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  本文選題：纖維素納米晶體　切入點：改性纖維素納米晶體　出處：《沈陽農(nóng)業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：本文以腐殖酸及纖維素納米晶體為原料,用不同級別的腐殖酸溶液對纖維素納米晶體進行改性,獲得十五種改性纖維素納米晶體。同時,分別對腐殖酸、纖維素納米晶體及改性纖維素納米晶體對Cd~(2+)的吸附特征進行研究。主要得出的結(jié)果如下:(1)通過傅里葉紅外光譜對腐殖酸及纖維素納米晶體的結(jié)構(gòu)進行分析,結(jié)果表明腐殖酸中含有的化學(xué)基團主要包括-OH,不飽和C-H,-NO2,C-O-C,C=C等;纖維素納米晶體主要包括-OH,C-H,C-O等化學(xué)基團;經(jīng)腐殖酸改性后得納米纖維素晶體引入了 C-O-C及-COOH官能團。(2)通過腐殖酸、纖維素納米晶體及腐殖酸改性后的纖維素納米晶體對Cd~(2+)的等溫吸附及吸附動力學(xué)特性研究,可知腐殖酸與纖維素納米晶體對Cd~(2+)符合單分子層吸附模型;腐殖酸與纖維素納米晶體對Cd~(2+)的吸附符合準二級動力學(xué)吸附模型,且模擬出的平衡吸附量與實驗得出的平衡吸附量結(jié)果相近;改性后纖維素納米晶體對Cd~(2+)的吸附用Langmuir方程與Freundlich方程擬合的效果都比較好。改性纖維素納米晶體對Cd~(2+)的吸附作用包括化學(xué)吸附與物理吸附,其吸附原理不能單獨使用改性纖維素納米晶體的化學(xué)官能團結(jié)構(gòu)進行解釋,需要對其物理結(jié)構(gòu)進行觀察,做進一步分析。(3)通過對纖維素納米晶體與改性纖維素納米晶體的吸附效果的比較,可以看出改性后的纖維素納米晶體對Cd~(2+)的吸附量有了提升,當(dāng)Cd~(2+)的初始濃度相同時,改性后的纖維素納米晶體吸附量較原纖維素納米晶體增加范圍為:0.3%～93.8%,且除了用混合腐殖酸改性后的劍麻纖維素納米晶體及用分析純腐殖酸改性后的棉花纖維素納米晶體與原纖維素納米晶體對Cd~(2+)的吸附量無顯著差異外,其他的腐殖酸處理纖維素納米晶體與原纖維素納米晶體對Cd~(2+)的吸附量存在顯著差異;經(jīng)過高活性腐殖酸改性后的纖維素納米晶體比其它腐殖酸改性的纖維素納米晶體對Cd~(2+)的吸附量大。
[Abstract]:In this paper, 15 kinds of modified cellulose nanocrystals were obtained by modifying cellulose nanocrystals with humic acid and cellulose nanocrystals with different levels of humic acid solution. The adsorption characteristics of cellulose nanocrystals and modified cellulose nanocrystals to Cd~(2) were studied. The main results are as follows: 1) the structure of humic acid and cellulose nanocrystals was analyzed by Fourier transform infrared spectroscopy. The results showed that the chemical groups contained in humic acid mainly included -OH, unsaturated C-H _ (no _ 2O) C-O-C _ (C), cellulose nanocrystalline mainly consisted of -OHH _ (C) -H _ (C) C-O, and modified by humic acid, the C-O-C and -COOH functional groups were introduced into the nanocellulose crystal through humic acid, and the humic acid was introduced into the nanocellulose crystal by humic acid, and then the C-O-C and -COOH functional groups were introduced into the nano-cellulose crystal by humic acid. The isothermal adsorption and adsorption kinetics of cellulose nanocrystalline and cellulose nanocrystalline modified by humic acid for Cd~(2) were studied. The results show that the adsorption of Cd~(2 by humic acid and cellulose nanocrystalline conforms to the monolayer adsorption model. The adsorption of humic acid and cellulose nanocrystals for Cd~(2) was in accordance with the quasi-second-order kinetic adsorption model, and the simulated equilibrium adsorption capacity was similar to the experimental results. The adsorption of modified cellulose nanocrystals to Cd~(2) was well fitted by Langmuir equation and Freundlich equation. The adsorption of Cd~(2 on modified cellulose nanocrystals included chemisorption and physical adsorption. The adsorption principle can not be explained by the chemical functional group structure of modified cellulose nanocrystalline alone, and the physical structure of the modified cellulose nanocrystalline should be observed. By comparing the adsorption effect of cellulose nanocrystals with modified cellulose nanocrystals, we can see that the adsorption capacity of modified cellulose nanocrystals to Cd~(2) has been increased, when the initial concentration of Cd~(2) is the same, The adsorption capacity of modified cellulose nanocrystalline was increased by 0.33% or 93.8% compared with the original cellulose nanocrystalline. Besides the modified sisal cellulose nanocrystalline modified with mixed humic acid and cotton cellulose nanocrystalline modified with analytical pure humic acid, the modified cellulose nanocrystalline was modified with humic acid. There was no significant difference in adsorption amount of Cd~(2 between crystal and cellulose nanocrystalline. Other humic acid-treated cellulose nanocrystals had significant differences in adsorption capacity between cellulose nanocrystals and original cellulose nanocrystals. The adsorption capacity of cellulose nanocrystalline modified by high active humic acid to Cd~(2 was higher than that of other HA modified cellulose nanocrystals.
【學(xué)位授予單位】：沈陽農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X703
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本文編號：1598845