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Markov-type evolution of materials into a polar state.
Journal article

Markov-type evolution of materials into a polar state.

  • Hulliger J Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, (Switzerland). juerg.hulliger@iac.unibe.ch
  • 2002-10-04
Published in:
  • Chemistry (Weinheim an der Bergstrasse, Germany). - 2002
English Assembling polar building blocks into a solid material by a Markov-chain process of unidirectional growth principally results in a metastable state that shows effects of macroscopic polarity. Stochastic polarity formation can be described by probabilities for the attachment of building blocks to a surface. Because of the polar symmetry of the building blocks, there is a fundamental difference in the probabilities for attaching them "tip-first" or "back-first" to growth sites at a surface. A difference in the corresponding probabilities drives the evolution of a vectorial property through a gain in configurational entropy. Examples from the mechanical, the crystalline and the biological world demonstrate growth-induced macroscopic polarity. In crystals, growth upon centrosymmetric seeds can produce twinned crystals with a "sectorwise" pyroelectric effect. Polarity formation in connective tissues is explained by a Markov-chain mechanism, which drives the self-assembly of collagen fibril segments. An unified stochastic growth model brings up a general concept for the formation of materials with polar properties.
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  • English
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https://sonar.ch/global/documents/192127
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