scholarly journals Slippery Surface with Petal-like Structure for Protecting Al Alloy: Anti-corrosion, Anti-fouling and Anti-icing

2021 ◽  
Author(s):  
Junfei Huang ◽  
Jiajie Kang ◽  
Jiaxu Zhang ◽  
Jinxia Huang ◽  
Zhiguang Guo
Keyword(s):  
Hydrothermal Reaction ◽  
Chemical Properties ◽  
Working Environment ◽  
Alkaline Solutions ◽  
Al Alloy ◽  
Sliding Angle ◽  
Automotive Manufacturing ◽  
Oil In Water ◽  
Slippery Surface ◽  
High Shearing

AbstractThe harsh working environment affects the performance and usage life of Al and its alloys, thus limiting their application. In recent years, Slippery Liquid-infused Porous Surface (SLIPS) has attracted much attention due to excellent anti-corrosion, anti-fouling and anti-icing properties. This may be an effective way to improve the properties of Al and its alloys. Here, the SLIPS with petal-like structure was constructed on the Al alloy via simple hydrothermal reaction, Stearic Acid (STA) modification and lubricant injection. A variety of droplets (including oil-in-water emulsions) can slide on the SLIPS at a low angle, even the Sliding Angle (SA) of the water droplet is only 3°. Furthermore, the SLIPS exhibits outstanding mechanical and chemical properties. It can maintain fine oil-locking ability under high shearing force and keep slippery stability after immersion in acid/alkaline solutions. In addition, the SLIPS possesses excellent anti-corrosion, anti-fouling and anti-icing properties, which provides a new way to promote the application of Al and its alloys. Therefore, the SLIPS is expected to be an effective way to improve the properties of Al and its alloys, as well as play a role in anti-fouling and self-cleaning in construction, shipbuilding and automotive manufacturing industries, thereby expanding the practical application of Al and its alloys.

Astaxanthin–garlic oil nanoemulsions preparation using spontaneous microemulsification technique: optimization and their physico–chemical properties

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Seyedalireza Mortazavi Tabrizi ◽  
Afshin Javadi ◽  
Navideh Anarjan ◽  
Seyyed Javid Mortazavi Tabrizi ◽  
Hamid Mirzaei
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Subcritical Water ◽  
Chemical Properties ◽  
Polydispersity Index ◽  
Garlic Oil ◽  
Physico Chemical ◽  
Minimum Particle Size ◽  
Oil In Water ◽  
Technique Optimization

AbstractGarlic oil in water nanoemulsion was resulted through subcritical water method (temperature of 120 °C and pressure of 1.5 bar, for 2 h), using aponin, as emulsifier. Based on the prepared garlic oil nanoemulsion, astaxanthin–garlic oil nanoemulsions were prepared using spontaneous microemulsification technique. Response surface methodology was employed to evaluate the effects of independent variables namely, amount of garlic oil nanoemulsion (1–9 mL) and amount of provided astaxanthin powder (1–9 g) on particle size and polydispersity index (PDI) of the resulted nanoemulsions. Results of optimization indicated that well dispersed and spherical nanodroplets were formed in the nanoemulsions with minimum particle size (76 nm) and polydispersity index (PDI, 0.358) and maximum zeta potential value (−8.01 mV), using garlic oil nanoemulsion amount of 8.27 mL and 4.15 g of astaxanthin powder. Strong antioxidant activity (>100%) of the prepared astaxanthin–garlic oil nanoemulsion, using obtained optimum amounts of the components, could be related to the highest antioxidant activity of the colloidal astaxanthin (>100%) as compared to that of the garlic oil nanoemulsion (16.4%). However, higher bactericidal activity of the resulted nanoemulsion against Escherichia coli and Staphylococcus aureus, were related to the main sulfur bioactive components of the garlic oil in which their main functional groups were detected by Fourier transform-infrared spectroscopy.

