银纳米线的超声波焊接及其在透明导电薄膜上的应用

发布时间：2018-07-02 19:54

  本文选题：银纳米线 + 低温烧结　； 参考：《深圳大学》2017年硕士论文

【摘要】：银纳米线(AgNWs)因其具有优异的导电性、导热性及良好的生物相容性、抗菌性、催化性等特点,被广泛应用于透明电极、医药抗菌、工业催化等领域。由银纳米线制备的透明导电薄膜不仅导电性好、透光率高,而且还耐弯折,然而尽管银纳米线透明导电薄膜具有如此多的优点,但是由于银纳米线之间的接触电阻较大,在透明导电薄膜的制备中往往需要加入粘接剂来增强其与基底的结合力。为解决这一问题,尝试通过超声波焊接工艺来实现银纳米线的焊接,以达到不添加粘接剂的目的。采用多元醇还原法制备出了平均长度20μm,直径50-70nm的高纯度银纳米线。对该银纳米线在不同氛围下的低温烧结性能进行了研究,结果表明:在三种气氛下,银纳米线在150℃以下烧结时,其形貌均不发生明显变化,与原始形貌基本保持一致。当温度上升至200℃时,银纳米线发生局部熔融现象,且最早出现在银纳米线接触的节点处,并随着烧结温度的升高,熔融现象越发明显。温度上升至250℃时,由于银纳米线上存在较多的缺陷,随着烧结时间的延长,缺陷部位容易发生熔断,使银纳米线熔断成为数段短棒状的纳米线。当烧结温度达到300℃时,银纳米线开始球化,由原来的线状变为短棒状与球状的混合体,最终完全熔融为球状的银纳米颗粒。以此为基础,比较了银纳米线压力焊接及热压焊接效果,在银纳米线的超声波焊接工艺的过程中,对影响超声波焊接效果的时间、压力、温度因素进行了研究,得到了各因素在焊接过程中的影响规律:在静压力作用下,银纳米线首先发生微量变形,其变形量与施加的压力值成正比。焊接开始后,银纳米线表面附着的PVP在超声波的作用下被去除,使其表面出现粗糙化,银纳米线表面得以直接接触并开始出现连接,随着焊接时间的延长,银纳米线逐渐形成一张连通的导电网络,在此过程中温度对银纳米线的形貌几乎没有影响,但适当的加热能够进一步增加银纳米线与基底的结合力。选用PET材料作为基底,利用旋涂工艺制备了银纳米线透明导电薄膜,并通过引入超声波焊接来实现银纳米线间的相互连接,使得银纳米线嵌入基底以达到增强导电层与基底的结合力的作用,最终获得的透明导电薄膜方阻下降了约50%,雾度降低了约20%。
[Abstract]:Silver nanowires (AgNWs) have been widely used in the fields of transparent electrode, pharmaceutical antibacterial and industrial catalysis because of their excellent electrical conductivity, thermal conductivity and good biocompatibility, antibacterial and catalytic properties. The transparent conductive films prepared by silver nanowires have good conductivity, high transmittance and bending resistance. However, although silver nanowires have so many advantages, the contact resistance between silver nanowires is large. In the preparation of transparent conductive films, adhesive is often added to enhance its adhesion to the substrate. In order to solve this problem, we try to realize the welding of silver nanowires by ultrasonic welding technology, so as to achieve the purpose of not adding adhesive. High purity silver nanowires with average length of 20 渭 m and diameter of 50-70nm were prepared by polyol reduction method. The low temperature sintering properties of the silver nanowires in different atmosphere were studied. The results showed that the morphology of silver nanowires sintered below 150 鈩，

本文编号：2090742