View Single Post
  #2  
Old June 21st 13, 05:44 PM posted to sci.astro
Pentcho Valev
external usenet poster
 
Posts: 8,078
Default GETTING RID OF THE SECOND LAW OF THERMODYNAMICS

https://data.epo.org/publication-ser...9&iepatch=.pdf
Dan Urry (pp. 14-15): "When the pH is lowered (that is, on raising the chemical potential, mu, of the protons present) at the isothermal condition of 37°C, these matrices can exert forces, f, sufficient to lift weights that are a thousand times their dry weight."

http://pubs.acs.org/doi/abs/10.1021/jp972167t
J. Phys. Chem. B, 1997, 101 (51), pp 11007-11028, Dan W. Urry, Physical Chemistry of Biological Free Energy Transduction As Demonstrated by Elastic Protein-Based Polymers, p. 11025, fig. 16A

Lowering the pH (increasing the concentration of the hydrogen ion, H+) in the polymer-containing system can be achieved by transferring H+ to the system from another system. Note that one GAINS work as one transfers H+ to the polymer-containing system from a reservoir at higher H+ concentration, but then LOSES work as one moves the same amount of H+ back to the reservoir. If both transfers are performed isothermally and reversibly, the net work involved in these two steps (steps 1 and 3) is zero.

The polymer-containing system and the H+ reservoir can be regarded as the half-cells of a concentration cell - the following reference can be useful:

http://fds.oup.com/www.oup.com/pdf/1...6_chapter1.pdf
Oxford University Press 2010. Peter Atkins and Julio de Paula: Physical Chemistry for the Life Sciences 2e : Thermodynamics of ion and electron transport

A rigorous analysis would show that the net work extracted from steps 1 and 3 is not exactly zero. For the polymers considered by Katchalsky (see reference in my previous posting) it is negative (we LOSE work in steps 1 and 3) but for polymers considered by Urry it is positive (we GAIN work from steps 1 and 3).

Pentcho Valev