Valve action of moisture transfer through the stem wall of forage grasses

Abstract

The issues of increasing the technological component of current in the processes of electroosmotic dehydration of forage grasses and electroplasmolysis in order to increase the energy efficiency of the listed electro-technological processes is an urgent scientific and practical task. The research findings are based on the conclusions of the author’s previous scientific works devoted to the substantiation of the electrical equivalent substitution scheme of the stem wall of plant materials in the processes of electroosmotic dehydration. The goal is to confirm the hypothesis of non-ideal rectification effect of forage grass stem wall on moisture transfer. Theoretical and experimental methods and means of electrochemical kinetics were used. The analysis of the obtained results allows formulating the following statements. The stem wall has non-ideal one-sided conductivity in relation to the electrolyte aqueous solution carried through it under the action of an external electric field. The rate of moisture transfer in the “forward” direction - from the inner surface of the stem wall to the outer one - decreases with increasing frequency of electromagnetic oscillations. The electrokinetic potential which is a component of the surface potential of the stem wall increases with increasing electric field strength in the “forward” direction and decreases in the “reverse” direction. In this connection, an increase in the electrokinetic potential in the “forward” direction is accompanied by an increase in the potential on the inner surface of the stem wall while a decrease in the electrokinetic potential in the "reverse" direction is accompanied by an increase in the potential on the outer surface. This character of surface potential change causes increase in the potential difference between the outer and inner surfaces of the stem wall as the external electric field strength increases regardless of the direction of current flow, which is the reason for the existence of a non-ideal valve effect of the stem wall both in terms of current and moisture transfer.