Laterally attached liquid-crystalline polymers as stationary phases in reversed-phase high-performance liquid chromatography: III. Effect of the local anisotropic order on the separation of polycyclic aromatic hydrocarbons

• Published in: Journal of Chromatography A Vol. 913; no. 1; pp. 147 - 157
• Main Authors: Gritti, F., Félix, G., Achard, M.-F., Hardouin, F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 13-04-2001; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - methods; Crystallization; Exact sciences and technology; Other chromatographic methods; Polycyclic Compounds - isolation & purification; Polymers - chemistry; Polynuclear aromatic hydrocarbons; Polynuclear aromatic hydrocarbons; Liquid crystals; Liquid crystalline stationary phases; Stationary phases, LC; Hydrocarbon; Molecular structure; HPLC chromatography; Temperature effect; Selectivity; Polycyclic aromatic compound; Experimental study; Side chain; Ultraviolet detector; Anisotropy; Liquid crystal polymers; Siloxane polymer; Recognition; Stationary phase
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(00)01091-8

Specific stationary phases based upon non-liquid-crystalline polymers, liquid-crystalline molecules and side-on fixed liquid-crystalline polymers (SO-LCP) have been synthesized for use as silica modified stationary phases in high-performance liquid chromatography (HPLC). The mesogenic side group of the SO-LCP was composed of three phenyl ring benzoate type with terminal alkoxy chains and was laterally linked to a polysiloxane backbone via an alkyl ester spacer arm. This study demonstrated that the shape recognition of stationary phases based upon SO-LCP towards the length-to-breath ratio (
L/
B) was strongly connected to the existence of a local liquid-crystalline order into the pores of silica gel, warranting the interest of the collective organization of mesomorphic materials in liquid chromatography. Furthermore, the chromatographic performances depended on the kind of anisotropic order and it was more advantageous to use smectic side-on liquid-crystalline polymer than nematic and obviously non-liquid-crystalline ones. Finally, for a series of polymers having the same mesomorphism, the larger the temperature stability range of the mesophase, the more pronounced the local order effect and the higher the shape recognition.