本文選題：水熱法　切入點(diǎn)：殼聚糖　出處：《安徽建筑大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：碳質(zhì)材料是一類富碳的物質(zhì),它除含碳元素以外,還含有豐富氧、氫元素元素�？赏ㄟ^水熱碳化生物質(zhì)制備得到。它有著優(yōu)良的物理化學(xué)性質(zhì),在能源、環(huán)境以及生物工程等領(lǐng)域表現(xiàn)出潛在的價(jià)值。特別作為吸附劑使用時(shí),其表面含有的功能基團(tuán),如羥基、氨基、羧基以及磺酸基等,能作為活性位點(diǎn)進(jìn)行吸附,也為高效的選擇性吸附提供了條件。殼聚糖是自然界含量豐富的甲殼素脫N-乙�；漠a(chǎn)物,含有豐富的羥基和氨基基團(tuán)。然而,由于受溶解性的限制,很少用于水熱過程制備碳質(zhì)材料。本文報(bào)道利用殼聚糖為碳源水熱制備碳質(zhì)材料,并根據(jù)產(chǎn)物的結(jié)構(gòu)特點(diǎn)研究了碳質(zhì)材料對(duì)水污染物,特別是重金屬離子的選擇性吸附性能。具體內(nèi)容如下:(1)采用一步水熱制備了~830nm的α-Fe2O3@C微球的復(fù)合材料,其中碳質(zhì)含量達(dá)80%。通過研究不同條件下產(chǎn)物的形貌結(jié)構(gòu)特點(diǎn),得出殼聚糖的加入量是決定產(chǎn)物形貌的關(guān)鍵因素。當(dāng)沒有殼聚糖加入到反應(yīng)溶液中時(shí),只能得到尺寸分布不均一的α-Fe2O3顆粒。殼聚糖加入后,會(huì)對(duì)產(chǎn)物形貌進(jìn)行調(diào)控,促進(jìn)產(chǎn)物尺寸均勻。當(dāng)殼聚糖加入量為0.15g/50mL時(shí),會(huì)得到大小尺寸相對(duì)均勻的α-Fe2O3顆粒。當(dāng)0.50g/50m L殼聚糖加入反應(yīng)體系時(shí),幾乎沒有產(chǎn)物獲得。當(dāng)殼聚糖加入量為1.00g/50m L時(shí),得到碳質(zhì)微球?yàn)橹鞯牟牧�。進(jìn)一步增加殼聚糖的量1.50g/m L,得到α-Fe2O3成分居多的α-Fe2O3@C微球。因此殼聚糖加入量不同,產(chǎn)物的形貌與結(jié)構(gòu)也會(huì)發(fā)生變化。結(jié)合時(shí)間變量實(shí)驗(yàn),得出碳質(zhì)復(fù)合微球的形成機(jī)理:以α-Fe2O3模板,H+進(jìn)行蝕刻,水熱碳質(zhì)微粒填補(bǔ)空位,最終形成微球形貌。重要的是,這種碳質(zhì)材料具有氨基和羧基功能基團(tuán),表現(xiàn)出選擇性吸附性能。調(diào)控不同pH條件,發(fā)現(xiàn)Cu(II)和Cr(VI)混合溶液中,微球?qū)r(VI)在pH=2時(shí)有選擇性。即pH=2時(shí),微球?qū)r(VI)的最大吸附量1.90mmol/g,對(duì)Cu(II)吸附量僅為0.022mmol/g,表現(xiàn)出選擇性吸附Cr(VI)。當(dāng)pH=3,4,5時(shí),Cu(II)的吸附量隨pH的增加而提高,最大吸附量為1.32 mmol/g,而Cr(VI)的吸附量會(huì)減小,最最小到1.33mmol/g。高pH條件下,微球不表現(xiàn)對(duì)Cr(VI)的選擇性吸附。(2)以葡萄糖作為添加劑,加入到殼聚糖氯化鐵水溶液,一步水熱得到~830nm的α-Fe2O3@C空心球材料,碳質(zhì)含量為6.50%。通過表征不同反應(yīng)時(shí)間條件下的產(chǎn)物,發(fā)現(xiàn)空心球形成符合Ostwald熟化過程。此外殼聚糖的加入也起到很明顯的作用,未加入殼聚糖時(shí),只能得到大小形貌不規(guī)則的實(shí)心顆粒;加入0.15g殼聚糖后,發(fā)現(xiàn)產(chǎn)物尺寸變化均勻,同時(shí)有些顆粒變成空心結(jié)構(gòu);當(dāng)殼聚糖加入量為0.5g時(shí),才能夠獲得形貌一致大小均一的α-Fe2O3@C空心球。作為吸附劑,空心球表現(xiàn)出對(duì)痕量As(Ⅴ)(156.2μg/L)離子很好的去除能力,去除率高達(dá)98%。(3)采用尿素作為沉淀劑,殼聚糖為碳源制備了碳質(zhì)與Fe3O4復(fù)合材料,碳質(zhì)含量20.65%。結(jié)果顯示碳質(zhì)材料表面含有豐富的羧基官能團(tuán),在pH=9的水溶液中表現(xiàn)負(fù)電荷特性。作為吸附劑,它對(duì)亞甲基藍(lán)(Methylene Blue;MB)表現(xiàn)快速去除能力,同時(shí)能選擇性的將MB從MB與甲基橙(Methyl Orange;MO)混合溶液中移除。
[Abstract]:Carbonaceous material is a kind of carbon rich material, which in addition to the carbon element, also contains rich oxygen, hydrogen elements. Can be prepared by hydrothermal carbonization of biomass. It has excellent physical and chemical properties, in energy, environmental and biological engineering and other fields to show the potential value. Especially as adsorbent when in use, the surface containing functional groups, such as hydroxyl, amino, carboxyl and sulfonic groups, can be used as active sites for adsorption, but also provides the conditions for the selective adsorption efficiency. Chitosan is a natural product of the rich content of chitin by N- acetyl, rich in hydroxyl and amino groups. However, due to due to the limit of solubility, rarely used in the hydrothermal process for preparing carbonaceous materials. This paper reported the preparation of carbonaceous materials as carbon source heat prepared by chitosan, and studied the pollutants on water pollution of carbonaceous materials according to the structural characteristics of products, especially Is the performance of selective adsorption of heavy metal ions. The specific contents are as follows: (1) a -Fe2O3@C ~830nm composite microspheres were prepared by one-step hydrothermal method, the carbon content of 80%. by