14 research outputs found
Photoluminescence properties of self-assembled chitosan-based composites containing semiconductor nanocrystals
The photoluminescence (PL) properties of composites obtained by embedding green-emitting semiconductor nanocrystals (NCs) of two different types (thiol-capped CdTe and CdSe/ZnS) into chitosan-based biopolymer particles were investigated. The synthesis of self-assembled particles from oppositely charged polysaccharides involved a preliminary electrostatic binding of positively charged chitosan chains by negatively charged functional groups of NC stabilizing ligands. The amount of NCs and the acidity of the solution were found to be important parameters influencing the PL. The PL properties were mainly discussed in terms of the colloidal stability of the particles and changes in energy gap of NCs. Generally, the obtained biocompatible composites with NCs randomly distributed within a biopolymer particle demonstrated a higher PL resistance to the solution acidity that expands the applicability range of thiol-capped NCs
Phosphorescence and delayed fluorescence properties of fluorine dyes in bio-related films
Raman spectroscopy studies of the terahertz vibrational modes of a DUT-8 (Ni) metal-organic framework
Low-frequency lattice vibration modes have been discussed to play a crucial role in phase transformation process of switchable metalβorganic frameworks (MOFs). Therefore, Raman spectroscopy was applied to study lattice dynamics of the pillared layer DUT-8(Ni) framework (DUT β Dresden University of Technology), existing in rigid and flexible form. The open pore phase and the close pore phase could be unanimously identified by breathing modes in the corresponding Raman character of low-frequency vibrations. The flexible version of DUT-8 could be distinguished by orientation dependent Raman spectroscopy experimen
Laser-induced Interaction of Multilevel Quantum Dots
A theoretical model is developed for describing the laser-induced interaction of a pair of multilevel semi-
conductor quantum dots. Spectral dependencies of interaction energy are calculated in dipole-dipole ap-
proximation for a pair of CdSe quantum dots in a quasi-resonant laser field, for cases of two identical
quantum dots and those with differing transition wavelengths. Interaction energy of pair of multilevel
quantum dots in the long-wavelength potential well is much higher than that of pair of two-level quan-
tum dots. The increase of difference of resonance wavelengths of two interacting quantum dots leads to
decrease of the potential well depth
Laser-induced Interaction of Multilevel Quantum Dots
A theoretical model is developed for describing the laser-induced interaction of a pair of multilevel semi-
conductor quantum dots. Spectral dependencies of interaction energy are calculated in dipole-dipole ap-
proximation for a pair of CdSe quantum dots in a quasi-resonant laser field, for cases of two identical
quantum dots and those with differing transition wavelengths. Interaction energy of pair of multilevel
quantum dots in the long-wavelength potential well is much higher than that of pair of two-level quan-
tum dots. The increase of difference of resonance wavelengths of two interacting quantum dots leads to
decrease of the potential well depth
Single particle Raman spectroscopy analysis of the metal-organic framework DUT-8(Ni) switching transition under hydrostatic pressure
Experimental in situ observations of phase coexistence in switchable metal-organic frameworks are reported to provide a fundamental understanding of dynamic adsorbents that can change their pore structure in response to external stimuli. A prototypical flexible pillared layer framework DUT-8(Ni) (DUT = Dresden University of Technology) was studied under hydrostatic pressure by in situ Raman spectroscopy on single crystals. The closing transition of the open pore phase (op) containing DMF in the pores in silicon oil as a pressure transmitting fluid, as well as the closed pore phase (cp) to op transition under pressure in methanol, were studied. Phase coexistences during both transitions were observed
