摘要
以微晶纤维素为研究对象,设计了离子液体1-丁基-3-甲基咪唑氯盐(1-butyl-3-methylimidazolium chloride,[BMIM]Cl)预处理微晶纤维素Avicel的实验方法以实现纤维素的高效酶解糖化.在[BMIM]Cl中Avicel完全溶解,经水洗沉淀得到再生纤维素,回收后的离子液体可重复利用.预处理后底物酶解的可溶性糖转化率在24h时高达94.65%,较之同样条件下未经预处理底物的酶解糖转化率(48.57%)有飞跃性提升.进一步考察了离子液体预处理对纤维素结构及形态的影响,结果表明:[BMIM]Cl预处理后Avicel氢键减弱;结晶度明显下降,结晶型态由纤维素I型转变为纤维素II型;由规整的平行排布转变为疏松有孔的无序形貌.正是离子液体预处理引起的纤维素微观与宏观结构性质的显著改变使得再生后纤维素酶解的可溶性糖转化率大幅提高.
Microcrystalline cellulose Avicel was subjected to an ionic liquid （IL） 1-butyl-3-methylimidazolium chloride （[BMIM]CI） pretreatment step to obtain a high conversion of soluble sugars in the enzymatic hydrolysis of cellulose. Avicel was dissolved completely in [BMIM]CI, followed by precipitating it into deionized water to obtain the regenerated cellulose. The high performance liquid chromatography （HPLC） analysis results indicated that after 24 h, the sugar released from IL-treated Avicel was 94.65%, much higher than that from the original Avicel （48.57%）. Structure, crystallinity and morphology of the IL-treated Avicel were also investigated as follows： the hydrogen bonding, detected by FTIR, decreased; the crystallinity, monitored by XRD, changed significantly from crystalline to amorphous pattern; the morphology, examined by SEM, demonstrated that the orderly structure was destroyed remarkably with some pores and holes appearing in the cellulose substrates. These changes of Avicel pretreated with [BMIM]CI led to the increase of sugar conversion during cellulose enzymatic hydrolysis.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2009年第1期88-92,共5页
Acta Chimica Sinica
基金
国家自然科学基金(No.20576095)
国家科技支撑计划(No.2007BAD42B02)
国际科技合作计划(No.2006DA62400)
教育部创新团队(2007IRT0641)
教育部科学技术研究重点项目(No.108031)基金资助项目
关键词
纤维素
离子液体
预处理
酶解
cellulose
ionic liquid
pretreatment
enzymatic hydrolysis
