Daisuke Ishii - Light-Scattering Analysis of Native Wood Holocelluloses Totally Dissolved in LiCl–DMI Solutions: High Probability of Branched Structures in Inherent Cellulose

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      Publication Details (including relevant citation   information):

    Biomacromolecules201112 (11), pp 3982–3988
    DOI: 10.1021/bm201211z
    Publication Date (Web): September 19, 2011


        Three holocelluloses (i.e., cellulose and hemicellulose   fractions) are prepared from softwood and hardwood by the Wise   method. These holocelluloses completely dissolve in 8% lithium   chloride/1,3-dimethyl-2-imidazolidinone (LiCl/DMI) after an   ethylenediamine (EDA) pretreatment. After diluting the   holocellulose solutions to 1% LiCl/DMI, they are subjected to   size-exclusion chromatography/multiangle laser-light   scattering/photodiode array (SEC-MALLS-PDA) analysis. All   holocelluloses exhibit bimodal molecular weight distributions   primarily due to high-molecular-weight (HMW) cellulose and   low-molecular-weight hemicellulose fractions. Plots of molecular   weight vs root-mean-square radius obtained by SEC-MALLS analysis   revealed that all the wood celluloses comprise dense   conformations in 1% LiCl/DMI. In contrast, bacterial cellulose,   which was used as a pure cellulose model, has a random coil   conformation as a linear polymer. These results show that both   softwood and hardwood HMW celluloses contain branched structures,   which are probably present on crystalline cellulose microfibril   surfaces. These results are consistent with those obtained by   permethylation analysis of wood celluloses.

      Address (URL): http://pubs.acs.org/doi/abs/10.1021/bm201211z