We have studied photoinduced reduction of absorption and emission in p3ht, a semiconducting polymer, and found that the rate of photodegradation (destruction of the constituent thiophene rings) does not correlate with the luminescence intensity and, correspondingly, does not depend on the excited state concentration. This conclusion rules out Purcell enhancement of radiative decay rate as a pos...

abstract: â in this study, the change in the crystalline structure of gas hydrate was predicted for ternary mixture of methane-ethane-water. for this purpose, the tangent plane distance (tpd) minimization method was used. first, the calculations were performed for the binary mixtures of methane-water and ethane-water as the gas and liquid phases. the results show that for a binary mixture of th...

The crystallinity of cadmium titanate (CdTiO3) was greatly improved when synthesized under mild reaction conditions, in the presence of chloride. The highly crystalline CdTiO3 showed much enhanced photodegradation of methyl orange (MO) under simulated sunlight. CdTiO3 was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS),...

The photodegradation of pesticides is reviewed, with particular reference to the studies that describe the mechanisms of the processes involved, the nature of reactive intermediates and final products. Potential use of photochemical processes in advanced oxidation methods for water treatment is also discussed. Processes considered include direct photolysis leading to homolysis or heterolysis of...

We report a comparative study on the photodegradation of the widely used benzodiazepine psychoactive drug alprazolam (8-chloro-1-methyl-6-phenyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepine, ALP) using direct photolysis, and titanium dioxide photocatalyzed reaction. Titanium dioxide photocatalysts were prepared as nanoparticles by acidic sol-gel methods, calcined at two different temperatures, ...

A multivariate kinetic model of aqueous fipronil photodegradation was developed as a function of dissolved organic matter (DOM), bicarbonate, and nitrate at concentrations that bracketthose commonly observed in natural waters (ca. 0-10 mg/L). Several pathways were available for fipronil photodegradation in this system, including direct photolysis and indirect photooxidation by species produced ...

The present paper demonstrates the increased photostability of isotretinoin when loaded in microemulsion. The photodegradation of isotretinoin, in methanol and microemulsion formulation was studied under direct sun light. The photodegradation process was monitored by UV spectrophotometry. In methanol solution, isotretinoin undergoes complete photodegradation just within a few minutes of light e...

The literature on gas phase nucleophilic substitution reactions at aliphatic carbon has been reviewed. The emphasis has been on journal articles published in the period 1990–2001. The present review outlines our current understanding of concepts such as potential energy surfaces, structure–energy relationships, microsolvation, and dynamical and mechanistic details based on both experimental and...

We report on two gas phase nanoparticle integration processes to assemble nanomaterials onto desired areas on a substrate. We expect these processes to work with any material that can be charged. The processes offer self-aligned integration and could be applied to any nanomaterial device requiring site specific assembly. The Coulomb force process directs the assembly of nanoparticles onto charg...

In this review, we demonstrate a real-time time-frequency two-dimensional (2D) pump-probe imaging spectroscopy implemented on a single shot basis applicable to excited-state dynamics in solid-state organic and biological materials. Using this technique, we could successfully map ultrafast time-frequency 2D transient absorption signals of β-carotene in solid films with wide temporal and spectral...