scholarly journals Synthesis of a Novel Gemini Cationic Surfactant and Its Inhibition Behaviour and Mechanism Study on 2024 Al-Cu-Mg Alloy in Acid Solution

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Juan Du ◽  
Qiaochu Chen ◽  
Qingmao Liu ◽  
Xuelan Hu
Keyword(s):  
Langmuir Model ◽  
Raw Material ◽  
Mg Alloy ◽  
Inhibition Mechanism ◽  
Synthesis Product ◽  
Adsorption Model ◽  
Mechanism Study ◽  
Synthetic Product ◽  
Gemini Cationic Surfactant ◽  
Microscopic Morphology

Isopropylamine was taken as a raw material to synthesize a new multi-alkyl multiple quaternary-ammonium salts gemini surfactant bis[2-hydroxy-3-(dodecyldimethylammonio)propyl]-isopropylamine dichloride. The structure of the synthetic product was characterized by 1H NMR and FTIR. The surface activity was investigated; the inhibition efficiencies and inhibition mechanism of the synthetic product were studied by weight loss method, electrochemical method, microscopic morphology observation, and adsorption model calculation. The results indicate that cmc of synthetic product was 9.204 × 10-4 mol/L; when the concentrations were lower than cmc, the inhibition efficiencies rose substantially, which was up to 89.3% with the concentration of 9.204 ×  10-4 mol/L; when they were higher than cmc, inhibition efficiencies were basically unchanged; polarization tests showed that the synthesis product could restrain both anodic and cathodic reactions; when the concentrations were lower than cmc, the adsorption of the synthetic product conformed to the Langmuir model, which formed monolayer on the 2024 Al-Cu-Mg alloy surface; when they were higher than cmc, it formed bilayer, so the adsorption of the synthetic product did not conform to the Langmuir model anymore.

scholarly journals Investigation of ammonium–lauric salt as shale swelling inhibitor and a mechanism study

2018 ◽  
Vol 37 (1-2) ◽  
pp. 49-60 ◽  
Author(s):  
Jie Zhang ◽  
Weimin Hu ◽  
Li Zhang ◽  
Tiehu Li ◽  
Dan Cai ◽  
...  
Keyword(s):  
Lauric Acid ◽  
Physical Adsorption ◽  
Drilling Fluid ◽  
Superior Performance ◽  
Inhibition Mechanism ◽  
Mechanism Study ◽  
X Ray Diffraction ◽  
Expansion Test ◽  
Mud Cake ◽  
Swelling Rate

In this work, a series of ammonium–lauric salts (ALS) was prepared with lauric acid and amines as small molecular shale swelling inhibitor. The inhibitors were screened by the linear expansion test first, and the result shows that the inhibitor prepared by lauric acid and diethylenetriamine with the mole ratio of 2:1 (ALS-2) displays excellent inhibition effect on the hydration expansion of bentonite. The inhibition of ALS-2 to bentonite was fully evaluated by various methods in the following work, including clay linear swelling test and particle distribution measurement. The results show that ALS-2 has superior performance to inhibit the hydration swelling and dispersion of bentonite, and the swelling rate of bentonite in 0.5% ALS-2 was reduced to 29.7%. In water-based drilling fluid, ALS-2 is compatible with the conventional additives, and it can improve the lubricity of the mud cake obviously after aged under 120°C. Besides, it can control the particle size of bentonite in water. The inhibition mechanism of the ammonium–lauric salts was discussed in detail through physical adsorption, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy.

Corrosion Inhibition Study of Mild Steel in the Acidic Mediums Containing a Mineral Compound-Based Phosphate

2020 ◽  
pp. 187-206
Author(s):  
Moussa Ouakki ◽  
Mouhsine Galai ◽  
Mohammed Cherkaoui ◽  
Mohamed Ebn Touhami ◽  
E. H. Rifi ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Electrochemical Impedance ◽  
Adsorbed Layer ◽  
Inhibition Mechanism ◽  
Double Layer Capacitance ◽  
Adsorption Model ◽  
Transfer Resistance

The corrosion inhibition of mild steel in hydrochloric, sulfuric, and phosphoric acids solutions containing a mineral compound-based phosphate (apatite) was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy. Potentio-dynamic polarization measurements reveal that the inhibition efficiency increased with the concentration of the apatite, which appears to be a cathodic type inhibitor in the three mediums. Electrochemical impedance spectroscopy confirms this result; indeed, the transfer resistance increases with apatite concentration. The authors note that the double layer capacitance decreases simultaneously suggesting the formation of an adsorbed layer on the mild steel surface. The inhibition mechanism has been elucidated by a thermodynamic study, which showed that the film was formed by physi-sorption. The adsorption model obeys to the Langmuir adsorption isotherm. The parameters of activation energy were evaluated and discussed.

