at 100 GHz, respectively. The composite demonstrated excellent heat dissipation, thanks to its outstanding out-of-plane thermal conductivity, which reached 1.971 W/mK. I believe that my proposed method for producing an all-in-one composite thin film with excellent EMI shielding and thermal management capabilities could be a useful approach for the next generation of smart electronic devices.

국문 초록 (Abstract)

전자파 간섭(EMI) 차폐재는 전자파의 유해한 영향으로부터 전자 기기와 인간의 건강을 보호하는 가장 효과적인 솔루션 중의 하나이다. 끊임없이 발전하는 4차 산업혁명 시대에 EMI 차폐 소재에 대한 연구가 더욱 증가되고 있다. 또한, 소형 다기능 전자기기에 대한 엄청난 수요로 인해 EMI 차폐 재료에 새로운 기능이 추가되는 요구가 높아지고 있다. 다기능 EMI 차폐 재료는 추가된 특별한 기능으로 인해 전자 시스템에서 EMI 차폐재 이상의 다양한 기능성을 부과하는 역할을 하게 된다.
또한, 전자 기기의 소형화 및 집적화로 인해 열 축적이 크게 증가하여 소자나 시스템의 정상적인 기능을 방해할 수 있다. 최근, mmWaves로 확장된 5세대 통신 기술과 최대 110 GHz의 6세대 통신 주파수의 급속한 발전으로 인해 발생하는 풍부한 전자파 간섭(EMI)에 의해 소자나 시스템의 기능이 심각한 오동작 등의 영향을 받고 있다. 따라서 EMI 차폐 효과와 방열 특성이 우수한 복합재료의 개발이 시급한 실정이다.
본 논문은 탄소나노튜브(CNT), 질화붕소(BN), 열가소성 폴리우레탄(TPU)을 층상 캐스팅 방식을 이용하여, 일체형 박막 복합재로 제작하여, 수소결합을 지지하는 복합재를 제작하였으며, 매우 우수한 EMI 차폐 및 열 방출 특성을 갖는 것을 확인하였다. CNT-BN-TPU 복합체의 높은 전기전도도는 복합재 필름 두께 100 μm에서 90.66 dB(Ka 대역), 79.8 dB(W 대역)로 매우 높은 EMI 차폐 효과를 나타냈으며, 흡수 효율은 34 GHz에서83.07%, 100 GHz에서80.85%로 확인되었다. 또한 제작된 복합재는 1.971 W/mK에 달하는 뛰어난 수직 열전도율로 인해 매우 우수한 방열 성능을 보여주었다. 결론적으로 매우 우수한 EMI 차폐 특성 및 열 방출 기능을 갖는 완전 일체형 복합소재 박막을 제작하기 위해서 본 논문에서 기술한 제조 방법이 차세대 스마트 전자 기기에 매우 유용하게 적용될 수 있을 것으로 기대합니다.

목차 (Table of Contents)

• CHAPTER 1: INTRODUCTION 1
• 1. Background 1
• 1.1 Electromagnetic interference shielding. 1
• 1.2 Thermal conductivity 6
• 2. Multifunctionality of EMI shielding materials 8
• 2.1 EMI shielding material with strain sensing function 11
• 2.2 EMI shielding material with humidity sensing function 21
• 2.3 EMI shielding material with temperature sensing function 27
• 2.4 EMI shielding material with heating function 32
• 2.5 EMI shielding material with heat dissipation 44
• CHAPTER 2: MOTIVATION 46
• CHAPTER 3: METHODOLOGY 50
• 1. Chemicals 50
• 2. Preparation of functionalized-CNT solution 50
• 3. Preparation of functionalized-BN solution 50
• 4. Preparation of TPU solution 51
• 5. Preparation of BN/TPU solution 51
• 6. Preparation of CNT/BN/TPU composite 51
• 7. Characterization 52
• CHAPTER 4: RESULTS AND DISCUSSION 56
• 1. Fabrication of CNT-BN-TPU-based composite thin film 56
• 2. Analysis of CNT-BN-TPU-based composite film 59
• 3. EMI shielding performance of CNT-BN-TPU-based composite film64
• 4. EMI shielding performance of CNT-BN-TPU-based composite film at
• 40~110 GHz 82
• 5. Heat dissipation of CNT-BN-TPU-based composite film 88
• CHAPTER 5: CONCLUSION 94
• BIBLIOGRAPHY.96

참고문헌 (Reference)

1. Rehydration and recovery after exercise, Maughan, R. J., Shirreffs, S. M., Science Sports, 19(5), 234–238. https://doi. org/10.1016/J. SCISPO.2004.05.003, , 2004

2. Raman spectroscopy for carbon nanotube applications, Jorio, A., Saito, R., 129(2). https://doi. org/10.1063/5.0030809, , 2021

3. Stretchable, porous, and conductive energy textiles, Choi, J. W., Pasta, M., Deshazer, H. D., Jeong, S., Hu, L., Cui, L., Han, S. M., La Mantia, F., Cui, Y., 10(2), 708–714. https://doi. org/10.1021/NL903949M/SUPPL_FILE/NL903949M_SI_001. PDF, , 2010

4. Block5GIntell: Blockchain for AI-Enabled 5G Networks, Singh, S. K., Pan, Y., Azzaoui, A. El, Park, J. H., IEEE Access, 8, 145918–145935. https://doi. org/10.1109/ACCESS.2020.3014356, , 2020

