CHARGE-TRANSPORT AND WATER MOLECULAR-MOTION IN VARIABLE MOLECULAR-WEIGHT NAFION MEMBRANES - HIGH-PRESSURE ELECTRICAL-CONDUCTIVITY AND NMR

被引:57
作者
FONTANELLA, JJ [1 ]
WINTERSGILL, MC [1 ]
CHEN, RS [1 ]
WU, Y [1 ]
GREENBAUM, SG [1 ]
机构
[1] CUNY HUNTER COLL,NEW YORK,NY 10021
关键词
NAFION; ELECTRICAL CONDUCTIVITY; NUCLEAR MAGNETIC RESONANCE; TRANSPORT MECHANISM; ACTIVATION VOLUME; HIGH PRESSURE;
D O I
10.1016/0013-4686(95)00186-I
中图分类号
O646 [电化学、电解、磁化学];
学科分类号
081704 ;
摘要
Measurements of the electrical conductivity and deuteron NMR spin-lattice relaxation times (T-1) in three different molecular weights of acid form NAFION conditioned at various levels of relative humidity have been carried out. Complex impedance studies were made along the plane of the film at frequencies from 10-10(8) Hz at room temperature and pressures up to 0.3 GPa. The high pressure electrical data were only obtained for water contents less than 8 wt%. The NMR measurements were also made at room temperature and pressures up to 0.25GPa. The NMR data are primarily for water contents greater than 6wt%. The calculated activation volume exhibits a large decrease (from 16 to 3 cm(3)/mol) as the water content is increased from 2.4-8 wt%. In addition, the activation volumes are larger and the electrical conductivity is smaller for the higher molecular weight material. These results represent further evidence that the transport mechanism in low water content materials is dominated by segmental motions of the polymer chain and that proton transport and water molecular rotation are correlated. The activation volumes extracted from the NMR data show only a small further decrease as the water content is increased from 6-22 wt%. Possible explanations for the high water content NMR pressure results are given.
引用
收藏
页码:2321 / 2326
页数:6
相关论文
共 16 条
  • [1] AC-IMPEDANCE INVESTIGATIONS OF PROTON CONDUCTION IN NAFION(TM)
    CAHAN, BD
    WAINRIGHT, JS
    [J]. JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1993, 140 (12) : L185 - L186
  • [2] HIGH-PRESSURE NMR AND ELECTRICAL-CONDUCTIVITY STUDIES IN ACID FORM NAFION MEMBRANES
    CHEN, RS
    STALLWORTH, PE
    GREENBAUM, SG
    FONTANELLA, JJ
    WINTERSGILL, MC
    [J]. ELECTROCHIMICA ACTA, 1995, 40 (03) : 309 - 313
  • [3] DIELECTRIC-RELAXATION STUDIES OF ACID-CONTAINING SHORT-SIDE-CHAIN PERFLUOROSULFONATE IONOMER MEMBRANES
    DENG, ZD
    MAURITZ, KA
    [J]. MACROMOLECULES, 1992, 25 (09) : 2369 - 2380
  • [4] ELECTRICAL-IMPEDANCE STUDIES OF ACID FORM NAFION(R) MEMBRANES
    FONTANELLA, JJ
    MCLIN, MG
    WINTERSGILL, MC
    CALAME, JP
    GREENBAUM, SG
    [J]. SOLID STATE IONICS, 1993, 66 (1-2) : 1 - 4
  • [5] EFFECT OF HIGH-PRESSURE ON ELECTRICAL RELAXATION IN POLY (PROPYLENE-OXIDE) AND ELECTRICAL-CONDUCTIVITY IN POLY(PROPYLENE OXIDE) COMPLEXED WITH LITHIUM-SALTS
    FONTANELLA, JJ
    WINTERSGILL, MC
    SMITH, MK
    SEMANCIK, J
    ANDEEN, CG
    [J]. JOURNAL OF APPLIED PHYSICS, 1986, 60 (08) : 2665 - 2671
  • [6] ELECTRICAL RELAXATION IN IN-SITU DRIED ACID-FORM NAFION
    FONTANELLA, JJ
    MCLIN, MG
    WINTERSGILL, MC
    [J]. JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS, 1994, 32 (03) : 501 - 507
  • [7] PROTONIC CONDUCTION AND H-1 SELF-DIFFUSION IN NAFION FILM STUDIED BY AC CONDUCTIVITY AND PULSED FIELD GRADIENT NMR TECHNIQUES
    SLADE, RCT
    BARKER, J
    STRANGE, JH
    [J]. SOLID STATE IONICS, 1989, 35 (1-2) : 11 - 15
  • [8] SORPTION OF CHEMICALS BY PERFLUOROCARBON POLYMERS
    STARKWEATHER, HW
    [J]. MACROMOLECULES, 1977, 10 (05) : 1161 - 1163
  • [9] CONDUCTIVITY OF NAFION MEMBRANES AT LOW-TEMPERATURES
    UOSAKI, K
    OKAZAKI, K
    KITA, H
    [J]. JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1990, 287 (01): : 163 - 169
  • [10] WODSKI R, 1985, J APPL POLYM SCI, V30, P769