Roland Bakuradze

One of the actual directions of modern polymer science is creation and research of graded materials with different (mechanical, optical, electrical, magnetic, etc.) properties. There are different methods of receiving such materials. We have developed and patented the original technical solution for obtaining graded polymer and composite mate-rials, according to which the creation of gradient of properties is conditioned by graded orientation of isotropic materials. Graded orientation is created using specific devices. The improvement of the technical characteristics of these devices significantly contributes to the development of graded material science. The constriction of the addon device is proposed that allows to carry out of graded orientation in combination of addon device with any standard stretching machine. A mathematical model of graded orientation of polymer materials is developed, which enables to work out polymer materials with preset dimensions and distribution of relative elongation.

Widespread method of the structural modification of the linear polymers is the uniaxial oriented stretchingaction of the homogenous mechanical field on the polymer sample. The relative elongation in the entire volume of the obtained oriented polymer is identical. Uniaxial oriented ted polymer is identical. Uniaxial oriented stretching can be carried out in another mode. Previously we have developed stretching and established the conception about new structural state of thethermoplastic polymers about gradually oriented state (GOS).

  Transition of the isotropic polymers in the GOS is produced by the action of inhomogeneous mechanical field on the polymer sample. Quantitative parameters of the obtained graduallyoriented po-lymers are: range of change of relative elongation/ orienta-tion degree, extent andprofile (linear, hyperbolic, parabolic, logarithmic, etc.).             

 The simplest and most common kind of orientation of polymers is the uniaxial orientationaction of a uniform mechanical field on the polymer sample. Uniaxial oriented stretching can be carried out in another mode. Scientific basis of this innovations is a concept about newstructural state of the thermoplastic polymers about gradually oriented state (GOS)

proposed by us for the first time. This state quantitatively is described by three parameters:range of the relative elongation change, its extent and distri-bution profile (linear, hyperbolic, parabolic, logarithmic, sinusoidal, etc). On the basis of this conception a fundamentally technical solution of the uniaxial orientedstretching is developed. This is the ori-entation of thermoplastic polymers in the gradient

mode, which is done by action of the inhomogeneous mechanical field on the izotropic poly mer films. There are elaborated some guided graded orientation methods.            

A quantum-chemical study of indoline spiropyrans during the transition from an uncolored state to a colored one at room temperature was carried out. To study the effect of substituents in the 3',3'-position of unsubstituted indoline spiropyrans, we performed quantum chemical calculations using the AM1 method. It can be seen from the calculation that in unsubstituted indoline spiropyrans in positions 3',3', the replacement of methyl groups by phenyl ones causes an increase in the external bond angle, which in turn leads to a decrease in the internal angle of the five-membered ring and an increase in the C–O bond length of the pyran ring, and a decrease in the difference between the heats formation of closed and open forms from 4 Kcal/mol to 1 Kcal/mol. These data show that in unsubstituted indoline spiropyrans containing phenyl groups in the 3',3'-position, the transition from the uncolored state to the colored state occurs at room temperature. These calculations are in full agreement with the experimental data.

A major focus of polymer science twentyfirst century is to obtain materials and elements with agradient of different properties. The gradient of the properties in the polymer body may be formed by

the gradient of chemical composition, as well using a gradient orientation of polymers. The idea of the degree of gradient orientation, as a new characterzation of polymer material new structural state (gradientoriented state) in science was first introduced by us. According to this view, the transition of the polymer in a gradient oriented state makes it possible to obtain polymer materials of new genera-tion, with a gradient of mechanical, thermal, optical, electrical, magnetic, acoustic and other properties. Obtaining materials with desired properties stimulate the emergence of new scientific directions. Gradientoriented state is created under the influence of inhomogeneousmechanical field on the polymer body.In the present study investigated to obtain rectangular pieces with a hyperbolic distribution ofrela-tive elongations perpendicular to the single axle stretching of the polymer film. Essence of the method described below         

Previously we have developed a new understanding of the structural state of linear polymers to gradient oriented state.In the present study provides decision management laws making the sample base in the segments for any coefficient of single axle deformation.

