scholarly journals Probing P25 TiO2 Photocatalysis Using Photoinduced Absorption Spectroscopy (PIAS)

2021 ◽  
Author(s):  
Andrew Mills ◽  
Christopher O'Rourke
Keyword(s):  
Absorption Spectroscopy ◽  
Photoinduced Absorption ◽  
Tio2 Photocatalysis ◽  
Mesoporous Film ◽  
First Time ◽  
Film Form

Photoinduced absorption spectroscopy, PIAS, is used for the first time to probe the kinetics exhibited by the most commonly employed powder photocatalyst, P25 TiO2, in mesoporous film form, in the...

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

The synthesis of polymeric dyes based on waterborne polyurethane: a reaction kinetics study using UV absorption spectroscopy

2020 ◽  
Vol 44 (7) ◽  
pp. 2930-2940 ◽  
Author(s):  
Jun Zhu ◽  
Jie Li ◽  
Chao Sang ◽  
Yunjun Luo
Keyword(s):  
Reaction Kinetics ◽  
Absorption Spectroscopy ◽  
Waterborne Polyurethane ◽  
Uv Absorption ◽  
Kinetics Study ◽  
Uv Absorption Spectroscopy ◽  
First Time ◽  
Polymeric Dyes

The preparation of waterborne polyurethane based polymeric dyes (DWPU) with anthraquinone chromophores was monitored by using UV absorption spectroscopy for the first time.

scholarly journals Visible-NIR absorption spectroscopy study of the formation of ternary plutonyl(vi) carbonate complexes

2020 ◽  
Vol 49 (33) ◽  
pp. 11605-11612
Author(s):  
Yongheum Jo ◽  
Hye-Ryun Cho ◽  
Jong-Il Yun
Keyword(s):  
Absorption Spectroscopy ◽  
Spectroscopy Study ◽  
Nir Absorption ◽  
First Time ◽  
Carbonate Complexes

The formation of CaPuO2(CO3)32− and MgPuO2(CO3)32− complexes was identified for the first time using visible-NIR absorption spectroscopy.

Photoinduced Absorption Spectroscopy of Poly-3-Alkylthiophenes

1992 ◽  
Vol 247 ◽  
Author(s):  
C. Botta ◽  
S. Luzzati ◽  
A. Bolognesi ◽  
R. Tubino ◽  
A. Borghesi
Keyword(s):  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Laser Intensity ◽  
Electronic States ◽  
Chain Mechanism ◽  
Photoinduced Absorption ◽  
Polymer Aggregates ◽  
Cast Films ◽  
Solution Cast

ABSTRACTWe report a study of the near infrared photoinduced absorption of a series of poly -3-decylthiophene with different supermolecular organization as solution cast films, good solvent and aggregated bad solvent solutions.Photoinduced subgap electronic states are detected both in the solid and in solutions independently from the presence of polymer aggregates. The study of the photoinduced activity Δ/T on the laser intensity I indicate a I0.6 dependence for the films and a I0.95 dependence for the solutions. This is the evidence that the photoinduced states are generated in the solid via an inter-chain mechanism while in the solution via an intra-chain mechanism.A possible role of the solvent into the photoexcitation pathway is discussed.

Electronic relaxation pathways of the biologically relevant pterin chromophore

2017 ◽  
Vol 19 (20) ◽  
pp. 12720-12729 ◽  
Author(s):  
R. M. DiScipio ◽  
R. Y. Santiago ◽  
D. Taylor ◽  
C. E. Crespo-Hernández
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Relaxation Mechanism ◽  
Transient Absorption Spectroscopy ◽  
Electronic Relaxation ◽  
Biologically Relevant ◽  
Ultrafast Relaxation ◽  
First Time

Femtosecond-to-microsecond transient absorption spectroscopy is used to report the ultrafast relaxation mechanism of 2-amino-1H-pteridin-4-one (pterin) for the first time.

