Micelles detergency

The oil analyses have shown that the TBN values of lubricating oils deplete completely while at the same time, the corrosion rate can be considerably reduced. The relationship between the solubilization of large quantities of acid, total base number (TBN), and total acid number (TAN) values with the rate of corrosion is still unresolved. TAN values are not a good prediction of corrosion, and the source of extra TBN is much more important in the neutralization of corrosive acids than the simple numerical value of TBN. The effect of hard-core RMs shows poor correlation between used oil sample TAN values and the potential for bearing corrosion (Denison, 1944 Kreuz, 1970). Where corrosion rates are reduced by treatment with hard-core reverse micelle detergent, and no significant reduction in TAN has occurred, corrosion protection must have occurred by a... 

The experiments and the necessary theory were developed by Mohammad Abu-Hamdiyyah, Pasupati Mukerjee, and myself in connection with a related but different problem—an attempt to determine unambiguously the rate of transport of simple non-micellized detergent ions through a membrane (I, 18). We needed information about the ability of the micelles to cross the membrane, and the insoluble material was used mainly to indicate micelle behavior. The paper reporting that work (I) gives experimental details and further interpretation of the results. Since then I found that Dean and Vinograd (4) developed the qualitative aspects of this argument 25 years ago. 

Alternatively, if introduction of water in the system is not considered a problem (e.g. if water is used as a solvent or cosolvent in a homogenous or heterogeneous, two-phase, system), the enzyme can be added as an aqueous formulation. Advantages are also reported on the use of reversed micelles (detergent micelles containing aqueous enzyme in organic media). In any case, for all reaction conditions, the use of an immobilized enzyme preparation should be considered as outlined below. 

In Protocol IB, a soluble whole cell extract is produced by lysis in RIPA, a mixed micelle detergent-containing buffer. RIPA buffer results in extraction of proteins without complete denaturation and cellular antigens are maintained in conformations that can be detected by immrmopredpitation (Protocol 14B). How-... 

In Protocol 14C, immunoprecipitation is performed under disruptive conditions in a mixed micelle detergent buffer (RIPA). Most physiological interactions are dissociated imder these stringent conditions, and usually only the antigen protein and veiy tightly-associated proteins are recovered by immunoprecipitation. This method is useful to quantitate levels of pS]methionine labelled protein antigen, and to study synthesis and degradation rates by pulse chase analysis. 

Much of our information about lipases comes from studies on the enzyme isolated from pancreatic juice this is the enzyme primarily responsible for the digestion of dietary lipids in the animal digestive tract, a process that is described in detail in section 5.3.1. Pancreatic lipase is a glycoprotein of molecular mass 50kDa. The first step in the catalytic process is the adsorption of the enzyme on to the hydrophobic interface of the substrate micelles. Detergent molecules, like bile salts, tend to compete with the lipase for binding sites and the adsorption of the enzyme is assisted by a helper molecule called co-lipase, which is a small protein. In vitro, it can be shown that the activity of lipase is inhibited by high concentrations of bile salts and that this inhibition can be overcome by the addition of co-lipase. 

In the case of lubricant detergents, the hydrophilic or polar part is a metallic salt (calcium, magnesium) and at the center of the micelle it is possible to store a reserve of a metal base (lime or magnesia) the detergent will be able therefore to neutralize the acids produced by oxidation of the oil as soon as they are created. 

The type of behavior shown by the ethanol-water system reaches an extreme in the case of higher-molecular-weight solutes of the polar-nonpolar type, such as, soaps and detergents [91]. As illustrated in Fig. Ul-9e, the decrease in surface tension now takes place at very low concentrations sometimes showing a point of abrupt change in slope in a y/C plot [92]. The surface tension becomes essentially constant beyond a certain concentration identified with micelle formation (see Section XIII-5). The lines in Fig. III-9e are fits to Eq. III-57. The authors combined this analysis with the Gibbs equation (Section III-SB) to obtain the surface excess of surfactant and an alcohol cosurfactant. 

Detergents are substances including soaps that cleanse by micellar action A large number of synthetic detergents are known One example is sodium lauryl sulfate Sodium lauryl sulfate has a long hydrocarbon chain terminating m a polar sulfate ion and forms soap like micelles m water... 

Detergents are designed to be effective in hard water meaning water containing calcium salts that form insoluble calcium carboxylates with soaps These precipitates rob the soap of Its cleansing power and form an unpleasant scum The calcium salts of synthetic deter gents such as sodium lauryl sulfate however are soluble and retain their micelle forming ability even m hard water... 

Anionic Surfactants. PVP also interacts with anionic detergents, another class of large anions (108). This interaction has generated considerable interest because addition of PVP results in the formation of micelles at lower concentration than the critical micelle concentration (CMC) of the free surfactant the mechanism is described as a "necklace" of hemimicelles along the polymer chain, the hemimicelles being surrounded to some extent with PVP (109). The effective lowering of the CMC increases the surfactant s apparent activity at interfaces. PVP will increase foaming of anionic surfactants for this reason. 

Aqueous-detergent solutions of appropriate concentration and temperature can phase separate to form two phases, one rich in detergents, possibly in the form of micelles, and the other depleted of the detergent (Piyde and Phillips, op. cit.). Proteins distribute between the two phases, hydrophobic (e.g., membrane) proteins reporting to the detergent-rich phase and hydrophilic proteins to the detergent-free phase. Indications are that the size-exclusion properties of these systems can also be exploited for viral separations. These systems would be handled in the same way as the aqueous two-phase systems. 

B30 611 1976 gave m 69-70°). Hydrolysis using an equivalent of base in methanol gave the desired glueoside. This is a non-ionie detergent for reeonstituting membrane proteins and has a critieal micelle concentration of 30 mM. [Shimamoto et al. J Biochem (Tokyo) 97 1807 I985 Saito and Tsuchiya Chem Pharm Bull Jpn 33... 

Salt formation. The resin acids have a low acid strength. The pa s (ionization constants) values of resin acids are difficult to obtain, and values of 6.4 and 5.7 have been reported [23] for abietic and dehydroabietic acids, respectively. Resin acids form salts with sodium and aluminium. These salts can be used in detergents because of micelle formation at low concentrations. Other metal salts (resinates) of magnesium, barium, calcium, lead, zinc and cobalt are used in inks and adhesive formulations. These resinates are prepared by precipitation (addition of the heavy metal salt to a solution of sodium resinate) or fusion (rosin is fused with the heavy metal compound). 

Further addition of fatty acid eventually results in the formation of micelles. Micelles formed from an amphipathic lipid in water position the hydrophobic tails in the center of the lipid aggregation with the polar head groups facing outward. Amphipathic molecules that form micelles are characterized by a unique critical micelle concentration, or CMC. Below the CMC, individual lipid molecules predominate. Nearly all the lipid added above the CMC, however, spontaneously forms micelles. Micelles are the preferred form of aggregation in water for detergents and soaps. Some typical CMC values are listed in Figure 9.3. 

FIGURE 9.3 The structures of some common detergents and their physical properties. Micelles formed by detergents can be quite large. Triton X-100, for example, typically forms micelles with a total molecular mass of 90 to 95 kD. This corresponds to approximately 150 molecules of Triton X-100 per micelle. 

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