scholarly journals TiO2 modified by ammonia as a long lifetime photocatalyst for dyes decomposition

2009 ◽  
Vol 11 (4) ◽  
pp. 1-6 ◽  
Author(s):  
Julia Choina ◽  
Diana Dolat ◽  
Ewelina Kusiak ◽  
Magdalena Janus ◽  
Antoni Morawski
Keyword(s):  
Photocatalytic Degradation ◽  
Azo Dye ◽  
Reaction Medium ◽  
Charged Surface ◽  
Reactive Red 198 ◽  
Long Lifetime ◽  
Positively Charged

TiO2 modified by ammonia as a long lifetime photocatalyst for dyes decomposition Ammonia-modified TiO2 (TiO2/N), prepared in a pressure reactor was used as the well- active and longlife photocatalyst for the azo dye (Reactive Red 198) decomposition. The effect of aeration and the different value of the pH of the reaction medium on the photocatalytic degradation of Reactive Red 198 in water has been investigated. It has been reported that the degradation is greatly influenced by the reaction pH and the faster decomposition of azo dye took place at pH 3.5. When the solution was acidic, a larger amount of azo dye on the positively charged surface of TiO2 photocatalysts was adsorbed. From the obtained results it can be seen that the effectiveness of the decolourisation of the solution was faster by using the nitrogen-modified TiO2.

SIGNIFICANT EFFECT OF PH ON PHOTOCATALYTIC DEGRADATION OF ORGANIC POLLUTANTS USING SEMICONDUCTOR CATALYSTS

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Nur Farhana Jaafar ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono ◽  
Adnan Ripin ◽  
Mohamad Wijayanuddin Ali
Keyword(s):  
Carbon Dioxide ◽  
Methyl Orange ◽  
Physicochemical Properties ◽  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Ph Value ◽  
Effect Of Ph ◽  
Electrolysis Method ◽  
Ph Range ◽  
Positively Charged

Photocatalytic is one of the inexpensive and non-toxic techniques for degradation of organic pollutants into harmless substances such as water and carbon dioxide. In this study, simple electrolysis method was used in preparation of Ag/TiO2 and α-Fe2O3/HY catalysts. The physicochemical properties of the catalysts were studied using XRD, FTIR, FESEM-EDX and surface area analysis. The pH of solution plays an important role in the photocatalytic degradation of organic pollutants which influences the surface-charge properties of the catalysts. Ag/TiO2 and α-Fe2O3/HY were used as catalyst on degradation of 2-chlorophenol (2-CP) and methyl orange (MO), respectively. The effect of pH on degradation of 2-CP and MO were investigated over a pH range from 2 to 9. Higher degradation of 2-CP and MO were obtained at pH 5 (74%) and pH 2 (80%), respectively. This finding might be explained by the amphoteric performance of the catalyst using point zero charge (pHZPC). The pHZPC for Ag/TiO2 and α-Fe2O3/HY was found to be at pH 6.3 and pH 7.2, respectively. Hence, the activities of the catalysts may have been affected by the existence of a strong electrostatic field between the positively charged catalysts surface and negatively charged 2-CP and MO caused a pH value lower than their pHZPC give greater degradation.

Fabrication of a novel ZnO/MMO/CNT nanohybrid derived from multi-cationic layered double hydroxide for photocatalytic degradation of azo dye under visible light

RSC Advances ◽  
2015 ◽  
Vol 5 (25) ◽  
pp. 19675-19685 ◽  
Author(s):  
Fatemeh Khodam ◽  
Zolfaghar Rezvani ◽  
Ali Reza Amani-Ghadim
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Layered Double Hydroxide ◽  
Azo Dye ◽  
Double Hydroxide ◽  
Degradation Of Azo Dye

A facile and effective approach for assembling ZnO/MMO/CNT nanohybrid with excellent photodegradation performance under visible light is reported.

scholarly journals Prospects for the use of mixed micellar structures as a template in synthesis of MCM-41-type silicas

2021 ◽  
pp. 79-89
Author(s):  
N.V. Roik ◽  
◽  
L.O. Belyakova ◽  
М.О. Dziazko
Keyword(s):  
Azo Dye ◽  
Cetyltrimethylammonium Bromide ◽  
Mixed Micelles ◽  
Hydrophobic Interactions ◽  
Sol Gel ◽  
Standard Free Energy ◽  
Reaction Medium ◽  
Total Pore Volume ◽  
Methyl Red ◽  
Sol Gel Synthesis

