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Old November 23rd 17, 08:07 AM posted to sci.astro
Pentcho Valev
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Default pH-Sensitive Polymers: Obvious Violators of the Second Law of Thermodynamics

A. Katchalsky, POLYELECTROLYTES AND THEIR BIOLOGICAL INTERACTIONS, pp. 13-15: "Let the polymolecule be a negatively charged polyacid in a stretched state and have a length L. Now let us add to the molecule a mineral acid to provide hydrogen ions to combine with the ionized carboxylate groups and transform them into undissociated carboxylic groups according to the reaction RCOO- + H+ = RCOOH. By means of this reaction, the electrostatic repulsion which kept the macromolecule in a highly stretched state vanishes and instead the Brownian motion and intramolecular attraction cause a coiling up of the polymeric chains. Upon coiling, the polymolecule contracts and lifts the attached weight through a distance ΔL. On lifting the weight, mechanical work f*ΔL was performed... [...] FIGURE 4: Polyacid gel in sodium hydroxide solution: expanded. Polyacid gel in acid solution: contracted; weight is lifted." http://www.ncbi.nlm.nih.gov/pmc/arti...00645-0017.pdf

Mineral acid (hydrogen ions, H+) is added to the system and "the polymolecule contracts and lifts the attached weight through a distance ΔL". Then added H+ can be removed and the macromolecule resumes its initial stretched state, ready to lift another weight. The net work involved in adding and removing hydrogen ions, if the process is carried out quasi-statically, is virtually zero, while the net work extracted from contracting and stretching is obviously positive. The system is cyclically lifting weights at the expense of heat absorbed from the surroundings, in violation of the second law of thermodynamics.

Pentcho Valev