本文關鍵詞： 碳量子點(CQDs) 硝酸氧化 微波法 滲析 熒光量子產率(QY)　出處：《中國地質大學(北京)》2017年碩士論文　論文類型：學位論文

【摘要】：迄今為止應用最廣的是金屬半導體量子點,且廣泛應用于電子器件和量子計算等領域,而該量子點存在的最大弊端是有較大的毒性,制備成本較高,因此科學家們嘗試尋找一種可以取代的新型量子點即碳量子點。碳量子點的直徑在20nm左右。而碳量子點最大的優(yōu)點在于低毒性、良好的生物相容性,較強的發(fā)光性、以及光穩(wěn)定性,可廣泛應用于生物傳感器及生物分子的檢測、細胞成像等。在此基礎上,為了制備碳量子點開始尋找豐富的原料,煤炭是我國的主要能源,依據(jù)結構和組成不同,煤炭分為無煙煤、煙煤、褐煤三大類,其中煙煤分為低變質煙煤、中變質煙煤,其中低變質煙煤和褐煤一起統(tǒng)稱為低階煤。因為目前為止對于低階煤結構的認知還沒有準確的結論,而且其種類繁多導致結構也會相應不同,因此低階煤的研究以及應用是目前一個很重要的課題。論文通過硝酸氧化法和微波消解法制備碳量子點,研究了不同產地的低階煤制備碳量子點的工藝,優(yōu)化溫度、時間、酸濃度、提純等實驗條件,發(fā)現(xiàn)龍口脫灰煤效果較好,反應溫度為130℃,反應時間為12h。通過紅外(FTIR)、碳核磁共振(13CNMR)、X射線衍射(XRD)、光電子能譜(XPS)、透射電鏡(TEM)、原子力顯微鏡(AFM)、拉曼光譜(Raman)、熒光光譜(PL)等,表征了碳量子點的結構(粒徑、官能團等)和性質。并表征了碳量子點在激光下激發(fā)下的熒光。提出煤與硝酸反應生成CQDs的機理:除了煤大分子的硝化的過程,同時還伴隨Scholl反應導致的芳香簇稠并過程。分別用聚乙二醇(PEG)、超酸(雙(三氟甲烷)磺酰亞胺TFSI)改性碳量子點,發(fā)現(xiàn)改性后熒光量子產率提高。利用碳量子點制備出有熒光性質的靜電紡絲PVA膜和熒光墨水,得到了較好的效果。
[Abstract]:So far the most widely used metal semiconductor quantum dots, and widely used in electronic devices, quantum computing and other fields, and the biggest disadvantage of this quantum dot is that it has greater toxicity and high cost of preparation. So scientists try to find a new quantum dot which can be replaced by carbon quantum dot. The diameter of carbon quantum dot is about 20nm. The biggest advantage of carbon quantum dot is its low toxicity and good biocompatibility. Because of its strong luminescence and photostability, it can be widely used in biosensors and biomolecules detection, cell imaging and so on. On this basis, we began to search for rich raw materials for the preparation of carbon quantum dots. Coal is the main energy in China. According to the structure and composition, coal is divided into anthracite, bituminous coal and lignite, among which bituminous coal is divided into low metamorphic bituminous coal and medium metamorphic bituminous coal. Low metamorphic bituminous coal and lignite are referred to as low rank coal together, because there is no accurate conclusion about the structure of low rank coal so far, and many kinds of bituminous coal lead to different structures. Therefore, the research and application of low-rank coal is a very important subject at present. In this paper, carbon quantum dots are prepared by nitric acid oxidation and microwave digestion, and the process of preparing carbon quantum dots from low-rank coal from different habitats is studied. Optimizing the experimental conditions such as temperature, time, acid concentration, purification and so on, it was found that Longkou desliming coal had better effect, reaction temperature was 130 鈩，

本文編號：1466830