Material properties (thermodynamics)


Material properties (thermodynamics)

The thermodynamic properties of materials are intensive thermodynamic parameters which are specific to a given material. Each is directly related to a second order differential of a thermodynamic potential. Examples for a simple 1-component system are:

  • Isothermal compressibility
\beta_T=-\frac{1}{V}\left(\frac{\partial V}{\partial P}\right)_T
\quad = -\frac{1}{V}\,\frac{\partial^2 G}{\partial P^2}
  • Adiabatic compressibility
\beta_S=-\frac{1}{V}\left(\frac{\partial V}{\partial P}\right)_S
\quad = -\frac{1}{V}\,\frac{\partial^2 H}{\partial P^2}
  • Specific heat (Note - the extensive analog is the heat capacity)
  • Specific heat at constant pressure
c_P=\frac{T}{N}\left(\frac{\partial S}{\partial T}\right)_P
\quad = -\frac{T}{N}\,\frac{\partial^2 G}{\partial T^2}
  • Specific heat at constant volume
c_V=\frac{T}{N}\left(\frac{\partial S}{\partial T}\right)_V
\quad = -\frac{T}{N}\,\frac{\partial^2 A}{\partial T^2}
\alpha=\frac{1}{V}\left(\frac{\partial V}{\partial T}\right)_P
\quad = \frac{1}{V}\,\frac{\partial^2 G}{\partial P\partial T}

where P  is pressure, V  is volume, T  is temperature, S  is entropy, and N  is the number of particles.

For a single component system, only three second derivatives are needed in order to derive all others, and so only three material properties are needed to derive all others. For a single component system, the "standard" three parameters are the isothermal compressibility βT, the specific heat at constant pressure cP, and the coefficient of thermal expansion α.

For example, the following equations are true:

c_P=c_V+\frac{TV\alpha^2}{N\beta_T}
\beta_T=\beta_S+\frac{TV\alpha^2}{Nc_P}

The three "standard" properties are in fact the three possible second derivatives of the Gibbs free energy with respect to temperature and pressure.

Sources

The Dortmund Data Bank is a factual data bank for thermodynamic and thermophysical data.

See thermodynamic databases for pure substances.

References

Callen, Herbert B. (1985). Thermodynamics and an Introduction to Thermostatistics (2nd Ed. ed.). New York: John Wiley & Sons. ISBN 0-471-86256-8. 



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Thermodynamics — Annotated color version of the original 1824 Carnot heat engine showing the hot body (boiler), working body (system, steam), and cold body (water), the letters labeled according to the stopping points in Carnot cycle …   Wikipedia

  • thermodynamics — thermodynamicist, n. /therr moh duy nam iks/, n. (used with a sing. v.) the science concerned with the relations between heat and mechanical energy or work, and the conversion of one into the other: modern thermodynamics deals with the properties …   Universalium

  • Properties and features of black holes — According to the No Hair theorem a black hole has only three independent physical properties: mass, charge and angular momentum. [citation|last=Heusler |first=M. |year=1998 |title=Stationary Black Holes: Uniqueness and Beyond |journal=Living Rev …   Wikipedia

  • Non-equilibrium thermodynamics — Thermodynamics …   Wikipedia

  • Endoreversible thermodynamics — Thermodynamics …   Wikipedia

  • Third law of thermodynamics — Thermodynamics …   Wikipedia

  • Conjugate variables (thermodynamics) — For a more general mathematical discussion, see Conjugate variables. Thermodynamics …   Wikipedia

  • Failure theory (material) — v · d · e Materials failure modes Buckling · Corro …   Wikipedia

  • Critical point (thermodynamics) — Carbon dioxide creating a fog when cooling from supercritical to critical temperature In physical chemistry, thermodynamics, chemistry and condensed matter physics, a critical point, also called a critical state, specifies the conditions… …   Wikipedia

  • Second law of thermodynamics — The second law of thermodynamics is an expression of the universal law of increasing entropy, stating that the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.