Chloride-containing Media Research Articles

Zeta Potential Measurements on Passive Metals

In this study, one shows that the zeta potential can be determined on stainless steel sheet surfaces by streaming potential measurements. These surfaces are in fact covered with a thin oxyhydroxide film known as "the passive film." Zeta potential depends on the solution composition and the surface final conditions. The zeta potentials on AISI 304 stainless steel with 2B and BA surface finishes were measured in KNO3-containing media for several cleaning treatments. Depending on the cleaning treatments and the industrial finish conditions, the zeta potentials range as follows: ζ2B,BASoda/acid < ζ2BEthanol < ζ2B,BADetergent < ζBAEthanol. Measurements were also performed in chloride-containing media after an ethanol cleaning. At pH higher than the isoelectric point, the zeta potential also depends on the finish conditions. After an ethanol cleaning, one finds ζPolish < ζBA finish < ζ2B finish. These results are discussed with respect to the properties of the passive film/solute interface. It is shown that the isoelectric point depends on the surface condition of the steel and ranges around pH 4, indicating a negative surface charge for neutral electrolytes.

Role of Na,K-ATPase in regulating acidification of early rat liver endocytic vesicles

Endocytic vesicles are acidified by an electrogenic proton pump and a parallel chloride conductance; however, acidification might be decreased if electrogenic transporters, such as Na,K-ATPase, that increase vesicle interior-positive membrane potential were also present. We examined this issue in early rat liver endosomes using ion substitution and inhibitors to alter Na,K-ATPase activity. These early endosomes, labeled for 2 min with the fluorescent fluid-phase marker fluorescein isothiocyanate-dextran, consistently acidified faster than endosomes similarly labeled for a 10-min period. In chloride-free media initial rates of acidification of early endosomes were faster in K+ media than in Na+ medium, although addition of K+ to Na+ or Na+ to K+ media to allow Na,K-ATPase to function did not decrease the rate of acidification. In chloride-containing media, rates were the same regardless of cation composition. The Na,K-ATPase inhibitor vanadate was prepared from orthovanadate by several methods, all of which inhibited liver ATPase activity. Two hundred mumol/L vanadate, prepared Cl(-)-free, tended to decrease rates of acidification in all media tested and these effects achieved statistical significance in Cl(-)-free media containing 150 mmol/L K+ or mixtures of Na+ and K+ and in 145 mmol/L KCl/5 mmol/L NaCl medium. Vanadate stocks pH-adjusted with hydrogen chloride increased rates of acidification in sodium gluconate buffers, probably as a result of the effects of the included Cl-. Five mmol/L ouabain (loaded into vesicles by endocytosis) and the membrane-permeable analog strophanthidin (2 mmol/L) both markedly inhibited endosome acidification, regardless of buffer ion composition. Collectively, these results suggest that Na,K-ATPase does not regulate acidification of rat liver early endocytic vesicles, that vanadate may modestly inhibit endosome acidification and that ouabain at high concentrations may inhibit acidification from the vesicle interior face.

Biofilms and corrosion interactions on stainless steel in seawater

Abstract Biofouling and biocorrosion lead to an important modification of the metal/ solution interface inducing changes in the type and concentration of ions, pH values, oxygen levels, flow velocity, etc. Metal dissolution in seawater is mainly conditioned by two different processes: (a) biofouling settlement and (b) corrosion products formation. Corrosion-resistant alloys such as stainless steel present an ideal substratum for microbial colonization, rather similar to inert non-metallic surfaces, due to the lack of corrosion products. Stainless steels are sensitive to pitting and other types of localized corrosion in chloride-containing media such as seawater. Biofilms and bacterial metabolism may accelerate the initiation of crevice attack by depletion of oxygen in the crevice solution due to microbial respiration. Bacterial colonization occurs within a period of 24–72 h on stainless steel samples exposed to natural seawater and, depending on environmental conditions, a copious and patchy biofilm is generally formed. Different interpretations of biofilms' effects on corrosion are critically discussed. A practical case, involving polluted harbour seawater, is reported to illustrate biofilm and corrosion interactions on stainless steel samples.