Simple Fabrication of PEG Modified W18O49 for Enhanced Adsorption Performance towards Methylene Blue

2021 ◽  
Vol 67 ◽  
pp. 81-87
Author(s):  
Hai Yang Fu ◽  
Xue Jiao Li ◽  
Wei Sun ◽  
Dong Yue Liu ◽  
Xiao Fei Gao ◽  
...  
Keyword(s):  
Methylene Blue ◽  
High Surface ◽  
Raw Material ◽  
Adsorption Model ◽  
Polyethylene Glycol 400 ◽  
Adsorption Performance ◽  
Peg 400 ◽  
Colored Wastewater ◽  
Enhanced Adsorption ◽  
Tungsten Chloride

The W18O49 nanoparticles were synthesized by solvothermal method with tungsten chloride as raw material and n-propanol as solvent. Polyethylene glycol 400 (PEG-400) was modified for W18O49 nanoparticles (W18O49@PEG). The structure and morphology of W18O49 and W18O49@PEG were characterized by XRD and SEM. Methylene blue aqueous solution was used as wastewater adsorption model. And the comparative experiments with other absorbent materials, such as artificial zeolite and activated carbon were also conducted. The results revealed that after modifying by PEG-400, W18O49 has a better adsorption performance than other materials due to its large specific surface area and high surface energy. Finally adsorption circulation experiment was performed，the results indicate that the W18O49@PEG nanoparticles show great potential in the treatment of colored wastewater.

Specific Properties of Artificial [Buna] Rubber

1937 ◽  
Vol 10 (1) ◽  
pp. 17-28
Author(s):  
Albert Koch
Keyword(s):  
Natural Rubber ◽  
Raw Materials ◽  
Small Extent ◽  
Raw Material ◽  
World War ◽  
Methyl Group ◽  
Synthetic Product ◽  
Laboratory Results ◽  
Short Time ◽  
Resistance To Heat

Abstract Developments in the Synthesis of Rubber Because of the peculiar properties of natural rubber, its usefulness is somewhat limited, and in many fields of application it is quite unsuitable. In contact with oils and fats it swells rapidly and loses almost completely its good mechanical properties, and besides this natural rubber has poor resistance to heat. Again it is attacked rather easily by oxygen, and on exposure to oxygen and light simultaneously there is a particularly strong tendency to develop cracks within a short time; it is for such reasons that the chemical industries of various countries have been looking for an artificial or synthetic product which is free from the shortcomings of natural rubber or exhibits them to only a relatively small extent. Experimentation on artificial rubber has depended fundamentally on the discovery of Harries that the natural rubber molecule is constructed of isoprene units. Isoprene and its allied hydrocarbons were prepared by Hoffmann and his coworkers at the Elberfeld dye works, and these compounds were in turn polymerized to masses similar to rubber. These experiments were carried out before the World War. Because of a shortage of raw materials during the War, it was necessary to adapt the laboratory results to a factory scale sooner than should logically have been done. At that time the most readily available technical raw material was dimethylbutadiene, a compound which differs from isoprene by the presence of an extra methyl group, as may be seen in Table I.

Removal of Cu2+ from Aqueous Water by Adsorption onto the Efficient and Recyclable Durian Shell-Derived Activated Carbon

2018 ◽  
Vol 876 ◽  
pp. 46-51 ◽  
Author(s):  
Long Giang Bach ◽  
Dai Viet Nguyen Vo ◽  
Nguyen Duy Trinh ◽  
Van Thi Thanh Ho ◽  
Van Thuan Tran
Keyword(s):  
Activated Carbon ◽  
Langmuir Model ◽  
Raw Material ◽  
P Value ◽  
Optimal Conditions ◽  
Considerable Decrease ◽  
Maximum Capacity ◽  
Monolayer Adsorption ◽  
Confirmation Test ◽  
Order Polynomial

We investigated the use of durian shell-derived activated carbon (DSAC) for the removal of Cu2+. To determine the optimal condition for Cu2+ removal, the response surface methodology (RSM) was used to establish a second-order polynomial model with variables such as Cu2+ concentration (Ci), adsorbent dosage (dDSAC) and pH. With R2 = 0.9847 and P-value < 0.0001, the model was proved to be statistically significant. The RSM based confirmation test revealed that the removal of Cu2+ was maximum (99.6%) at optimal conditions: Ci = 61.6 mg/L, dDSAC = 5.0 g/L and pH = 5.2. Based on calculated R2, data fitness for adsorption isotherms were positioned as follows: Langmuir > Tempkin > Freundlich. In other words, monolayer adsorption was the most favorable behavior with maximum capacity of 76.92 mg/g from Langmuir model. Interestingly, DSAC was reused at least five times without a considerable decrease of Cu2+ removal efficiency. Therefore, durian shell can be used as a highly effective, reusable and promising raw material to fabricate the activated carbon.

