Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York (SUNY) , Buffalo, New York 14260-4200, United States.
Biomacromolecules. 2018 Feb 12;19(2):640-651. doi: 10.1021/acs.biomac.7b01745. Epub 2018 Feb 2.
With the aim of informing the selection of biomass pretreatment options and to assist in interpreting experimental results from different biomass/solvent combinations, this study addresses the impact of crystallinity and size on the kinetics of semicrystalline cellulose fiber swelling and dissolution. To this end, a newly developed phenomenological model is utilized that accounts for the role of decrystallization and disentanglement as two rate-determinant steps in the cellulose dissolution process. Although fibers with lower crystallinity swell more and faster, the degree of crystallinity does not affect the dissolution rate. Fibers of smaller diameter swell more and become amorphous faster. When decrystallization is important, the solubility of thinner fibers increases more with a reduction in the crystallinity compared to the diameter. However, when the dissolution is controlled by chain disentanglement, or in the case of dissolution of fibers having larger diameters, milling the fibers to reduce the particle size could increase the solubility.
为了为生物质预处理方案的选择提供信息，并帮助解释来自不同生物质/溶剂组合的实验结果，本研究探讨了结晶度和尺寸对半结晶纤维素纤维溶胀和溶解动力学的影响。为此，利用了一种新开发的唯象模型，该模型考虑了脱晶和解缠结作为纤维素溶解过程中两个速率决定步骤的作用。尽管结晶度较低的纤维溶胀更多且更快，但结晶度并不影响溶解速率。直径较小的纤维溶胀更多且更快地变得无定形。当脱晶很重要时，与直径相比，更细纤维的溶解度随结晶度的降低而增加更多。然而，当溶解受链解缠结控制时，或者在溶解较大直径的纤维的情况下，将纤维研磨以减小粒径可能会增加溶解度。
