FIBER DIFFRACTION STUDIES OF CELLULOSE SOLUBILIZATION

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 纤维素是地球上最丰富的生物聚合物，是一种可再生资源。这使其成为可再生能源研究的一个有吸引力的研究目标，特别是生物乙醇生产。无定形纤维素是用于生物燃料生产的更易处理的原料。我们已经确定了一种用离子液体溶解纤维素以产生无定形材料的方法。在用水或乙醇代替离子液体时，经处理的纤维素原纤表现出不同程度的结晶度。我们正在使用纤维衍射跟踪处理材料的结晶度，以确定纤维素晶格破坏和无定形纤维素生产的参数。需要同步加速器X射线通量来产生来自无定形样品的信号，以确定晶格保持的水平以及对单个纤维素微晶溶解与总原纤降解的影响。具体地说，我们问的问题是，与在整个原纤维中看到的变化相比，单个纤维素微晶是如何受到溶解的影响的。对起始原纤维、离子液体处理的各个时间步骤后的原纤维和离子液体用水或乙醇置换后的材料进行曝光。将纤维保持在氮气流中以防止大气水在衍射实验期间置换离子液体。由于离子液体是无毒的，因此这些实验没有健康危害。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cellulose is the most abundant biopolymer on earth and is a renewable resource. This makes it an attractive research target for renewable energy studies, especially for bioethanol production. Amorphous cellulose is a much more tractable feedstock for biofuel production. We have identified a method that solubilizes cellulose with ionic liquid to produce amorphous material. On replacement of ionic liquid with water or ethanol the treated cellulose fibrils manifest varying degrees of crystallinity. We are following the crystallinity of treated material with fiber diffraction to determine the parameters of cellulose lattice disruption and amorphous cellulose production. Synchrotron X-ray fluxes are needed to produce a signal from the amorphous samples to determine the level of lattice preservation and the effects on single cellulose crystallite dissolution vs. gross fibrillar degradation. Specifically, we are asking the question of how the single cellulose crystallite is affected by solubilization, as compared with the changes seen in the overall fibril. Exposures are made of the starting fibril, the fibril after various time steps of ionic liquid treatment, and the material after the ionic liquid has been displaced with water or ethanol. The fiber is kept in a nitrogen gas stream to prevent atmospheric water from displacing the ionic liquid during diffraction experiments. As the ionic liquid is non-toxic, these experiments represent no health hazard.