ADSORPTION PHENOMENA AND MACROSCOPIC PROPERTIES OF FERRONEMATICS CAUSED BY ORIENTATIONAL INTERACTIONS V. I. Zadorozhnii, I. P. Pinkevich, and V. Yu. Reshetnyak Physics Faculty, Kyiv National Taras Shevchenko University, Prosp. Glushkova 6, Kyiv, 03680, Ukraine S. V. Burylov Institute of Transport Systems and Technologies, Nat. Acad. of Sci. of Ukraine, Pisargevskogo St. 5, Dnepropetrovsk, 49005, Ukraine T. J. Sluckin School of Mathematics, University of Southampton, Southampton, SO17 1BJ, United Kingdom We have studied the effect of adsorption and desorption of rod-like magnetic grains on the macroscopic properties of ferronematics in a ferronematic cell. An external magnetic field controls the equilibrium between ferroparticles in the bulk and those adsorbed on the cell surfaces. The magnetic field can thus influence the anchoring and the nematic orientational texture. In the presence of ferroparticle adsorption, the segregation effect is diminished, and the system becomes less susceptible to bulk ferroparticle coagulation. Keywords: adsorption; ferroparticle; liquid crystal; magnetic field INTRODUCTION Ferronematics (FN’s) are highly dispersed colloidal suspensions of ferrite grains, in which the suspending medium is a nematic liquid crystal (NLC). These systems were first proposed on theoretical grounds This work has been partially supported by INTAS grant N 99-00312. Address correspondence to V. I. Zadorozhnii, Physics Faculty, Kyiv National Taras Shevchenko University, Prosp. Glushkova 6, Kyiv, 03680, Ukraine. 285 Mol. Cryst. Liq. Cryst., Vol. 409, pp. 285–292, 2004 Copyright # Taylor & Francis Inc. ISSN: 1542-1406 print=1563-5287 online DOI: 10.1080/15421400490431417