scholarly journals YAP Inhibition by Nuciferine via AMPK-Mediated Downregulation of HMGCR Sensitizes Pancreatic Cancer Cells to Gemcitabine

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 620 ◽  
Author(s):  
Ling Zhou ◽  
Qiaoyun Wang ◽  
Han Zhang ◽  
Youjie Li ◽  
Shuyang Xie ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Therapeutic Strategy ◽  
Cultured Cells ◽  
Raw Material ◽  
Mechanism Study ◽  
Aporphine Alkaloid ◽  
Pancreatic Cancer Cells ◽  
Lotus Leaves ◽  
Coa Reductase ◽  
Gemcitabine Treatment

Nuciferine, a major aporphine alkaloid constituent of lotus leaves, is a raw material for obesity treatment. Extensive studies have revealed that obesity is associated with pancreatic cancer (PC). However, it has not been clarified whether nuciferine could be used in PC treatment or prevention. Here, we show that nuciferine could enhance the sensitivity of PC cells to gemcitabine in both cultured cells and the xenograft mouse model. The mechanism study demonstrated that nuciferine induced YAP Ser127 phosphorylation [pYAP(Ser127)] through AMPK-mediated 3-hydroxy-3-methyl-glutaryl-coA reductase (HMGCR) downregulation. Remarkably, wild-type YAP overexpression or YAP Ser127 mutant could resist to nuciferine and no longer sensitize PC cells to gemcitabine. Knockdown of AMPK attenuated pYAP(Ser127) induced by nuciferine. Moreover, knockdown of AMPK reversed nuciferine-mediated HMGCR downregulation. Notably, HMGCR inhibiting could restrain YAP by phosphorylation Ser 127, and therefore enhance the efficiency of gemcitabine in PC cells. In line with this consistent, overexpression of HMGCR reduced growth inhibition caused by nuciferine and/or gemcitabine treatment in PC cells. In summary, these results provide an effective supplementary agent and suggest a therapeutic strategy to reduce gemcitabine resistance in PC.

scholarly journals Synthesis of Biomaterial Hydroxyapatite from Limestone by Using Two-Step Conversion

2020 ◽  
Vol 5 (1) ◽  
pp. 236-238
Author(s):  
Saiful Arif
Keyword(s):  
Total Synthesis ◽  
Ceramic Material ◽  
Raw Material ◽  
Synthesis Process ◽  
Synthesis Product ◽  
Bone Reconstruction ◽  
Artificial Bone ◽  
Wet Chemical ◽  
The Difference

Hydroxyapatite [Ca10(PO4)6(OH)2] is natural ceramic material which is often used for artificial bone reconstruction. In this research, hydroxyapatite was synthesized from mineral of Calcite (CaCO3) which obtained from the Campurdarat, Tulungagung. The hydroxyapatite synthesis steps are encompassed by the preparation of precursors and the synthesis process by using wet chemical manipulation or routes. The XRF characterization shows that the percentage of calcium from the raw material is around 99%. This study succesfully obtains the compound of Ca(OH)2as a source of hydroxyapatite. The concentration of H3PO4 in hydroxyapatite synthesis process influences the synthesis results. For the concentration of H3PO4 0.6 M is still found the compound of Ca(OH)2. The difference result is shown H3PO4 with concentration 0.8 M which the total synthesis product is hydroxyapatite.

scholarly journals Adaption of Theoretical Adsorption Model on Coal: Physical Structure

2021 ◽  
Vol 9 ◽  
Author(s):  
Wu Guodai ◽  
Pan Linhua ◽  
Huang Bingxiang ◽  
Luan Jinhua ◽  
Zhang Ye ◽  
...  
Keyword(s):  
Physical Structure ◽  
Langmuir Model ◽  
Structural Deformation ◽  
Adsorption Model ◽  
Rock Composition ◽  
R And D ◽  
Adsorption Performance ◽  
Coal Deformation ◽  
Coal Rock ◽  
Coal Reservoir

With the motivation to investigate the role of coal physical structure on the adsorption performance of coal reservoir, 18 different types of coal samples with different coal structures were collected from six coal profiles of four production mines located at China. The adsorption characteristics of CH4 on coal samples with different coal structures were examined, and then experimental results were fitted and analyzed by the Langmuir model and the adsorption potential model (D-R and D-A). The prominent factors in terms of adsorption capacity of coal with different coal structures and its adaptability to the model were discussed. Results indicate the following: a) under the condition of a similar coal rank, the adsorption performance of coal is governed by coal rock composition and adsorption heat, the effect of structural deformation on the adsorption performance of coal is not obvious; b) the Langmuir model has a certain adaptability to coal samples with different coal structures, while the D-R model is evidently not suitable to describe coal samples with scaly coal, part of broken coal with small vitrinite content; c) the D-A model has a high adaptability to coal samples with various coal structure types, and the stronger the coal deformation is, the higher the accuracy is.

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