ETD system

Electronic theses and dissertations repository

 

Tesi etd-10192003-214820


Thesis type
Tesi di laurea vecchio ordinamento
Author
Bizzarri, Marco
email address
marco78zz@virgilio.it
URN
etd-10192003-214820
Title
Simulazione di trasformazioni di fase e dinamica del 4-pentil-4'-cianobifenile (5CB)con potenziale derivato da calcolo ab-initio
Struttura
SCIENZE MATEMATICHE, FISICHE E NATURALI
Corso di studi
CHIMICA
Supervisors
relatore Tani, Alessandro
Parole chiave
  • Nessuna parola chiave trovata
Data inizio appello
19/11/2003;
Consultabilità
Parziale
Data di rilascio
19/11/2043
Riassunto analitico
In this work, an intermolecular potential for the interaction between 5CB pairs has been reconstructed from a database of interaction energies of the molecular fragments, calculated
from ab-initio methods at MP2 level. This function has been employed in a series of molecular dynamics simulations at various temperatures. The simulation results show the experimental cristalline structure stays kinetically stable throughout the temperature range of experimental cristalline phase. We also found a nematic phase at higher temperature and an isotropic liquid phase at still higher temperature. The various phase have been characterized from a structural
( radial distribution functions and conformational
distribution function of the chain )and dynamic ( diffusion coefficient ) point of view. In the case of nematic phase we have calculated total
and local orientational order parameters to compare to the data obtained from NMR
spectroscopy while translational diffusion has been studied for both longitudinal ( i.e. along the director ) and both transverse motions.
File