本論文旨在研究利用多壁奈米碳管(MWCNTs)與石墨烯(graphene)製備透明導電膜，並探討利用不同改質方式的MWCNTs與graphene所製備出的透明導電膜，其表面阻抗與透光率的表現值。本研究共分為五部份。
第一部份探討將MWCNT接枝methyl methacrylate/acrylic acid (MMA/AA)單體，並沉積於polyethylene terephthalate(PET)上，製備透明導電膜，接枝在MWCNTs表面的PAA鏈段，也能因環境pH值的提高而產生延展，此現象將使MWCNTs具有較佳的分散性。碳奈米管含量在8.3wt%時，當pH為2.5時，表面阻抗約為8.71×105 Ω/□，透光率為38%，當pH值提高至9.0時，表面阻抗可降低至5.0×105 Ω/□，透光度也可提升至61%。
本研究第二個部分，是將MWCNTs分別改質接枝上acrylic acid (AA) 或N-vinyl pyrrolidone(NVP)，這些帶有不同電荷的高分子鏈段會因離子的鍵結而產生交聯的現象，¬而形成互穿的網狀結構，進而提升MWCNTs於基材表面的黏著力。在相同的MWCNTs含量下，使用具可交聯性的高分子透明導電膜，經硝酸處理後的表面阻抗值，大約下降了1.5個orders(由8.83x104Ω/□降低至2.65x103Ω/□)，而使用未交聯高分子的透明導電膜，僅下降了1個order左右，由6.85x105Ω/□降低至5.42x104Ω/□。
第三部份為利用接枝反應，將poly (acryl amide)/poly (acrylic acid) (PMA)插層入graphite oxide (GO)中，插層在GO層間的PMA高分子鏈，可有效地抑制GNS在還原過程中常發生的再聚集現象，由接枝上PMA的GNS(NE-PMA-GNS)所製備而成的透明導電膜，其最低表面阻抗可達2.11×102 Ω□-1，相較於無接枝高分子的GNS薄膜(NE-GNS)，其表面阻抗為1.86×103 Ω□-1，低了大約一個數量級。
本論文之第四及第五部份旨在研究結合電紡絲技術與導電奈米材料(如:graphene、silver nanoparticles)，製備透明導電膜。此部分先經由電紡技術製備出直徑為奈米等級的高分子纖維，並於透明基材上建構出二維的網狀結構，再利用高分子纖維引導奈米導電材料的沉積，使其自組裝成二維網狀結構的導電通路，此導電通路，可保持原材料的電子傳導能力，且因材料在表面的覆蓋率較低，故能提供較高的光穿透率:
第四部份研究結果指出， GO可經由奈米纖維的導引，建構出2D的網狀導電通路，由於奈米纖維間的空隙，會造成光散射而降低薄膜透明度，故進一步加熱熔解高分子纖維，導電薄膜的透明性將大幅提升，且GO也會因熱還原的作用下，形成結構完整性較高的GNS，進而提升其導電性質。透明玻璃基材經過180 秒的Nylon 66電紡纖維沉積，再浸泡於0.050 wt% PVP-GO的溶液後，在84%的光穿透度下，表面阻抗為1.32 × 106 Ω/□，而經過350℃的熱處理之後，其性質可提升至88%的光穿透度，其表面阻抗為8.61 × 103 Ω/□。
第五部分研究為進一步提升GNS薄膜導電性，於GNS表面沉積上導電性極高的奈米銀金屬顆粒(AgNps-GNS)，由於GNS具有極佳的機械彎折度，對於沉積在表面的AgNps也有優異的接著力，因此，AgNps-GNS同時具備了GNS的可撓性與AgNps的高導電性。PET軟性透明基板經過120秒的PU電紡纖維沉積，再浸泡於0.050 wt% AgNps-GNS (5:1) 的溶液並熱熔解PU奈米纖維後，其透明導電薄膜在85%的光穿透度下，表面阻抗為150 Ω/□。另外，經由抗折性質測試可得知，當AgNps:GNS比例為3:1時，薄膜具有最佳的電學性能及穩定度，當彎折角度達900時，相較於AgNps-GNS (5:1)薄膜的表面阻抗值上升了兩個數量級，而AgNps-GNS (3:1)薄膜表面阻抗僅上升了一個數量級。
綜合上述之結果，本研究已成功使用奈米碳材製備出透明導電膜，其性質表現，與奈米碳材之分散性、表面修飾及沉積方式有關，奈米碳材透明導電膜，相較於常見的ITO薄膜，具有製程溫度低，受彎折時，表面阻抗值穩定等優點，對於發展可撓式透明導電膜，有極大的助益。

The objectives of this research are the preparation and characterization of transparent conductive films (TCFs) by utilizing Multi-walled carbon nanotubes and graphene. There are five parts in this dissertation.
