Dynamics of water in molecular sieves by dielectric spectroscopy

被引:79
作者
Jansson, H [1 ]
Swenson, J [1 ]
机构
[1] Chalmers Univ Technol, Dept Appl Phys, S-41296 Gothenburg, Sweden
关键词
D O I
10.1140/epjed/e2003-01-013-5
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We present recent dielectric data on the dynamics of water confined in molecular sieves with pore sizes 5 and 10 Angstrom. The dielectric measurements in the frequency and temperature ranges 10(-2)-10(6) Hz and 120-300 K show three relaxation processes for both samples. In the case of the 10 Angstrom pore the slowest process shows an Arrhenius temperature dependence at low temperatures (<220 K), while at high temperatures the relaxation appears to follow a more Vogel-Fulcher-Tammann (VFT) like behaviour. The relaxation time for this process is 100 s at about 170 K. The second slowest process is at low temperatures very similar to the main process of (bulk-like) water in a fully hydrated clay, but also this process seems to exhibit some kind of dynamical transition, in this case at Tapproximate to 185 K. All the three processes in the 5 Angstrom pore exhibit Arrhenius temperature dependence, and two of them are considerably slower than the main relaxation in the hydrated clay. Thus, dynamics of bulk-like water is only observed in the 10 Angstrom molecular sieves, and most of the water molecules in both 5 and 10 Angstrom pores have considerably slower dielectric relaxation than has been observed for water confined in clay, most likely due to strong interactions with the considerably more hydrophilic inner surfaces of molecular sieves.
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页码:S51 / S54
页数:4
相关论文
共 24 条
[1]   FORMATION OF GLASSES FROM LIQUIDS AND BIOPOLYMERS [J].
ANGELL, CA .
SCIENCE, 1995, 267 (5206) :1924-1935
[2]  
ANGELL CA, 1991, J NONCRYST SOLIDS, V13, P131
[3]   Dynamics of supercooled water in confined geometry [J].
Bergman, R ;
Swenson, J .
NATURE, 2000, 403 (6767) :283-286
[4]   Dielectric study of supercooled 2D water in a vermiculite clay [J].
Bergman, R ;
Swenson, J ;
Börjesson, L ;
Jacobsson, P .
JOURNAL OF CHEMICAL PHYSICS, 2000, 113 (01) :357-363
[5]   Water confined in Vycor glass. I. A neutron diffraction study [J].
Bruni, F ;
Ricci, MA ;
Soper, AK .
JOURNAL OF CHEMICAL PHYSICS, 1998, 109 (04) :1478-1485
[6]   Dispersion and absorption in dielectrics I. Alternating current characteristics [J].
Cole, KS ;
Cole, RH .
JOURNAL OF CHEMICAL PHYSICS, 1941, 9 (04) :341-351
[7]  
Crupi V, 2000, J PHYS CHEM A, V104, P11000, DOI [10.1021/jp001736l, 10.1021/jp0017361]
[8]   Confinement influence in liquid water studied by Raman and neutron scattering [J].
Crupi, V ;
Magazù, S ;
Majolino, D ;
Migliardo, P ;
Venuti, V ;
Bellissent-Funel, MC .
JOURNAL OF PHYSICS-CONDENSED MATTER, 2000, 12 (15) :3625-3630
[9]   Unusual relaxation behavior of water inside the sodalite cages of Faujasite-type molecular sieves [J].
Frunza, L ;
Kosslick, H ;
Frunza, S ;
Schönhals, A .
JOURNAL OF PHYSICAL CHEMISTRY B, 2002, 106 (36) :9191-9194
[10]   Supercooled confined water and the mode coupling crossover temperature [J].
Gallo, P ;
Rovere, M ;
Spohr, E .
PHYSICAL REVIEW LETTERS, 2000, 85 (20) :4317-4320