Combining small-angle and intermediate-angle neutron scattering to study the hierarchical structure in microbial cellulose

小角及び中角中性子散乱法で微生物産生セルロースにおける階層構造に関する研究

Zhao, Y.; 小泉 智

Zhao, Y.; Koizumi, Satoshi

In this study, we employed intermediate angle neutron scattering (IANS) technique to correct the small angle neutron scattering (SANS) data of the water-swollen microbial cellulose (MC) sample, the system of which has a significant incoherent contribution from the water solvent, and we described the effects that the corrections have on the structural analysis. In order to elucidate the structure efficiently, the solvent was exchanged in situ between protonated water and deuterated water to give different scattering contrasts, and the water-exchange processes were followed by time-resolved SANS and IANS simultaneously. Our results showed that: (1) after incoherent correction, the microstructure of MC sample was proved to be invariant with solvents; (2) the scattering intensity depended only on the contrast factor, revealing a two-phase system composed of waterresistant crystalline cellulose phase and hydrated amorphous phase; (3) the cellulosecrystallites have a constant scattering length density of 2.010 cm, determined by the matching point at which the scattering contrast between the two phases is minimum. This value was consistent with that of 1.910 cm estimated from its chemical structure.