The X-ray spectroscopy and X-ray electron study of the electronic structure of unsubstituted phth... more The X-ray spectroscopy and X-ray electron study of the electronic structure of unsubstituted phthalocyanines MPcH16 and hexadecafluorophthalocyanines MPcF16 with M = Cu, Co is reported. Quantum-chemical calculation of the electronic structure of these compounds was performed. The calculation was used to analyze the metal-ligand electronic interaction in the complexes. The theoretically calculated energy position and composition of the highest occupied molecular orbitals were compared with experimental data obtained from X-ray fluorescence spectra.
In stimulation application, currently available degradable fiber-laden viscoelastic self-divertin... more In stimulation application, currently available degradable fiber-laden viscoelastic self-diverting acids (FLVSDA) are limited to moderate reservoir temperatures due to the lack of fiber integrity and stability. The upper bound temperature for current fiber is limited by the rate of polymer hydrolysis, which results in inadequate stability and fast degradation in an aqueous environment. As reservoirs are being encountered with higher temperatures, there is an industry need to expand the technology application to higher temperature environment (up to 350°F) for enhanced diversion and leakoff control. A novel high-temperature degradable fiber (HTF) was developed with two distinct features. First, the modified polymer is used with a highly ordered structure, resulting in higher melting point and enhanced thermal and hydrolytic stability compared to contemporary mid-temperature fiber (MTF). Second, the morphology is crimped, which enables better material dispersion and plugging efficienc...
Chemistry and the materials portfolio play a central role in fracturing success. Challenges in a ... more Chemistry and the materials portfolio play a central role in fracturing success. Challenges in a achieving successful and productive proppant pack are resolved using varying products and fit-for-purpose chemistry utilization. The conventional understanding of using fluid loss additive (FLA) only for reducing fluid leakoff in high-permeability formations can be extended with advanced digital tools for optimum realization of a broader application spectrum for well-specific challenges. Polylactic acid-based powdered degradable FLA (DFLA) was developed with engineered particle size distribution to plug rock pore throats. Core flow tests were conducted with and without DFLA with borate crosslinked base fluid to measure the performance metrics. The application spectrum was extended beyond the fluid loss control in high-permeability rock to aid in screening out multiple fractures and natural fractures, reducing poroelastic tendency of tight, tectonically influenced formations. An advanced ...
Herein investigation of the effects of substrate temperature on the structural and morphological ... more Herein investigation of the effects of substrate temperature on the structural and morphological features of both cobalt(II) phthalocyanine (CoPc) and cobalt(II) hexadecafluorophthalocyanine (CoPcF16) thin films is presented. For these purposes thin films of CoPc and CoPcF16 prepared by organic molecular beam deposition were investigated by means of optical absorption spectroscopy, X-ray diffraction, Raman spectroscopy, and atomic force microscopy. Concerning the
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2011
The charged states of atoms in unsubstituted copper(II) phthalocyanine (CuPcH16) and hexade-caflu... more The charged states of atoms in unsubstituted copper(II) phthalocyanine (CuPcH16) and hexade-cafluorinated copper(II) phthalocyanine (CuPcF16) complexes and in thin films of them deposited on silicon substrates by vacuum thermal evaporation are investigated by X-ray photoelectron spectroscopy (XPS). The C(1s), N(1s), Cu(2p) core level energies and the charged states of atoms in the studied complexes are calculated using the DFT method.
... 163 REFERENCES 1. J. Simon and J.-J. Andre, Molecular Semiconductors (Springer-Verlag, Berlin... more ... 163 REFERENCES 1. J. Simon and J.-J. Andre, Molecular Semiconductors (Springer-Verlag, Berlin, 1985; Mir, Moscow, 1988). ... 19. AN Darovskikh and OV Frank-Kamenetskaya, in Problems of Crystal Chemistry (Nauka, Moscow, 1988) [in Russian]. 20. ...
