奈米銀線/石墨烯之複材製備、熱電性質暨機械性質之研究

The investigations of preparing, thermal, electrical, and mechanical properties of silver nanowires/graphene nanocomposites

許宸豪(Hsu, Chen Hao)

指導教授 ： 蔡宏營

國立清華大學/工學院/動力機械工程學系/碩士(2016年)

摘要

本篇研究是透過製備奈米銀線(Silver nanowires)混參Benzoxazine與環氧樹脂(Epoxy)製成之複材薄膜，研究其電熱特性與機械性質之研究。研究首先以多元醇(polyol)還原法製備奈米銀線，透過乙二醇為還原劑，並加入PVP軟模板，還原銀離子，並成長為奈米銀線(Silver nanowires)。
透過高長徑比的奈米銀線(aspect ratio)混參至高分子基材中，使奈米銀線形成導電與導熱的路徑，以提高奈米複合材料的電熱特性。並將奈米銀線與石墨烯0.75 wt%之混合，使奈米複合材料與奈米銀線具有較佳之熱穩定性，並提升奈米複合材料之電熱性質，降低奈米銀線之氧化程度；由於Benzoxazine之優異的阻水阻氣之性質，於熱氧化製程下，亦可提升奈米複合材料之熱穩定性。當材料間之介面發生模數mismatch之現象，對於聲子於材料內部之傳遞，產生較大之阻礙，較易發生聲子散射現象，對於導熱性質，具有負面效果。
將奈米銀線塗浸(dip-coating)於碳纖維，並製備成積層板複合材料。塗浸奈米銀線，加劇積層板複合材料之脫層現象，塗浸兩次之彎曲強度，較純環氧樹脂之積層板複合材料，下降31.86%；扭轉性質亦下降18.28%，由扭轉疲勞試驗中發現，於小角度(30°)之扭轉疲勞試驗，奈米銀線可抑制裂縫延伸，大角度(40°, 50°)之之扭轉疲勞試驗則發生快速脫層破壞之現象，顯示奈米銀線之塗浸，較無法抵抗較為快速之破壞模式。

關鍵字

奈米銀線 ； Benzoxazine 樹脂 ； 石墨烯 ； 複合材料 ； 聲子 ； 機械性質 ； 疲勞

並列摘要

Silver nanowire (AgNWs) is a new kind of one-dimensional nanomaterial. AgNWs have been prepared with the polyol reduction method. In this research, the nanocomposites content silver nanowires and graphenes has been studied. The synergic effects of silver nanowires and graphene nanocomposites had been researched for their thermal and electrical properties. The addition of graphene has improved the thermal and electrical properties of nanocomposite. In the same time, the thermal stability of nanocomposites AgNWs and can be enhanced due to the gas impermeability of graphene. A new type of polymer resin, benzoxazine, has mixed with epoxy became co-polymer to enhance the thermal oxidation stability with their batter water and gas impermeability.
The AgNWs has been coated on the carbon fibers with dip-coating method. The mechanical properties of carbon fiber reinforced polymers (CFRP) content AgNWs are fail easily, because of the serious delamination of CFRPs. The flexural and torsion tests were decreased obviously. In the torsion fatigue, with the small angle twisting (30°), the fatigue life of CFRP contents AgNWs have barely negative effects, de to the AgNWs may resist the crack propagation. However, with the larger angle twisting (40°, 50°), the fatigue life of CFRP contents AgNWs reduced dramatically with the weakly interfacial interaction between AgNWs, carbon fibers, and epoxy.

並列關鍵字

Silver nanowire ； Benzoxazine ； Graphene ； Nanocomposite ； Mechanical properties ； Fatigue ； Phonon

參考文獻

[48] J. Chiguma, E. Johnson, P. Shah, N. Gornopolskaya and W. E. Jones Jr, “Thermal Diffusivity and Thermal Conductivity of Epoxy-Based Nanocomposites by the Laser Flash and Differential Scanning Calorimetry Techniques,” Open Journal of Composite Materials, 3, 51-62, 2013.

[1] Y. Sun, Y. Yin, B .T. Mayers, T. Herricks and Y. Xia, “Uniform Silver Nanowires Synthesis by Reducing AgNO_3with Ethylene Glycol in the Presence of Seeds and Poly(Vinyl Pyrrolidone),” Chemical Materials; 14, 4736-4745, 2002.

[2] B. Wiley, Y. Sun and Y. Xia, “Synthesis of Silver Nanostructures with Controlled Shape and Properties,” Accounts of Chemical Research; 40, 1067–1076, 2007.

[3] S. E. Skrabalak, B. J. Wiley, M. Kim,E. V. Formo and Y. Xia,

[5] Y. Zhu, Q. Qin, F. Xu, F. Fan, Y. Ding, T. Zhang, B. J. Wiley and Z. L. Wang, “Size effects on elasticity, yielding, and fracture of silver nanowires: In situ experiments,” PHYSICAL REVIEW B, 85, 045443, 2012.