Comparative study of local structure of two cyanobiphenyl liquid crystals by molecular dynamics method
2014 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 141, no 7, 074503- p.Article in journal (Refereed) Published
Fully-atomistic molecular dynamics simulations were carried out on two similar cyanobiphenyl nematogens, HO-6OCB and 7OCB, in order to study effects of hydrogen bonds on local structure of liquid crystals. Comparable length of these two molecules provides more evident results on the effects of hydrogen bonding. The analysis of radial and cylindrical distribution functions clearly shows the differences in local structure of two mesogens. The simulations showed that anti-parallel alignment is preferable for the HO-6OCB. Hydrogen bonds between OH-groups are observed for 51% of HO-6OCB molecules, while hydrogen bonding between CN- and OH-groups occurs only for 16% of molecules. The lifetimes of H-bonds differ due to different mobility of molecular fragments (50 ps for N center dot center dot center dot H-O and 41 ps for O center dot center dot center dot H-O). Although the standard Optimized Potentials for Liquid Simulations - All-Atom force field cannot reproduce some experimental parameters quantitatively (order parameters are overestimated, diffusion coefficients are not reproduced well), the comparison of relative simulated results for the pair of mesogens is nevertheless consistent with the same relative experimental parameters. Thus, the comparative study of simulated and experimental results for the pair of similar liquid crystals still can be assumed plausible.
Place, publisher, year, edition, pages
2014. Vol. 141, no 7, 074503- p.
Cylindrical Submicrometer Confinement, Hydrogen-Bonded Systems, Mesogenic Biphenyls, Homologous Series, Simulation, Bipolar, Heptyloxycyanobiphenyl, Monomers, Mixture, Polar
Physical Sciences Chemical Sciences
IdentifiersURN: urn:nbn:se:kth:diva-151335DOI: 10.1063/1.4892877ISI: 000340714600032ScopusID: 2-s2.0-84906569353OAI: oai:DiVA.org:kth-151335DiVA: diva2:748162
QC 201409182014-09-182014-09-182014-09-18Bibliographically approved