scholarly journals Oxidation Modification of Fuorinated Graphite and Its Reaction Mechanism

Author(s):  
Hao Li ◽  
Song Bi ◽  
Xiaojing Yuan ◽  
Zhaohui Liu ◽  
Yongzhi Song ◽  
...  

Abstract In this paper, Hummers method was used to oxidize fluorinated graphite in order to study the modification mechanism. The chemical composition and microstructure of the products before and after the reaction were characterized and analyzed. Oxidized fluorinated graphite (OFG) obtained by oxidation has a thin layered structure and different oxygen content. The main mechanism of KMnO4 modification is that MnO3+ with Lewis acid property can catalyze the activation of the fluorocarbon bond, which breaks to form F ion. At the same time, the unsaturated carbon bond is oxidized, resulting in the increase of carbon oxygen bond content and the generation of some OFG nano fragments. With the increase in KMnO4 dosage, the fluorocarbon bond will be gradually catalyzed to react according to its activity while the unsaturated carbon bond is oxidized, finally there are still some isolated fluorocarbon bonds with weak activity.

2013 ◽  
Vol 652-654 ◽  
pp. 749-752
Author(s):  
Dan Dan Yuan ◽  
Hong Jun Wu ◽  
Hai Xia Sheng ◽  
Xin Sui ◽  
Bao Hui Wang

In order to meet the need of separating oil from water in the settling tank of the oilfield, ClO2 treatment for oil-water transition layer in settling tank is introduced. The field test displayed that the technique was achieved by a good performance. For understanding the oxidation and mechanism, compositions of oil-water transition layer were comparatively studied for before/after ClO2-treatment in this paper.The experimental results show that the compositions before and after ClO2-treatment, including physical structure and chemical composition, were varied in the great extension. The physical structure, consisting of water, oil and solid phase, was reduced to less than 5% of water and 0.5% of solid particle and increased to 95% of oil in layer compared with before-treatment, easily leading to clearly separating water from oil. The chemical composition of iron sulfide and acid insoluble substance in solid phase was decreased to more than 90% while the carbonate was reduced more than 70% . After the treatment, the viscosity reduction of the water phase in the layer was reached to 50% after oxidation demulsification with ClO2. The chemistry was discussed based on the principles and experiments. Due to ClO2 destroying (oxidizing) the rigid interface membrane structure which is supported by natural surfactant, polymer and solid particles with interface-active materials, the action accelerates the separating of water and oil and sedimentation of insoluble residue of acid in the layer. By demonstrating the experimental data and discussion, we can effectively control the oxidation performance of chlorine dioxide, which is very meaningful for oilfield on the aspect of stable production of petroleum.


2021 ◽  
Vol 410 ◽  
pp. 778-783
Author(s):  
Pavel V. Matyukhin ◽  
Daler I. Mirzoev

The paper presents the results of ferriferous wastes modification process research carried on the basis of JCS “Leninobad rare metals Plant” located in the Republic of Tajikistan. The wastes for the study were taken from the western tailing. The article presents the justification of the chosen wastes as a filling material in the development of new radiation protective composite building materials. The data on the initial ferriferous chemical composition of the tailing wastes and the chemical composition of the material that passed the enrichment process is presented. The study contains microphotos of ferriferous haematite raw material particles surface before and after completing the modifying process. The paper presents and describes the study of X-ray phase analysis diffractograms of enriched iron-containing wastes before and after the modification process. The current research proves that the enrichment ferriferous wastes particles modification process is possible and as a result it can be used as a filling for the development of new kinds of radioprotective composite materials.


2021 ◽  
Vol 316 ◽  
pp. 893-898
Author(s):  
Natalya Gabelchenko ◽  
Artem Belov ◽  
Artem Kravchenko ◽  
Oleg Kryuchkov

We conducted comparative tests of the wear resistance of metals operating under abrasive conditions. Samples were cut from the working parts of mixer-pneumosuperchargers. The chemical composition and mechanical properties were determined. To compare samples under abrasive wear conditions, we designed and assembled a carousel installation. The principle of its operation is based on mixing the abrasive medium by the samples being studied with a given speed. Wear resistance was evaluated by weight loss by samples after several test cycles. To determine changes in the structure of the metal during abrasive wear, metallographic studies of the samples were carried out before and after the tests. It is shown that the best complex of service and mechanical properties is possessed by 110G13L steel.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Zоrаn Pеtrоvić ◽  
Pеrо Dugić ◽  
Vојislаv Аlеksić ◽  
Sаbinа Bеgić ◽  
Vlаdаn Мićić ◽  
...  

