纖維素奈米材料複合奈米紙之性質探討

Abstract

隨著環保意識上升，減少使用石化產品並以生物可降解材料取代之已成為近年全球趨勢。其中，因來源可再生、低成本、生物相容性佳、輕量、熱穩定性佳等優勢，纖維素成為取代石化產品的熱門材料。纖維素紙張相較於塑膠與玻璃更有可撓性佳、環境友善、可印性佳與卷對卷製程相容性佳等優點，可應用於電子元件的基板。使用纖維素奈米材料製成的纖維素奈米紙除了有紙張的優點，更有表面粗糙度低與透明度高等優勢，惟纖維素上的羥基引起的親水性仍會阻礙纖維素奈米紙的應用。是故，本研究透過檸檬酸改質纖維素奈米紙，以改善其抗濕性，同時使用不同纖維素奈米材料製成的纖維素奈米紙，探討環境友善的製程下纖維素奈米材料比例的不同造成的性質差異。研究結果顯示，含有CNF的纖維素奈米紙因纖維的團聚，造成纖維素奈米紙的表面粗糙度高與透明度低，但對於機械性質有正向的作用。含有TOCN雖可提升纖維素奈米紙的透射率高，但熱穩定性差。含有CNC的纖維素奈米紙除了有透射率高的優點，更展現材料的鐵電性。而藉由檸檬酸的改質，顯著改善了纖維素奈米紙的吸濕性，同時提升熱穩定性，酯化改質效果良好。綜上所述，藉由調整纖維素奈米材料的複合比例，可得到理想的性質，加上檸檬酸的改質，在無毒性且生物可降解的製程下，製造出可因應各方應用的纖維素奈米紙。

With the rising awareness of environmental friendliness, reducing and replacing the use of petrochemicals has become a global trend in recent years. Among all the candidates for materials to replace petrochemicals, cellulose has gained much attention due to its advantages such as renewability, low cost, good biocompatibility, lightweight, and thermal stability. Because of its flexibility, environmental friendliness, printability, and compatibility with the roll-to-roll process, cellulose paper is more competitive with plastic and glass as a substrate for electronic components. Moreover, with the addition of cellulose nanomaterials, cellulose nanopaper becomes smoother and more transparent. Still, there are obstacles to the application of cellulose nanopaper because of its hydrophilicity. In this study, we modified cellulose with citric acid to improve its moisture resistance. Meanwhile, different cellulose nanomaterials were combined to gain preferable properties. The results showed that the cellulose nanopaper containing CNF had higher roughness and lower transparency due to the agglomeration of fibers, yet had a positive effect on the mechanical properties. Although TOCN can improve the transmittance of cellulose nanopaper, it had poor thermal stability. Not only did the presence of CNC improve the transparency of the nanopaper, it also exhibited ferroelectricity. On the other hand, by the modification of citric acid, the water resistance and thermal stability of the cellulose nanopaper were significantly improved. To sum up, by adjusting the composite ratio of cellulose nanomaterials, ideal properties can be obtained, and with esterification, a non-toxic and environmentally friendly process can be used to fabricate cellulose nanopaper.