Characterization of relaxation processes over static permittivity frequency regime and compliance of the Stokes-Einstein-Nernst relation in propylene carbonate

2017 ◽  
Vol 225 ◽  
pp. 42-49 ◽  
Author(s):  
R.J. Sengwa ◽  
Shobhna Choudhary ◽  
Priyanka Dhatarwal
2020 ◽  
Vol 21 (8) ◽  
pp. 2836
Author(s):  
Elisa Fresch ◽  
Elisabetta Collini

A thorough characterization of the early time sub-100 fs relaxation dynamics of biologically relevant chromophores is of crucial importance for a complete understanding of the mechanisms regulating the ultrafast dynamics of the relaxation processes in more complex multichromophoric light-harvesting systems. While chlorophyll a has already been the object of several investigations, little has been reported on chlorophyll b, despite its pivotal role in many functionalities of photosynthetic proteins. Here the relaxation dynamics of chlorophyll b in the ultrafast regime have been characterized using 2D electronic spectroscopy. The comparison of experimental measurements performed at room temperature and 77 K allows the mechanisms and the dynamics of the sub-100 fs relaxation dynamics to be characterized, including spectral diffusion and fast internal conversion assisted by a specific set of vibrational modes.


2014 ◽  
Vol 597 (1) ◽  
pp. 45-51
Author(s):  
Thi Nga Tran ◽  
Thanh Binh Mai ◽  
Long Giang Bach ◽  
Yeon Tae Jeong ◽  
Suman L. Jane ◽  
...  

2000 ◽  
Vol 77 (26) ◽  
pp. 4301-4303
Author(s):  
L. Worschech ◽  
W. Ossau ◽  
J. Nürnberger ◽  
W. Faschinger ◽  
G. Landwehr

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Tahani Al-Garni ◽  
Nada Al-Jallal ◽  
Ahmed Aouissi

Carbon nanotubes (CNTs) were functionalized and were then used as supports of Fe1.5PMo12O40 (FePMo) Keggin heteropolyanions catalysts. The characterization of the resulting catalysts was investigated by inductively coupled plasma spectrometry (ICP), Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) light spectroscopy, and transmission electron microscopy (TEM). FTIR and XRD results confirmed that FePMo was bounded on CNTs successfully and the Keggin structure was preserved. Characterization by TEM showed that solids with high FePMo content exhibited aggregation of FePMo in large particles. The as-prepared catalysts were tested in the synthesis of propylene carbonate (PC) from CO2 and propylene oxide (PO) in a solvent-free reaction and under mild conditions. Effects of various parameters, such as reaction temperature, reaction time, FePMo content on the support, and catalyst loading on the reaction, were investigated. It has been found that CNTs supported FePMo achieved 57.7% PO conversion and 99.0% PC selectivity, whereas unsupported FePMo led only to 8.5% conversion and 48.6% selectivity. The remarkable enhancement of the catalytic activity over the supported catalyst can be attributed mainly to the better dispersion and reactivity of the FePMo catalyst in the supported material.


1997 ◽  
Vol 387 (1-3) ◽  
pp. 199-212 ◽  
Author(s):  
Guorong Zhuang ◽  
Kuilong Wang ◽  
P.N. Ross

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