發(fā)布時(shí)間：2018-05-20 18:26

  本文選題：ZIF-8 + 苯系物�。� 參考：《北京化工大學(xué)》2015年碩士論文

【摘要】：沸石一咪唑酯一金屬有機(jī)骨架結(jié)構(gòu)材料(ZIFs)因其具有的水熱穩(wěn)定性好、比表面積大、高孔容、柔性結(jié)構(gòu)以及官能團(tuán)豐富等優(yōu)點(diǎn),而ZIF-8作為一種具有方鈉石結(jié)構(gòu)的新型ZIFs微孔結(jié)構(gòu)材料,不僅具備了上述ZIFs材料的優(yōu)點(diǎn),且因其所具有的特殊的旋轉(zhuǎn)門效應(yīng),能吸附比自身孔大的多的分子。因此,本文進(jìn)行了ZIF-8吸附性能的研究。本文考察了在不同條件下ZIF-8對(duì)苯系物分子的吸附性能。對(duì)在不同溫度條件下ZIF-8的吸附性能進(jìn)行了研究,結(jié)果表明：吸附量隨著溫度的增加而增加；探究了苯系物不同的初始濃度對(duì)吸附性能的影響,結(jié)果表明具有小孔體積的苯系物分子在ZIF一8中被吸附的更多；還考察了吸附性能隨時(shí)間的變化及吸附動(dòng)力學(xué),結(jié)果表明,吸附開始時(shí)ZIF-8中有大量的可被利用的吸附活性位,但隨著吸附時(shí)間的增加可利用的吸附活性位逐漸減少直至吸附活性位達(dá)到飽和,通過pseudo-second-order來解釋吸附量隨吸附時(shí)間的變化的吸附動(dòng)力學(xué),實(shí)驗(yàn)結(jié)果表明,苯系物分子的形狀和大小對(duì)吸附作用同樣起到了重要的影響；還考察了不同PH值對(duì)ZIF-8吸附苯系物分子性能的影響,實(shí)驗(yàn)結(jié)果表明,隨著PH值的升高吸附量成遞減趨勢(shì),這可能歸因于靜電相互作用不是ZIF-8吸附苯系物分子的主要機(jī)理,而ZIF-8上的咪唑酯環(huán)、官能團(tuán)以及苯環(huán)上π-π鍵之間的相互作用應(yīng)是ZIF一8材料吸附苯系物的主要機(jī)理；還探討了苯系物分子的形狀結(jié)構(gòu)對(duì)吸附性能的影響,通過實(shí)驗(yàn)得到的數(shù)據(jù)可知,ZIF-8對(duì)具有小分子直徑的苯、甲苯、乙苯、對(duì)二甲苯比相對(duì)具有大分子結(jié)構(gòu)的間二甲苯和鄰二甲苯具有更高的吸附能力。本文還進(jìn)行了成型前后的ZIF-8對(duì)烴類氣體的動(dòng)態(tài)吸附性能的研究,通過不同的壓力和溫度條件進(jìn)行了成型前后的ZIF-8的吸附性能的研究,并繪制了穿透曲線。實(shí)驗(yàn)結(jié)果表明,在低壓條件下,系統(tǒng)內(nèi)的堆積空隙及樣品孔隙內(nèi)的死體積與體系超額吸附量的比值較小,故可以忽略；但是管道閥門內(nèi)的死體積中所積累的烴類氣體的量對(duì)吸附量的影響較大,且隨著壓力的升高,系統(tǒng)內(nèi)的堆積空隙及樣品孔隙內(nèi)的死體積中堆積的烴類氣體的量與超額吸附量的比值增人,均須排除。成型后的ZIF-8的吸附量小于成型前的,這說明成型過程中添加的結(jié)構(gòu)助劑堵塞了一部分孔道。通過實(shí)驗(yàn)證明丙烯的吸附量大于乙烯,這說明了烯烴與吸附劑之間為物理吸附,作用力主要為范德華力。本文還進(jìn)行了不同的外界條件對(duì)ZIF-8材料吸附水中污染物氨氮的性能的影響,實(shí)驗(yàn)結(jié)果證明ZIF-8適合吸附低濃度條件下的NH4+,可考慮將其應(yīng)用于水中氨氮污染物的后續(xù)處理。
[Abstract]:Zeolite-imidazole-metal-organic skeleton structure material (ZIFs) has the advantages of good hydrothermal stability, large specific surface area, high pore volume, flexible structure and rich functional groups. As a new type of ZIFs microporous material with square sodium structure, ZIF-8 not only has the advantages of the above-mentioned ZIFs materials, but also can adsorb much larger molecules than its own pore because of its special rotary gate effect. Therefore, the adsorption properties of ZIF-8 were studied in this paper. In this paper, the adsorption properties of benzene series molecules by ZIF-8 under different conditions have been investigated. The adsorption properties of ZIF-8 at different temperatures are studied. The results show that the adsorption capacity increases with the increase of temperature, and the influence of different initial concentrations of benzene series on the adsorption performance is investigated. The results show that the benzene molecules with small pore volume are adsorbed more in ZIF 8, and the adsorption energy changes with time as well as the adsorption kinetics. The results show that there are a large number of available adsorption active sites in ZIF-8 at the beginning of adsorption. However, with the increase of adsorption time, the available adsorption sites gradually decreased until the adsorption sites reached saturation. The adsorption kinetics of adsorption capacity with adsorption time was explained by pseudo-second-order. The shape and size of benzene series molecules also played an important role in the adsorption, and the effects of different PH values on the adsorption properties of benzene series compounds by ZIF-8 were also investigated. The experimental results showed that the adsorption amount decreased with the increase of PH value. This may be attributed to the fact that electrostatic interaction is not the main mechanism of adsorption of benzenes by ZIF-8, while the interaction between imidazolyl ester rings, functional groups and 蟺-蟺 bonds on ZIF-8 is the main mechanism of adsorption of benzene series by ZIF-8 materials. The influence of the shape and structure of benzene series on the adsorption properties was also discussed. The experimental data showed that ZIF-8 had small molecular diameters of benzene, toluene and ethylbenzene. The adsorption ability of p-xylene is higher than that of m-xylene and o-xylene with macromolecular structure. The dynamic adsorption of hydrocarbon gases by ZIF-8 before and after molding was also studied. The adsorption properties of ZIF-8 before and after molding were studied under different pressure and temperature conditions, and the penetrating curves were drawn. The experimental results show that under the low pressure conditions, the ratio of the dead volume in the system and the dead volume in the sample pores to the excess adsorption capacity of the system is small, so it can be neglected. However, the amount of hydrocarbon gas accumulated in the dead volume of the pipe valve has a great effect on the adsorption capacity, and with the increase of pressure, Both the accumulation void in the system and the ratio of the accumulation of hydrocarbon gas in the dead volume of the sample pore to the excess adsorption should be eliminated. The adsorption amount of ZIF-8 after molding is smaller than that before molding, which indicates that some pore channels are blocked by adding structural auxiliaries in the molding process. The experimental results show that the adsorption capacity of propylene is larger than that of ethylene, which indicates that the adsorption between olefins and adsorbents is physical, and the main force is van der Waals force. The effects of different external conditions on the adsorption properties of ammonia nitrogen in water by ZIF-8 materials were also studied. The experimental results show that ZIF-8 is suitable for the adsorption of NH4 at low concentration and can be applied to the subsequent treatment of ammonia nitrogen pollutants in water.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X703;TQ424.3

