本文選題：磁性Fe_3O_4/HA復合微粒 + 機械混合法　； 參考：《沈陽大學》2017年碩士論文

【摘要】：近年來,隨著生活水平的提高,人們的環(huán)保意識逐漸提高,對工業(yè)排放廢水中重金屬離子的處理問題成為熱點。羥基磷灰石(HA)晶體結構具有的獨特性,使其對重金屬離子的容納性更為廣泛,吸附固定性和交換能力較強。除此之外,它還具有制備方便簡單、原料豐富、成本較低等優(yōu)勢。因此,HA成為一種可以用于吸附去除廢水中以及土壤里的重金屬離子的新型環(huán)境功能材料。而粉體不利于回收的情況限制了HA的實際應用。本文通過引入納米Fe3O4磁性粒子,使HA的復合材料具有磁性,在添加外界磁場的條件下,利于粉體分離回收。本文以Ca(NO3)2·4H2O水溶液和(NH4)2HPO4水溶液為前驅體,用高濃度的十二烷基基硫酸鈉(SDS)作為模版,采用水熱法制備出納米HA,并通過X-射線衍射儀、掃描電鏡(SEM)、傅里葉紅外光譜分析(FT-IR)等方法對其進行綜合表征。結果表明:通過此法可以制備出分布均勻棒狀納米HA。在pH=7時,會生成少量的Ca HPO4(DCP)雜相;當pH=11時,可制備純凈的HA粉體。通過在80℃和600℃進行燒結發(fā)現(xiàn),600℃進行燒結獲得的粉體結晶度更高,粉體尺寸增大。以Fe Cl2.4H2O和FeCl3.6H2O為前驅體,以NaOH為沉淀劑,通過共沉淀的方法制備納米四氧化三鐵(Fe3O4)并通過XRD、SEM等方法對其進行表征,結果表明:可以獲得納米級的Fe3O4磁性微球,并且獲得的Fe3O4粒子分布比較均勻,無明顯團聚現(xiàn)象。本文通過機械混合法和原位復合法兩種方法合成了磁性Fe3O4/HA復合微粒,并利用XRD、SEM、粉體磁性吸附測試等方法對其進行分析。結果表明,通過兩種方法均能獲得磁性Fe3O4/HA復合微粒,但是通過機械混合法獲得的粉體團聚現(xiàn)象較為嚴重,隨著Fe3O4含量的增加,團聚現(xiàn)象更加明顯。而原位復合法獲得的粉體粒徑分布均勻,隨著Fe3O4與HA摩爾比由1:1變?yōu)?:3,其粉體的結晶程度更高,粉體分散性更好,晶胞尺寸更大。隨著反應溫度由60℃升高至80℃,Fe3O4/HA磁性復合材料的結晶效果更加的明顯,晶粒尺寸更大。但當反應溫度為180℃時,Fe3O4被氧化生成Fe2O3,導致粉體失去磁性。分別用HA、Fe3O4以及磁性Fe3O4/HA復合微粒對濃度為20mg/L的重金屬Cu2+離子進行吸附性能實驗研究。結果表明:兩種復合方法制備磁性Fe3O4/HA復合微粒對重金屬離子都具有一定的去除能力。原位復合法制備的磁性Fe3O4/HA比機械混合法制備的磁性Fe3O4/HA去除率更高,可達95%以上。對比兩種方法制備的粉體吸附容量,原位復合法制備的磁性粉體平衡吸附容量為11.17mg/g,高于機械混合法。因此,原位復合法制備生成的磁性Fe3O4/HA吸附性能比機械混合法制備的粉體更好。
[Abstract]:In recent years, with the improvement of living standards, people's awareness of environmental protection has gradually improved, and the treatment of heavy metal ions in industrial wastewater has become a hot issue. The crystal structure of hydroxyapatite (HA) is unique, which makes it more tolerant to heavy metal ions, and has stronger adsorption, fixation and exchange ability. In addition, it has the advantages of simple preparation, abundant raw materials and low cost. Therefore, hyaluronic acid (HA) has become a new environmental functional material for the adsorption and removal of heavy metal ions in wastewater and soil. However, the fact that the powder is unfavorable to recovery limits the practical application of HA. In this paper, the nano-Fe _ 3O _ 4 magnetic particles were introduced to make the HA composite have magnetic properties, and it is advantageous to the separation and recovery of the powder under the condition of adding external magnetic field. In this paper, Nano-HAs were prepared by hydrothermal method using aqueous solution of Cagno _ 3H _ 3H _ 2O and NH _ 4N _ 2HPO _ 4 as precursors, using high concentration of sodium dodecyl sulfate (SDS) as template, and using X-ray diffractometer. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize them. The results show that the uniform rod shaped nano-HAA can be prepared by this method. At pH = 7, a small amount of CaHPO _ 4 / DCP-phase was formed, and when pH = 11:00, pure HA powder could be prepared. By sintering at 80 鈩，

本文編號：1994536