Orientation behavior of cellulose microcrystals in magnetic and electric fields and its application for new material design.

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Following results on the orientation behavior by strong static magnetic field of microcrystalline cellulose and chitin in aqueous suspensions has been produced.(1) Both cellulose and chitin microcrystals in suspensions oriented in such a way that their molecular axs were laid perpendicular to the field direction. The same orientation was observed when the suspension was dried in the field.(2) Degree of orientation was improved with increasing field strength. However, the perfect orientation could not be achieved even using the strongest field at 17.5 Tesla. In general, the microcrystals having longer length as well as uniform length distribution tended to orient better.(3) In the case of shorter microcrystals such from wood or chitin, the better orientation was observed when the suspension was dried in the field. For this, the liquid crystalline character of the corresponding suspension-so called self-ordering behavior-seemed to play an important role in addition to the effect of the magnetic field.(4) The calculation of magnetic anisotropy was in good accord with the experimental results. The result that the pyranose ring was laid perpendicular to the fields was theoretically demonstrated.The experiments using strong static electric fields, the test of new material design using the physical fields, were also planned. However, we could not investigated as thoroughly as we have done on the basic magnetic field experiments. The work along these line was left for further studies.