The specific heat of a liquid varies as its structure and molecular vibrational frequencies vary with the temperature. We report the magnitude of the structural or configurational part for five molecular liquids by measuring their dynamic and the apparent specific heats, and find that the unrelaxed or vibrational specific heat, of the equilibrium liquid, is not greatly different from that of the nonequilibrium glass. Therefore, the vibrational part of the specific heat does not change substantially when a glass becomes an ultraviscous liquid. This contradicts the inference that there is a large sigmoid-shape (discontinuous) increase in as the structure of a glass kinetically unfreezes on heating above its , and further that is 20%–50% of the net change at the glass transition.
REFERENCES
1.
J. D.
Bernal
, Trans. Faraday Soc.
33
, 37
(1937
).2.
G.
Adam
and J. H.
Gibbs
, J. Chem. Phys.
43
, 139
(1965
).3.
See, for detailed discussion,
E.
Donth
, The Glass Transition, Relaxation Dynamics in Liquids and Disordered Materials
(Springer
, Berlin
, 2001
).4.
C. T.
Moynihan
, P. B.
Macedo
, C. J.
Montrose
et al., Ann. N.Y. Acad. Sci.
279
, 15
(1976
).5.
I. M.
Hodge
, J. Non-Cryst. Solids
169
, 211
(1994
).6.
7.
8.
G. P.
Johari
, J. Chem. Phys.
116
, 2043
(2002
).9.
M.
Goldstein
, Phys. Rev. B
71
, 136201
(2005
).10.
A.
Zürcher
and T.
Keyes
, Phys. Rev. E
55
, 6917
(1997
).11.
G.
Diezemann
, U.
Mohanty
, and I.
Oppenheim
, Phys. Rev. E
59
, 2067
(1999
).12.
U.
Buchenau
, Phys. Rev. B
63
, 104203
(2001
);U.
Buchenau
,J. Phys.: Condens. Matter
15
, S995
(2003
).13.
14.
M.
Goldstein
, J. Chem. Phys.
51
, 3728
(1969
).15.
P. G.
Debenedetti
and F. H.
Stillinger
, Nature (London)
410
, 259
(2001
).16.
17.
F.
Sciortino
, J. Stat. Mech.: Theory Exp.
2005
, 050515
.18.
A technique in which a single frequency was used was developed independently by Christensen. See
T.
Christensen
, J. Phys. (Paris), Colloq.
46
, C8
–635
(1985
).19.
N. O.
Birge
, Phys. Rev. B
34
, 1631
(1986
).20.
I.-K.
Moon
and Y.-H.
Jeong
, Phys. Rev. B
52
, 6381
(1995
).See also,
I.-K.
Moon
and Y.-H.
Jeong
,Pure Appl. Chem.
69
, 2321
(1997
).21.
N.
Menon
, J. Chem. Phys.
105
, 5246
(1996
).22.
C. A.
Angell
, L. M.
Wang
, S.
Mossa
, Y.
Yue
, and J. R. D.
Copley
, in Slow Dynamics in Complex Systems
, Third International Symposium
, edited by M.
Tokuyama
and I.
Oppenheim
[AIP Conf. Proc.
708
, 473
(2004
)]. The ratio has been occasionally confused with , by using in place of , where is either taken as the difference between the supercooled liquid’s and extrapolated or taken as the difference between the liquid’s and measured of the crystal state.23.
G. P.
Johari
, J. Chem. Phys.
126
, 114901
(2007
).24.
L.-M.
Wang
and R.
Richert
, Phys. Rev. Lett.
99
, 185701
(2007
).25.
Acetaminophen [-(4-hydroxyphenyl)acetamide, mol wt. 151.17] is an analgesic and antipyretic drug, griseofulvin [-7-chloro--trimethoxy--methyl-, -spiro[1-benzofuran--cyclohex[2]ene]--dione; mol wt. 352.77], an antifungal drug, and nifedipine (dimethyl 2,6-dimethyl-4-(2-nitrophenyl)- 1,4-dihydropyridine-3,5-dicarboxylate; mol wt. 346.34), an angina pectoris, and hypertension drug. The pharmaceutical value of these substances is incidental to our purpose here.
26.
A.
Boller
, C.
Schick
, and B.
Wunderlich
, Thermochim. Acta
266
, 97
(1995
)..See also papers in Special issues on Calorimetry in
A.
Boller
, C.
Schick
, and B.
Wunderlich
, Thermochim. Acta
304–305
, (1997
)27.
J. E. K.
Schawe
, Thermochim. Acta
361
, 97
(2000
).28.
A.
Toda
, T.
Arita
, and M.
Hikosaka
, J. Therm Anal. Calorim.
60
, 821
(2000
).29.
S.
Weyer
, M.
Merzlyakov
, and C.
Shick
, Thermochim. Acta
377
, 85
(2001
).30.
