Alexander G. Petrov
Encyclopedia
Alexander Georgiev Petrov is a Bulgarian professor of physics. He is a member of the Bulgarian Academy of Sciences
.
physics (liquid crystals, Biophysics
, biomolecular electronics
and nanophysics).
He works in the Institute of Solid State Physics
at the Bulgarian Academy of Sciences, where the laboratory of liquid crystals has created in the beginning. Soft matter physics as a scientific subject in the area of condensed matter physics
investigates thermotropic
and lyotropic
liquid crystals, biological liquid crystal structures as a membranes.
optoelectronics
.
In the living matter
physics
he created new theoretical model for description of the elasticity
and flexoelectricity
of biological membranes from the common molecular asymmetry point of view.
He found out gradient flexoelectric effect
in nematic liquid crystals under the action of the not homogeneous electric field (1971 - 1974); flexoelectric oscillations in nematic liquid crystals (1975 - 1979); right flexoeffect of the biological membrane
with ion
channels (1988 - 1993); feroelectricity in lyotropic
chiral lipid
phases (aquatic
and non aquatic) (1988 - 1989); reverse flexoeffect bilayer of lipid
membranes (1993); photoflexoeffect of photo-active membranes (1992 - 1994).
He has magister degree on atomic physics
from the Sofia University
(1970) and Ph.D. on liquid crystals from the Institute of Solid State Physics
(1974).
He has scientific doctoral degree (D. Sc.) since 1987 and became a member of Bulgarian Academy of Sciences since 2003.
Bulgarian Academy of Sciences
The Bulgarian Academy of Sciences is the National Academy of Bulgaria, established in 1869. The Academy is autonomous and has a Society of Academicians, Correspondent Members and Foreign Members...
.
Area
The main area of his research is soft matterSoft matter
Soft matter is a subfield of condensed matter comprising a variety of physical states that are easily deformed by thermal stresses or thermal fluctuations. They include liquids, colloids, polymers, foams, gels, granular materials, and a number of biological materials...
physics (liquid crystals, Biophysics
Biophysics
Biophysics is an interdisciplinary science that uses the methods of physical science to study biological systems. Studies included under the branches of biophysics span all levels of biological organization, from the molecular scale to whole organisms and ecosystems...
, biomolecular electronics
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
and nanophysics).
He works in the Institute of Solid State Physics
Institute of Solid State Physics
Institute of Solid State Physics is one of the physical institutes at the Bulgarian Academy of Sciences. Created by Decree No 362 in October 16, 1972 by the Ministry Council of Bulgaria it is successor of the Institute of Physics with Atomic Scientific Experimental Center at the Bulgarian Academy...
at the Bulgarian Academy of Sciences, where the laboratory of liquid crystals has created in the beginning. Soft matter physics as a scientific subject in the area of condensed matter physics
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
investigates thermotropic
Thermotropic
A liquid crystal is thermotropic if the order of its components is determined or changed by temperature.If temperature is too high, the rise in energy and therefore in motion of the components will induce a phase change: the LC will become an isotropic liquid.If, on the contrary, temperature is...
and lyotropic
Lyotropic
A material is called lyotropic if it forms liquid crystal phases because of the addition of a solvent. Historically the term was used to describe materials composed of amphiphilic molecules. Such molecules comprise a water-loving 'hydrophilic' head-group attached to a water-hating 'hydrophobic'...
liquid crystals, biological liquid crystal structures as a membranes.
Research
Petrov has investigated experimentally dielectic, elastic, flexoelectric and surface properties of nematic liquid crystals with diferent type of molecular asymmetry. This achievement has applications in liquidLiquid
Liquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
optoelectronics
Optoelectronics
Optoelectronics is the study and application of electronic devices that source, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light...
.