Preparation of Ginger Oil in Water Nanoemulsion Using Phase Inversion Composition Technique: Effects of Stirring and Water Addition Rates on their Physico-Chemical Properties and Stability

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Ashraf Farshbaf-Sadigh ◽  
Hoda Jafarizadeh-Malmiri ◽  
Navideh Anarjan ◽  
Yahya Najian
Keyword(s):  
Particle Size ◽  
Phase Inversion ◽  
Antimicrobial Properties ◽  
Chemical Properties ◽  
Water Addition ◽  
Chromatography Method ◽  
Stirring Rate ◽  
Physico Chemical ◽  
Oil In Water ◽  
Addition Rate

Abstract Ginger oil in water (O/W) nanoemulsions, were produced using phase inversion composition method and Tween 80, as emulsifier. Effects of processing parameters namely, stirring rate (100 to1000 rpm) and water addition rate (1–10 mL/min) were evaluated on the physico-chemical, morphological, antioxidant and antimicrobial properties of the prepared O/W nanoemulsions using response surface methodology (RSM). Results indicated that well dispersed and spherical ginger nanodroplets were formed in the nanoemulsions with minimum particle size (8.80 nm) and polydispersity index (PDI, 0.285) and maximum zeta potential value (−9.15 mV), using stirring rate and water addition rate of 736 rpm and 8.18 mL/min, respectively. Insignificant differences between predicted and experimental values of the response variables, indicated suitability of fitted models using RSM. Mean particle size of the prepared nanoemulsion using optimum conditions were changed from 8.81 ± 1 to 9.80 ± 1 nm, during 4 weeks of storage, which revealed high stability of the resulted ginger O/W nanoemulsion. High antioxidant activity (55.4%), bactericidal (against Streptococcus mutans) and fungicidal (against Aspergillus niger) activities of the prepared nanoemulsion could be related to the presence of gingerols and shogaols, a group of phenolic alkanones, in the ginger oil, which those were detected by gas chromatography method.

Silver Nanoparticles Supported on Ordered Mesoporous Carbon for Formaldehyde Electrooxidation

2011 ◽  
Vol 110-116 ◽  
pp. 508-513
Author(s):  
Ling Bin Kong ◽  
Ru Tao Wang ◽  
Xiao Wei Wang ◽  
Zhen Sheng Yang ◽  
Yong Chun Luo ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Mesoporous Carbon ◽  
Chemical Reduction ◽  
Chemical Properties ◽  
Ordered Mesoporous Carbon ◽  
Alkaline Solutions ◽  
Cyclic Voltammograms ◽  
Peak Current Density ◽  
Ordered Mesoporous ◽  
Physical And Chemical

Metal nanocatalysts, as the anodic materials, have become increasingly important in fuel cells due to their unique physical and chemical properties. Here we report the ordered mesoporous carbon (CMK-3) supported silver nanocatalysts have been prepared through the wet chemical reduction by using the reduction of formaldehyde. The electrochemical properties of the Ag/CMK-3 nanocatalysts for formaldehyde oxidation are studied by cyclic voltammograms (CV) and chronoamperometric curves (i-t) in alkaline aqueous solutions. The results show that the peak current density (from CV) of the Ag/CMK-3 electrode is 112 mA cm-2, above 2 times higher than that of Ag/XC-72 at the same Ag loading (14.15 μg cm-2). Furthermore, the i-t curves demonstrate that the Ag/CMK-3 nanocatalysts are efficient and stable electrocatalysts for anodic oxidation of formaldehyde in alkaline solutions. Our results indicate that the application potential of Ag/CMK-3 nanocatalysts with the improved electrocatalytic activity has far reaching effects on fuel cells and sensors.

Safety Management System - Workplace Activities at Toyota Motor Manufacturing, Texas, Inc.

2012 ◽  
Author(s):  
Stephane Roussel ◽  
Norma Jean King
Keyword(s):  
Management System ◽  
Safety Management ◽  
Health And Safety ◽  
Working Environment ◽  
Process Safety ◽  
Employee Morale ◽  
Automotive Manufacturing ◽  
Safety Management System ◽  
Legal Obligations ◽  
Illness Prevention

Implementation of a safety management system (SMS) in automotive manufacturing and assembly has been recognized as an effective way to provide a safe working environment for employees, increase employee morale, and reduce corporate costs. Toyota Motor Manufacturing, Texas, Inc. (TMMTX) has implemented a SMS in part of a regional goal initiated by Toyota Engineering & Manufacturing North America, Inc. (TEMA) to support the OSHA’s Injury & Illness Prevention Program (I2P2). This system provides a systematic way to identify hazards; eliminate or control the risk and incorporate in Toyota Production System. In addition, the established management system provides a framework to meet legal obligations under occupational health and safety regulation. The system implemented provides methods to manage injury and illness related to process safety, ergonomic, and industrial hygiene risks. The system uses joint labor and management teams to identify and evaluate jobs and develop and implement solutions. This paper summarizes the efforts of TMMTX in implementing and maintaining workplace activities that meet the requirements of this safety management system. The methodologies, strategies, and challenges are outlined to provide important links that are critical in sustaining these activities.