S. L.
Simon
, Thermochim. Acta
374
, 55
(2001
).31.
S.
Weyer
, H.
Huth
, and C.
Schick
, Polymer
46
, 12240
(2005
).32.
G.
Salvetti
, C.
Cardelli
, C.
Ferrari
, and E.
Tombari
, Thermochim. Acta
364
, 11
(2000
).33.
G.
Salvetti
, E.
Tombari
, L.
Mikheeva
, and G. P.
Johari
, J. Phys. Chem. B
106
, 6081
(2002
).34.
E.
Tombari
, C.
Ferrari
, G.
Salvetti
, and G. P.
Johari
, J. Chem. Phys.
126
, 021107
(2007
).35.
E.
Tombari
, S.
Presto
, G. P.
Johari
, and R. M.
Shanker
, J. Pharm. Sci.
95
, 1006
(2006
).36.
E.
Tombari
, G.
Salvetti
, C.
Ferrari
, and G. P.
Johari
, J. Phys. Chem. B
111
, 496
(2007
).37.
E.
Tombari
, C.
Ferrari
, G.
Salvetti
, and G. P.
Johari
, J. Chem. Phys.
126
, 024903
(2007
).38.
T.
Christensen
, N. B.
Olsen
, and J. C.
Dyre
, Phys. Rev. E
75
, 041502
(2007
).39.
T.
Christensen
and J. C.
Dyre
, “Solution of the spherically symmetric linear thermoviscoelastic problem in the inertia free limit
,” Phys. Rev. E
(in press).Also arXiv: cond-mat/0801.4202v1..
40.
S.
Takahara
, O.
Yamamuro
, and H.
Suga
, J. Non-Cryst. Solids
171
, 259
(1994
).41.
H.
Leyser
, A.
Schulte
, W.
Doster
, and W.
Petry
, Phys. Rev. E
51
, 5899
(1995
).42.
E.
Tombari
, C.
Ziparo
, G.
Salvetti
, and G. P.
Johari
, J. Chem. Phys.
127
, 014905
(2007
).43.
M.
Pyda
and B.
Wunderlich
, Macromolecules
38
, 10472
(2005
).44.
M.
Pyda
, Macromolecules
35
, 4009
(2002
).45.
M.
Pyda
, J. Polym. Sci., Part B: Polym. Phys.
39
, 3038
(2001
).46.
47.
E.
Tombari
, C.
Ferrari
, G.
Salvetti
, and G. P.
Johari
, Phys. Rev. B
77
, 024304
(2008
).48.
M.
Goldstein
, J. Chem. Phys.
64
, 4767
(1976
).49.
G. P.
Johari
, Philos. Mag. B
41
, 41
(1980
).50.
G. P.
Johari
, J. Chem. Phys.
112
, 7518
(2000
), see Eq. (7).51.
J. G.
Shim
and G. P.
Johari
, Philos. Mag. B
79
, 5654
(1999
).52.
53.
L.-M.
Martinez
and C. A.
Angell
, Nature (London)
410
, 663
(2001
).54.
55.
W. A.
Phillips
, U.
Buchenau
, N.
Nucker
, A.-J.
Dianoux
, and W.
Petry
, Phys. Rev. Lett.
63
, 2381
(1989
).56.
G. P.
Johari
, Philos. Mag.
35
, 1077
(1977
).57.
C. K.
Majumdar
, Solid State Commun.
9
, 1087
(1971
).58.
A.
Sillescu
, J. Non-Cryst. Solids
243
, 81
(1999
).59.
G. P.
Johari
and M.
Goldstein
, J. Chem. Phys.
53
, 2372
(1970
).60.
G. P.
Johari
, J. Chem. Phys.
58
, 1766
(1973
).61.
62.
K. L.
Ngai
and M.
Paluch
, J. Chem. Phys.
120
, 857
(2004
).63.
K.
Kishimoto
, H.
Suga
, and S.
Seki
, Bull. Chem. Soc. Jpn.
46
, 3020
(1973
).64.
H.
Fujimori
and M.
Oguni
, J. Chem. Thermodyn.
26
, 367
(1994
).65.
H.
Fujimori
, M.
Muzikami
, and M.
Oguni
, J. Non-Cryst. Solids
204
, 38
(1996
).66.
J.
Haddad
and M.
Goldstein
, J. Non-Cryst. Solids
30
, 1
(1978
).67.
G. P.
Johari
, J. Chem. Phys.
77
, 4619
(1982
).68.
H.
Wagner
and R.
Richert
, J. Phys. Chem.
103
, 4071
(1999
).69.
E.
Tombari
, C.
Ferrari
, G. P.
Johari
, and R. M.
Shanker
, “Calorimetric relaxation in molecular pharmaceutical glasses and its utility in understanding their stability against crystallization
,” J. Phys. Chem. B
(in press).© 2008 American Institute of Physics.
2008
American Institute of Physics
You do not currently have access to this content.
