本文選題：聚谷氨酸　切入點：納米纖維　出處：《天津工業(yè)大學》2017年碩士論文　論文類型：學位論文

【摘要】：質子交換膜燃料電池(PEMFC)是一種可以將化學能直接轉換成電能的裝置,其具有功率密度高、能源利用率高、環(huán)保、啟動快等優(yōu)點,是能源利用的一種新方式。質子交換膜(PEM)是其核心部件之一,起到傳遞質子和隔絕燃料的作用,其性能的優(yōu)劣直接決定電池的性能。目前商業(yè)化的全氟磺酸膜具有昂貴的成本、高溫低濕時較低的質子傳導率、較高的甲醇滲透率等缺陷,嚴重阻礙了質子交換膜燃料電池的廣泛應用。因此高性能、高性價比質子交換膜的開發(fā)成為當前研究熱點。近年來,具有大比表面積、較高長徑比、較好機械性能的納米纖維,被許多科研工作者應用到質子交換膜中以提高質子交換膜的機械性能和質子傳導性能。本論文以磺化聚醚砜為基礎,通過引入聚谷氨酸納米纖維來構建質子傳輸通道的方式制備高性能的質子交換膜。主要研究內容如下:通過溶液噴射紡絲技術制備不同PGA含量的納米纖維,分析了牽伸風速和聚谷氨酸的含量對纖維成型的影響。通過FESEM測試、FTIR分析、XPS分析和TGA分析表明隨著牽伸風速的增加納米纖維的成型性逐漸增加,當牽伸風速過大時纖維纏結嚴重;隨著PGA含量的增大纖維表面疵點增多,纖維直徑增大,熱穩(wěn)定性增加。通過電化學測試表明PGA納米纖維隨著溫度和濕度的升高納米纖維的電導率逐漸增大,另外隨著PGA含量的增加,纖維電導率也逐漸增加。通過溶液浸漬的方法制備了不同聚谷氨酸納米纖維含量的SPES復合膜,復合膜的表面平整致密,納米纖維被SPES基質完全包覆兩者相容性好。TG測試結果顯示,納米纖維的加入復合膜具有足夠的熱穩(wěn)定性適用于直接甲醇燃料電池質子交換膜。聚谷氨酸納米纖維復合膜的吸水率隨纖維含量的增大而增加,相比于SPES膜,復合膜的吸水率得到了極大的改善,復合膜的溶脹率在合理范圍內。通過引入納米纖維成功構建了質子傳輸通道,并改善了 SPES膜的質子傳導率,且復合膜的質子傳導率隨著納米纖維含量的增加呈增加趨勢。SPES-30復合質子交換膜的質子傳導率最好,在80℃時高達0.261 Scm~(-1)。所有復合膜的阻醇性能均優(yōu)于純SPES膜,并且隨著聚谷氨酸納米纖維的增加甲醇滲透系數(shù)減小。同時SPES-30具有最好的選擇性其值為29.72×104sscm-3。利用輔助電極法靜電紡絲技術成功制備取向PGA納米纖維,通過溶液浸漬的方法,將納米纖維與SPES形成了復合質子交換膜。通過掃描電鏡、XPS、XRD以及TG測試表明取向PGA納米纖維成功制備,并且具有較好的取向性和熱穩(wěn)定性;通過電化學性能測試表明所制備的取向PGA納米纖維復合膜具有較好的質子傳到導性能,在復合膜的取向方向上質子電導率在100%濕度和80℃時為0.368 Scm~-1。
[Abstract]:Proton exchange membrane fuel cell (PEMFC) is a device that can convert chemical energy directly into electric energy. It has the advantages of high power density, high energy efficiency, environmental protection, fast start-up and so on. PEM is one of the core components of PEM, which plays the role of proton transfer and fuel isolation. The performance of PEM directly determines the performance of the battery. At present, the commercial perfluorosulfonic acid membrane has high cost. Low proton conductivity and high methanol permeability at high temperature and low humidity seriously hinder the wide application of proton exchange membrane fuel cells. Therefore, the development of proton exchange membrane with high performance and high performance-to-price ratio has become a research hotspot in recent years. Nanofibers with large surface area, high aspect ratio and good mechanical properties have been applied to proton exchange membranes to improve the mechanical properties and proton conductivity of proton exchange membranes. This paper is based on sulfonated polyether sulfone (sulfonated polyether sulfone). High performance proton exchange membranes were prepared by introducing poly (glutamic acid) nanofibers to construct proton transport channels. The main research contents are as follows: different PGA nanofibers were prepared by solution jet spinning. The effects of draft velocity and content of poly (glutamic acid) on fiber molding were analyzed. The results of FESEM, FTIR and TGA analysis showed that the formability of nanofibers increased with the increase of draft velocity. With the increase of PGA content, fiber surface defects increase and fiber diameter increases. The electrical conductivity of PGA nanofibers increases with the increase of temperature and humidity, and the electrical conductivity increases with the increase of PGA content. The SPES composite films with different content of polyglutamic acid nanofibers were prepared by solution impregnation, and the surface of the composite films was smooth and compact. The nanofibers were completely coated with SPES matrix with good compatibility. TG test showed that, The thermal stability of nanofiber composite membrane is suitable for direct methanol fuel cell proton exchange membrane. The water absorption of polyglutamic acid nanofiber composite membrane increases with the increase of fiber content, compared with that of SPES membrane. The water absorption of the composite membrane was greatly improved and the swelling rate of the composite membrane was within a reasonable range. The proton transport channel was successfully constructed by introducing nanofibers and the proton conductivity of the SPES membrane was improved. The proton conductivity of the composite membrane increased with the increase of nano-fiber content. The proton conductivity of SPES-30 composite proton exchange membrane was the best, and reached 0.261 Scm-1 ~ (-1) at 80 鈩，

本文編號：1629481