功能性奈米塗料之開發與精密圖案繪製

Abstract

功能性奈米塗料開發隨著現今印刷技術的廣泛應用和功能性需求增加而備受矚目，並用於結構電子上的精密線路圖樣和繪製微型化精密線路，包含皮膚電路、溫度、應變或聲音感測器和生物無線感測器等。為了滿足新興市場上不斷增長的需求，本論文將開發功能性奈米塗料來解決塗料顆粒穩定於塗佈薄膜平整性與在曲面或平面上繪製精密圖樣的不足之處。此外，填料尺寸大小和塗佈製程選用的影響也是本文論述的重點。當施予單一方向的力產生低剪切速率時，塗料中奈米顆粒堆疊微結構會影響薄膜表面粗糙度或液線邊界粗糙度；在高剪切速率時，塗料中具有高長寬比的填料會產生優先順向性排列，使得微米/奈米級細線纖維強度和韌性提升。本論文第一章部分將概述各種列印技術原理與相關比較、液線斷裂理論和塗料對於流變性質的影響。而後續章節，將探討功能性塗料運用於製作出高阻水氣性質薄膜、曲面噴塗液線並用於天線感測和繪製微型化圖樣線路，並且對新領域進行系統性的試驗。 第二章是使用溶膠凝膠法製備出具有良好阻水氣的奈米複合塗料，由於二氧化矽奈米顆粒表面富有羥基，造成二氧化矽奈米顆粒發生團聚，因此藉由釩氧化物能幫助二氧化矽奈米顆粒表面上進行去羥基化反應，使得二氧化矽奈米顆粒得到較好的分散性。在使用滾線棒塗佈時，奈米顆粒穩定性提升能有效改善奈米複合薄膜的表面平整性，進而縮小整體孔洞尺寸和增加水氣穿透的路徑通道，因而提升水氣穿透能力，從原先PET薄膜約為12.2 g m-2day-1下降至以塗佈氧化釩/二氧化矽/氧化鋁奈米複合薄膜的PET薄膜0.095 g m-2day-1。因此，氧化釩/二氧化矽/氧化鋁奈米複合薄膜能有效抑制水氣穿透的能力。 第三章是建立曲面上噴塗液線的列印品質分析，使得提升曲面噴塗圖樣天線的保真度。在曲面上噴塗液線時，液線會受到重力影響引起液線線寬與邊界粗糙度增加，並且液線寬度和邊界粗糙度會隨著截面半徑增加而增加。本章利用染料型和顆粒型墨水分析屈服應力在曲面上列印品質的影響。因此，可用於曲面上噴塗良好電子線路，並進一步做為直寫式噴塗無線感測隱形眼鏡之應用。 第四章是為了解決牽引紡絲技術繪製微型化圖樣線路的困難，由於牽引紡絲技術大部分繪製幾何圖案皆以直線構成，鮮少有弧形相關圖樣線路。利用聚乙二醇溶液中添加1 wt%奈米纖維素來提升本身的拉伸黏度和拉伸延延遲時間，有助於提升牽引液線的穩定性並且繪製完整的邊界線路。此外，利用常見噴塗針頭即可繪製出線寬380 nm的細線纖維和簡單的直線相關陣列圖樣。接著，使用塑膠針頭製作成類似鋼筆結構形狀並且同時移除頭端和尾端的液珠，繪製出除了直線以外的幾何圖形，因此可提供未來繪製精密圖樣化線路或導電線路的開發。 最後，在末章節部分即總結功能性塗料對於薄膜塗佈和精密圖樣繪製研究上的成果，對於繪製微型化精密圖樣應用之新的領域進行相關評估，為了未來研究鋪展邁向成功的路徑，提升未來商業化發展的可能性。

The development of functional coating nanomaterials has considerably attracted attention with widespread applications of printing and the increase in functionality requirements. The functional coating nanomaterials would be used to print structural electronics and draw miniaturized precision circuits including skin circuits, temperature, strain, or sound sensors, and bio-wireless sensors. To satisfy the growing demand in the emerging market, we develop various functional coating nanomaterials to address the deficiencies of nanoparticles stability for film flatness and precision patterns for printed electronics. Additionally, the influence of filler size and printing process selection is also important in this work. When a force is applied in a single direction produces a low shear rate, the particle packing in the microstructure would affect film surface roughness or liquid edge raggedness; At a high shear rate, the filler with high aspect ratios would activate a preferential directional alignment, resulting in the improved strength and resilience of micro-/nano- fiber. In the first chapter of this thesis, it outlines various types of printing technologies and the related comparison, liquid breakup principle, and the influence of the coating on rheological properties. In the subsequent chapters, we will discuss the applications of functional coating nanomaterials to fabricate the moisture barrier films, print liquid lines on the curvilinear surface as antenna sensing, and draw the miniaturized pattern circuits, as well as systematic experiments in the new fields. In chapter 2, the hybrid nanocomposite coating with moisture barrier was fabricated by the sol-gel method. The aggregation of silicon nanoparticles (SO2) occurs because the residual hydroxyl groups retain on the surface of SO2 nanoparticles. To improve the dispersion of silicon nanoparticles, vanadium oxide (VO) is added due to its dehydroxylation capability. When using a rod coating could improve the surface flatness of the hybrid nanocomposite films due to the enhancement of nanoparticle stability. Furthermore, the hybrid nanocomposite film with the smaller pore radius can yield higher tortuosity to enhance moisture barrier properties. After coating onto a PET film, the water vapor transmittance rate was reduced from12.2 to 0.095 g m-2day-1. Thus, VO/SiO2/Al2O3 films provide a promising moisture barrier capacity. In chapter 3, to establish the print quality analysis of liquid line on the curvilinear surface, it could enhance the fidelity of the printed antenna. When the liquid line is printed on the curvilinear surface, it could be susceptible to widen liquid line and increase line edge raggedness by gravity with the increasing cross-sectional radius. This chapter uses dye-based and pigment-based inks to analyze the effect of yield stress on the print quality on the curvilinear surface. Thus, it could be used for printing good electronic circuits and further direct-write printing wireless sensing contact lens application. In chapter 4, to resolve the deficiency of draw spinning for micro-patterns because most of the geometric patterns are composed of straight-line, just less than a few related micro-lines. The addition of 1 wt% cellulose nanofibrils in the polyethylene oxide solution to increase its extensional viscosity and relaxation time resulting in the enhancement of the stability of drawing liquid stability and obtain the complete boundary micro-lines. Moreover, using common printing tips to print the fiber with the linewidth of 380 nm and the simple line array patterns. Furthermore, applying a plastic tip as the pen tip structure would remove the droplet at head and tail for draw fiber simultaneously. It could draw the geometric patterns other than straight lines. Thus, the drawing fiber could provide the future development of precision patterns and conductive circuits. Finally, in chapter 5 summarizes the achievements of the functional coating nanomaterials on the film flatness and precision patterns in this research. The emerging application field is evaluated for the miniaturized precision patterns to pave the way for success in commercial development.