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Title: Computational studies of polyelectrolytes containing zeolitic fragments

Abstract

The structures and sodium affinities of a series of zeolitic fragments [H{sub 3}Al(OCH{sub 3}){sub x}(OSiH{sub 3}){sub 1{minus}x}{sup {minus}}, 2T, H{sub 2}Al(OCH{sub 3}){sub x}(OSiH{sub 3}){sub 2{minus}x}{sup {minus}}, Al(OCH{sub 3}){sub x}(OSiH{sub 3}){sub 4{minus}x}{sup {minus}}, 5T], that mimic the charge sites in polyelectrolytes are calculated by ab initio molecular orbital methods at different levels of theory. At the HF/6-31G{sup *} level, the decrease in the sodium affinity due to the substitution of an OCH{sub 3} group by an OSiH{sub 3} group is about 8 kcal/mol in the 2T and 3T systems. In the 5T systems, the replacement of a sodium-coordinated OCH{sub 3} group by an OSiH{sub 3} group causes a decrease of 7 kcal/mol in the sodium affinity, while the substitution for a non-sodium-coordinated OCH{sub 3} group results in a 2.7 kcal/mol decrease. The lower sodium affinity indicates a weaker Coulombic interaction, suggesting an enhanced ionic conductivity with the substitution of carbon by silicon, consistent with experimental results. Natural bond orbital (NBO) analyses show that silicon-bonded oxygen atoms have smaller lone-pair dipole moments, resulting in a lower sodium affinity. The substitution of aluminum by boron leads to a higher sodium affinity, although the effect of replacing an OCH{sub 3} group by an OSiH{submore » 3} group still reduces the sodium affinity. The effect of the sodium cation on the bond angles in these systems is also investigated.« less

Authors:
; ;  [1];  [2]
  1. Northwestern Univ., Evanston, IL (United States)
  2. Argonne National Lab., IL (United States). Materials Science Div.
Publication Date:
Research Org.:
Argonne National Laboratory (ANL), Argonne, IL
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
682065
DOE Contract Number:  
W-31109-ENG-38
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
Additional Journal Information:
Journal Volume: 103; Journal Issue: 31; Other Information: PBD: 5 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; ZEOLITES; ELECTROLYTES; AFFINITY; SODIUM; IONIC CONDUCTIVITY; MOLECULAR ORBITAL METHOD; CATIONS; POLYETHYLENE GLYCOLS

Citation Formats

Lee, Y.C., Ratner, M.A., Shriver, D.F., and Curtiss, L.A. Computational studies of polyelectrolytes containing zeolitic fragments. United States: N. p., 1999. Web. doi:10.1021/jp990649u.
Lee, Y.C., Ratner, M.A., Shriver, D.F., & Curtiss, L.A. Computational studies of polyelectrolytes containing zeolitic fragments. United States. doi:10.1021/jp990649u.
Lee, Y.C., Ratner, M.A., Shriver, D.F., and Curtiss, L.A. Thu . "Computational studies of polyelectrolytes containing zeolitic fragments". United States. doi:10.1021/jp990649u.
@article{osti_682065,
title = {Computational studies of polyelectrolytes containing zeolitic fragments},
author = {Lee, Y.C. and Ratner, M.A. and Shriver, D.F. and Curtiss, L.A.},
abstractNote = {The structures and sodium affinities of a series of zeolitic fragments [H{sub 3}Al(OCH{sub 3}){sub x}(OSiH{sub 3}){sub 1{minus}x}{sup {minus}}, 2T, H{sub 2}Al(OCH{sub 3}){sub x}(OSiH{sub 3}){sub 2{minus}x}{sup {minus}}, Al(OCH{sub 3}){sub x}(OSiH{sub 3}){sub 4{minus}x}{sup {minus}}, 5T], that mimic the charge sites in polyelectrolytes are calculated by ab initio molecular orbital methods at different levels of theory. At the HF/6-31G{sup *} level, the decrease in the sodium affinity due to the substitution of an OCH{sub 3} group by an OSiH{sub 3} group is about 8 kcal/mol in the 2T and 3T systems. In the 5T systems, the replacement of a sodium-coordinated OCH{sub 3} group by an OSiH{sub 3} group causes a decrease of 7 kcal/mol in the sodium affinity, while the substitution for a non-sodium-coordinated OCH{sub 3} group results in a 2.7 kcal/mol decrease. The lower sodium affinity indicates a weaker Coulombic interaction, suggesting an enhanced ionic conductivity with the substitution of carbon by silicon, consistent with experimental results. Natural bond orbital (NBO) analyses show that silicon-bonded oxygen atoms have smaller lone-pair dipole moments, resulting in a lower sodium affinity. The substitution of aluminum by boron leads to a higher sodium affinity, although the effect of replacing an OCH{sub 3} group by an OSiH{sub 3} group still reduces the sodium affinity. The effect of the sodium cation on the bond angles in these systems is also investigated.},
doi = {10.1021/jp990649u},
journal = {Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical},
number = 31,
volume = 103,
place = {United States},
year = {1999},
month = {8}
}