發(fā)布時(shí)間：2018-07-25 14:40

【摘要】：本文首先采用改良共沉淀法制備Fe_3O_4磁性納米粒子,然后分別用γ-氯丙基三甲氧基硅烷偶聯(lián)劑和聚乙烯亞胺(PEI)逐步對(duì)磁性納米粒子進(jìn)行表面改性,最后將PEI改性磁性納米粒子與功能性單體進(jìn)行接枝共聚制備PEI改性磁性聚合物吸附劑,考察了聚合反應(yīng)參數(shù)和吸附條件對(duì)PEI改性磁性聚合物吸附劑重金屬離子吸附性能的影響,采用多種現(xiàn)代表征手段對(duì)磁性吸附劑的結(jié)構(gòu)進(jìn)行了表征,研究PEI改性磁性聚合物吸附劑重金屬離子的吸附動(dòng)力學(xué)和吸附熱力學(xué),考察PEI改性磁性聚合物吸附劑的磁響應(yīng)性、解吸和循環(huán)再生利用性能,初步探討PEI改性磁性聚合物吸附劑對(duì)重金屬離子的吸附機(jī)理,主要研究結(jié)果如下:1、XRD表明磁性納米粒子、硅烷偶聯(lián)劑改性磁性納米粒子以及PEI改性磁性納米粒子的結(jié)晶度較高,PEI改性磁性聚合物吸附劑的聚合物基體為非晶態(tài)結(jié)構(gòu),磁性Fe_3O_4以高結(jié)晶結(jié)構(gòu)分散于聚合物基體中。2、SEM表明PEI改性磁性聚合物吸附劑表面粗糙不平整,具有較多微孔和連續(xù)貫穿的溝壑結(jié)構(gòu),有利于重金屬離子通過(guò)快速滲透和擴(kuò)散進(jìn)入到PEI改性磁性聚合物吸附劑凝膠網(wǎng)絡(luò)內(nèi)部,使PEI改性磁性聚合物吸附劑具有良好的重金屬離子吸附性能。3、FTIR表明硅烷偶聯(lián)劑和PEI接枝到磁性納米粒子表面,制備的PEI改性磁性聚合物吸附劑具有目標(biāo)結(jié)構(gòu)。TGA結(jié)果表明硅烷偶聯(lián)劑和PEI接枝到磁性納米粒子表面,PEI改性磁性聚合物吸附劑具有較高的磁含量和熱穩(wěn)定性。4、磁性納米粒子分散液、硅烷偶聯(lián)劑改性磁性納米粒子分散液和PEI改性磁性納米粒子分散液均具有快速的磁響應(yīng)性。磁性納米粒子的飽和磁化強(qiáng)度達(dá)67.76 emu/g,硅烷偶聯(lián)劑改性磁性納米粒子和PEI改性磁性納米粒子的飽和磁化強(qiáng)度略有降低,PEI改性磁性聚合物吸附劑飽和磁化強(qiáng)度降低幅度較大,但仍然具有一定的磁響應(yīng)性。磁性納米粒子、硅烷偶聯(lián)劑改性磁性納米粒子、PEI改性磁性納米粒子和PEI改性磁性聚合物吸附劑均具有超順磁性。5、當(dāng)丙烯酸/丙烯酰胺質(zhì)量比為60:40,丙烯酸中和度為70%,交聯(lián)劑用量為0.75%,引發(fā)劑用量為0.8%,PEI改性磁性Fe_3O_4納米粒子含量為15%,PEI改性磁性聚合物吸附劑重金屬離子吸附性能分別達(dá)到最大值。6、隨著pH和重金屬離子初始濃度的增加,PEI改性磁性聚合物吸附劑對(duì)重金屬離子Cu~(2+)、Cd~(2+)、Pb~(2+)吸附容量均呈現(xiàn)先快速增加然后趨緩的趨勢(shì)。PEI改性磁性聚合物吸附劑對(duì)重金屬離子Cu~(2+)、Cd~(2+)、Pb~(2+)的吸附速率較快,吸附45 min重金屬離子吸附量趨于平衡。7、PEI改性磁性聚合物吸附劑對(duì)重金屬離子Cu~(2+)、Cd~(2+)、Pb~(2+)的吸附過(guò)程符合Langmuir等溫吸附模型和準(zhǔn)二級(jí)動(dòng)力學(xué)方程。8、經(jīng)過(guò)5次循環(huán)再生利用后,PEI改性磁性聚合物吸附劑重金屬離子Cu~(2+)、Cd~(2+)、Pb~(2+)的解吸率仍高于85%,重金屬離子Cu~(2+)、Cd~(2+)、Pb~(2+)的吸附容量分別為第一次吸附容量的71.6%、72.1%和72.8%。
[Abstract]:In this paper, Fe_3O_4 magnetic nanoparticles were prepared by modified coprecipitation method, and then modified by 緯 -chloropropyl trimethoxysilane coupling agent and polyethylimine (PEI) respectively. Finally, PEI modified magnetic nanoparticles were grafted with functional monomers to prepare PEI modified magnetic polymer adsorbents. The effects of polymerization parameters and adsorption conditions on the adsorption properties of heavy metal ions of PEI modified magnetic polymer adsorbents were investigated. The structure of magnetic adsorbent was characterized by many modern methods. The adsorption kinetics and thermodynamics of heavy metal ions of PEI modified magnetic polymer adsorbent were studied. The magnetic response of PEI modified magnetic polymer adsorbent was investigated. The adsorption mechanism of PEI modified magnetic polymer adsorbents for heavy metal ions was studied. The main results were as follows: 1: 1 PEI showed magnetic nanoparticles. The polymer matrix of magnetic polymer adsorbent modified by silane coupling agent and magnetic nanoparticles modified by PEI was amorphous. Magnetic Fe_3O_4 was dispersed in polymer matrix with high crystalline structure. The results showed that the surface of