本文選題：纖維素　切入點：接枝共聚　出處：《山東大學(xué)》2017年碩士論文

【摘要】：纖維素基重金屬離子吸附劑是近年來生物質(zhì)重金屬離子吸附劑的研究熱點之一,因其良好的吸附性能、機械性能及再生性,纖維素基吸附劑在用于水中重金屬離子吸附方面有較大的開發(fā)潛力。本文以微晶纖維素為基礎(chǔ)骨架,以硝酸鈰銨為引發(fā)劑,通過自由基接枝共聚反應(yīng)制備纖維素接枝聚丙烯酸甲酯(cellulose-g-poly methyl acrylate,Cell-g-PMA),隨后對其進(jìn)行肼解,得到水合肼改性纖維素接枝聚丙烯酸甲酯(hydrazinolyzed cellulose-g-poly methyl acrylate,Cell-g-PMA-HZ)。通過對合成條件的討論,優(yōu)化合成工藝,以提高產(chǎn)物的螯合基團含量,并利用FT-IR、元素分析、熱重分析、C13-NMR及掃描電鏡等分析方法對產(chǎn)物進(jìn)行驗證。通過靜態(tài)及動態(tài)吸附實驗研究所制備Cell-g-PMA-HZ吸附劑對Cu(Ⅱ)、Ni(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)離子的吸附性能。研究結(jié)果表明,己成功制備得到Cell-g-PMA-HZ。當(dāng)選用0.5g微晶纖維素,硝酸鈰銨引發(fā)劑量為0.0558g,單體丙烯酸甲酯量為2mL,反應(yīng)溫度為35℃時,經(jīng)3h接枝聚合反應(yīng),可制備出接枝率為326%的Cell-g-PMA;當(dāng)投入接枝率為326%的Cell-g-PMA,使其中丙烯酸甲酯單元與水合肼的摩爾比為1:60時,在55℃下反應(yīng)3h,得到產(chǎn)物Cell-g-PMA-HZ,含N量最高可達(dá)20.81%。吸附實驗結(jié)果表明,Cell-g-PMA-HZ 吸附劑對 Cu(Ⅱ)、Ni(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)離子的吸附性能受Cell-g-PMA接枝率、金屬離子溶液初始pH、初始濃度、吸附時間、吸附溫度等因素影響。Cell-g-PMA接枝率為326%時,Cell-g-PMA-HZ吸附劑對 Cu(Ⅱ)的吸附量最高;Cell-g-PMA-HZ 吸附劑對 Cu(Ⅱ)、Ni(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)離子的吸附的最佳pH值在4.0-5.0之間,對這四種重金屬離子的吸附動力學(xué)均更符合準(zhǔn)二級動力學(xué)模型;Cell-g-PMA-HZ吸附劑對Cu(Ⅱ)、Ni(Ⅱ)、Cd(Ⅱ)的吸附可用Langmuir等溫吸附模型進(jìn)行擬合,計算所得的最大吸附量(qm)分別為 229.36mgg-1,173.91mgg-1,235.85mgg-1,對 Pb(Ⅱ)的吸附則更符合 Freundlich等溫吸附模型,所測平衡吸附量(qe)為249.89mgg-1;Cell-g-PMA-HZ吸附劑對Cu(Ⅱ)、Ni(Ⅱ)、Pb(Ⅱ)的吸附均為放熱且熵減過程,而對Cd(Ⅱ)的吸附為吸熱且熵增的過程。動態(tài)吸附研究表明,Cell-g-PMA-HZ吸附劑對Cu(Ⅱ)、Ni(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)離子的吸附較為迅速,洗脫過程使用1molL-1HCl溶液,在20mL以內(nèi)均可完全洗脫下來,且在6次循環(huán)利用后,吸附量仍能保持初始吸附容量的80%以上,表明Cell-g-PMA-HZ吸附劑具有良好的再生性能。
[Abstract]:Cellulose based heavy metal ion adsorbents are one of the research hotspots in recent years, because of their good adsorption, mechanical properties and regenerative properties.Cellulose-based adsorbents have great potential in heavy metal ion adsorption in water.In this paper, cellulose-g-poly methyl acrylic Cell-g-PMAA was prepared by free radical graft copolymerization of cellulose onto microcrystalline cellulose and cerium ammonium nitrate as initiator.Hydrazine hydrate modified cellulose grafted with polymethyl acrylate (HPAM) was obtained. Cellulose-g-poly methyl acrylic acid Cell-g-PMA-HZN was obtained.In order to improve the content of chelate group, the synthesis conditions were discussed and the products were verified by FT-IR, elemental analysis, thermogravimetric analysis (TGA), C13-NMR and scanning electron microscopy (SEM).Cell-g-PMA-HZ adsorbents were prepared by static and dynamic adsorption experiments. The adsorption properties of Cell-g-PMA-HZ adsorbents for Cu (鈪，

本文編號：1721054