"Semi-empirical computation of selected molecular properties for eight conductive polymers (PANI, PITN, PPP, PPS, PPV, PPY, PT, Graphite)"

Date

10-2002

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Ernesto J Del Rosario

Abstract

RITUALO, FRANCISCO JR., F. University of the Philippines Los Banos, October 2002. Semi-empirical Computation of Selected Molecular Properties for Eight Conductive Polymers (PANT, PITN, PPP, PPS, PPV, PPY, PT, Graphite).

Adviser: Dr. Ernesto J. del Rosario .

Molecular properties that correlate with electrical conductivity were computed in vacuum for eight conductive polymers at different degrees of polymerization using HyperChem 6.0 software. HOMO-LUMO energy gap results which were corrected by subtracting 4 eV were found to be comparable with experimental values. An exception was found in the case of polyisothianaphene (PITN), which had large difference compared to experimental values. Total dipole moments were found to be high among polymers with odd number of monomer units and low for those with even monomers. Relatively large dipole moments were observed for polyisothianaphene (PITN), polypyrrole (PPY) and polythiophene (PT) - polymers containing heteroatoms like sulfur and nitrogen. Exceptions were polyaniline (PANT) and polyphenylene sulfide (PPS) which both have nonplanar polymer backbone. Hydrocarbon polymers — polyparaphenylene (PPP) and polyphenylene vinylene (PPV) have almost zero total dipole moments. Polarizability was found to be especially high among polymers composed of bulky monomer units such as PITH.

The planar hydrocarbon graphite was included in the computations and was found to have a very low energy gap even without correcting the results. The polarizability, however, was lowest at 106 A3 for graphite with 20 monomer units and total dipole moment was almost zero comparable with PPP and PPV.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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