Observation of intermediate cuprous chloride species during the anodic dissolution of copper using atomic force microscopy

Electrochemical oxidation and reduction reactions of Cu were studied in chloride-containing media by observing changes to the surface morphology of graphite and Cu working electrodes using in-situ electrochemistry atomic force microscopy (ECAFM). AFM images combined with cyclic voltammograms identified three overpotential (η) regions corresponding to the anodic dissolution of Cu in low-concentration (0.002 M HCI) chloride solutions. At low η, «the Tafel region», AFM images showed the dissolution of Cu, which was accompanied by an exponential increase in current density. At higher η, the current-limiting region, AFM images showed the growth of CuCl crystals, which was accompanied by an abrupt decrease in current density

Electrochemical Investigations of the Activation Mechanism of Aluminum

Abstract The aim of this work was to study the activation mechanism of pure aluminum in the absence and presence of indium ions in a chloride-containing medium using the electrochemical noise technique. A correlation was obtained between the noise response and the type of corrosion morphology observed by scanning electron microscopy (SEM). Noise measurements were compared with electrochemical impedance data for an aluminum-zinc-indium alloy (Al-5Zn-0.5ln) in a chloride solution. Polarizing conditions when indium ions are present promote chloride adsorption, which is responsible for the initiation of the activation process.

Foreign anion substitution for chloride in human red blood cells: effect on ionic and osmotic equilibria

In human red blood cells, when chloride was replaced isosmotically with a permeant chaotropic anion of the lyotropic series (NO3, I, or SCN), an immediate and significant loss of cell water was observed. In contrast, replacement of chloride by a substituted monovalent sulfonate, such as methanesulfonate or sulfamate, had no significant effect on cell water. Cell water loss in the presence of lyotropic anions was not the result of hemolysis or cation loss but was associated with a significant fall in the distribution ratios of protons (out/in) and chloride (in/out), suggesting an increase in nondiffusible intracellular negative charges. This hypothesis was examined using the equilibrium dialysis technique of Freedman and Hoffman (J. Gen. Physiol. 74: 157-185, 1979) in which fixed charges are titrated in cells permeabilized by nystatin. The equilibrium concentration ratios (in/out) of potassium, sodium, and chloride were determined at various external pH (pHo) values. The point at which anion and cation ratios are equal is the effective isoelectric point for the intracellular charges. In normal chloride-containing medium at 24 degrees C, this point was found at a pHo of 6.93. When chloride was replaced by a chaotropic anion, the isoelectric point at 24 degrees C shifted to a lower pHo: NO3 (6.38), I (5.98), and SCN (5.70). The substituted monovalent sulfonates had little effect on isoelectric point: methyl sulfate (6.81), sulfamate (7.00), and methanesulfonate (7.07). Calculation of the intracellular charges from titration data, as well as equilibrium distribution studies with [14C]SCN, suggests that lyotropic anion binding to intracellular sites (mainly hemoglobin) is responsible for the observed changes in cell water, cell pH, and chloride distribution.

Effects of anions on the Na(+)‐H+ exchange of trout red blood cells.

1. Replacement of chloride by foreign anions in the suspending medium of trout erythrocytes can affect in a complex manner both the activation by catecholamines of the latent Na(+)-H+ exchanger and its subsequent desensitization. These changes are discussed in relation to other cellular modifications (distribution of permeant anions and accumulation of cyclic AMP) induced by foreign anions. 2. The transfer of trout erythrocytes from a chloride-containing medium to media containing lyophilic permeable anions, NO3- or SCN-, immediately induces a decrease of distribution ratios of permeable anions across the red cell membrane (i.e. Donnan ratios). It is probable that the binding of lyophilic anions to haemoglobin, by altering the amount of negative fixed charges, results in changes of distribution of permeant anions across the membrane. 3. The effectiveness of anions in decreasing both the activation of the Na(+)-H+ exchanger and the Donnan ratio follows the same sequence in both cases, i.e., SCN- greater than NO3- greater than Cl- = propionate. It was demonstrated that a change in Donnan ratio affects antiport activity possibly through a shift in intracellular pH; such a mechanism however cannot account for all the effects of foreign anions on antiport activity. 4. The present results show that lyophilic anions do not modify the affinity of the antiporter for sodium ions but greatly decrease the transport capacity of the exchange system. This is interpreted as indicating that the binding of lyophilic anions to some component of the transport system prevents antiporters from establishing their activated configuration once stimulated. Since the inhibitory effect of anions on Na(+)-H+ exchange has been demonstrated in all erythrocytes studied but in no other cell, the crucial substance involved in this inhibition could well be haemoglobin, which appears to control antiport activity in erythrocytes. 5. Some anions affect desensitization of the exchanger. This effect is not related to the lyophilic character of the anion and is not mediated by a change in intracellular cyclic AMP. 6. Propionate and acetate drastically reduce the intracellular level of cyclic AMP and seem to facilitate the activated configuration of the exchanger.