PEI modified magnetic polymer adsorbent was rough and uneven, with more micropores and continuous trench structure. It is advantageous for heavy metal ions to penetrate into the gel network of PEI modified magnetic polymer adsorbent through rapid permeation and diffusion. The magnetic polymer adsorbents modified by PEI have good adsorption properties of heavy metal ions. 3FTIR showed that silane coupling agent and PEI were grafted onto the surface of magnetic nanoparticles. The PEI modified magnetic polymer adsorbent has the target structure. The results show that the silane coupling agent and PEI grafted onto the surface of magnetic nanoparticles have higher magnetic content and thermal stability. Nanoparticles dispersions, Both silane coupling agent modified magnetic nanoparticles dispersion and PEI modified magnetic nanoparticles dispersion have fast magnetic response. The saturation magnetization of magnetic nanoparticles was 67.76 emu / g. The saturation magnetization of silane coupling agent modified magnetic nanoparticles and PEI modified magnetic nanoparticles decreased slightly. But it still has a certain magnetic response. Magnetic nanoparticles, The magnetic nanoparticles modified by silane coupling agent and the magnetic polymer adsorbent modified by PEI have superparamagnetic properties. When the mass ratio of acrylic acid to acrylamide is 60: 40, the neutralization degree of acrylic acid is 70. 0.75, the amount of initiator is 0.8 and the content of magnetic Fe_3O_4 nanoparticles modified by PEI is 15%. The adsorption properties of heavy metal ions of magnetic polymer adsorbents are respectively up to the maximum of .6. with the increase of pH and the initial concentration of heavy metal ions, the magnetic polymers are modified by PEI-modified magnetic polymers with the increase of pH and initial concentration of heavy metal ions. The adsorption capacity of Cu ~ (2) C ~ (2) O ~ (2) CD ~ (2) and Pb ~ (2) for heavy metal ions increased rapidly and then slowed down. The adsorption rate of Cu ~ (2) C ~ (2) O ~ (2) CD ~ (2) and Pb ~ (2) was higher than that of the magnetic polymer adsorbent modified by PEI. The adsorption capacity of heavy metal ions for 45 min tends to be in equilibrium. The adsorption process of heavy metal ions Cu ~ (2) CD ~ (2) CD ~ (2) Pb ~ (2) is in accordance with the Langmuir isothermal adsorption model and quasi second-order kinetic equation .8. after 5 cycles, the adsorption rate of Cu ~ (2) and CD ~ (2) Pb ~ (2) is reclaimed. The desorption rate of heavy metal Cu ~ (2) O ~ (2) CD ~ (2) Pb2 is still higher than that of 85wt%, and the adsorption capacity of Cu ~ (2) C ~ (2) O ~ (2) Pb ~ (2) is 71.672.1% of the first adsorption capacity and 72.8% of the first adsorption capacity of the heavy metal ion Cu ~ (2) ~ (2) ~ (2) ~ (2) ~ (2) ~ (2) Pb ~ (2).
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O647.33

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