Vitaliy Smokal

Second- and third-order nonlinearities of novel push-pull azobenzene polymers.

In this work, the second- and third-order nonlinear optical response of spin-deposited thin films of three different push-pull side chain azobenzene polymers is investigated by the second- and third-harmonic Maker fringes techniques using 30 ps laser pulses at a fundamental wavelength of 1064 nm. Measurements were carried out before and after aligning the chromophores by corona poling of the films, while different polarization configurations have been utilized. Strong dependence of the response upon the structure of the systems has been found, which is related to the different charge transfer within the molecules. The reported findings are compared with already published results.

Nonlinear Optical Effects In Polymeric Azoesters

The methacrylic monomers containing azobenzene moiety with flexible alkyl spacers of different lengths and groups of different nature are synthesized, and their physicochemical properties were determined by electronic absorption, 1H NMR spectroscopy, and element analysis. In the present work, the homopolymers built with the use of the free radical polymerization of methacrylic monomers incorporating an azobenzene side-group have been synthesized and structurally characterized. The results of photochemical and optical activities of the corresponding polymers are presented. Third-order nonlinear optical (NLO) properties of the azopolymer solutions are studied by the degenerate four wave mixing (DFWM) method.

New Methacrylic Oxazolone and Thiazolidinone Containing Polymers for Nonlinear OpticalApplications

Oxazalone and thiazolidinone derivatives were synthesized and their physicochemical properties are determined by absorption, HNMR spectroscopies. The third order nonlinear optical properties of oxazolone and thiazolidinone containing compounds were investigated in solutions using degenerate four wave mixing (DFWM) method at 532 nm.

Optical properties of disperse dyes doped poly(methyl methacrylate)

ABSTRACT In this paper, we investigated Disperse Red (DR1, DR13) and Disperse Orange (DO3, DO13) dyes embedded into poly(methyl methacrylate) (PMMA) polymeric matrix. The linear optical properties such as absorption coefficient, refractive index and energy band-gap of guest-host polymeric thin films were studied using spectroscopy and spectroscopic ellipsometry combined with transmittance measurements.  We found that the refractive index of DR1 is higher than the refractive indices for other studied azo dyes compounds. We also observed that the energy band-gap of studied materials varies from about 2 eV to 2.3 eV.

Photochemical Surface Modification of Polyethylene Films by New Azidobenzenesulfonamides

New azidobenzenesulfonamides are synthesized. Their photophysical and photochemical properties have been investigated. The photophysical properties of these compounds were investigated by 1H NMR, IR, and UV spectroscopy. The surface photomodification of polyethylene (PE) films by using new azidobenzenesulfonamides is carried out. The wetting angles for three liquids of different polarities (water, formamide, and diiodomethane) have been studied to estimate the surface modification performed. The obtained wetting angles are used for the determination of the surface free energy γS (γ), as well as its polar , dispersive Owens–Wendt , Lifshits–van der Waals γLW, and acid-base γAB components, by applying the Lifshits–van der Waals/acid-base methods.

Synthesis of Photoactive Styrylquinoline Containing Polymers

In this chapter, we report the synthesis of side chain methacrylic polymers functionalized with styrylquinoline fragments. The polymerization was carried out in dimethylformamide with azobisisobutyronitrile as initiator. The products of polymerization were characterized by 1H NMR. The results of photochemical and optical activities of the corresponding polymers are presented.

Electro-optic properties of novel azobenzene polymers

Polymers containing azobenzene dyes or azobenzene lateral groups are of special interest for their application as optically active media, particularly, as polarization sensitive media for such applications: optical data storage, surface nanostructuration, photoswitching, alignment of liquid crystals, active optical elements etc. An intensive research was carried out previous years on synthesizis and investigation of the second order nonlinear optical response of azobenzene/polymer systems. The desirable properties of these materials are attributed to the highly efficient photoinduced trans-cis and vice versa isomerization of azobenzene moieties. This transformation is connected with the volume change of molecules, followed by an increase of their rotational mobility. The trans-cis izomerization process is exploited also in all optical poling of polymers and plays an important role in optical depoling. Generally these phenomena are induced by light with frequencies corresponding to one-photon absorption. They are possible also by multiphoton absorptions. In this paper we report the synthesis of side chain methacrylic polymers functionalized with azobenzene chromophores. A reversible change of thin film absorption is observed when illuminating it with monochromatic, linearly polarized light under the applied external DC field. The amount of change depends on the angle between the light polarization and the DC electric field direction.

Side-Chain Azobenzene Polymers: Synthesis and Photochemical Properties

A series of methacrylic monomers containing azobenzene moiety with alkyl spacer and different substituents is synthesized. Their photophysical and photochemical properties have been investigated. The photophysical properties of these compounds are investigated by 1H NMR, IR, and UV spectroscopies.

Synthesis and photophysical properties of new styrylquinoline-containing polymers

ABSTRACT A series of novel polymers with styrylquinoline moiety and different substituents units have been successfully synthesized by radical polymerization. Styrylquinoline polymers were obtained by a three-step synthetic approach. This includes the condensation, preparation of a methacrylic monomers and their polymerization. The synthesized polymers are soluble in common organic solvents. Their photophysical and photochemical properties of the initial styrylquinoline and the polymer have been investigated by UV–vis and photoluminescence spectroscopy. Polymers were characterized by 1HNMR-spectroscopy and DSC techniques.

Synthesis, Characterization, and Study of Novel Push-Pull Azobenzene Polymers

In this paper, novel polymers with azobenzene moiety with alkyl spacer and different substituents units are presented. Azopolymers were obtained by a two-step synthetic approach. This includes the preparation of a methacrylic monomers and their polymerization. Their photophysical and photochemical properties have been investigated. Polymers were characterized and evaluated by 1HNMR, IR, UV spectroscopy. Thermal stability was characterized by DSC method. The synthesized polymers exhibited glass transition temperatures in the range of 110–140°C.