印刷奈米材料於電化學應用之研究

Abstract

利用印刷技術來製備電化學元件的方法備受矚目，可用來製作感測器、燃料電池、超級電容…等元件。印刷方式製備元件除了具備可減化製造程序、降低製作成本、減少材料浪費、不須開模等特性，也可將此技術運用在柔性基材，甚至智慧衣物等穿戴式電子設備。為了滿足市場上不斷增長的需求，本論文將使用新材料或新想法，來增進印刷製備電化學應用的多元性。此外，墨水的穩定性、基材的處理、印刷的參數、或者印刷方式的選擇也是本文論述的重點。本文將使用點膠印刷以及噴墨印刷技術，分別屬於接觸式及非接觸式的印刷製程，使不同元件其材料、墨水或基材所需要的印刷條件皆能滿足。論文第一章部分將介紹各式印刷方式以及理論基礎、塗佈品質的控制及目前利用印刷方式製備電化學應用之發展近況。而後續的章結，將探討印刷技術運用於生物感測器、葡萄糖燃料電池、電催化以及濕度感測器等應用，對新領域進行系統性的試驗。 本論文的第二章，將利用印刷技術可精準定位塗佈之特性，連續修飾氧化石墨烯奈米帶和導電高分子(PEDOT:PSS)，在同一個電極上。不需使用多個試片或者合成複雜的複合材料，即可達到同時偵測多樣物質的特性。其結果顯示，此感測器能夠在同時分辨維生素C、尿酸、多巴胺和亞硝酸鹽存在的混合溶液，並且有良好的偵測極限。 第三章為了能使燃料電池陰陽極的材料，能夠客製化且微小化去製備成電極，可用於生物植入或穿戴式電子等需微小化之應用，將使用印刷技術來取代傳統刮刀大範圍塗佈之無法圖樣化及微小化的缺點。本章將分別塗佈雙金屬修飾的石墨烯，和氮參雜的氧化石墨烯奈米帶在各別的電極上，隨之將兩電極間夾上納菲(Nafion®)薄膜，製備成非酵素的葡萄糖燃料電池，並在中性溶液下測試。此電池相較於酵素型葡萄糖燃料電池，使用上條件的限制較少，電池在5度到80度C的環境下皆能使用，且不會有久放酵素失活的問題。 本文第四章，將利用噴墨印刷可疊層且精準定位之優點，使有機金屬框架(MOF)快速製備成可圖樣化的薄膜，並用於電催化之應用。取代原本如需要有圖樣化的薄膜，要有遮罩或在基材上先噴塗前驅液，再浸泡溶液使其緩慢長晶的程序。本章也會並探討顆粒大小、及薄膜厚度對於電性展性之影響。結果顯示，噴墨印刷製作的薄膜具有良好的電催化特性，相較於以往緩慢且複雜的製程也有相似的靈敏度和檢測極限。 第五章，將利用印刷技術可減少浪費材料、能非接觸式堆疊塗佈之特性。噴塗預先合成好的聚乙二醇（PEG）所修飾金奈米顆粒之貴金屬溶液在指叉電極上，製備成薄膜並用於濕度感測器。取代傳統旋轉塗佈須開版且易浪費材料之缺點，而本章因PEG和金奈米粒子能夠均勻的分佈，使得薄膜的導電度因而提升，進而能大幅的降低薄膜的厚度，使吸脫附水氣的時間減少，即可降低響應時間。並且能夠在極低的相對濕度下進行濕度偵測。此感測器響應時間快，除了可用濕度偵測外，也能應用在呼吸行為的評估上。 最後，在末章節部分即總結印刷技術使用在電化學應用元件研究上的成果，對印刷技術製備電化學應用之新的領域進行了評估，為未來的研究鋪平了道路，提升未來商業化發展的可能性。

Recently, printing technology has used to fabricate electrochemical devices, such as biosensors, fuel cells, super capacitors and so on. Printing technology not only can simplify the fabrication process, reduce production costs, decrease material waste, remove the use of mask, but can also apply to flexible substrates and smart clothes such as wearable electronic devices. In order to meet the continuously increasing demand of the market, we enhance the diversity of electrochemical applications of printing technology by new materials and concepts in this work. In addition, we also aim to understand ink stability, substrate treatment, printing parameters, and the choice of printing method. Dispensing printing and inkjet printing technology, which are contact and non-contact printing process, respectively, will be used in this thesis. This enables the printing conditions for different devices of all the materials, ink, substrates to be satisfied. In the first chapter of the thesis, various types of printing methods and theoretical basis, control of the printing quality, and recent developments of using printing methods to prepare electrochemical applications will be introduced. In the follow-up chapters, we will discuss the application of printing technology on biosensors, glucose fuel cells, electrocatalysis, and humidity sensors to conduct systematic tests in new areas. In chapter 2, printing technology, which can precisely control liquid deposition effectively for patterning, is used to continuously modify graphene oxide nanoribbon and conductive polymer (PEDOT:PSS) on the same electrode. Multiple substances can be simultaneously detected without using multiple test strips or synthesizing complex composite materials. The results show that this sensor can detect the mixed solution of ascorbic acid, uric acid, dopamine and nitrite at the same time, and provides good detection limits. In chapter 3, in order to customize and miniaturize the anode and cathode materials of the fuel cell and apply it to bio implantation or wearable electronics, printing technology were used instead of traditional blade coating. In this chapter, bimetallic modified graphenes and nitrogen-doped graphene oxide nanoribbons are printed respectively on the anode and the cathode electrodes. Next, the Nafion® film is sandwiched between the two electrodes to assemble non-enzymatic glucose fuel cells and test in neutral solution. Compared with the enzyme glucose fuel cell, this non-enzymatic fuel cell has less restrictions for application. The fuel cells can be used in an environment between 5 oC and 80 oC, and can be stored for long term without malfunction caused by enzyme inactivation. In chapter 4, inkjet printing technology, which has good characteristics of stacking and precisely positioning, is used to rapidly fabricate metal organic frameworks (MOFs) into patternable films for electrocatalytic applications. The traditional process, which needs mask or to print the precursor on the substrate solution and soak into solutions to slowly grow crystals, can be replaced to fabricate the patternable films. In this chapter, we will also discuss the effect of particle sizes and film thicknesses on electrical properties. The results show that the inkjet-printed films have similar sensitivity and detection limits compared to the traditional processes. In chapter 5, we use inkjet printing technology, which has good characteristics of reducing waste of materials and multilayer deposition, to print pre-synthesized precious metal solution of polyethylene glycol-modified gold nanoparticle on the interdigitated electrode to fabricate thin film for the humid sensor. It will replace spin-coating, which needs masks and waste materials. Due to the uniform distribution of PEG and gold nanoparticles, the electrical conductivity of the thin film will increase, and the thickness of the film can significantly reduce. It can reduce time for adsorption and desorption, so the response time can be shortened. Moreover, it can also detect extremely low relative humidity. To conclude, this sensor has a short response time and great humid sensibility that can be applied to detect breathing behavior. Finally, in chapter 6, we conclude and summarize the achievements of this research. The new field of electrochemical applications by printing technology is evaluated and can be applied to business development of printing nanomaterials for electrochemical devices in the future.