Effect of encapsulation in MCM-41 type molecular sieves on vibrational spectra of liquid crystalline state

The paper deals with the investigation of IR absorption spectra of a pure 4 -n-pentyl-4'-cyanobiphenyl (5CB) liquid crystal in nematic liquid crystalli ne (LC) state, pure aluminosilicate molecular sieves of MCM-41 type (with c hannels about 40 Angstrom in diameter) and their heterogeneous binary syste ms. It was shown that 5CB molecules are able to interact with active center s in the MCM-41 channels forming sufficiently strong hydrogen bonds of the -C=N ... H-O- type. This conclusion was confirmed by the data obtained from DSC measurements. Relative amount of the 5CB molecules interacting with th e channel walls and that of the molecules retaining the LC state when encap sulated in molecular sieves MCM-41 and CuMCM-41 were estimated. (C) 2000 El sevier Science B.V. All rights reserved.