The first part of this dissertation discusses the optically transparent and electrically conductive thin films composed of multi-walled carbon nanotube (MWCNT) reinforced polymethyl methacrylate/acrylic acid (PMMA/AA) which were fabricated using a wire coating technique. Poly(acrylic acid) controls the dispersibility of MWCNT in aqueous mixtures and retains the well-dispersion of MWCNT in the polymer matrix after solidification resulted from extended polymer chains by adjusting the pH value. It causes the lower surface electrical resistance at the same MWCNT content.
The second part of this dissertation used Poly (acrylic acid) and Poly (N-vinyl pyrrolidone) as adhesion promoters to improve MWCNT coating significantly. The cross-linked polymer resulted in a better bond between the MWCNTs and substrates. The surface electrical resistance showed significantly lower than that of the original sheet after nitric acid (HNO3) treatment. The lower electrical resistance of PVP/PAA-g-MWCNT conductive films on the PET substrate was due to more complete conductive paths with the cross-linked polymer. Such the electrical resistance was enhanced from 8.83x104Ω/□ to 2.65x103Ω/□ with 0.90mg/cm2 PVP/PAA-g-MWCNT content deposited on the PET after acid treatment.
The third part examines the intercalation reaction of graphite oxide (GO) with poly (acryl amide)/poly (acrylic acid) (PMA) as a method to control the spacing between GOs. The intercalated polymer chains of poly (acrylic acid) between GNSs efficiently inhibit GNS aggregation and restacking. The PMA grafted GNS (NE-PMA-GNS) composite films show the lowest sheet resistance of 2.11×102 Ω□-1, which is one order of magnitude less than that without grafting polymer (NE-GNS, 1.86×103 Ω□-1).
The fourth part developes a simple method to assemble graphite oxide (GO) densely onto the electrospun (ES) Nylon 66 nanofibrous membranes, used as a guide for the deposition of graphene nanosheets (GNS) conductive networks for preparing the TCFs. The main advantage of this technique by comparison with previous methods is that graphene does not form a uniform coating, but a percolated conductive network is existed, when guided by Nylon 66 nanofiber templates. A low surface coverage of the transparent substrate by GNS resulted in high transmittance. The resulting PVP-GO material could adsorb well on Nylon 66 nanofibers due to stronger hydrogen bond. The TCF optical transmittance was improved after thermal annealing at 350°C above the Nylon 66 melting point. A fused film, obtained after electrospinning Nylon 66 solution for 120 s, and immersing in 0.050 wt% PVP-GO solution, exhibiting a surface resistance of 8.6 × 103 Ω/□, while maintaining 88% light transmittance.
The fifth part demonstrates a simple method of integrating hybrid thin films consisted of graphene nanosheets (GNS) and silver nanoparticles (AgNps) via in situ chemical reduction (AgNps-GNS) for preparing the TCFs. In order to obtain conductive films without compromising much on transmittance, the polyurethane (PU) nanofibers were introduced as guides to build the two-dimensional conductive networks of AgNps-GNS. By taking the advantage of the flexible mechanical property of GNS and great conductivity of AgNps, the potential application of hybrid AgNps-GNS as a highly flexible and transparent conductive thin film was demonstrated. A fused film, obtained after electrospinning PU solution for 120 s, and immersing in 0.05 wt% AgNps-GNS (5:1) solution, exhibits a surface resistance of 150 Ω/□, while maintaining 85 % light transmittance.