Bentonites are aluminosilicate minerals which, due to their porosity, layered structure and composition have a wide application. Structural and textural characteristics of bentonite may be improved by different modification procedures. The aim of this study was to investigate compositional, structural and textural characteristics of domestic bentonite in place Gerzovo, before and after the activation with sulfuric acid. These characteristics were investigated by analytical methods, X-ray diffraction (XRD) and the method of low-temperature nitrogen adsorption (BET). Characteristics of acid-activated bentonite were compared with the characteristics of commercial active clay. The obtained results showed that the activation of bentonite with sulfuric acid leads to a significant improvement in structural and textural characteristics. Using these results it can be assumed that this bentonite will have good adsorption characteristics and can serve as an alternative in comparison with imported commercial aluminosilicate-based adsorbents.


e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 40-49
Author(s):  
Cuiyu Li ◽  
Yameng Shi ◽  
Rui Zhang ◽  
Gaopan Wang ◽  
Jingyan Jia

AbstractIn this study, ultrahigh-molecular-weight polyethylene (UHMWPE) fibres, modified by acetic acid, sulfuric acid and water at a ratio of 20:25:2 for different time periods and modified UHMWPE/EP composites were prepared. The micromorphology, chemical composition, contact angle, H sample extraction, tensile properties and bending performance of the composite material of the UHMWPE fibres before and after modification were tested and analysed. The results show that, after the UHMWPE fibres were treated with the modified liquid, the surface roughness of the fibre increased, the contact angle decreased, and the surface chemical composition and species significantly changed; the mechanical properties of the composites are best when the fibres were treated for 9 min. For the same fibre content, the specific strength, specific modulus and bending load of UHMWPE composites treated for 9 min were increased by 16.7%, 82.9% and 55.3%, respectively, compared with untreated samples.


2020 ◽  
Vol 145 ◽  
pp. 112068 ◽  
Author(s):  
Stefania Garzoli ◽  
Stefania Petralito ◽  
Elisa Ovidi ◽  
Giovanni Turchetti ◽  
Valentina Laghezza Masci ◽  
...  

1994 ◽  
Vol 42 (4) ◽  
pp. 305-314 ◽  
Author(s):  
Margaret J. Gillespie ◽  
Christopher M. Lythgo ◽  
Andrew D. Plumb ◽  
John P. G. Wilkins

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1868 ◽  
Author(s):  
Florina Jaggy ◽  
Spiros Zinelis ◽  
Georgios Polychronis ◽  
Raphael Patcas ◽  
Marc Schätzle ◽  
...  

The aim of this study was to estimate possible differences in the chemical composition and relaxation of orthodontic aligner materials. Four commercially available thermoplastic materials CAM (Scheu-Dental, Iserlohn, Germany), COP (Essix, Dentsply Raintree Essix Sarasota, FL, USA), DUR (Great Lakes Dental Technologies, Tonawanda, NY) and ERK (Erkodent Erich Kopp, Pfalzgrafenweiler Germany) were included in this study. Rectangular strips from each material were prepared according to the manufacturer’s instructions and subjected to attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and stress relaxation characterization. The reduction in applied stress (RAS) after one week was estimated and statistically analyzed by one-way ANOVA at the 0.05 level of significance. All specimens were subjected to optical microscopy before and after stress relaxation testing under transmittance polarized illumination. ATR-FTIR microscopy revealed that all materials are made of polyethylene terephthalate glycol (PETG) while no significant differences were identified in RAS values among materials tested, which ranged from 6%–10% (p ≥ 0.05). All samples illustrated the developments of shear bands during relaxation testing according to optical microscopy findings. The tested materials illustrated similar chemical composition and relaxation behavior and thus no differences in their clinical efficacy are anticipated.


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