生物质废弃物羽毛的改性及应用研究

【作者】 孙平；

【导师】 刘昭铁；

【作者基本信息】 陕西师范大学 ， 应用化学， 2009， 博士

【摘要】 由于环境问题日益突出,使环境友好材料取代部分合成材料成为研究热点。羽毛角蛋白具有可再生、贮量丰富、质量及供应稳定等优点。本研究以羽毛为中心进行了如下研究:1、综述了羽毛的形成、形态、结构及组成。系统介绍了羽毛研究中的表征方法,红外光谱、拉曼光谱、x-射线衍射是研究羽毛的主要方法,光学显微镜、电子显微镜也是研究羽毛重要手段。对羽毛的应用进行了分类讨论。羽毛首先被用于填充保温材料,近来的研究还可以利用羽毛进行纺织;大多数羽毛应用研究均集中在水解羽毛领域,其中酸水解、碱水解以及在氧化剂或还原剂存在下的酸、碱水解均有较多的研究,也有利用高温水及近临界水水解羽毛的研究。生物法水解羽毛是近年来的研究热点,但目前的研究主要集中在寻找有效的角蛋白水解酶及菌类。羽毛可用于高分子增强材料,羽毛还被用于吸附有机物及无机重金属离子。2、以离子液体氯化1-丁基-3-甲基咪唑为溶剂,溶解羽毛,用乙醇再生后得到再生羽毛颗粒（RF）。RF的结晶度有所下降,其β-折叠的比例为31.71%,低于羽毛（47.19%）。原羽毛为疏水性物质而RF颗粒表面却变成了亲水性表面,其水接触角由羽毛的138°降低为76°。RF颗粒能高效地去除污水中的Cr（Ⅵ）离子。羽毛的离子液体溶液经水或乙醇再生,直接过滤可得到羽毛角蛋白纸,其机械性能很差。加入少量成膜剂聚乙烯醇或聚乙烯醇缩丁醛后的羽毛离子液体溶液可制备透明的羽毛角蛋白膜。由于聚乙烯醇缩丁醛的疏水性较强,其虽然可以提高膜的机械性能,但所得膜仍很脆。聚乙烯醇的亲水性远大于聚乙烯醇缩丁醛,所以其能极大地提高膜的机械性。该工作为离子液体及废弃羽毛的利用提供了新途径。3、通过多种化学方法对羽毛进行了处理,（1）以不同浓度的氢氧化钠溶液进行处理;（2）在氢氧化钠溶液中用环氧氯丙烷（Epi）进行交联,制得Epi修饰羽毛（EpiF）;（3）在氢氧化钠溶液中,以Epi为交联剂,用乙二胺进行修饰,制得乙二胺修饰羽毛（EAEpiF）。利用FT-IR、XRD、SEM、元素分析和水接触角对化学处理羽毛的结构进行了研究。结果表明,当仅以氢氧化钠溶液处理羽毛时,反应只在羽毛表面进行,羽毛表面的角蛋白片段将分层脱落,进而溶解在氢氧化钠溶液中。不同浓度的碱处理后的羽毛在结构及性质上均相似,对阴离子型金属离子Cr（Ⅵ）离子的吸附能力虽然较原羽毛有所提高,但仍较弱,吸附属于物理吸附。碱处理羽毛对金属阳离子Cu（Ⅱ）离子的吸附能力有很大的提高,但吸附仍是物理吸附。EpiF对低浓度的Cr（Ⅵ）离子有很强的吸附能力。EAEpiF为亲水性材料,在很宽的浓度范围内（10-80ppm）,对Cr（Ⅵ）离子均有90%以上的去除率,其吸附可能属化学吸附;但对铜离子的吸附较弱,属物理吸附。4、以羽毛为原料,钛酸丁酯为前驱体,通过在羽毛表面的缓慢水解胶凝过程,制备了纳米二氧化钛/羽毛复合材料。最佳制备条件为:羽毛经0.1 mol·L^-1的NaOH水溶液处理后,在1。5%的钛酸丁酯乙醇溶液中回流反应24 h。通过x-射线衍射分析表明复合材料中的TiO₂为无定型态。扫描电子显微镜结果显示,复合材料中的TiO₂为一均匀涂层。虽然成功制备了二氧化钛/羽毛复合材料,但实验表明此复合材料无光催化性能。5、利用溶胶-凝胶法制备了二氧化钛/羽毛复合材料。XRD结果表明,复合材料中的二氧化钛为锐钛矿型。以酸性大红3R和丁基罗丹明B为模型污染物,对复合材料的光催化降解能力进行了考察。结果表明,复合材料对酸性大红3R的去除率很高,在20 min内可去除80%。复合材料对阴离子型染料有极强的吸附作用,对酸性大红3R的吸附可达到0.27g·g^-1,其吸附为化学吸附。对阳离子型染料丁基罗丹明B的吸附较弱。由于羽毛纤维的固有性质,其可以很方便地通过过滤回收,解决了TiO₂光催化剂回收困难的问题。6、利用硝酸、醋酸、乙醇的不同配方,研究酸处理羽毛的结构及性质。羽毛经硝酸处理后,其角蛋白中的部分胺基被阳离子化。硝酸处理后的羽毛（NF）对阴离子型染料酸性大红3R有极强的吸附能力,属于化学吸附。对阳离子型染料丁基罗丹明B的吸附能力相对很弱,但吸附作用力很强,属于化学吸附:NF对阴离子型金属离子Cr（Ⅵ）离子有强的吸附能力,与Cr（Ⅵ）离子之间存在强相互作用,可能为阴阳离子之间的静电相互作用,属于化学吸附:Cr（Ⅲ）离子虽然属阳离子,NF对其也有一定的吸附,但相互作用较弱,属物理吸附;NF对其它金属阳离子如:Cu（Ⅱ）离子、Mn（Ⅱ）离子、Co（Ⅱ）离子等均无吸附,因此,经硝酸处理的羽毛可用于选择性吸附污水中的总铬。更多还原

