Modulation of structure and optical properties micro-fibrils of plants by means of electrical, deformation and optical treatments

Abstract

Variations of structure and optical properties of micro-fibrils of plants induced by optical, electrical, deformation and water treatments were studied in situ by means of optical polarization microscopy. Bundles of dry fibrils pulled out from nettle, maple and spruce were used for the experiments. Strong enhancement of the optical anisotropy in all of the fibrils has been found just after their wetting with water. Appearance of this anisotropy is attributed to orientation ordering of cellulose molecules in the neighbor layers of the walls of the fibrils. This ordering is explained by penetration of water molecules into the interfaces between cellulose layers and amorphous lignin polymers bound with cellulose molecules in the dry state of the fibrils. Relatively week electrical fields applied to the fibrils removes this anisotropy by pushing out the molecules of water from these interfaces. Evaporation of water returns the fibrils to optically isotropic state as well. The changes of the anisotropy of the fibrils are followed with their deformations These deformations induce internal electrical fields. Hence the interactions of the fibrils with water, electrical and deformation fields result in self-consistent propagation of electromechanical waves along the plants vessels. These waves are capable to transport feeding nutrients. Irradiation of wood components immersed in water by ultraviolet light induces dissolving of lignin and produces pure cellulose fibers. This phenomenon provides the development of new ecologically safety technology of production of cellulose.