Nanoscale Thermodynamics
John Enriquez
Chem. 5369 (Molecular Electronics)
Professor: Dr. Elizabeth Gardner
UT-El Paso (Fall 2006)
Brief Overview

What is nano-thermodynamics and where did it
begin?

Who is the first person to research this topic?

How is it being used today?

Physical data and thermodynamic properties
regarding selected compounds found in many
nanoHUB presentations.
Compounds Found in Molecular
Electronic Articles
 While
viewing selected presentations on
the nanoHUB website, the same organic
compounds are used in almost every SAM
procedure. Also, one metallic solid is
used.
 They
are: Dodecanethiol, Ethanol,
Tetrahydrofuran (THF), Ammonium
Hydroxide, and Gold.
What is Nano-Thermodynamics?

First, thermodynamics is the investigation of
changes in energy coming from a physical or
chemical reaction.
Gibbs Free Energy
G = H – T(S)

The thermodynamic variables of enthalpy (H),
entropy (S), and free energy (G) are used in
the Gibbs free energy equation.
What is Nanothermodynamics?

Nano-thermodynamics studies these same changes.

The two differences are chemical potential and an
ensemble term.
G = H – T(S) + [Σ(μ·dn)] + (E·dN)
Nanothermodynamics connects
nanosystems to macroscale
thermodynamics
What is Nano-thermodynamics?

The chemical potential term, [Σ(μ·dn)] was
added by Gibbs in 1961


The symbols μ is the chemical potential and n is the
amount in moles.
Hill included the nano-thermodynamics term
which is added at the ensemble level of the
system, [E·dN].

The variable E is similar to a system’s chemical
potential. The variable N is the number of individual
systems in that one solution component.
• An ensemble of N equivalent and noninteracting small
systems is itself a macroscopic system.
What is Nano-thermodynamics?

Usefull in analyzing both experimental and
theoretical equilibrium properties of
nanosystems


Ex. Mean field cluster model of ferromagnetism (ref.6)
For a thorough treatment of the theory and
derivations of the equation, see reference 4.
When did this idea begin?

The idea and the study of small systems at equilibrium
can be traced back to Terrell L. Hill.

From 1961 to 1963, Hill researched these small systems
in great detail.

Without being aware of it, he was researching ways to
connect macro-thermodynamic systems to nanothermodynamic systems.

He published his results in 1962 and 1963, but little
attention was given to it since it was based on theoretical
and statistical models. Nanoscience was not yet
discovered.
New attention for an old topic?

In recent years, research in nanoscience has
caught up with Hill’s theoretical work.

In 2000, R.V. Chamberlin, who was investigating
ferromagnetism, was one of the first scientist to
use nanothermodynamic theory to explain his
findings.

Hill reexamined nanothermodynamics as a
useful tool for nano-systems at equilibrium.
Nanothermodynamics Today
 Professor
Hill’s theories have been
published in “Thermodynamics of Small
Systems.” (Ref. 8)
 R.
Chamberlin was instrumental in reviving
interest in small system thermodynamics.
 In
2005, A link was established between
Hill’s nanothermodynamics and Tsallis
(nonextensive) thermodynamics. (Ref. 10)
Nanothermodynamics Today
 Since
this area is still new, few articles
about this subject are available.
 Nanothermodynamics
has the potential to
be an important contributor to nanoscience
and technology
Physical Data & Thermodynamic Properties of
Common Compounds Used in Nanoscience

Dodecanethiol (C12H26S)

Ethanol (CH3-CH2-OH)

M.W.: 202.4 g/mol

M.W.: 46.07 g/mol

M.P.: unknown

M.P.: -114.1 °C at 760 mmHg

B.P.: 143.5 °C at 15 mmHg

B.P.: 78.2 °C at 760 mmHg

Density: 0.8435 g/cm3 at 20 °C

Density: 0.7893 g/cm3 at 20 °C

Solubility: Soluble in ethanol,
ethyl ether and chloroform.
Insoluble in water.

Solubility: Miscible in water,
ethanol, ethyl ether and
acetone.

Enthalpy (H) = -253.3 kJ/mol

Enthalpy (H) = -277.6 kJ/mol

Entropy (S) = 689.9 J/mol·K

Entropy (S) = 160.7 J/mol·K

Gibbs (G) = 78.01 kJ/mol

Gibbs (G) = -174.8 kJ/mol
Physical Data & Thermodynamic Properties, Cont.

Tetrahydrofuran (THF): C4H8O

Ammonium Hydroxide: NH4OH

M.W.: 72.11 g/mol

M.W.: 35.05 g/mol

M.P.: -108.3 °C at 760 mmHg

M.P.: -77 °C

B.P.: 65 °C at 760 mmHg

B.P.: 36 °C

Density: 0.8892 g/cm3at 20 °C

Density: Approx. 0.9 g/mL

Solubility: Soluble in water.
Very soluble in ethanol, ethyl
ether and acetone.

Solution Conc.: 14.8 mol/L

Enthalpy (H) = -216.2 kJ/mol

Entropy (S) = 204.3 J/mol·K

Gibbs (G) =
Physical Data & Thermodynamic Properties, Cont.









Gold (Element Symbol: Au)
Atomic Number: 79
M.W.: 196.96 g/mol
M.P.: 1064.18 °C
B.P.: 2856 °C
Specific Gravity: 19.3 at 20 °C
Solubility: Aqua Regia
H (Fusion): 12.7 kJ/mol
H (Vaporization): 343.1kJ/mol



Reference:
CRC Handbook of Chemistry
& Physics, 2001-2002
Helgeson, H.C.; Owen, C.E.;
Knox, A.M.; Richard, L.
Geochim. Cosmochim. Acta,
1998, 62, 6, 985
References

1. CRC Handbook of Chemistry & Physics, 2001-2002

2. Helgeson, H.C.; Owen, C.E.; Knox, A.M.; Richard, L. Geochim. Cosmochim.
Acta, 1998, 62, 6, 985

3. Hill, T.L. J. Chem. Phys. 1962, 36, 3182

4. Hill, T.L. Nano Letters, 2001, 1, 273

5. Hill, T.L. Nano Letters, 2001, 1, 111

6. Hill, T.L. Nano Letters, 2001, 1, 159

7. Hill, T.L.; Chamberlin, R.V. Proc. Natl. Acad. Sci. U.S.A. 1998, 95,
12779

8. Hill, T.L. Thermodynamics of Small Systems; Dover: New York, 1994

9. Chamberlin, R.V. Nature 2000, 408, 337

10. Garcia-Morales, V., Cervera, J., & Pellicer, J. Physics Letter A,
2005, 336, 82
Acknowledgements
 Dr.
Elizabeth Gardner
 Dr.
Michael I. Davis
 My
fellow classmates in Dr. Gardner’s
Molecular Electronics course at UTEP, UTEl Paso.