【Abstract】 A concern for the environment is driving research into environmentally friendly materials as replacements for part of synthetic materials.While much current research focuses on cellulose,we highlight that feather keratin should also be considered.It is renewable,commercially abundant, consistent quality,and has guaranteed supply.In this dissertation,the modification and application of feathers were investigated.1.The generation,configuration,structure and composition of feathers were reviewed.IR, Raman and x-ray diffraction are mainly used to characterize the structure of feathers,and optical microscope and electron microscope are also used.The applications of feathers were discussed. Feathers were firstly used for filled heat insulation materials and used for spin and weave in recent research.Most research focused on the hydrolysis of feather,including acid hydrolysis,base hydrolysis and acid or base hydrolysis in the presence of oxidant or reducer.Superheated water and sub-critical water were also used to hydrolyze feather.Many research focused on the hydrolysis of feather using bio-method currently;however,most of them focused on finding and culturing keratin hydrolyzing enzyme and keratin degrading bacteria.Feather can be used to prepare fiber-reinforced polymer.Feathers are also used to adsorb organic molecules and heavy metal ions.2.The dissolution and regeneration of the waste feather in an ionic liquid of 1-butyl-3-methylimi-dazolium chloride（[BMIM]Cl） were demonstrated for preparing feather based particles.The crystallinity of the regenerated feathers（RF） decreases and the content ofβ-sheet is 31.71%,which is clearly lower than the raw feather（47.19%）.The surface property of feather changed from hydrophobicity to hydrophilicity after regenerated from[BMIM]Cl as indicated by the change of the water contact angle from 138 to 76°.RF shows an excellent efficiency for removing Cr（Ⅵ） ions in water.The stress and strain of the film made from feather can be significantly improved by adding a small amount of poly（vinyl alcohol）（PVA） as an additive.The hydroxyl groups in the molecule of PVA can form hydrogen bonds with the groups of amino and carboxyl in keratin chains of the feathers.On the contrary,in the case of polyvinyl butyral（PVB） as an additive, most oxygen atoms in PVB molecules are existed as butyral,and the butyl are hydrophobic,while keratin chains of feathers are hydrophilic.Thus,the film of adding PVB shows a poor mechanical property due to the weaker interaction between PVB and keratin chains.This work demonstrated a new application of the ionic liquid for dissolving feather and a renewable application of waste feather.3.Feather was chemically treated by several methods.（1） Feather was treated with a range of concentrations of NaOH aqueous solutions.（2） Feather was cross-linking modified with epichlorohydrin（Epi） in NaOH aqueous solution（EpiF）,and（3） Feather was modified with ethylenediamine（EA） in NaOH aqueous solution by cross-linking with Epi（EAEpiF）.The structure and properties of chemically treated feather were investigated by FT-IR,XRD,SEM,elemental analysis and water contact angle measurements.When feather is treated in NaOH aqueous solution, the reactions occurred on the surface rather than in the interior of feather,and keratin