Oxygen reaction with aluminum

X-ray Photoelectron Spectroscopy (XPS) tests were conducted on surfaces lubricated with a sulfur-containing extreme pressure additive, dibenzyl sulfide (Baldwin, 1976 Bird and Galvin, 1976). The films can arise from the use of additives that contain sulfur, phosphorus, chlorine, bromine, or boron and the differences in reactivity are affected by the formation of protective layers. Triboinduced electrons are said to activate the formation of iron halides, iron phosphates and iron sulfides (Dorison and Ludema, 1985 Grunberg, 1966 Kajdas, 2001 McFadden et al., 1998 ). When a chemical reaction takes place, e.g., oxygen interacts with aluminum to form aluminum oxide, a large oxygen peak is seen at approximately 500 eV in the Auger electron spectra (Benndorf et al., 1977 Nakayama et al., 1995). 

Some boron compounds containing oxygen are good oxygen sources in reactions with aluminum alkyls to form aluminoxanes and dialuminoxanes... 

Normalization is based on the average value of oxygen Auger (510 eV) signals from specimens exposed to water vapor for 6.65 x 10 to 1.33 Pa-s. Comparable results were obtained from the companion XPS studies. The results show that the initial rate of reaction of clean aluminum surfaces with water vapor is rapid and reaches saturation after about 2.7 x 10 Pa-s exposure that is, the extent of reaction with aluminum is limited. XPS results indicate that the reactions are associated with the formation of an oxide or a hydrated oxide layer. The limited reactions with water vapor are consistent with previous results on a high-strength AISI 4340 steel [4], The rate of reaction, however, is 10 to 10 times faster than the corresponding rate (associated with the slow, second step) of reaction with AISI 4340 steel. 

PERCHLOROBENZENE (118-74-1) CjClj Combustible liquid (flash point 467°F/242°C Fire Rating 1). Violent reaction with strong oxidizers, including silver nitrate strong acids dimethylformamide (DMF), liquid oxygen. Incompatible with aluminum, potassium, sodium. On small fires, use dry chemical powder (such as Purple-K-Powder), foam, or CO2 extinguishers. 

AMATIN (118-74-1) Combustible liquid (flash point 467°F/242 C). Violent reaction with strong oxidizers, dimethylformamide, liquid oxygen. Incompatible with aluminum, potassium, sodium. 

Persulfates are strong oxidizers they decompose violently upon heating, releasing oxygen. Reactions with organic and other easily oxidizable compounds can be violent. A mixture of ammonium persulfate powder with aluminum powder and water explodes (Pieters and Creyghton 1957). Ammonium persulfate and sodium peroxide mixture explodes when crushed in a mortar or heated (Mellor 1946). 

Titanium compounds bonded to the surface OH groups of Mg(OH)2 are mainly inactive. The active sites are the ones associated with the coordinated and unsaturated negative oxygen ions. Reactions with aluminum alkyls activate the catalysts. For high efficiency, special carriers must be used together with a correct balance of the reactants, and proper reaction conditions. Some choice combinations of reactants are ... 

Reactions with Elements and Inorganic Compounds. Aluminum reacts with oxygen [7782-44-7] having a heat of reaction of... 

Beryllium, calcium, boron, and aluminum act in a similar manner. Malonic acid is made from monochloroacetic acid by reaction with potassium cyanide followed by hydrolysis. The acid and the intermediate cyanoacetic acid are used for the synthesis of polymethine dyes, synthetic caffeine, and for the manufacture of diethyl malonate, which is used in the synthesis of barbiturates. Most metals dissolve in aqueous potassium cyanide solutions in the presence of oxygen to form complex cyanides (see Coordination compounds). 

Aluminum alloys are essentially unaffected by dissolved oxygen in pure water up to 350°F (180°C). Although much of aluminum s corrosion resistance is due to the presence of an adherent oxide film, oxygen is not necessary to form the layer. Direct reaction with water can pro-... 

The disbonding rate decreases with time [35], which can be attributed to the consumption of OH" ions by reaction with adhesive groups. This consumption is obviously partly compensated for by the formation of OH" ions through oxygen reduction these permeate inward from the outer surface of the coating. If this permeation is hindered by an aluminum foil gas seal, the disbonding rate falls off... 

The mechanism of the cycloaddition reaction of benzaldehyde 2a with Danishefsky s diene 3a catalyzed by aluminum complexes has been investigated theoretically using semi-empirical calculations [14]. It was found that the reaction proceeds as a step-wise cycloaddition reaction with the first step being a nucleophilic-like attack of Danishefsky s diene 2a on the coordinated carbonyl compound leading to an aldol-like intermediate which is stabilized by interaction of the cation with the oxygen atom of the Lewis acid. The next step is the ring-closure step, giving the cycloaddition product. 

Khanna et al. [136] proposed a mechanism of the reactions of aluminum based clusters with O, which lends a physical interpretation as to why the HOMO-LUMO gap of the clusters successfully predicts the oxygen etching behaviors. The importance of the HOMO-LUMO gap strongly suggests that the reactions of the metal clusters belong to the pseudoexcitation band. 

The reaction proceeds via a cyclic TS involving coordination of both the alcohol and ketone oxygens to the aluminum. Computational (DFT) and isotope effect studies are consistent with the cyclic mechanism.190 Hydride donation usually takes place from... 

---