Interaction of monomeric and polymeric species of metal ions with clay surfaces. I. Adsorption of iron(III) species

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 221 ◽  
Author(s):  
P Rengasamy ◽  
JM Oades
Keyword(s):  
Iron Atom ◽  
Positive Charge ◽  
Molecular Size ◽  
Ferric Nitrate ◽  
Distilled Water ◽  
Critical Coagulation Concentration ◽  
Sodium Bentonite ◽  
Polymeric Species ◽  
Surface Hydroxyls ◽  
Nitrate Solutions

Uitrafiltration or dialysis against distilled water was used to separate polymerized ferric hydroxy cations from the monomeric cations in hydrolysed solutions of ferric nitrate. Separated poly[Fe(III)-OH] cations were polydispersed and the positive charge was inversely related to molecular size. The separated poly[Fe(III)-OH] cations were found to be stable and did not condense further during a period of 6 months. The association of iron(III) with the surfaces of sodium-kaolinite, sodium-bentonite and sodiumillite was studied using hydrolysed ferric nitrate solutions and separated poly[Fe(III)-OH] cations. As the OH/Fe ratio (and pH) of the ferric nitrate solutions increased, the critical coagulation concentration (CCC) and the maximum adsorption of iron(III) increased. The amount of iron adsorbed in the form of separated po1y[Fe(III)-OH] cations was small and was related to the positive charge per iron atom of the polycations. It is proposed that iron(III) in solutions containing only polycations and solutions containing a mixture of mono- and polycations reacted differently with clay surfaces. A reaction of polycations with the surface hydroxyls leading to chemisorption and irreversible flocculation of clays is proposed.

Interaction of monomeric and polymeric species of metal ions with clay surfaces. II. Changes in surface properties of clays after addition of iron(III)

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 235 ◽  
Author(s):  
P Rengasamy ◽  
JM Oades
Keyword(s):  
Negative Charge ◽  
Point Of Zero Charge ◽  
Ferric Nitrate ◽  
Net Charge ◽  
Clay Particles ◽  
Polymer Bridging ◽  
Ph Values ◽  
Polymeric Species ◽  
Surface Hydroxyls ◽  
Nitrate Solutions

The adsorption of poly [Fe(III)-OH] cation by claysurfaces led to flocculation of clay particles possibly by polymer bridging while the addition of iron(III) from hydrolysed ferric nitrate solutions resulted in flocculation and cementation by precipitated iron(III). Electrokinetically clays with adsorbed iron(III) behaved similarly to amorphous ferric hydroxides with positive mobilities below the point of zero charge (PZC). Polycations reversed the charge on the clay particles at maximum adsorption, which probably represents neutralization of charge due to surface hydroxyls. When hydrolysed ferric nitrate solutions were added to kaolinite and illite charge reversal occurred at pH values below 6. Adsorption of iron(III) resulted in a partial reduction of negative charge in clays. The reduction of negative charge in kaolinite and illite was close to the charge due to surface hydroxyls. The net charge estimated at all pH values corresponded with the electrophoretic mobility in all the iron(III) clay complexes except bentonite with adsorbed polycations.

Interaction of monomeric and polymeric species of metal ions with clay surfaces. III. Aluminium(III) and chromium(III)

Soil Research ◽  
1978 ◽  
Vol 16 (1) ◽  
pp. 53 ◽  
Author(s):  
P Rengasamy ◽  
JM Oades
Keyword(s):  
Molecular Weight ◽  
Metal Ion ◽  
Negative Charge ◽  
Positive Charge ◽  
Gel Filtration ◽  
Charge Reversal ◽  
Original Solution ◽  
Polymeric Species ◽  
Surface Hydroxyls ◽  
Nitrate Solutions