5. Ion-Exchange and Cation Solvation Reactions in Ti3C2 MXene, Barsoum, M. W., Halim, J., Gogotsi, Y., Bish, D., Ghidiu, M., Kota, S., 28(10), 3507–3514. https://doi. org/10.1021/ACS. CHEMMATER.6B01275/ASSET/IMAGES/LARGE/CM-2016-01275U_0008. JPEG, , 2016

6. Next Generation 5G Wireless Networks: A Comprehensive Survey, Saxena, N., Roy, A., Agiwal, M., 18(3), 1617–1655. https://doi. org/10.1109/COMST.2016.2532458, , 2016

7. Multifunctional Aramid Nanofiber/Carbon Nanotube Hybrid Aerogel Films, Chen, Y., Zhang, X., Liao, J., Fu, C., Lu, W., Hu, P., Lyu, J., Gong, W. Bin, 14(1), 688–697. https://doi. org/10.1021/ACSNANO.9B07459/ASSET/IMAGES/LARGE/NN9B07459_0005. JPEG, , 2020

8. A wearable patch for continuous analysis of thermoregulatory sweat at rest, Bariya, M., Nyein, H. Y. Y., Brown, B. J., Tran, B., Ahn, C. H., Ji, W., Javey, A., Davis, N., 2021 12:1, 12(1), 1–13. https://doi. org/10.1038/s41467-021-22109-z, , 2021

9. 25th Anniversary Article: MXenes: A New Family of Two-Dimensional Materials, Mochalin, V. N., Barsoum, M. W., Gogotsi, Y., Naguib, M., Advanced Materials, 26(7), 992–1005. https://doi. org/10.1002/ADMA.201304138, , 2014

10. Large Area Few-Layer Hexagonal Boron Nitride as a Raman Enhancement Material, Satya Bharathi, M. S., Yadav, K., Basu, N., Soma, V. R., Sharma, M., Parmar, A. S., Lahiri, J., 11(3), 622. https://doi. org/10.3390/nano11030622, , 2021

11. An Adaptive Multispectral Mechano-Optical System for Multipurpose Applications, Liang, L., Yu, R., Ji, G., Xu, Z. J., Ong, S. J. H., Zhang, B., Yang, Y., 17(13), 12409–12421. https://doi. org/10.1021/ACSNANO.3C01836/SUPPL_FILE/NN3C01836_SI_004. PDF, , 2023

12. Microwave absorption performance of porous heterogeneous SiC/SiO2 microspheres, Xiang, Z., Yin, X., Wang, Y., He, Q., 451, 138742. https://doi. org/10.1016/j. cej.2022.138742, , 2023

13. Electromagnetic interference shielding with 2D transition metal carbides (MXenes), Shahzad, F., Anasori, B., Hong, S. M., Gogotsi, Y., Alhabeb, M., Hatter, C. B., Koo, C. M., Science, 353(6304), 1137–1140. https://doi. org/10.1126/SCIENCE. AAG2421/SUPPL_FILE/SHAHZAD. SM. PDF, , 2016

14. EMI shielding effectiveness of metal-coated carbon fiber-reinforced ABS composites, Chang, F. Y., Tzeng, S. S., A, 302(2), 258–267. https://doi. org/10.1016/S0921-5093(00)01824-4, , 2001

15. Water Sorption in MXene/Polyelectrolyte Multilayers for Ultrafast Humidity Sensing, An, H., Zhao, X., Radovic, M., Gao, H., Shah, S., Green, M. J., Lutkenhaus, J. L., Habib, T., Echols, I., Patel, A., 2, , 2019

16. Electromagnetic Shielding Hybrid Nanogenerator for Health Monitoring and Protection, Liang, Q., Liao, Q., Gao, F., Ding, Y., Ma, M., Zhang, Z., Zhang, Y., Zhao, X., Zhang, Q., Kang, Z., 28(1), 1703801. https://doi. org/10.1002/ADFM.201703801, , 2018

17. Progress in polymers and polymer composites used as efficient materials for EMI shielding, Hudec, I., Hložeková, K., Kruželák, J., Kvasničáková, A., 3(1), 123–172. https://doi. org/10.1039/D0NA00760A, , 2021

18. Review of electromagnetic interference shielding materials fabricated by iron ingredients, Shukla, V., 1(5), 1640–1671. https://doi. org/10.1039/C9NA00108E, , 2019

19. An All-Stretchable, Ultraviolet Protective, and Electromagnetic-Interference-Free E-Textile, Park, S., Wang, Z., Long, J., Liu, T., Huang, Y., Peng, Y., Dong, J., Zhang, Y., 33(45), 2308426. https://doi. org/10.1002/ADFM.202308426, , 2023

20. Enhancing the Performance of Stretchable Conductors for E-Textiles by Controlled Ink Permeation, Jin, H., Lee, S., Matsuhisa, N., Someya, T., Yokota, T., Abbas, M., Advanced Materials, 29(21), 1605848. https://doi. org/10.1002/ADMA.201605848, , 2017

21. Carbon Nanocoil-Based Fast-Response and Flexible Humidity Sensor for Multifunctional Applications, Wu, J., Wang, G. P., Sun, Y. M., Li, X., Wang, N., Tao, K., Wu, Z., 11(4), 4242–4251. https://doi. org/10.1021/ACSAMI.8B18599/ASSET/IMAGES/LARGE/AM-2018-18599K_0006. JPEG, , 2019

22. Multifunctional Cellulose/rGO/Fe3O4 Composite Aerogels for Electromagnetic Interference Shielding, Pionteck, J., Qi, H., Pötschke, P., Chen, Y., Voit, B., 12(19), 22088–22098. https://doi. org/10.1021/acsami.9b23052, , 2020