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Stochastische Polaritätserzeugung in Kristallen und natürlichem Gewebe

English title Stochastic Polarity Generation in Crystals and Natural Tissues
Applicant Hulliger Jürg
Number 129472
Funding scheme Project funding (Div. I-III)
Research institution Departement für Chemie und Biochemie Universität Bern
Institution of higher education University of Berne - BE
Main discipline Condensed Matter Physics
Start/End 01.04.2010 - 31.03.2013
Approved amount 490'712.00
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All Disciplines (2)

Discipline
Condensed Matter Physics
Physical Chemistry

Keywords (7)

stochastic; tissue; molecular crystals; polarity; bi-polar state; scanning pyroelectric microscopy; phase sensitive second harmonic microscopy

Lay Summary (English)

Lead
Research within this project has led to fundamental knowledge on the real structure of polar molecular crystals, investigated by modern physical technique and numerical simulation. In essence, molecular crystal made of polar constituents should develop into a bi-polar state.
Lay summary
This project attempts to investigate stochastic polarity formation where ever it appears in nature, along with basic theoretical modeling and application of advanced experimental techniques for investigation. In practice this will cover the growth of molecular crystals, the preparation of natural tissue and their analysis by scanning pyroelectric and phase sensitive second harmonic microscopy. In theory, statistical mechanics and Monte Carlo simulations will be applied to a phenomenon called "switching", i.e. the reversal of dipoles along the growth of polar crystals.
Direct link to Lay Summary Last update: 08.05.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Molecular Origin of Piezo- and Pyroelectric Properties in Collagen Investigated by Molecular Dynamics Simulations
Hulliger Jürg, Ravi H. K., Simona F., Cascella M. (2012), Molecular Origin of Piezo- and Pyroelectric Properties in Collagen Investigated by Molecular Dynamics Simulations, in J. Phys. Chem., B2012(116), 1901-1907.
Observation of Permanent Polarization Distributions in Bioorganic Materials Using a Highly Sensitive Scanning Pyroelectric Microscope
Hulliger Jürg, Wübbenhorst M., Putzeys T., Burgener Matthias (2011), Observation of Permanent Polarization Distributions in Bioorganic Materials Using a Highly Sensitive Scanning Pyroelectric Microscope, in IEEE, 14th International Symposium on Electrets (ISE), 2011, 187-188.
One-hundered eighty degree domain detection by surface phase sensitive second harmonic generation microscopy of polar materials
Aboufadl Hanane, Hulliger Jürg (2011), One-hundered eighty degree domain detection by surface phase sensitive second harmonic generation microscopy of polar materials, in Cryst Growth Des., 11(2011), 3045-3048.
Aligment of PHTP-DNAA inclusion crystals by zone casting
Makowski T, Berger Ricarda, Aboulfadl Hanane, Hulliger Jürg, Tracz A (2011), Aligment of PHTP-DNAA inclusion crystals by zone casting, in Optical Mater, 33(2011), 1464-1468.
A stochastic principle behind polar properties of condensed molecular matter
Hulliger Jürg, Wüst Thomas, Brahimi Khadidja, Burgener Matthias, Aboulfadl Hanane, A stochastic principle behind polar properties of condensed molecular matter, in New J. Chem..
Can mono domain polar molecular crystals exist?
Hulliger Jürg, Wüst Thomas, Brahimi Khadija, Martinez Garcia Julio Cesar, Can mono domain polar molecular crystals exist?, in Cryst. Growth Des. , 2012.
Polar alignment of dye molecules in sectors of host lattices reveled by phase sensitive second harmonic generation and scanning pyroelectric microscopy
Hulliger Jürg, Aboulfadl H., Burgener Matthias, Benedict J., Kahr B, Polar alignment of dye molecules in sectors of host lattices reveled by phase sensitive second harmonic generation and scanning pyroelectric microscopy, in CrystEngComm, 2012(14), 4391-4395.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
IEEE International Symposium on Electrets 20.06.2011 Montpellier


Self-organised

Title Date Place
E. Crystallographic Meeting 2011, Madrid, organization of a microsymposium 20.06.2011 Madrid

Associated projects

Number Title Start Funding scheme
146413 Stochastische Polaritätserzeugung in Kristallen und natürlichem Gewebe 01.04.2013 Project funding (Div. I-III)
140309 Fundamentale Wachstumsinstabilität für Kristalle welche einer uniaxialen polaren Punktgruppe angehören 01.04.2012 Project funding (Div. I-III)
146413 Stochastische Polaritätserzeugung in Kristallen und natürlichem Gewebe 01.04.2013 Project funding (Div. I-III)

Abstract

Polar symmetry of real objects, molecules and crystals is a fundamental property for establishing complex functions. In the world of crystals, there are two essentially different ways to generate a polar structure : (i)by nucleation and replication, or (ii)by a Markov-type process involving polarity by growth - irrespective of the symmetry created by nucleation.This completely new concept (ii) for developing / understanding materials by a Markov chain mechanism was independently discovered by Harris et al. and Hulliger et al. in 1997. Since then the group in Berne has elaborated basic theoretical and experimental means to investigate this phenomenon covering all kind of materials: macroscopic heap formation, crystals of low molecular weight and long chain proteins forming tissues. In 2003, the applicant presented a first theoretical model explaining experimentally known pyroelectric effects in collagenous tissues. Nowadays, new scanning probe techniques reveal more and more of the fine structure of growth induced polarity in tissues.In view of basic features associated with stochastic polarity formation being elaborated in detail, there are still basic issues which merit full understanding and experimental demonstration.The present proposal will thus focus on the following main issues :1) Stochastic theory predicts for natively polar molecular crystals a fundamental process of dipole inversion along only one of the directions of the unique axis. Here, a full theoretical elaboration of the phenomenon along with experimental confirmation by crystallization is attempted. This would establish a general mechanism expressed for a polar space group of dipolar compounds.2) Monte Carlo simulations and analytical theory have shown that forming solid solutions is an approach yielding polar materials by high probability. Here, specific molecular examples will be investigated to confirm basic features of polar solid solutions. Examples are e.g. mixtures of natively non polar crystals of dipolar components which by solid solution formation become polar.3) The number of investigated single component crystals featuring grown-in polarity is still small, although preliminary tests on most materials have revealed such an effect. Here, prime examples for further studies are to be found.4) Phase sensitive second harmonic generation will be applied to thin cuts of tissues to establish maps of bi-polarity distributions at micrometer resolution. Theoretical and experimental work will attempt to determine the absolute sign of tissue polarity, this to verify / disproof theoretical predictions made by the applicant (2003). Polarity maps may serve as diagnostic tool and knowledge on tissue polarity is a base to understand regenerative healing of tissues by treatment with ultra sound.In essence, this proposal attempts to investigate polarity formation where ever it appears in nature, along with basic theoretical modeling and application of advanced experimental techniques for investigation.
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