PMID- 18630955
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20080922
LR  - 20080808
IS  - 1520-6106 (Print)
IS  - 1520-5207 (Linking)
VI  - 112
IP  - 32
DP  - 2008 Aug 14
TI  - Time-resolved mapping of water diffusion coefficients in a working soft actuator 
      device.
PG  - 9761-8
LID - 10.1021/jp803792c [doi]
AB  - Diffusion-weighted imaging was employed to spatially map the distribution of the 
      diffusion coefficient of water, D, in bare, water-soaked, Li(+)-exchanged, cast 
      Nafion and in an ionic polymer-metal composite (IPMC) soft actuator element, 
      prepared from this bare Nafion by impregnation with Pt electrodes. D was 
      evaluated in two orthogonal directions: along one of the long dimensions of the 
      sample (Dx) and through its thickness (Dz). D-maps of the IPMC element were 
      obtained both in the absence of an applied potential and in situ during the 
      application of a 3 V dc potential across the thickness of the sample. In the bare 
      Nafion, D-maps showed uniform values of both Dx and Dz of about 6 x 10 (-10) m(2) 
      s(-1). In the IPMC two effects were observed: (i) D at the electroded surfaces of 
      the IPMC was higher than at the center of the sample; (ii) this difference was 
      much greater in Dz than in Dx . Both effects were explained by the influence of 
      the impregnated Pt electrodes on polymer structure. The D-maps in the 
      electrochemical measurements showed high values of D (up to 8 x 10(-10) m(2) 
      s(-1)) at the cathode and low values (from 1 x 10(-10) m(2) s(-1)) at the anode. 
      This was explained in terms of the effect on the Nafion nanostructure of the 
      forced electro-migration of Li(H2O)x(+) species toward the cathode.
FAU - Naji, Leila
AU  - Naji L
AD  - EaStChem, School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 
      9ST, UK.
FAU - Chudek, John A
AU  - Chudek JA
FAU - Baker, Richard T
AU  - Baker RT
LA  - eng
PT  - Journal Article
DEP - 20080717
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
EDAT- 2008/07/18 09:00
MHDA- 2008/07/18 09:01
CRDT- 2008/07/18 09:00
PHST- 2008/07/18 09:00 [pubmed]
PHST- 2008/07/18 09:01 [medline]
PHST- 2008/07/18 09:00 [entrez]
AID - 10.1021/jp803792c [doi]
PST - ppublish
SO  - J Phys Chem B. 2008 Aug 14;112(32):9761-8. doi: 10.1021/jp803792c. Epub 2008 Jul 
      17.