Localization of l-glutamate binding sites in chick brain by quantitative autoradiography

Quantitative autoradiography was used for the localization of l-[ 3H]glutamate binding sites in chick brain. The highest concentration of these sites was observed in the molecular layer of cerebellum. High concentrations were also observed in the hippocampus, area parahippocampalis, neostriatum, neostriatum intermedium and hyperstriatum ventrale. In most areas binding of l-[ 3H]glutamate was increased when incubation was done in chloride-containing medium. This increase was statistically significant in only few of these areas.

Corrosion of austenitic-martensitic and ferritic steels in chloride-containing media

Corrosion of austenitic-martensitic and ferritic steels in chloride-containing media

Glutaraldehyde fixation of the cAMP-dependent Na+/H+ exchanger in trout red cells.

It has been shown that the addition of a beta-adrenergic catecholamine to a trout red blood cell suspension induces a 60-100-fold increase of sodium permeability resulting from the activation of a cAMP-dependent Na+/H+ antiport. Subsequent addition of propranolol almost instantaneously reduces the intracellular cAMP concentration, and thus the Na permeability, to their basal values (Mahé et al., 1985). If glutaraldehyde (0.06-0.1%) is added when the Na+/H+ exchanger is activated after hormonal stimulation, addition of propranolol no longer inhibits Na permeability: once activated and fixed by glutaraldehyde, the cAMP dependence disappears. Glutaraldehyde alone causes a rapid decrease in the cellular cAMP concentration. In its fixed state the antiporter is fully amiloride sensitive. The switching on of the Na+/H+ exchange by cAMP is rapidly (2 min) followed by acute but progressive desensitization of the exchanger (Garcia-Romeu et al., 1988). The desensitization depends on the concentration of external sodium, being maximal at a normal Na concentration (145 mM) and nonexistent at a low Na concentration (20 mM). If glutaraldehyde is added after activation in nondesensitizing conditions (20 mM Na), transfer to a Na-rich medium induces only a very slight desensitization: thus the fixative can "freeze" the exchanger in the nondesensitizing conformation. NO3- inhibits the activity of the cAMP-dependent Na+/H+ antiporter of the trout red blood cell (Borgese et al., 1986). If glutaraldehyde is added when the cells are activated by cAMP in a chloride-containing medium, the activity of the exchanger is no longer inhibited when Cl- is replaced by NO3-. Conversely, after fixation in NO3- medium replacement of NO3- by Cl- has very little stimulatory effect. This indicates that the anion dependence is not a specific requirement for the exchange process but that the anion environment is critical for the switching on of the Na+/H+ exchanger and for the maintenance of its activated configuration.

Leakage of Cellular Materials and Damage to the Cellular Surface of Escherichia coli by Glycine and/or Sodium Chloride

The combined antimicrobial effect of glycine and sodium chloride against Escherichia coli IFO3301 was examined in terms of membrane damage. The cellular materials, protein, phospholipid, lipopolysaccharide and 260nm-absorbing materials, leaked from the cells treated with glycine proportionally to the glycine concentration. The leakage was suppressed by the addition of sodium chloride. On the other hand, the largest leakage was observed when the cells grown in 2% sodium chloride-containing medium were treated with glycine. Consequently, the antimicrobial activity of glycine and sodium chloride was not enhanced in the case of combined treatment, but that of glycine was enhanced by the change of the bacterial surface caused by prior sodium chloride treatment during cell growth.The observations by electron microscopy also supported the above results. The membrane of the cells treated with sodium chloride was intact, although a remarkable plasmolysis was observed. On treatment of the cells grown in sodium chloride-containing medium with glycine, extensive blebbing of the membrane and extracellular vesicles was found. The results reflect the injury to the membrane.

The stress corrosion cracking of duplex stainless steel in H 2S/CO 2/Cl − environments

The stress corrosion cracking susceptibility of duplex stainless steel (DIN W.St. no. 1.4462) in various H 2S-, CO 2- and chloride-containing media has been investigated with slow strain rate test techniques at 20, 80 and 160°C. The objective of this investigation was to determine limiting conditions for the application of this material in sour environments. It was found that duplex stainless steel at its free corrosion potential is susceptible to stress corrosion cracking in the media of our tests only at temperatures higher than 80° and when subjected to a slow plastic strain rate. This was observed at H 2S partial pressures as low as 0.1 bar. The stress corrosion cracking mechanism of duplex stainless steel in H 2S-, CO 2- and Cl −1-containing environments conforms to a combination of repetitive slip-step emergence/anodic dissolution and hydrogen embrittlement.