In the living matter
Matter
Matter is a general term for the substance of which all physical objects consist. Typically, matter includes atoms and other particles which have mass. A common way of defining matter is as anything that has mass and occupies volume...
physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
he created new theoretical model for description of the elasticity
Elasticity
Elasticity may refer to:*Elasticity , continuum mechanics of bodies that deform reversibly under stressNumerous uses are derived from this physical sense of the term, which is inherently mathematical, such as used in Engineering, Chemistry, Construction and variously in Economics:*Elasticity , the...
and flexoelectricity
Flexoelectricity
Flexoelectricity is a property of a dielectric material whereby it exhibits a spontaneous electrical polarization induced by a strain gradient. Flexoelectricity is not the same as Ferroelasticity....
of biological membranes from the common molecular asymmetry point of view.
He found out gradient flexoelectric effect
Effect
Effect may refer to:* A result or change of something** List of effects** Cause and effect, an idiom describing causalityIn pharmacy and pharmacology:* Drug effect, a change resulting from the administration of a drug...
in nematic liquid crystals under the action of the not homogeneous electric field (1971 - 1974); flexoelectric oscillations in nematic liquid crystals (1975 - 1979); right flexoeffect of the biological membrane
Membrane
-In biology:* Biological membrane* Cell membrane, a biological type of Membrane ** Inner membrane** Outer membrane * The two fetal membranes** amnion** chorion* Basement membrane* Mucous membrane* Serous membrane...
with ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
channels (1988 - 1993); feroelectricity in lyotropic
Lyotropic
A material is called lyotropic if it forms liquid crystal phases because of the addition of a solvent. Historically the term was used to describe materials composed of amphiphilic molecules. Such molecules comprise a water-loving 'hydrophilic' head-group attached to a water-hating 'hydrophobic'...
chiral lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
phases (aquatic
Aquatic
Aquatic means relating to water; living in or near water or taking place in waterAquatic may also refer to:* Aquatic animal, either vertebrate or invertebrate, which lives in water for most or all of its life...
and non aquatic) (1988 - 1989); reverse flexoeffect bilayer of lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
membranes (1993); photoflexoeffect of photo-active membranes (1992 - 1994).
Professional experience
- Director of the Institute of Solid State PhysicsInstitute of Solid State PhysicsInstitute of Solid State Physics is one of the physical institutes at the Bulgarian Academy of Sciences. Created by Decree No 362 in October 16, 1972 by the Ministry Council of Bulgaria it is successor of the Institute of Physics with Atomic Scientific Experimental Center at the Bulgarian Academy...
at the Bulgarian Academy of SciencesBulgarian Academy of SciencesThe Bulgarian Academy of Sciences is the National Academy of Bulgaria, established in 1869. The Academy is autonomous and has a Society of Academicians, Correspondent Members and Foreign Members...
(since 1999 up to now) - Petrov is a head of Soft Matter Physics Division
- Head of Biomolecular Layers Laboratory, ISSP-BAS (since 1991 up to November 2011)
Awards
Petrov has "Frederiks" Medal by the Russian Liquid Crystal Society (2004) for outstanding contributions in the field of liquid crystal physics.Biography
Petrov has born in town Stara Zagora, Bulgaria (27 May 1948).He has magister degree on atomic physics
Atomic physics
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and...
from the Sofia University
Sofia University
The St. Clement of Ohrid University of Sofia or Sofia University is the oldest higher education institution in Bulgaria, founded on 1 October 1888...
(1970) and Ph.D. on liquid crystals from the Institute of Solid State Physics
Institute of Solid State Physics
Institute of Solid State Physics is one of the physical institutes at the Bulgarian Academy of Sciences. Created by Decree No 362 in October 16, 1972 by the Ministry Council of Bulgaria it is successor of the Institute of Physics with Atomic Scientific Experimental Center at the Bulgarian Academy...
(1974).
He has scientific doctoral degree (D. Sc.) since 1987 and became a member of Bulgarian Academy of Sciences since 2003.