1.N. M. Yeji KIM, Weihong ZHU, Said KAZAOUI, Reiko AZUMI and Mutsuyoshi MATSUMOTO,Langmuir–Blodgett Films of Single-Wall Carbon Nanotubes: Layer-by-layer Deposition and In-plane Orientation of Tubes, 42,7629(2003)
2.B. Z. Hui Hu, Mikhail E. Itkis, and Robert C. Haddon,Nitric Acid Purification of Single-Walled Carbon Nanotubes, 107,13838(2003)
3.Z. C. Wu, Z. H. Chen, X. Du, J. M. Logan, J. Sippel, M. Nikolou, K. Kamaras, J. R. Reynolds, D. B. Tanner, A. F. Hebard,A. G. Rinzler,Transparent, conductive carbon nanotube films, Science, 305,1273(2004)
4.M. Kaempgen, G. S. Duesberg,S. Roth,Transparent carbon nanotube coatings, Appl Surf Sci, 252,425(2005)
5.X. Yu, R. Rajamani, K. A. Stelson,T. Cui,Carbon nanotube-based transparent thin film acoustic actuators and sensors, Sensor Actuat a-Phys, 132,626(2006)
6.D. H. Zhang, K. Ryu, X. L. Liu, E. Polikarpov, J. Ly, M. E. Tompson,C. W. Zhou,Transparent, conductive, and flexible carbon nanotube films and their application in organic light-emitting diodes, Nano Lett, 6,1880(2006)
7.W. J. Ma, L. Song, R. Yang, T. H. Zhang, Y. C. Zhao, L. F. Sun, Y. Ren, D. F. Liu, L. F. Liu, J. Shen, Z. X. Zhang, Y. J. Xiang, W. Y. Zhou,S. S. Xie,Directly synthesized strong, highly conducting, transparent single-walled carbon nanotube films, Nano Lett, 7,2307(2007)
8.B. B. Parekh, G. Fanchini, G. Eda,M. Chhowalla,Improved conductivity of transparent single-wall carbon nanotube thin films via stable postdeposition functionalization, Appl Phys Lett, 90,(2007)
9.H. Z. Geng, K. K. Kim, K. P. So, Y. S. Lee, Y. Chang,Y. H. Lee,Effect of acid treatment on carbon nanotube-based flexible transparent conducting films, J Am Chem Soc, 129,7758(2007)
10.E. D. Z. Li, V. Saini,Carbon Nanotube Based Electrically Conductive and Optically Transparent Thin Films, 1018-EE08-13,(2007)
11.R. Jung, H. S. Kim, Y. Kim, S. M. Kwon, H. S. Lee,H. J. In,Electrically conductive transparent papers using multiwalled carbon nanotubes, J Polym Sci Pol Phys, 46,1235(2008)
12.Z. R. Li, H. R. Kandel, E. Dervishi, V. Saini, Y. Xu, A. R. Biris, D. Lupu, G. J. Salamo,A. S. Biris,Comparative study on different carbon nanotube materials in terms of transparent conductive coatings, Langmuir, 24,2655(2008)
13.H. Z. Geng, D. S. Lee, K. K. Kim, S. J. Kim, J. J. Bae,Y. H. Lee,Effect of carbon nanotube types in fabricating flexible transparent conducting films, J Korean Phys Soc, 53,979(2008)
14.M. H. A. Ng, L. T. Hartadi, H. Tan,C. H. P. Poa,Efficient coating of transparent and conductive carbon nanotube thin films on plastic substrates, Nanotechnology, 19,(2008)
15.M. D. Lima, M. J. de Andrade, C. P. Bergmann,S. Roth,Thin, conductive, carbon nanotube networks over transparent substrates by electrophoretic deposition, J Mater Chem, 18,776(2008)
16.D. O. Kim, M. H. Lee, J. H. Lee, T. W. Lee, K. J. Kim, Y. K. Lee, T. Kim, H. R. Choi, J. C. Koo,J. D. Nam,Transparent flexible conductor of poly(methyl methacrylate) containing highly-dispersed multiwalled carbon nanotube, Org Electron, 9,1(2008)
17.J. Zhang, L. Gao, J. Sun, Y. Q. Liu, Y. Wang, J. P. Wang, H. Kajiura, Y. M. Li,K. Noda,Dispersion of Single-Walled Carbon Nanotubes by Nafion in Water/Ethanol for Preparing Transparent Conducting Films, J Phys Chem C, 112,16370(2008)
18.H. J. Park, J. Kim, J. Y. Chang,P. Theato,Preparation of transparent conductive multilayered films using active pentafluorophenyl ester modified multiwalled carbon nanotubes, Langmuir, 24,10467(2008)
19.J. Sung, P. S. Jo, H. Shin, J. Huh, B. G. Min, D. H. Kim,C. Park,Transparent, low-electric-resistance nanocomposites of self-assembled block copolymers and SWNTs, Adv Mater, 20,1505(2008)
