發(fā)布時間：2018-06-21 19:37

  本文選題：CMC/Tb納米復合物 + HPCMC/Tb納米復合物�。� 參考：《華南理工大學》2015年碩士論文

【摘要】：稀土金屬是寶貴的戰(zhàn)略資源,而稀土納米材料更具有廣泛的工業(yè)應用。利用環(huán)境友好的生物質資源制備發(fā)光性能良好的稀土納米發(fā)光材料,不但具有實現(xiàn)生物質資源高值化利用的意義,而且符合現(xiàn)代綠色化學的發(fā)展需求。本論文利用水浴和微波輔助兩種不同的加熱方式,使用環(huán)境友好的羧甲基纖維素(CMC)、羥丙基羧甲基纖維素(HPCMC)與Tb3+進行化學反應,通過設計和控制反應體系的實驗條件,成功地合成發(fā)射較強熒光的CMC/Tb和HPCMC/Tb納米復合物。通過傅里葉紅外光譜(FT-IR)、X-射線光電子能譜(XPS)分析其分子化學結構;掃描電鏡(SEM)分析其形貌結構;廣角X射線衍射(WAXD)和透射電鏡(TEM)分析其結晶結構;紫外吸收光譜(UV-Vis)和熒光光譜(PL)分析其對光的吸收能力及熒光性能;熱重分析(TG-DSC)分析其熱穩(wěn)定性質,得出主要結論如下:1.水浴和微波輔助加熱下,Tb3+與CMC、HPCMC分子鏈上的-COO-、-OH以及-COC中的O原子分別通過離子鍵和共價鍵鍵合形成CMC/Tb、HPCMC/Tb復合物,其粒子尺寸可達到納米級。2.CMC、HPCMC作為主要的光能量吸收體,并能有效敏化Tb3+離子,使其具有窄的5D4→7F6(489 nm),5D4→7F5(545 nm),5D4→7F4(584 nm)和5D4→7F3(619 nm)電子軌道躍遷特征峰,其最強的5D4→7F5躍遷綠色熒光發(fā)射特征峰的半峰寬小于10 nm。3.CMC/Tb納米復合物的結構和熒光性能均受到pH值、反應物比例和反應時間的影響。在本論文實驗范圍內,水浴加熱時,最佳合成條件是:pH=8、反應物比例為CMC:Tb=5:1(wt:wt)、反應時間為30 min、反應溫度為70℃。微波輔助加熱時,最佳合成條件是:p H=8、反應物比例為CMC:Tb=1.65:1(wt:wt)、反應時間為10 min、反應溫度為70℃。4 HPCMC/Tb納米復合物的結構和熒光性能同樣受到pH值和反應時間的影響。水浴加熱時,最佳的合成條件是:pH=8、反應物比例為HPCMC:Tb=20:1(wt:wt)、反應時間為60 min、反應溫度為70℃。微波輔助加熱時,最佳的合成條件是:pH=7、反應物比例為HPCMC:Tb=20:1(wt:wt)、反應時間為15 min、反應溫度為70℃。此條件下合成的CMC/Tb、HPCMC/Tb納米復合物具有粒徑小、分布均勻、熒光強度大、熱穩(wěn)定性高等特點。5.高pH值下,微波輔助比水浴加熱方式更能提高CMC羧基與Tb3+反應能力,改變介觀形貌結構,提高產(chǎn)物的熒光強度;HPCMC自身較長的側鏈比CMC更容易與Tb3+反應,而且較強的結晶結構更能提高產(chǎn)物的熒光強度。
[Abstract]:Rare earth metals are valuable strategic resources, and rare earth nanomaterials are widely used in industry. The preparation of rare earth nano-luminescent materials with good luminescence performance by using environment-friendly biomass resources not only has the significance of realizing the high value utilization of biomass resources, but also meets the needs of the development of modern green chemistry. In this paper, water bath and microwave-assisted heating were used to react with Tb3 by using the environmentally friendly carboxymethyl cellulose (CMC) and hydroxypropyl carboxymethyl cellulose (HPCMC). The experimental conditions of the reaction system were designed and controlled. CMC / TB / HPCMC / TB nanocomposites with high fluorescence emission were successfully synthesized. Its molecular chemical structure was analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and scanning electron microscopy (SEM), and its crystalline structure was analyzed by WAXD and TEM (TEM). UV absorption spectra and fluorescence spectra were used to analyze their absorption ability and fluorescence properties. TG-DSCs were used to analyze their thermal stability. The main conclusions were as follows: 1. In water bath and microwave assisted heating, the CMC / Tb3 / TB complex was formed by ionic bonding and covalent bonding with the -COO-OH-OH and O-COC atoms in the molecular chain of CMC / HPCMC, respectively. The particle size of the CMC / TbCHPCMC / TB complex can reach nanometer level. 2. CMCHPCMC is used as the main absorber of light energy. The Tb3 ion can be sensitized effectively and has the characteristic peaks of the electron orbital transition of 5D4 + 7F6O489nmmH4 / 7F5D4 / 545nm / 545Nm / 5D4 and 5D4 / 7F3 / 619nm), respectively, and can be used to sensitize the Tb3 ion effectively, so that it has the characteristic peaks of electron orbital transition. The structure and fluorescence properties of the strongest green fluorescence emission characteristic peak of 5D4 / 7F5 transition are affected by pH value, reactant ratio and reaction time. The half-width of the peak width is less than 10nm.3.CMC / TB nanocomposite. In this paper, when heated in water bath, the optimum synthesis conditions are: 1: pH8, CMC: Tb5: 1: wt1: wt1, reaction time 30 min, reaction temperature 70 鈩，

本文編號：2049781