Formation of mixed micelles assisted by cetyltrimethylammonium bromide and methyl red was studied by means of conductometric and spectrophotometric methods. It follows from the analysis of conductometric dependences that the addition of azo dye leads to a decrease in critical micelle concentration of a long-chain quaternary ammonium salt. The respective thermodynamic parameters were calculated. The process of mixed micelles formation was stated to be spontaneous and the solubilization of azo dye by micelles of cetyltrimethylammonium bromide is profitable in terms of energy and accompanied by an increase in degrees of freedom of the system. Based on the data of spectrophotometric study of methyl red solutions in the presence of cetyltrimethylammonium bromide, the values of stability constant, partition coefficient and change in the standard free energy of methyl red distribution between aqueous and micellar medium were calculated. It was found that electrostatic and hydrophobic interactions arising between azo dye and cetyltrimethylammonium bromide molecules cause the orientation of methyl red from the shell towards the center of the micelles. It was shown that mixed micelles can be used as a template in sol-gel synthesis of mesoporous aminosilica of MSM-41 type. The results of low-temperature nitrogen adsorption-desorption and X-ray analysis revealed that the introduction of methyl red as a part of mixed micelles into the reaction medium of sol-gel synthesis causes substantial increase in specific surface area and total pore volume, noticeable reduction of pore diameter, thereby contributing to the formation of silica material with a pronounced long-range ordered mesoporous structure.

scholarly journals Myenteric Denervation of the Gut with Benzalkonium Chloride: A Review of Forty Years of an Experimental Model

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Sérgio Britto Garcia ◽  
Stefânia Bovo Minto ◽  
Isabela de Souza Marques ◽  
Vinicius Kannen
Keyword(s):  
Experimental Model ◽  
Benzalkonium Chloride ◽  
Charged Surface ◽  
Therapeutic Tool ◽  
Initial Report ◽  
Functional Aspects ◽  
Surface Active ◽  
Rat Gut ◽  
Shed Light ◽  
Positively Charged

Experimental denervation of organs plays a key role in understanding the functional aspects of the normal innervation as well as the diseases related to them. In 1978 the experimental model of myenteric denervation of the rat gut by serosal application of benzalkonium chloride (BAC) was proposed. BAC is a positively charged surface-active alkylamine and is a powerful cationic detergent, which destroys bacteria after ionic attraction and for this reason is largely used as a surgical antiseptic. Since its initial report, the BAC-induced myenteric denervation model has been used to study many functional and pathological aspects of the enteric nervous system. So far this is the only pure method of myenteric denervation available for research in this area. Promising reports in the literature have shed light on the possibilities for the development of new uses of the BAC-denervation experimental model as a therapeutic tool in some pathological situations. This review aims to shed light on the main historical and recent findings provided by this experimental model.

scholarly journals Characterization of distinct molecular interactions responsible for IRF3 and IRF7 phosphorylation and subsequent dimerization

2020 ◽  
Vol 48 (20) ◽  
pp. 11421-11433
Author(s):  
Louise Dalskov ◽  
Ryo Narita ◽  
Line L Andersen ◽  
Nanna Jensen ◽  
Sonia Assil ◽  
...  
Keyword(s):  
Immune Response ◽  
Transcription Factors ◽  
Molecular Interactions ◽  
Adaptor Proteins ◽  
Innate Immune ◽  
Charged Surface ◽  
Regulatory Domain ◽  
Phosphorylation Event ◽  
Positively Charged

Abstract IRF3 and IRF7 are critical transcription factors in the innate immune response. Their activation is controlled by phosphorylation events, leading to the formation of homodimers that are transcriptionally active. Phosphorylation occurs when IRF3 is recruited to adaptor proteins via a positively charged surface within the regulatory domain of IRF3. This positively charged surface also plays a crucial role in forming the active homodimer by interacting with the phosphorylated sites stabilizing the homodimer. Here, we describe a distinct molecular interaction that is responsible for adaptor docking and hence phosphorylation as well as a separate interaction responsible for the formation of active homodimer. We then demonstrate that IRF7 can be activated by both MAVS and STING in a manner highly similar to that of IRF3 but with one key difference. Regulation of IRF7 appears more tightly controlled; while a single phosphorylation event is sufficient to activate IRF3, at least two phosphorylation events are required for IRF7 activation.

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