FIBER DIFFRACTION STUDIES OF CELLULOSE SOLUBILIZATION

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 纤维素是地球上含量最丰富的生物聚合物，是一种可再生资源。这使得它成为可再生能源研究的一个有吸引力的研究目标，特别是在生物乙醇生产方面。无定形纤维素是一种更易处理的生物燃料生产原料。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。用水或乙醇代替离子液体时，处理后的纤维素纤维表现出不同程度的结晶度。我们用纤维衍射法跟踪处理材料的结晶度，以确定纤维素晶格破裂和无定形纤维素生产的参数。需要同步加速器X射线助熔剂从无定形样品中产生信号，以确定晶格保留的程度，以及对单纤维微晶溶解和总纤维降解的影响。具体地说，我们提出的问题是，与整体纤维的变化相比，单个纤维素微晶是如何受到增溶作用的影响的。对起始原纤维、离子液体处理不同时间步骤后的原纤维、离子液体用水或乙醇置换后的材料进行曝光。光纤保持在氮气气流中，以防止在衍射实验期间大气中的水取代离子液体。由于离子液体无毒，这些实验不会对健康造成危害。

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.