 An active research for creation molecular computers, where role of diode and triode playphotochromic organic so called intellectual‖ molecules, is carried out all over the world.Control of such molecules is possible by external factors: light, electric and magnetic field,chemical reaction and so on. Among numerous photochromic compounds (spirocompounds, azobenzens, fulgides, diarylethens and so on) spiropyrans are singled out by their high photosensitivity, resolution on molecular level and high cross-section of two photon absorption. The last parameter is significant to develop threedimensional optical memory element . It must be noted that the polarizational hologram was recorded on the films doped by spiropyrans .The molecules of spiropyran are characterized by bistability, that is ability to exist in two thermodynamically stable, different state. Uncolored, bulky molecule of spiropyran A, after exposition by UV-light, converts into colored, coplanar, merocianine B molecule.Return to A state takes place spontaneously, by heat or by visible light

 An active research for creation molecular computers, where role of diode and triode playphotochromic organic so called intellectual‖ molecules, is carried out all over the world.Control of such molecules is possible by external factors: light, electric and magnetic field,chemical reaction and so on. Among numerous photochromic compounds (spirocompounds, azobenzens, fulgides, diarylethens and so on) spiropyrans are singled out by their high photosensitivity, resolution on molecular level and high cross-section of two photon absorption. The last parameter is significant to develop threedimensional optical memory element . It must be noted that the polarizational hologram was recorded on the films doped by spiropyrans .The molecules of spiropyran are characterized by bistability, that is ability to exist in two thermodynamically stable, different state. Uncolored, bulky molecule of spiropyran A, after exposition by UV-light, converts into colored, coplanar, merocianine B molecule.Return to A state takes place spontaneously, by heat or by visible light

Due to the sensitivity of the reaction center of spiropyran molecule, any structural change in the molecule alters its properties. By the electronic nature of the transducer and its location it is possible to control the parameters of the object such as photo sensitivity, color stability, location of the absorption band in the visible region of the spectrum, and more. The geometric nature of the substitute is less studied than that of the electron. We achieved a structural change in the spiropyran molecule through the fixation of a nitrogen atom. We made a nitrogen atom for the shared indoline nucleus and tetrahydropyrion. The presence of a six-membered cycle in the molecule led to an increase in the skeletal stiffness of the molecule, which contributed to the increased stability of the merocyanine form. This was revealed by the equilibrium constant with a significant deviation towards the tinted shape.

Due to the sensitivity of the reaction center of spiropyran molecule, any structural change in the molecule alters its properties. By the electronic nature of the transducer and its location it is possible to control the parameters of the object such as photo sensitivity, color stability, location of the absorption band in the visible region of the spectrum, and more. The geometric nature of the substitute is less studied than that of the electron. We achieved a structural change in the spiropyran molecule through the fixation of a nitrogen atom. We made a nitrogen atom for the shared indoline nucleus and tetrahydropyrion. The presence of a six-membered cycle in the molecule led to an increase in the skeletal stiffness of the molecule, which contributed to the increased stability of the merocyanine form. This was revealed by the equilibrium constant with a significant deviation towards the tinted shape.

Doctoral Thesis Referee

Master Theses Supervisor

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Scientific editor of monographs in foreign languages

Scientific editor of a monograph in Georgian

Editor-in-Chief of a peer-reviewed or professional journal / proceedings

Review of a scientific professional journal / proceedings

Member of the editorial board of a peer-reviewed scientific or professional journal / proceedings

Participation in a project / grant funded by an international organization

Participation in a project / grant funded from the state budget

Patent authorship

Membership of the Georgian National Academy of Science or Georgian Academy of Agricultural Sciences

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National Award / Sectoral Award, Order, Medal, etc.

Honorary title

Monograph

Handbook

Research articles in high impact factor and local Scientific Journals

Publication in Scientific Conference Proceedings Indexed in Web of Science and Scopus