Influence of Macrocyclic Ligands on Ion Transport in Solid Polyelectrolytes

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INFLUENCE OF MACROCYCLIC LIGANDS ON ION TRANSPORT IN SOLID POLYELECTROLYTES

K. CHEN, K. DOAN, S. GANAPATHIAPPAN, M. RATNER AND D. F. SHRIVER Northwestern University, Department of Chemistry and Materials Research Center, 60208 Evanston, IL

ABSTRACT in

the cation transport

and crown ethers increase

Cryptands

phosphazene

Vibrational spectroscopy indicates that

and alkoxyaluminate polyelectrolytes.

the increased conductivity originates from reduced ion pairing.

Introduction salt

Polymer

complexes

have

been

in these materials, and there is substantially to

Ion aggregation appears to be strong

evidence that charged ion aggregates contribute

the conductivity

fundamental studies,

it

is

latter

consideration

The

electrolytes

containing polyether

agents

[4,5]. (crown

In

For both

[3].

applications

practical

and

desirable to reduce or eliminate the transport of ion

aggregates.

constant

from both

investigated

extensively

fundamental and applied viewpoints [1,2].

has

groups

led

to

to

the

achieve

a

synthesis favorable

of polydielectric

the present work we describe the influence of ion chelating

ethers,

and

cryptands)

properties of polyelectrolytes.

on

the

electrical

and

spectroscopic

Preliminary discussions of this work have been

published [6,7].

Experimental Polymers were synthesized as described in the literature samples of 15-crown-5 (l,4,7,10,13-pentaoxacyclopentadecane),

Commercial

[4]. 2,

and cryptand1, were used

2.2.2(4,7,13,16,21,24-hexaoxa-l,10-diazabicyclo[8.8.8]hexacosane), after extended prepared in to

an N2 atmosphere by adding weighed amounts of the chelating ligand

the polyelectrolyte

solvent.

or

polymer salt

After removal of solvent

complex

under vacuum,

dried under high vacuum and stored in properties

Samples were

evacuation to remove water and dissolved gases.

an N2 -filled

in

acetonitrile

the

glove box.

and spectra were determined as previously described

1

or methanol

sample was extensively

2

Mat. Res. Soc. Symp. Proc. Vol. 210. @1991 Materials Research Society

The dielectric [7].

212

Results and Discussion The influence of C-2.2.2 on the conductivity of polyphosphazene sulfonates and polyalkoxyaluminates

shown in

is

Upon addition of C-2.2.2,

Table I.

ty of the polyphosphazene of magnitude,

sulfonates,

increases by approximately one order

3,

a much larger increase for polyalkoxyaluminates,

whereas there is

the poly-alkoxyaluminate than in

This may be due to tighter ion pairing in

4.

the

The conductivi-

conductivities of both polyelectrolytes increase significantly.

the phosphazene sulfonates.

O(C 2 H40) 2 cH3

O(C2H40)2CH33 I

II iP = Ny 0C 2 H4 SO

"-P=

N'x ) O(C2 H4 0) 2 CH3

3

OC2 H4 0CH 3 Nan-+OAI(OC 2 H4-+n OC2 H4OCH 3

No

4

3 Table I.

Conductivity Data of Polyelectrolytes without Crypt-2.2.2 1

Polyelectrolyte

with and

a cm- S (80 No C-2.2.2

'C) C-2.2.2 added'

1.7 1.9 2.9 1.5

8.3 1.6 1.9 9.2

polyphosphazeneb x x x x

-

0.2 0.14 0.1 0.04

x x x x

10-6 10-6 10-6 10-6

x x x x

10-6 10