【作者】 夏敏；

【导师】 李艳红； 胡国新；

【作者基本信息】 上海交通大学 ， 工程热物理， 2010， 硕士

【摘要】 碳纤维等各种碳材料可广泛应用于各领域,是近年来的研究热点。而腐植酸HA(humic acid)是储量丰富,具较大比表面积的优秀天然碳源,探索HA在碳材料方面的开发应用具有现实的意义和光明前景。我们将HA通过层层自组装的方法将其涂膜于氧化铝纤维,之后将膜及纤维基体一起碳化。探讨了Fe3+浓度、涂膜层数对膜的厚度的影响,采用了FTIR、FESEM、EDX以及ICP-EDX对涂膜产物进行了分析。分析结果表明我们所采用的HA原料很可能是从煤中提取而来,氧化铝纤维可通过表面羟基-OH锚定HA,膜的厚度随Fe3+浓度和涂膜层数的不同而有所不同。高分辨HRTEM下可看到HA丰富的微孔结构,EDX结果表明未参与反应的Na+, Cl-离子在自组装过程中可被清洗去除,应用ICP-EDX测试技术,通过实验和计算可分别求得HA和Fe的负载量。将涂膜产物进行碳化后,应用FESEM、EDX、HRTEM、XRD及Raman光谱等对不同碳化产物进行了分析。研究结果表明:碳化温度不同,碳化产物和产物微观形貌差别很大;与HA络合的Fe3+在碳化后变成为铁的各种氧化物,单质Fe及Fe3C等;所得碳材料的石墨化和有序程度随碳化温度的升高而增加,800℃碳化后所得碳材料为无定型碳,1000℃碳化后所得碳材料的石墨化和有序程度也都还较低,膜可在高温下发生重组,使得样品形貌逐渐变有序平整;各温度下的碳化产物也都具有较丰富的微孔结构,微孔中的极微孔孔径随着碳化温度的升高逐渐长大。此外,我们还得到了碳纳米空心球副产物,该空心球比同条件下纤维上所得碳材料的石墨化和有序程度稍高,其直径在50-500nm之间。更多还原

【Abstract】 Various kinds of carbon material like carbon fiber are applied on many fields, and they are the study hot spots in current days. Humic acid(HA) is a excellent carbon resource with rich reserve amount and comparatively large specific surface area. Exploring the developing and applying of HA on carbon material has the practical meaning and bright prospect. We coat HA on alumina fiber using layer-by-layer (LBL) method and then carbonize the film with fiber matrix. Study the effects of solution concentration of Fe3+ and layer number on the film thickness. We analyze the coating products by using FTIR, FESEM, EDX and ICP-EDX. The results demonstrate that the HA we use is quite possibly purified from coal, alumina micro fibers can successfully immobilize HA through surface hydroxyl–OH groups, and the thickness of film differentiate with the solution concentration of Fe3+ and the number of film. In addition, affluent micro pores of HA can be observed from HRTEM, the EDX result shows that Na+, Cl- which don’t participate in reaction can be washed away during the cleaning process of LBL, and the loadings of HA and Fe can be obtained by using ICP-EDX testing technology with experiment and calculation. After the coating products are carbonized, the carbonization products are characterized by FESEM, EDX, XRD and Raman techniques. The analysis results indicate that the carbonization products and micro- morphology of products differ greatly with different carbonization temperature; the Fe3+ complexed with HA transform into various iron oxides, simple substance Fe and Fe3C; the degree of graphitization and order of carbon materials become high with the carbonization temperature, but the product obtained at 800℃carbonization temperature is amorphous carbon, and the graphitization and order degree of the carbon material are still low at 1000℃carbonization temperature, in addition, the film get reformed at high temperature, which makes the morphology of the film become neater and more order. All products under different carbonization temperature have rich micro pores, and the diameters of super-micro pores increase with the rise in carbonization temperature. Besides, we obtain by-product of carbon nano hollow sphere. These hollow sphere’s graphitization and order degree are higher than those of carbon material with the same carbonization condition, and their diameters are between decades and hundreds nanometers.更多还原