Publications
- А. G. Petrov, Y. G. Marinov, H. P. Hinov, L. Todorova, M. Dencheva-Zarkova, S. Sridevi, P. M. Rafailov, U. Dettlaff-Weglikowska, Observation of FlexoelectricityFlexoelectricityFlexoelectricity is a property of a dielectric material whereby it exhibits a spontaneous electrical polarization induced by a strain gradient. Flexoelectricity is not the same as Ferroelasticity....
in a Mixture of Carbon Single Walled Nanotubes with a Nematic Liquid Crystal, Mol. Cryst. Liq. Cryst. 545, no.1, pp. 58/[1282]-66/[1290] (2011) - Alexander G.Petrov, Y. G. Marinov, G.B.Hadjichristov, S. Sridevi, Uma S. Hiremath, C.V. Yelamaggad, and S. Krishna Prasad, New Photoactive Guest-Host Nematics Showing Photoflexoelectricity, Mol.Cryst.Liq.Cryst. 544, no.1, pp 3/[991]-13/[1001] (June 2011)
- A. G.Petrov, Flexoelectricity: a universal sensoric mechanism in biomembranes and chem.-biosensors, In: Functionalized Nanoscale Materials, Devices and Systems, A.Vaseashta and I.N.Mihailescu Eds., Springer (2008), pp.87-100.
- A. G. Petrov, Y. Marinov, S. D’Elia, S. Marino, C. Versace, N. Scaramuzza, Dielectric and flexoelectric oscillations in PDLC studied by flexoelectric spectroscopy and laser light diffraction, J.Optoelec.Adv. Mat. 9, 420 – 423 (2007)
- Alexander G. Petrov, Flexoelectricity and mechanotransduction (Invited Review), In: Current Topics in Membranes, vol. 58: Mechanosensitive channels, O.P.Hamil, Ed., Elsevier/Academic Press (2007), pp. 121-150.
- Alexander G. Petrov, Electricity and mechanics of biomembrane systems: Flexoelectricity in living мembranes (Invited Review), Anal.Chim.Acta, 568, 70-83 (2006)
- A. G. Petrov, Present state of the generalized molecular asymmetry model in liquid crystal physics, Bulg. J. Phys. 31, 1-27 (2004)
- A. G. Petrov, Mechanoelectric properties of BLMs, Chapter 6 in: Planar Lipid Bilayers (BLMs) and their Applications, Eds. HT Tien and A. Ottova, Elsevier Science, Amsterdam and New York, 2003, pp. 205-238
- A. G. Petrov, Flexoelectricity of model and living membranes, Biochim. Biophys. Acta - Review on Biomembranes 1561, 1-25 (2002)
- A. G. Petrov, F. Sachs, Flexoelectricity and elasticity of asymmetric biomembranes, Phys. Rev. E 65, 21905-10 (2002)
- A.G.Petrov, A new generation of surface-driven liquid crystal displays, Materials for Information Technology in the New Millenium, Eds. J.M.Marshall et al., Bookcraft, Bath (2001) pp. 74-81.
- A.G.Petrov, Measurements and interpretation of flexoelectricity (Invited review), Physical Properties of Liquid Crystals, EMIS Datareviews Series, Inst. Electrical Engineers, UK,vol. 25, 251-264 (2001)
- A.G.Petrov, H.Schmiedel, U. Kühnau, Polar surface interactions vs. long range interactions in the problem of nematic anchoring, Mol.Cryst.Liq.Cryst, 329, 349-356 (1999)
- A.G.Petrov, Liquid crystal physics and the physics of living matter, Mol.Cryst.Liq.Cryst. 332, 577-584 (1999)
- A. G. Petrov, Flexoelectricity and ion channels: a confirmation of the flexoelectric model for ion transport, Cell.& Molec.Biol.Lett. 2, suppl. 1, 231-253 (1997)mechano-electric aspects; statics and dynamics, Mol.Cryst.Liq.Cryst.A 292, 227-234 (1997)
- А. Г. Петров, Молекулна физика и биофизични аспекти на лиотропното течнокристално състояние на веществото, дисертация за D. Sc. (1987)
- А. Г. Петров, Електрическа поляризация на нематичните течни кристали: диелектрични и флексоелектрични свойства, PhD, СУ (1974)