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1、青島科技大學(xué)碩士學(xué)位論文離子液體體系下纖維素酶降解纖維素的研究姓名:徐翠枝申請(qǐng)學(xué)位級(jí)別:碩士專業(yè):化學(xué)工藝指導(dǎo)教師:于世濤;牛增元20100608青島科技大學(xué)研究生學(xué)位論文UlIUlIIIIIUllUIY1740506離子液體體系下纖維素酶降解纖維素的研究摘要本研究合成了26種具有代表性的離子液體,并利用紅外光譜和核磁共振波譜確定其組成和結(jié)構(gòu)。從這些離子液體中篩選出對(duì)纖維素具有良好溶解能力的中堿性離子液體作為溶劑,以1.乙基.3.甲基咪唑乙酸鯰鹽.[Emim]OAc為例研究溶解體系的濃度、反應(yīng)溫度以及溶解時(shí)間對(duì)纖維素溶解性能的影響
2、。之后分別對(duì)離子液體溶解前及再生后的纖維素進(jìn)行FT-IR、XRD及SEM表征,對(duì)離子液體作用于纖維素的過程從形貌和結(jié)構(gòu)上作出分析,并探討溶解機(jī)理。從能溶解纖維素的離子液體中篩選出對(duì)纖維素酶具有良好相容性的離子液體[Emim]OAc作為纖維素溶劑,構(gòu)建纖維素與[Emim]OAc的均相體系,研究微晶纖維素的原位酶解。選用3種不同性質(zhì)的纖維素酶,分別對(duì)離子液體體系中的微晶纖維素進(jìn)行降解試驗(yàn)對(duì)比。應(yīng)用3,5.二硝基水楊酸.DNS法測(cè)得酶解體系中還原糖的濃度,進(jìn)而求得反應(yīng)過程中總還原糖的收率來表征酶解效果。同樣的試驗(yàn)方法分別應(yīng)用于離子液體體
3、系中天然纖維素沙柳,秸稈和棉花的原位糖化,探討離子液體中天然纖維素的均相酶解反應(yīng)。對(duì)離子液體體系中各種纖維素的酶解反應(yīng)同常規(guī)條件下纖維素的酶解反應(yīng)進(jìn)行比較并總結(jié)出規(guī)律。最后,研究了離子液體[Emim]OAc的回收再利用情況。關(guān)鍵詞:離子液體纖維素均相反應(yīng)原位糖化青島科技大學(xué)研究生學(xué)位論文EFFICIENTENZYMATICINSITUSACCCHAlUFICATIoNOFCELLULOSEINIONICLIQUIDABSTRACTInthisstudy,26speciesionicliquids(ILs)weresynthesiz
4、edandcharacterizedbyFT-IRandNMRtechniques.Itwasfoundthationicliquid1-ethyl—·3·-methylimidazoliumacetate([Emim]OAc)wasofgoodsolubilitytocellulose.Theeffectssuchastheconcentration,thereactiontemperatureandreactiontimeonpropertiesofcellulosedissolutionwerediscussedinthed
5、issolvedsystem.Dissolutionandregenerationofcelluloseinthe[Emim]OAewereinvestigatedbyFT-m,X-rayandSEM,andthetheoryofcellulosedissolutioninionicliquidWasexploredandexplained.【Emim]OAcWaschosenasallenvironment-friendlysolventforenzymaticinsitusaccharificationinviewofitsb
6、iocompatibilitywithbothcellulosesolubilityandenzymeactivity.Theenzymaticdegradationofmicrocrystallinecelluloseinthehomogeneoussystemof[Emim]OAcandcellulosewasinvestigated.Threekindsofcellulasehadbeenselectedascatalystsinthesitusaccharification.Thedinitrosalicylicacid(
7、DNS)methodWasusedtomonitortheinfluenceofreactionconditionsontheresultsofdegradation.ThesamemethodWasappliedtostudythehomogeneousenzymatichydrolysisinsitusaccharificationofnaturalcellulosesuchaswillow,cornstalkandpledget,in【Emim]OAc.TheoptimumconditionfordegradationWas
8、obtainedinnormalandILconditions.Theenzymatichydrolysisofcelluloseinionicliquidsystemwascomparedwithgeneralconventionalenzyma