Effect of mechanical stress on kinetics of degradation of marine coatings

A comparative study of chemical stability of terfenadine (TER) and itsin vivometabolite fexofenadine (FEX) was performed. Both TER and FEX were subjected to high temperature at different pH and UV/VIS light at different pH and then quantitatively analyzed using new validated LC-UV methods. These methods were used to monitor the degradation processes and to determine the kinetics of degradation for both the compounds. As far as the effects of temperature and pH were concerned, FEX occurred more sensitive to degradation than TER. As far as the effects of UV/VIS light and pH were concerned, the both drugs were similarly sensitive to high doses of light. Using all stress conditions, the processes of degradation of TER and FEX followed the first-order kinetics. The results obtained for these two antihistaminic drugs could be helpful in developing their new derivatives with higher activity and stability at the same time.

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The Kinetics of Degradation of Chloramphenicol in Solution

Journal of the American Pharmaceutical Association (Scientific ed ) ◽

10.1002/jps.3030430905 ◽

1954 ◽

Vol 43 (9) ◽

pp. 530-535 ◽

Cited By ~ 16

Author(s):

Takeru Higuchi ◽

Arnold D. Marcus

Keyword(s):

Kinetics Of Degradation ◽

Kinetics Of

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The Kinetics of Degradation of Chloramphenicol in Solution

Journal of the American Pharmaceutical Association (Scientific ed ) ◽

10.1002/jps.3030430302 ◽

1954 ◽

Vol 43 (3) ◽

pp. 129-134 ◽

Cited By ~ 17

Author(s):

Takeru Higuchi ◽

Charles D. Bias ◽

Arnold D. Marcus

Keyword(s):

Kinetics Of Degradation ◽

Kinetics Of

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Analyzing the kinetics of degradation of Acid Red B dye through Fenton oxidation with online monitoring system

10.5004/dwt.2021.26863 ◽

2021 ◽

Vol 216 ◽

pp. 412-422

Author(s):

Aiguo Li ◽

Xiaofeng Fang ◽

Jiangyuan Sun ◽

Qianpeng Liu ◽

Yingying Lian ◽

...

Keyword(s):

Monitoring System ◽

Online Monitoring ◽

Fenton Oxidation ◽

Kinetics Of Degradation ◽

Online Monitoring System ◽

Kinetics Of

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Desorption and re-adsorption of PAHS on aircraft soot surface

Vietnam Journal of Earth Sciences ◽

10.15625/0866-7187/42/4/15287 ◽

2020 ◽

Vol 42 (4) ◽

Author(s):

Nguyen Mai Lan

Keyword(s):

High Performance ◽

Flow Reactor ◽

Activation Energies ◽

Binding Energies ◽

Desorption Kinetics ◽

Chemical Transformations ◽

Polycyclic Aromatic ◽

Kinetics Of Degradation ◽

Kinetics Of ◽

Pyrex Tube

Polycyclic Aromatic Hydrocarbons (PAHs) in aircraft soot are capable to distribute in the gas phase and particulate phase in chemical transformations in the atmosphere. The desorption of PAHs from the soot surface is a preliminary step in the study of the reactivity of particulate PAHs. The desorption kinetics of PAHs are measured from soot samples to determine desorption rate constants for different PAHs as a function of temperature and the binding energies between PAHs and soot. The kinetics of degradation of particulate PAHs were studied in the flow reactor. The soot samples previously deposited on a Pyrex tube are introduced into the reactor along its axis and the concentrations of PAHs adsorbed on soot are determined by the High-Performance Liquid Chromatography (HPLC) as a function of the desorption time. The results show a correlation between the size of PAHs and the thermodynamics of desorption: with the PAHs have the same number of carbon atoms, their energies of desorption are very similar and increase with this number. The activation energies EA and the number of carbon atoms in PAHs have a linear correlation. It is consistent with the additivity of the laws Van der Waals. The similarity between the activation energies of desorption of PAHs and the corresponding sublimation enthalpies is consistent with the similarity between the graphitic structure of soot and the structure of PAHs.

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Supported TiO2 on Borosilicate Glass Plates for Efficient Photocatalytic Degradation of Fenamiphos

Journal of Catalysts ◽

10.1155/2014/413693 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

A. El Yadini ◽

H. Saufi ◽

P. S. M. Dunlop ◽

J. Anthony Byrne ◽

M. El Azzouzi ◽

...

Keyword(s):

Photocatalytic Degradation ◽

Borosilicate Glass ◽

High Performance ◽

Order Kinetic ◽

Degussa P25 ◽

Plausible Mechanism ◽

Kinetics Of Degradation ◽

Glass Plates ◽

Kinetics Of ◽

Sulfonamide Group

Supported titanium dioxide (TiO2) was investigated for the photodegradation of the insecticide fenamiphos in water. The photocatalyst was immobilised on borosilicate glass plates and the kinetics of degradation were studied in a stirred tank reactor under UV irradiation. Two types of TiO2, for example, Millennium PC500 (100% anatase) and Degussa P25 (80% anatase, 20% rutile), were used. Their activities have been based on the rates of insecticide disappearance. Experiments were investigated to evaluate the effect of pH and initial concentrations of fenamiphos as well as catalyst doses on the photocatalytic degradation of fenamiphos. Kinetic parameters were experimentally determined and an apparent first-order kinetic was observed. For photolysis process of fenamiphos, two photoproducts were identified and characterized using high performance liquid chromatography/mass spectrometry (HPLC/MS). The plausible mechanism of photolysis involved is the oxidation of sulfonamide group. In presence of photocatalyst TiO2, photodegradation was observed. Under identical conditions, Degussa P25 shows higher photocatalytic activity in regard to PC500 Millennium and complete degradation was observed after 180 min.

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