ISSN:
1420-8911
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mathematics
Notes:
Abstract Changes of shape of macromolecules produced with chemical agents are translated to a macroscopic scale and used for the transformation of chemical energy into mechanical energy with a three-dimensional network of cross-linked filament molecules. Several high polymer systems are discussed: 1. “Homogeneous pH-muscle≓ reacting with contraction and dilation to pH changes in the embedding-fluid. 2. “Cross-striated pH-muscle≓ with length changes exceeding 100% at constant diameter. 3. “Redox-muscle≓ reacting with length changes to oxidation and reduction processes. 4. “Ca≓- or “Cu-precipitation-muscle≓ reacting with length changes to addition and elimination of Calcium or Copper ions. Investigations of the Donnan-equilibrium between the gel and embedding-fluid show theoretically and experimentally that stretching of the pH-muscle is associated with increased H+-ion activity in the embedding-fluid, and contraction with decreased H+-ion activity in the same fluid; the free chemical energy expended for a chemically-induced stretching of the system is exactly equal to the mechanical energy associated with the contraction. In analogy to the change of the hydrogen ion activity of the embedding liquid when stretching the pH-muscle, a change of the redox-potential is observed when stretching the redox-muscle, and a change of the Cu++-ion activity in the embedding liquid when stretching the Cu++-precipitation muscle. A quantitative transformation of chemical into mechanical energy is always possible if the degree of coiling of the network filaments of a gel can be changed by a chemical reaction; a general property of these gels being the reciprocal phenomenon that a mechanical stretching of the gel will be associated with an increase in the embedding medium of the reactants producing the contraction viz. an activity decrease of the reactants producing the dilation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02283932