Concentration-modulated absorption spectroscopy and the triplet state: Photoinduced absorption/bleaching in erythrosin B, rose bengal and eosin y

2006 ◽  
Vol 792-793 ◽  
pp. 121-129 ◽  
Author(s):  
W. Jeremy Jones ◽  
Andras Grofcsik ◽  
Miklos Kubinyi ◽  
Daniel Thomas
Keyword(s):  
Triplet State ◽  
Absorption Spectroscopy ◽  
Rose Bengal ◽  
Eosin Y ◽  
Photoinduced Absorption ◽  
Erythrosin B

Determination of Carrier Lifetime in Bulk-Heterojunction Solar Cells by Continuous-Wave Photoinduced Absorption Spectroscopy

2011 ◽  
Vol 4 (12) ◽  
pp. 126602 ◽  
Author(s):  
Takashi Kobayashi ◽  
Yosuke Terada ◽  
Takashi Nagase ◽  
Hiroyoshi Naito
Keyword(s):  
Solar Cells ◽  
Absorption Spectroscopy ◽  
Carrier Lifetime ◽  
Continuous Wave ◽  
Bulk Heterojunction ◽  
Photoinduced Absorption ◽  
Heterojunction Solar Cells ◽  
Bulk Heterojunction Solar Cells

Refinement of Plas Samples by Using Afm Image and First Observation of Plas Signals on Amorphous Carbon Nitridea-CNx Films

1998 ◽  
Vol 507 ◽  
Author(s):  
H. Furukawa ◽  
S. Nitta ◽  
M. Hioki ◽  
T. Iwasaki ◽  
T. Itoh ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Absorption Spectroscopy ◽  
Amorphous Carbon ◽  
Carbon Nitride ◽  
The Other ◽  
Etching Time ◽  
Atomic Force ◽  
Experimental Problem ◽  
Amorphous Carbon Nitride ◽  
First Time

ABSTRACTThe shape of several waveguide end of samples for photoluminescence absorption spectroscopy (PLAS) was studied by atomic force microscope (AFM), because there was an experimental problem where some samples for PLAS did not work. Using the result of AFM, the waveguide end was reshaped by plasma dry etching. The shortening of the etching time was an effective method to improve the structure of the waveguide end. Secondly, the PLAS method was extended to the other materials from a-Si:H. The PLAS signal of amorphous carbon nitride a-CNx was detected for the first time. Amorphous carbon nitride a-CNx film itself and the interface between a-CNx and a-Si02 are found as good as a-Si:H and the interface between a-Si:H and a-Si 3N4+x:H, respectively.

The Filmmaker as DJ

2017 ◽  
Vol 34 (2) ◽  
pp. 281-317
Author(s):  
Todd Decker
Keyword(s):  
Large Scale ◽  
Musical Form ◽  
Close Analysis ◽  
Constituent Element ◽  
Film Images ◽  
Multiple Levels ◽  
Racial Performance ◽  
First Time ◽  
Music Recordings ◽  
Film Form

Filmmaker Martin Scorsese’s Casino (1995) is structured around a compiled score of almost sixty popular music recordings. Scorsese himself, working with editor Thelma Schoonmaker and using digital editing tools for the first time, assembled and arranged a diverse body of pre-existing music into a unified score that plays for more than two of the film’s three hours. This article offers a close analysis of Scorsese acting as composer—crafting Casino’s compiled score in the manner of a DJ—and, in reciprocal fashion, editing film images and narrative to recorded music. Casino demonstrates highly varied, multivalent relationships between musical form and film form. Indeed, musical form proves a constituent element of Casino’s construction at multiple levels of magnification. The large-scale form of the score as a whole articulates the larger arc of Casino’s dual narrative. The strategic deployment of musical styles (from jazz to rock to pop) and the targeted use of lyrics as voiceover (often subtly deploying aspects of racial performance in popular styles) serve to differentiate narrative strands and fill out otherwise unspoken characterization. Scorsese builds several sequences in Casino on a direct, often audible relationship between song forms and narrative unfolding, creating song scenes in which compiled tracks heard as musical wholes grant a musical shape to discrete narrative units. Casino’s complex use of music does not, however, penetrate the inner lives of the film’s three primary characters, who seem unaware of the musical flow Scorsese employs to set their story dancing. The analysis draws upon the filmmaker’s own words about his creative process and offers select comparisons to other Scorsese films with compiled scores.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

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