【共引文獻(xiàn)】

相關(guān)博士學(xué)位論文 前4條

1 邵佳;氧化鋁中空纖維載體上NaA分子篩膜的制備與分離性能研究[D];浙江大學(xué);2014年

2 范黎黎;沸石分子篩膜和金屬—有機(jī)骨架材料膜的制備和應(yīng)用[D];吉林大學(xué);2014年

3 任春雷;膜蒸餾海水淡化和油水分離用疏水多孔陶瓷膜研究[D];中國科學(xué)技術(shù)大學(xué);2014年

4 劉亞光;ZnO誘導(dǎo)的ZIF-8膜制備及其滲透性能研究[D];大連理工大學(xué);2014年

相關(guān)碩士學(xué)位論文 前4條

1 張春娟;一種新型ZIF-9-67膜的制備及其對(duì)CO_2氣體分離性能的研究[D];北京化工大學(xué);2013年

2 韓麗琴;新型多孔金屬—有機(jī)骨架化合物的合成、結(jié)構(gòu)與性質(zhì)研究[D];哈爾濱師范大學(xué);2013年

3 徐姍姍;具有吸附功能的陶瓷基體的制備及鍍膜工藝的研究[D];北京化工大學(xué);2012年

4 李靜;ZIFs膜的制備及其在油氣回收中的應(yīng)用研究[D];常州大學(xué);2014年

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本文編號(hào)：1915754