20.S. Paul,D. W. Kim,Preparation and characterization of highly conductive transparent films with single-walled carbon nanotubes for flexible display applications, Carbon, 47,2436(2009)
21.S. De, P. E. Lyons, S. Sorel, E. M. Doherty, P. J. King, W. J. Blau, P. N. Nirmalraj, J. J. Boland, V. Scardaci, J. Joimel,J. N. Coleman,Transparent, Flexible, and Highly Conductive Thin Films Based on Polymer - Nanotube Composites, Acs Nano, 3,714(2009)
22.J. D. Songfeng Pei, You Zeng, Chang Liu and Hui-Ming Cheng,The fabrication of a carbon nanotube transparent conductive film by electrophoretic deposition and hot-pressing transfer, 20,235707(2009)
23.I. O'Connor, S. De, J. N. Coleman,Y. K. Gun'ko,Development of transparent, conducting composites by surface infiltration of nanotubes into commercial polymer films, Carbon, 47,1983(2009)
24.J. H. Shin, D. W. Shin, S. P. Patole, J. H. Lee, S. M. Park,J. B. Yoo,Smooth, transparent, conducting and flexible SWCNT films by filtration-wet transfer processes, J Phys D Appl Phys, 42,045305(4pp)(2009)
25.W. Y. Liangbing Hu, Paul Brochu, George Gruner, and Qibing Pei,Highly stretchable, conductive, and transparent nanotube thin films, 94,111608(2009)
26.M. R. S. Castro, N. Al-Dahoudi, P. W. Oliveira,H. K. Schmidt,Multi-walled carbon nanotube-based transparent conductive layers deposited on polycarbonate substrate, J Nanopart Res, 11,801(2009)
27.E. M. Doherty, S. De, P. E. Lyons, A. Shmeliov, P. N. Nirmalraj, V. Scardaci, J. Joimel, W. J. Blau, J. J. Boland,J. N. Coleman,The spatial uniformity and electromechanical stability of transparent, conductive films of single walled nanotubes, Carbon, 47,2466(2009)
28.H. A. Becerril, J. Mao, Z. Liu, R. M. Stoltenberg, Z. Bao,Y. Chen,Evaluation of solution-processed reduced graphene oxide films as transparent conductors, Acs Nano, 2,463(2008)
29.G. Eda, G. Fanchini,M. Chhowalla,Large-area ultrathin films of reduced graphene oxide as a transparent and flexible electronic material, Nat Nanotechnol, 3,270(2008)
30.X. L. Li, G. Y. Zhang, X. D. Bai, X. M. Sun, X. R. Wang, E. Wang,H. J. Dai,Highly conducting graphene sheets and Langmuir-Blodgett films, Nat Nanotechnol, 3,538(2008)
31.M. Song, D. Y. Cai,C. X. Xu,Highly conductive carbon-nanotube/graphite-oxide hybrid films, Adv Mater, 20,1706(2008)
32.D. H. Min,Y. K. Kim,Durable Large-Area Thin Films of Graphene/Carbon Nanotube Double Layers as a Transparent Electrode, Langmuir, 25,11302(2009)
33.C. Y. Su, Y. P. Xu, W. J. Zhang, J. W. Zhao, X. H. Tang, C. H. Tsai,L. J. Li,Electrical and Spectroscopic Characterizations of Ultra-Large Reduced Graphene Oxide Monolayers, Chem Mater, 21,5674(2009)
34.S. De, P. J. King, M. Lotya, A. O'Neill, E. M. Doherty, Y. Hernandez, G. S. Duesberg,J. N. Coleman,Flexible, Transparent, Conducting Films of Randomly Stacked Graphene from Surfactant-Stabilized, Oxide-Free Graphene Dispersions, Small, 6,458(2010)
35.V. C. Tung, L. M. Chen, M. J. Allen, J. K. Wassei, K. Nelson, R. B. Kaner,Y. Yang,Low-Temperature Solution Processing of Graphene-Carbon Nanotube Hybrid Materials for High-Performance Transparent Conductors, Nano Lett, 9,1949(2009)
36.J. H. Lee, D. W. Shin, V. G. Makotchenko, A. S. Nazarov, V. E. Fedorov, Y. H. Kim, J. Y. Choi, J. M. Kim,J. B. Yoo,One-Step Exfoliation Synthesis of Easily Soluble Graphite and Transparent Conducting Graphene Sheets, Adv Mater, 21,4383(2009)
37.L. J. Li, C. Y. Su, Y. P. Xu, W. J. Zhang, J. W. Zhao, X. H. Tang,C. H. Tsai,Electrical and Spectroscopic Characterizations of Ultra-Large Reduced Graphene Oxide Monolayers, Chem Mater, 21,5674(2009)