scholarly journals NARCOSIS AND EMULSION REVERSAL BY INERT GASES

1957 ◽  
Vol 40 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Dewey F. Sears ◽  
Wallace O. Fenn
Keyword(s):  
Nitrous Oxide ◽  
High Pressures ◽  
Chemical Properties ◽  
Inert Gases ◽  
Water Emulsion ◽  
Oil In Water ◽  
Oil In Water Emulsion

Investigations of the effect of high pressures of Na (100 to 130 atmospheres) and of Ar (60 to 80 atmospheres) showed that these gases are effective in reversing the phases of an oil in water emulsion. Nitrous oxide did not cause reversal at pressures as high as 53 atmospheres nor did helium as high as 107 atmospheres. We found CO2 most effective in reversing the emulsions and attributed this to its chemical properties. It is suggested that these observations may help to explain the narcotic effects of inert gases.

scholarly journals Electrochemical Polishing of 7075 Al Alloy in Phosphoric Acid

2021 ◽  
Author(s):  
Han Liu ◽  
Minheng Ye ◽  
Zuoyan Ye ◽  
Lili Wang ◽  
Yuting Hao ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Phosphoric Acid ◽  
Chemical Properties ◽  
Surface Finishing ◽  
Al Alloy ◽  
Electrochemical Polishing ◽  
Electronic Products ◽  
7075 Al Alloy ◽  
Optimized Conditions ◽  
Further Development

Abstract 7075 aluminum (Al) alloy has been widely used in aircraft structures and other high-end electronic products owing to its excellent mechanical and chemical properties, while its damage-free and highly efficient surface finishing remains a challenge. Herein, we demonstrate a systematic study of the anodic behaviors of 7075 Al alloy during the electrochemical polishing (ECP) process in phosphoric acid under different applied potentials, and the changes of surface morphology, roughness, electric current and resistance are studied intensively. According to the surface morphology and current density, ECP of 7075 Al can be divided into 4 stages including the negative leveling stage, leveling and corrosion stage, levelling and brightening stage, and pitting and corrosion stage. Different factors influencing each stage and the effects of impurity phases in the ECP process are experimentally validated. Under optimized conditions, a mirror surface with a roughness (Ra) of 46.7 nm (decreased from an initial value of 153.2 nm) can be obtained by ECP for 10 min. The presented findings are of great value for the further development of ECP process of multiphase alloys.

scholarly journals Interdisciplinary Projects Applied to Chemistry Lessons: Example of Chemistry Linked to Food Science

2020 ◽  
Vol 74 (3) ◽  
pp. 196-198
Author(s):  
Lydie Moreau ◽  
Véronique Breguet Mercier
Keyword(s):  
Ascorbic Acid ◽  
Network Formation ◽  
Chemical Properties ◽  
Working Environment ◽  
Food Science ◽  
Physico Chemical ◽  
Interdisciplinary Projects ◽  
The Impact ◽  
Design Experiments ◽  
Good Organization

An interdisciplinary project regarding the effect of ascorbic acid on bread dough's physico-chemical properties was proposed to bachelor students in chemistry and food sciences. Such an approach was proposed to develop both scientific and soft skills, in order to prepare students for their future working environment. Together, students deepened their knowledge regarding food science and chemistry. They were then able to plan and design experiments demonstrating the impact of gluten network formation and ascorbic acid influence onto bread dough and finished product characteristics. This way of teaching was very appreciated by students, nevertheless it highlighted the fact that the professors' investment was considerably high, and that good organization, alignment and preparation prior to the start of this project is key.

scholarly journals Dropwise condensation on bioinspired hydrophilic-slippery surface

RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39341-39351 ◽  
Author(s):  
L. Guo ◽  
G. H. Tang
Keyword(s):  
Heat Transfer ◽  
Contact Angle ◽  
Water Transport ◽  
Nucleation Rate ◽  
Copper Surface ◽  
Dropwise Condensation ◽  
Sliding Angle ◽  
Small Contact Angle ◽  
Slippery Surface

