Laterally attached liquid crystalline polymers as stationary phases in reversed-phase high-performance liquid chromatography II. Optimization of the molecular parameter of the polymer

Stationary phases obtained by coating side-chain liquid crystalline polymer s (LCPs) with the mesogenic rod like units laterally attached to a polysilo xane backbone via a flexible spacer have been already reported. These phase s show excellent planarity and shape recognition for polynuclear aromatic h ydrocarbon (PAH) solutes in reversed-phase liquid chromatography. Optimizat ion of these stationary phases in terms of molecular parameters of the poly mer is here described. Fifteen stationary phases have been prepared varying different parameters such as the spacer length, the aliphatic tail length, and the proportion of laterally attached mesogenic units along the polymer chain. The results show that the combination of a long spacer and long ter minal chains, which generates a smectic phase in the polymer bulk, leads to the best chromatographic performances towards planarity and shape recognit ion for PAH solutes. (C) 2000 Elsevier Science B.V. All rights reserved.