Fluorescence and photoinduced proton transfer in the protolytic forms of fluorescein:Experimental and computational study
Π’Π΅ΠΊΡΡ ΡΡΠ°ΡΡΠΈ Π½Π΅ ΠΏΡΠ±Π»ΠΈΠΊΡΠ΅ΡΡΡ Π² ΠΎΡΠΊΡΡΡΠΎΠΌ Π΄ΠΎΡΡΡΠΏΠ΅ Π² ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΠΈΠΈ Ρ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΎΠΉ ΠΆΡΡΠ½Π°Π»Π°
Effect of Spatial Distribution of Laser Radiation Intensity on Photobleaching Kinetics of Dye in Polymer Matrix
ΠΡΠΏΠΎΠ»Π½Π΅Π½ΠΎ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΊΠΈΠ½Π΅ΡΠΈΠΊΠΈ Π»Π°Π·Π΅ΡΠΎΠΈΠ½Π΄ΡΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΠΎΠ±Π΅ΡΡΠ²Π΅ΡΠΈΠ²Π°Π½ΠΈΡ ΡΠΎΠ·ΠΈΠ½Π° Π² ΡΠ°ΠΌΠΊΠ°Ρ
ΡΠ΅-
ΡΡΡΠ΅Ρ
ΡΡΠΎΠ²Π½Π΅Π²ΠΎΠΉ ΡΡ
Π΅ΠΌΡ (S0, S1, T1, Tn) Ρ ΡΡΠ΅ΡΠΎΠΌ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠΈ Π² TEM00 ΠΌΠΎΠ΄Π΅. ΠΠΎ-
ΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΠΏΡΠΈ ΡΡΠ΅ΡΠ΅ Π³Π°ΡΡΡΠΎΠ²Π° ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠΈ Π»Π°Π·Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡ
ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ»ΠΎΡΠ½ΠΎΡΡΠΈ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² ΠΎΡ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ ΠΎΡΠ»ΠΈΡΠ°Π΅ΡΡΡ ΠΎΡ ΠΌΠΎΠ½ΠΎΡΠΊΡΠΏΠΎΠ½Π΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ
ΡΡΠ½ΠΊΡΠΈΠΈ, Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠ½ΠΎΠΉ Π΄Π»Ρ Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅Π°ΠΊΡΠΈΠΈ ΠΏΠ΅ΡΠ²ΠΎΠ³ΠΎ ΠΏΠΎΡΡΠ΄ΠΊΠ°. Π‘ΡΠΎΡΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½Ρ ΡΠ΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°ΡΠΈΠΈ
Π΄Π»Ρ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡΠ΅Π³ΠΎ ΠΊΠΎΡΡΠ΅ΠΊΡΠ½ΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΡΡ ΠΊΠΈΠ½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈ-
ΠΊΠΈ ΡΠΈΡΡΠ΅ΠΌΡ.The modeling of light-induced bleaching of eosin in polymer in the frame of four-level energy scheme
(S0, S1, T1, Tn) was made taking the distribution of intensiviti in TEM00 mode into account. It was
shown that the time dependence of optical dentisty of the samples differs from the exponential relationship
inherent for first order chemical reaction in the case of taking the normal intensity distribution into
consideration. The conditions of experemental realization of correct definition kinetic paremeters of
system were revealed
Effect of Spatial Distribution of Laser Radiation Intensity on Photobleaching Kinetics of Dye in Polymer Matrix
ΠΡΠΏΠΎΠ»Π½Π΅Π½ΠΎ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΊΠΈΠ½Π΅ΡΠΈΠΊΠΈ Π»Π°Π·Π΅ΡΠΎΠΈΠ½Π΄ΡΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΠΎΠ±Π΅ΡΡΠ²Π΅ΡΠΈΠ²Π°Π½ΠΈΡ ΡΠΎΠ·ΠΈΠ½Π° Π² ΡΠ°ΠΌΠΊΠ°Ρ
ΡΠ΅-
ΡΡΡΠ΅Ρ
ΡΡΠΎΠ²Π½Π΅Π²ΠΎΠΉ ΡΡ
Π΅ΠΌΡ (S0, S1, T1, Tn) Ρ ΡΡΠ΅ΡΠΎΠΌ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠΈ Π² TEM00 ΠΌΠΎΠ΄Π΅. ΠΠΎ-
ΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΠΏΡΠΈ ΡΡΠ΅ΡΠ΅ Π³Π°ΡΡΡΠΎΠ²Π° ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠΈ Π»Π°Π·Π΅ΡΠ½ΠΎΠ³ΠΎ ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡ
ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ»ΠΎΡΠ½ΠΎΡΡΠΈ ΠΎΠ±ΡΠ°Π·ΡΠΎΠ² ΠΎΡ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ ΠΎΡΠ»ΠΈΡΠ°Π΅ΡΡΡ ΠΎΡ ΠΌΠΎΠ½ΠΎΡΠΊΡΠΏΠΎΠ½Π΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ
ΡΡΠ½ΠΊΡΠΈΠΈ, Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠ½ΠΎΠΉ Π΄Π»Ρ Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅Π°ΠΊΡΠΈΠΈ ΠΏΠ΅ΡΠ²ΠΎΠ³ΠΎ ΠΏΠΎΡΡΠ΄ΠΊΠ°. Π‘ΡΠΎΡΠΌΡΠ»ΠΈΡΠΎΠ²Π°Π½Ρ ΡΠ΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°ΡΠΈΠΈ
Π΄Π»Ρ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡΠ΅Π³ΠΎ ΠΊΠΎΡΡΠ΅ΠΊΡΠ½ΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΡΡ ΠΊΠΈΠ½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈ-
ΠΊΠΈ ΡΠΈΡΡΠ΅ΠΌΡ.The modeling of light-induced bleaching of eosin in polymer in the frame of four-level energy scheme
(S0, S1, T1, Tn) was made taking the distribution of intensiviti in TEM00 mode into account. It was
shown that the time dependence of optical dentisty of the samples differs from the exponential relationship
inherent for first order chemical reaction in the case of taking the normal intensity distribution into
consideration. The conditions of experemental realization of correct definition kinetic paremeters of
system were revealed