fragments exfoliate from the feather surface layer by layer,and then dissolve in aqueous solution.Feather treated with NaOH are similar in structure and properties to raw feather,and shows relatively low sorption capacity for removal of Cr（Ⅵ） ions from water,but higher capacity than that of raw feather and the sorption is physical adsorption.NaOH treated feather shows an excellent capacity of removing Cu（Ⅱ） ion from water,however,it is also physical adsorption.EpiF shows excellent capacity for adsorbing low concentrations of Cr（Ⅵ） ions,while low sorption capacity for Cu（Ⅱ） in water.EAEpiF is hydrophilic and shows 90%efficiency for removing Cr（Ⅵ） ions in the concentration ranges 10～80 ppm,the sorption maybe chemisorption;However,EAEpiF shows low sorption capacity of adsorption Cu（Ⅱ） ion.4.Titanium dioxide/feathers composite materials were prepared by using feather as raw materials,Ti（O-nBu）₄ as precursor and ethanol as solvent.The influence of the pretreated reagent concentration of NaOH and the Ti（O-nBu）₄ concentration on the modification rate of TiO₂ had been investigated,and the optimum reaction conditions were obtained.Feather was firstly treated with 0.1 mol·L^-1 of NaOH aqueous solution,then reacted with 1.5%of Ti（O-nBu）₄ ethanol solution at 78℃for 24 h.The XRD results demonstrated that the TiO₂ in composite material was amorphous phase. SEM indicated that the TiO₂ in composite material is a nanometer lay.The composite material does not show any photocatalytic activities;the possible reason is that the TiO₂ is not in crystallization phase.5.Titanium dioxide/feathers composite material was prepared using sol-gel method.The XRD results demonstrated that the TiO₂ in composite material was anatase.The photocatalytic activities of composite were investigated by using Ponceau 4R and Butyl rhodamine B as model pollutes.The results demonstrated that composite material shows excellent capacity of removing Ponceau 4R with 80%efficiency for removing of Ponceau 4R.The composite material shows excellent capacity of adsorbing anionic dye,the uptake of Poncean 4R can reach 0.27 g·g^-1,and the sorption is chemisorption.The composite material shows poor capacity for adsorption of Butyl rhodamine B. The composite material can be easily recovered by filtration for the fiber property of feather.6.The structure and property of acid treated feather were investigated by using different prescription of nitric acid,acetic acid and ethanol.Parts of amino group of keratin were changed to cation after treated with nitric acid.Nitric acid treated feather（NF） shows excellent sorption capacity of adsorbing Ponceau 4R,the sorption is chemisorption.However,NF shows low sorption capacity of adsorbing cationic dye Butyl rhodamine B,however the interactions between feather and Butyl rhodamine B are very strong,the sorption is chemisorption.NF shows excellent adsorption capacity of adsorbing anionic Cr（Ⅵ） with a possible strong interaction of electrostatic attraction,and the sorption is chemisorption.NF also can adsorb Cr（Ⅲ） ion with a relatively weak interaction,although it is a cation metal ion,and the sorption is physical adsorption.However,for Cu（Ⅱ）,Mn（Ⅱ） and Co（Ⅱ） ions,NF did not show any adsorption.Therefore,NF can be used as a material for selective adsorption of total Cr from wastewater.更多还原