morphology and structure characteristics of the product under different conditions, adding that chitosan is a key factor in determining the morphology of the product. When not chitosan is added into the reaction solution, only -Fe2O3 alpha particle size distribution is not uniform. After adding chitosan, will regulate the morphology of the products, promote the products of uniform size. When the chitosan addition is 0.15g/50mL, will get alpha -Fe2O3 particles is relatively uniform size. When 0.50g/50m L chitosan addition reaction system, almost no product obtained. When the chitosan addition is 1.00g/50m L, get the carbonaceous materials. Further increase of microspheres of chitosan is 1.50g/m L, alpha -Fe2O3 are more The alpha -Fe2O3@C microspheres. Therefore chitosan with different adding amount, morphology and structure of the product can also be changed. Combined with the time variable experiment, the formation mechanism of the carbon microspheres: a -Fe2O3 template, H+ etching, hydrothermal carbonaceous particles fill the vacancy, and ultimately the formation of microspheres morphology. Importantly, this kind of carbonaceous materials with the amino and carboxyl functional groups showed adsorption selectivity. Regulation of different pH conditions, Cu (II) and Cr (VI) in the mixed solution of Cr (VI), microspheres have selectivity in pH=2. PH=2, Cr (VI) microspheres on the adsorption capacity of Cu (1.90mmol/g, II) the adsorption capacity is only 0.022mmol/g, showed the selective adsorption of Cr (VI). When pH=3,4,5, Cu (II) adsorption capacity increases with the increase of pH, the maximum adsorption capacity was 1.32 mmol/g, and Cr (VI) adsorption capacity decreases, the minimum to 1.33mmol/g. high pH conditions, not on the performance of the microspheres Cr (VI) selection Selective adsorption. (2) using glucose as an additive is added into the chitosan ferric chloride aqueous solution, one-step hydrothermal alpha -Fe2O3@C hollow sphere materials of ~830nm, carbon content is 6.50%. through the characterization of different reaction time conditions, found that the hollow spheres with Ostwald ripening process. This is also adding chitosan an obvious role, without the addition of chitosan, only solid particle size irregular morphology; adding chitosan 0.15g, found that the size of the product changes uniformly, and some particles into a hollow structure; when the chitosan addition is 0.5g, a -Fe2O3@C hollow sphere was able to obtain consistent morphology of uniform size as. Adsorbent, hollow spheres exhibit for the determination of As (V) (156.2 g/L) ion removal ability is very good, the removal rate of up to 98%. (3) using urea as precipitating agent, chitosan as the carbon source to prepare carbon and Fe3O4 composite 20.65%. results showed that the content of carbonaceous materials containing carboxylic acid rich surface carbonaceous material, negative charge characteristics in the aqueous solution of pH=9. It was used as the adsorbent for methylene blue (Methylene Blue; MB) showed rapid removal ability, and selective MB from MB and methyl orange (Methyl Orange; MO) to remove the mixture in the solution.

【學(xué)位授予單位】：安徽建筑大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB33

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 吳雪艷;王開學(xué);陳接勝;;多孔碳材料的制備[J];化學(xué)進(jìn)展;2012年Z1期

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本文編號(hào)：1647016