38.B. H. Hong, K. S. Kim, Y. Zhao, H. Jang, S. Y. Lee, J. M. Kim, K. S. Kim, J. H. Ahn, P. Kim,J. Y. Choi,Large-scale pattern growth of graphene films for stretchable transparent electrodes, Nature, 457,706(2009)
39.J. Geng,H. Jung,Porphyrin Functionalized Graphene Sheets in Aqueous Suspensions: From the Preparation of Graphene Sheets to Highly Conductive Graphene Films, J Phys Chem C, 114,8227(2010)
40.H. Yamaguchi, G. Eda, C. Mattevi, H. Kim,M. Chhowalla,Highly Uniform 300 mm Wafer-Scale Deposition of Single and Multilayered Chemically Derived Graphene Thin Films, Acs Nano, 4,524(2010)
41.J. S. Park, S. M. Cho, W. J. Kim, J. Park,P. J. Yoo,Fabrication of Graphene Thin Films Based on Layer-by-Layer Self-Assembly of Functionalized Graphene Nanosheets, Acs Appl Mater Inter, 3,360(2011)
42.S. J. Wang, Y. Geng, Q. B. Zheng,J. K. Kim,Fabrication of highly conducting and transparent graphene films, Carbon, 48,1815(2010)
43.J. X. Geng, L. J. Liu, S. B. Yang, S. C. Youn, D. W. Kim,J. S. Lee, J. K. Choi,H. T. Jung,A Simple Approach for Preparing Transparent Conductive Graphene Films Using the Controlled Chemical Reduction of Exfoliated Graphene Oxide in an Aqueous Suspension, J Phys Chem C, 114,14433(2010)
44.T. K. Hong, D. W. Lee, H. J. Choi, H. S. Shin,B. S. Kim,Transparent, Flexible Conducting Hybrid Multi layer Thin Films of Multiwalled Carbon Nanotubes with Graphene Nanosheets, Acs Nano, 4,3861(2010)
45.H. X. He, M. Zhang, R. R. Parajuli, D. Mastrogiovanni, B. Dai, P. Lo, W. Cheung, R. Brukh, P. L. Chiu, T. Zhou, Z. F. Liu,E. Garfunkel,Production of Graphene Sheets by Direct Dispersion with Aromatic Healing Agents, Small, 6,1100(2010)
46.W. C. Ren, J. P. Zhao, S. F. Pei, L. B. Gao,H. M. Cheng,Efficient Preparation of Large-Area Graphene Oxide Sheets for Transparent Conductive Films, Acs Nano, 4,5245(2010)
47.H. W. Zhu, C. Y. Li, Z. Li, K. L. Wang, J. Q. Wei, X. A. Li, P. Z. Sun, H. Zhang,D. H. Wu,Graphene Nano-"patches" on a Carbon Nanotube Network for Highly Transparent/Conductive Thin Film Applications, J Phys Chem C, 114,14008(2010)
48.H. W. Tien, Y. L. Huang, S. Y. Yang, J. Y. Wang,C. C. M. Ma,The production of graphene nanosheets decorated with silver nanoparticles for use in transparent, conductive films, Carbon, 49,1550(2011)
49.R. R. Wang, J. Sun, L. A. Gao, C. H. Xu, J. Zhang,Y. Q. Liu,Effective post treatment for preparing highly conductive carbon nanotube/reduced graphite oxide hybrid films, Nanoscale, 3,904(2011)
50.K. Jo, T. Lee, H. J. Choi, J. H. Park, D. J. Lee, D. W. Lee,B. S. Kim,Stable Aqueous Dispersion of Reduced Graphene Nanosheets via Non-Covalent Functionalization with Conducting Polymers and Application in Transparent Electrodes, Langmuir, 27,2014(2011)
51.D. W. Lee, T. K. Hong, D. Kang, J. Lee, M. Heo, J. Y. Kim, B. S. Kim,H. S. Shin,Highly controllable transparent and conducting thin films using layer-by-layer assembly of oppositely charged reduced graphene oxides, J Mater Chem, 21,3438(2011)
52.H. W. Tien, Y. L. Huang, S. Y. Yang, S. T. Hsiao, J. Y. Wang,C. C. M. Ma,Graphene nanosheets deposited on polyurethane films by self-assembly for preparing transparent, conductive films, J Mater Chem, 21,14876(2011)
53.S. H. Domingues, R. V. Salvatierra, M. M. Oliveirab,A. J. G. Zarbin,Transparent and conductive thin films of graphene/polyaniline nanocomposites prepared through interfacial polymerization, Chem Commun, 47,2592(2011)
54.A. R. Madaria, A. Kumar,C. W. Zhou,Large scale, highly conductive and patterned transparent films of silver nanowires on arbitrary substrates and their application in touch screens, Nanotechnology, 22,2011)
55.J. M. Tour, Y. Zhu, Z. Z. Sun, Z. Yan,Z. Jin,Rational Design of Hybrid Graphene Films for High-Performance Transparent Electrodes, Acs Nano, 5,6472(2011)