The X-ray spectroscopy and X-ray electron study of the electronic structure of unsubstituted phth... more The X-ray spectroscopy and X-ray electron study of the electronic structure of unsubstituted phthalocyanines MPcH16 and hexadecafluorophthalocyanines MPcF16 with M = Cu, Co is reported. Quantum-chemical calculation of the electronic structure of these compounds was performed. The calculation was used to analyze the metal-ligand electronic interaction in the complexes. The theoretically calculated energy position and composition of the highest occupied molecular orbitals were compared with experimental data obtained from X-ray fluorescence spectra.
In stimulation application, currently available degradable fiber-laden viscoelastic self-divertin... more In stimulation application, currently available degradable fiber-laden viscoelastic self-diverting acids (FLVSDA) are limited to moderate reservoir temperatures due to the lack of fiber integrity and stability. The upper bound temperature for current fiber is limited by the rate of polymer hydrolysis, which results in inadequate stability and fast degradation in an aqueous environment. As reservoirs are being encountered with higher temperatures, there is an industry need to expand the technology application to higher temperature environment (up to 350°F) for enhanced diversion and leakoff control. A novel high-temperature degradable fiber (HTF) was developed with two distinct features. First, the modified polymer is used with a highly ordered structure, resulting in higher melting point and enhanced thermal and hydrolytic stability compared to contemporary mid-temperature fiber (MTF). Second, the morphology is crimped, which enables better material dispersion and plugging efficienc...
Chemistry and the materials portfolio play a central role in fracturing success. Challenges in a ... more Chemistry and the materials portfolio play a central role in fracturing success. Challenges in a achieving successful and productive proppant pack are resolved using varying products and fit-for-purpose chemistry utilization. The conventional understanding of using fluid loss additive (FLA) only for reducing fluid leakoff in high-permeability formations can be extended with advanced digital tools for optimum realization of a broader application spectrum for well-specific challenges. Polylactic acid-based powdered degradable FLA (DFLA) was developed with engineered particle size distribution to plug rock pore throats. Core flow tests were conducted with and without DFLA with borate crosslinked base fluid to measure the performance metrics. The application spectrum was extended beyond the fluid loss control in high-permeability rock to aid in screening out multiple fractures and natural fractures, reducing poroelastic tendency of tight, tectonically influenced formations. An advanced ...
Herein investigation of the effects of substrate temperature on the structural and morphological ... more Herein investigation of the effects of substrate temperature on the structural and morphological features of both cobalt(II) phthalocyanine (CoPc) and cobalt(II) hexadecafluorophthalocyanine (CoPcF16) thin films is presented. For these purposes thin films of CoPc and CoPcF16 prepared by organic molecular beam deposition were investigated by means of optical absorption spectroscopy, X-ray diffraction, Raman spectroscopy, and atomic force microscopy. Concerning the
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2011
The charged states of atoms in unsubstituted copper(II) phthalocyanine (CuPcH16) and hexade-caflu... more The charged states of atoms in unsubstituted copper(II) phthalocyanine (CuPcH16) and hexade-cafluorinated copper(II) phthalocyanine (CuPcF16) complexes and in thin films of them deposited on silicon substrates by vacuum thermal evaporation are investigated by X-ray photoelectron spectroscopy (XPS). The C(1s), N(1s), Cu(2p) core level energies and the charged states of atoms in the studied complexes are calculated using the DFT method.
... 163 REFERENCES 1. J. Simon and J.-J. Andre, Molecular Semiconductors (Springer-Verlag, Berlin... more ... 163 REFERENCES 1. J. Simon and J.-J. Andre, Molecular Semiconductors (Springer-Verlag, Berlin, 1985; Mir, Moscow, 1988). ... 19. AN Darovskikh and OV Frank-Kamenetskaya, in Problems of Crystal Chemistry (Nauka, Moscow, 1988) [in Russian]. 20. ...
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Papers by Vladimir Plyashkevich