4503

4237

كارشناسي ارشد

شيمي فيزيك

اصفهان:دانشگاه صنعتي اصفهان.دانشكده شيمي

1387

سيزده،108[II]ص:مصور رنگي،نمودار،جدول

ص.ع به: فارسي و انگليسي

سامان علوي، بيژن نجفي

عبدالحسين دباغ،حسين فرخ پور

1396/09/12

كتابنامه

شيمي

ID4237

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

Abstract Simple inorganic salts such as NaCl melt at very high temperature Salts with organic cations referredto as ionic liquids ILs open a new window for the liquid state at moderate temperature These salts are liquidat or near room temperature These compounds have been accepted as a designer solvent for many differentreactions Furthermore these salts as green solvents have been generated a revolution in the chemical reactionsdue to their potential and various characteristics such as an extremely low vapor pressure high efficiency andbiodegradation Also these compounds are being explored as green substitutes for volatile organic solvents Molecular Dynamics MD simulation is one of the principal and powerful methods in the theoreticalchemistry to explore the relationship between microstructure and macroscopic properties of ILs In thiscomputer simulation atoms and molecules are allowed to interact for a period of time under known laws ofphysics giving a view of the motion of the atoms MD simulations generate information at the microscopiclevel including atomic positions and velocities Computer simulations act as a bridge between microscopiclength and time scales and the macroscopic world of the laboratory This reliable method calculates the timedependent behavior of a molecular system In this thesis MD simulation is used to determine for some structural and dynamic properties of twoAmino Acids ionic liquids Tetrabutylphosphonium Alanine TBP Ala and Tetrabutylphosphonium Glycine TBP Gly These ILs show lower viscosities higher decomposition and efficiency than most of other ionicliquids AMBER based force field is used to determine the model of these ILs This force field is developed byZhou et al at 2007 Zhou G Liu X Yu G He H J Phys Chem 111 2007 7078 7084 DL POLY program version 2 18 is used to perform this simulation with using a time step of 0 001ps and Rcutoff 15 The NPTHoover ensemble was used for P 1atm and T 321 85K to calculate the structural properties and NVEensemble was used to calculate the dynamic properties of these ILs An important check for the accuracy of oursimulation and selected model is density Our predicted densities from our proposed force field are in properagreement with experimental data Microstructure properties of TBP Ala and TBP Gly have been investigated by looking at theRadial Distribution Function RDF plots for the cation cation anion anion and cation anion atomic sites of twoILs On the other hands we studied these RDF plots at different temperatures Also methyl group effect on theRDFs plots is studied For structural studies of cation the dihedral angles probabilities vs dihedral angles ofbutyl chains in TBP cation in the range of 0o until 360o is drawn and temperature effect on this plot is alsostudied Finally transport properties such as Mean Square Displacement MSD and Diffusion coefficient D of cation and anion of these ILs are also studied We have also evaluated qualitatively the effect of extra CH2 groups on these properties Keyword Ionic Liquids Molecular Dynamics Force Field RDF MSD

سامان علوي، بيژن نجفي

عبدالحسين دباغ،حسين فرخ پور