AVESTA STAINLESS 44LN

Abstract AVESTA STAINLESS 44LN is an austenitic-ferritic stainless steel with good resistance to various types of corrosion. It is highly resistant to stress-corrosion cracking in chloride-containing media. Its yield strength is approximately twice that of austenitic stainless steels. Other properties, such as machinability and weldability also are favorable. AVESTA STAINLESS 44LN is a very suitable material for equipment which comes into contact with sour gas or sour oil and other chloride-containing media. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-471. Producer or source: Avesta Stainless Inc..

CRONIFER 1925LC

Abstract CRONIFER 19251C is an austenitic chromium-nickel steel with a high molybdenum content. It has excellent corrosion resistance, particularly to sulfuric acid and phosphoric acid and to chloride-containing media. Its applications include chemical equipment, sulfuric and phosphoric acid production, pulp and paper industry and pickling equipment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-458. Producer or source: Vereingte Deutsche Metallwerke AG.

Combined Antimicrobial Effects of Glycine and Several Reagents

The combined antimicrobial effects of glycine and several reagents were examined to evaluate glycine as a food preservative. The following reagents were effective: hexameta-phosphate and ethylenediaminetetraacetate (which has a chelating action) against Staphylococcus aureus IFO 3060; sodium chloride against Escherrchia coli IFO 3301 and Staphylococcus aureus FUci; lysozyme against Staphylococcus aureus 209P. The combined effects of glycine and sodium chloride on Escherrchia coli IFO 3301 were examined. The cells grown in sodium chloride-containing medium became sensitive to glycine, whereas those cells simply treated with sodium chloride did not. It is suggested that the antimicrobial activity of glycine was enhanced through the injury to the bacterial surface caused by sodium chloride during cell growth.

Features of the corrosion cracking process of 07Kh16N6 and 04Kh25N5M2 steels in chloride-containing media

Features of the corrosion cracking process of 07Kh16N6 and 04Kh25N5M2 steels in chloride-containing media

Influence of chloride-containing media on the crack resistance of 07Kh16N6 steel

Influence of chloride-containing media on the crack resistance of 07Kh16N6 steel

EASTERN STAINLESS TYPE ES-2205

Abstract EASTERN STAINLESS ES-2205 is a very low carbon ferritic-austenetic stainless steel with an excellent combination of strength and corrosion-resistant properties under a wide variety of applications. It has twice the yield strength of the austenitic stainless steel. Both machinability and weldability are good. The uses of ES-2205 include heat exchangers, tubes and other components and equipment that must resist chloride-containing media, inorganic acids and organic acids. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-437. Producer or source: Eastern Stainless Steel Company.

Actions of pentobarbitone and derivatives with modified 5-butyl substituents on GABA and diazepam binding to rat brain synaptosomal membranes.

The effects of a variety of factors known to influence the enhancement of GABA binding by diazepam, were studied upon pentobarbitone stimulation of GABA binding to washed synaptosomal membranes prepared from whole rat brains. The differential kinetics of, and effects of temperature, chloride ions, a benzodiazepine receptor antagonist (Ro15-1788) and picrotoxinin upon pentobarbitone and diazepam enhancement of GABA binding, suggest that these drugs exert their actions upon GABA binding at different loci. The degree of enhancement of diazepam binding and of high affinity GABA binding in chloride-containing media at 25 degrees C by members of a series of twelve side chain methyl substituted and/or unsaturated derivatives of 5-butyl-5-ethyl-barbituric acid (pentobarbitone analogs) correlated significantly. For the sedative members of the series, enhancement of high affinity GABA binding correlated with their anaesthetic but not their anticonvulsant activities. It appears likely that the anaesthetic and anticonvulsant activities of barbiturates arise from different molecular actions.

Action of cyanide on the photosynthetic water-splitting process

KCN inhibits O 2 evolution from inside-out chloroplast thylakoid vesicles suspended in a low chloride-containing medium. Evidence is presented to suggest that the inhibition is due to CN − and that this anion blocks electron flow close to the water-splitting process by interacting with a photo-oxidised species.