A hydrophilic-slippery copper surface is fabricated, reconciling two required factors, enhanced condensation and efficient water transport. Nucleation rate, droplet mobility and heat transfer are enhanced by the small contact angle and sliding angle.

scholarly journals The Influence of the Structural and Morphological Properties of WO3 Thin Films Obtained by PLD on the Photoelectrochemical Water-Splitting Reaction Efficiency

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Florin Andrei ◽  
Andreea Andrei ◽  
Ruxandra Birjega ◽  
Eduard Nicolae Sirjita ◽  
Alina Irina Radu ◽  
...  
Keyword(s):  
Thin Films ◽  
Water Splitting ◽  
Chemical Properties ◽  
Decomposition Reaction ◽  
Photocurrent Density ◽  
Laser Wavelength ◽  
Morphological Properties ◽  
Alkaline Solutions ◽  
Transmission Electron Microscopy Analysis ◽  
Wo3 Thin Films

Due to its physical and chemical properties, the n-type tungsten oxide (WO3) semiconductor is a suitable photoanode for water decomposition reaction. The responses of the photoelectrochemical PEC water-splitting properties as an effect of structural and optical changes of WO3 thin films, as well as the nature of electrolyte solutions, were studied in this work. The WO3 thins films have been obtained by pulsed laser deposition (PLD) on silicon (Si(001)) covered with platinum substrates using three different laser wavelengths. As the XRD (X-ray diffraction) and XTEM (cross-section transmission electron microscopy) analysis shows, the formation of highly crystalline monocline WO3 phase is formed for the film deposited at 1064 nm wavelength and poor crystalline phases with a large ordering anisotropy, characteristic of 2D structures for the films deposited at 355 nm and 193 nm wavelengths, respectively. The photogenerated current densities Jph depend on the laser wavelength, in both alkaline and acidic electrolyte. The maximum values of the photocurrent density have been obtained for the sample prepared with laser emitting at 355 nm. This behavior can be correlated with the coherent crystallized atomic ordering that appear for long distances (10–15 nm) in the (001) plane of the monoclinic WO3 phase structure films obtained at 355 nm laser wavelength. All the samples show poor current density in dark conditions and they are very stable in both acidic and alkaline solutions. The highest photocurrent density value is obtained in acidic solution for the WO3 thin film prepared by 355 nm laser (29 mA/cm2 at 1.6 V vs. RHE (1.35 V vs. Ag/AgCl)).

scholarly journals Formation of Nanocrystalline Cobalt Oxide-Decorated Graphene for Secondary Lithium-Air Battery and Its Catalytic Performance in Concentrated Alkaline Solutions

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1122
Author(s):  
Si-Han Peng ◽  
Hsin-Chun Lu ◽  
Shingjiang Jessie Lue
Keyword(s):  
Cobalt Oxide ◽  
Hydrothermal Reaction ◽  
Catalytic Performance ◽  
Discharge Voltage ◽  
Alkaline Solutions ◽  
Carbon Cloth ◽  
X Ray Diffraction ◽  
Charge Voltage ◽  
Cobalt Solution ◽  
Air Battery

A potent cathode catalyst of octahedral cobalt oxide (Co3O4) was synthesized onto graphene (GR) nanosheets via a two-step preparation method. The precursor cobalt solution reacted with GR during the initial hydrolysis step to form intermediates. A subsequent hydrothermal reaction promoted Co3O4 crystallinity with a crystalline size of 73 nm, resulting in octahedral particles of 100–300 nm in size. Scanning electron microscopy, Raman spectroscopy, and X-ray diffraction analysis confirmed the successful formation of the Co3O4/GR composite. This catalyst composite was sprayed onto a carbon cloth to form a cathode for the hybrid electrolyte lithium-air battery (HELAB). This catalyst demonstrated improved oxygen reduction and oxygen evolution capabilities. The HELAB containing this catalyst showed a higher discharge voltage and stable charge voltage, resulting in a 34% reduction in overall over-potential compared to that without the Co3O4/GR composite. The use of saturated LiOH in 11.6 M LiCl aqueous electrolyte at the cathode further reduced the over-potential by 0.5 V. It is proposed that the suppressed dissociation of LiOH expedites the charging reaction from un-dissociated LiOH. This Co3O4/GR composite is a promising bi-functional catalyst, suitable as a cathode material for a HELAB operating in high relative humidity and highly alkaline environment.

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