Molecular dynamic study of the odd-even effect in some 4-n-alkyl-4 '-cyanobiphenyls
Küçük Resim Yok
Tarih
2006
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Amer Physical Soc
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Using a united atom model, we performed molecular dynamics (MD) simulations on the 4-n-alkyl-4 '-cyanobiphenyl (nCB) liquid crystal homologous series for n=5-9 at a constant reduced temperature in the nematic phase. To evaluate the rotational diffusion coefficient (RDC), the second- and fourth-rank order parameters (OP's) and correlation time were calculated from MD trajectories. We analyzed the rotational viscosity coefficient (RVC) by using the Nemtsov-Zakharov and Fialkowski methods based on statistical-mechanical approaches. The simulated RDC, RVC, and OP's were found to be reasonable when compared with previous theoretical and experimental data. These quantities were also calculated for the rigid core and alkyl chain segments separately for each mesogen, to take a closer look at the molecule tail-chain flexibility. The properties calculated for a rigid core were compared with those for an alkyl chain, and satisfactory results were obtained. Odd-even effects for RDF, RVC, and molecular ordering parameters were calculated for five mesogens.
Açıklama
Anahtar Kelimeler
Kaynak
Physical Review E
WoS Q Değeri
Q1
Scopus Q Değeri
Cilt
73
Sayı
6