Hydrolysis and polymerization in aluminium nitrate and chromic nitrate solutions with different metal/OH ratios were studied by gel filtration chromatography and ultrafiltration techniques. The characteristics of poly[Al(III)-OH] cations separated by ultrafiltration depended on the molecular weight which was controlled by the OH/Al ratio of the original solution. When the OH/Al ratio was <2.0, the polycations had molecular weight < 50 000, high positive charge and were stable. When the ratio was > 2.0 , the polycations had molecular weight > 100 000, low positive charge and rapidly condensed to gibbsite. Polymerization in chromic nitrate solutions was slow and the separated poly[Cr(III)-OH] cations had low molecular weight (<20000), high positive charge and were stable. The interaction of monomeric and polymeric species of aluminium(III) and chromium(III) with the surfaces of sodium-kaolinite, sodium-bentonite and sodium-illite was studied using hydrolysed nitrate solutions of aluminium and chromium, and separated polycations. The results obtained were consistent with the earlier observations of the iron(III) system, and the behaviour could be explained on the basis of positive charge and probable structure of polycations. The adsorption of aluminium(III) and chromium(III) on clay surfaces from hydrolysed metal ion solutions was related to OH/Al or OH/Cr ratios and pH. The adsorption of polycations was low and related to their positive charge. Maximum adsorption resulted in charge reversal on clays. Addition of the hydrolysed nitrate solutions to clays also caused charge reversal and reduction of negative charge. The adsorption from a mixture of monomers and polymers on bentonite surfaces reduced negative charge markedly due to interlayer formation, while the adsorption of separated polycations in low amounts neutralized the charge on surface hydroxyls and led to the flocculation of clays. The anomalous behaviour of the poly[Al(III)-OH] cations of molecular weight >100 000 could be explained if they consisted of planar sheets, formed from coalesced rings of aluminium octahedra, which crystallized into gibbsite.

The Effect of Pore Structural Factors on Diffusion in Compacted Sodium Bentonite

2000 ◽  
Vol 663 ◽  
Author(s):  
Haruo Sato
Keyword(s):  
Grain Size ◽  
Tritiated Water ◽  
Silica Sand ◽  
Single Fracture ◽  
Distilled Water ◽  
Structural Factors ◽  
Sodium Bentonite ◽  
Size Dependency ◽  
Through Diffusion ◽  
Effective Diffusivities

ABSTRACTFour kinds of diffusion experiments; (1) through-diffusion (T-D) experiments for diffusion direction dependency to compacted direction, (2) in-diffusion (I-D) experiments for composition dependency of silica sand in bentonite, (3) I-D experiments for initial bentonite grain size dependency, and (4) I-D experiments for the effect of a single fracture developed in bentonite, were carried out using tritiated water (HTO) to evaluate the effect of pore structural factors on diffusion. For (1), effective diffusivities (De) in Na-bentonites, Kunigel-V1Ŵ and Kunipia-FŴ, were measured for densities of 1.0 and 1.5 Mg.m-3 in the axial and perpendicular directions to compacted one. Although De values in Kunigel-V1Ŵ for both directions were similar over the density, De values for perpendicular direction to compacted one in Kunipia-FŴ were higher than those for the same direction as compacted one. For (2), apparent diffusivities (Da) in Kunigel-V1Ŵ with silica sand were measured for densities of 0.8 to 1.8 Mg.m-3. No significant effect of the mixture of silica sand was found. For (3), Da values for densities of 0.8 to 1.8 Mg.m-3 were measured for a granulated Na-bentonite, OT-9607Ŵ. However, no effect of initial bentonite grain size was found. For (4), Da values in Kunigel-V1Ŵ, in which a single fracture was artificially reproduced and immersed in distilled water, were measured. No effect of the fracture on Da was found. Based on this, it may be said that the composition of smectite in bentonite affects the orientation property of clay particle and also affects diffusion. Furthermore, a penetrated fracture formed in bentonite is restored for a short while and does not affect diffusion.

Effects of acidity, cations and alcoholic fractionation on absorption of heparin from gastrointestinal tract

1976 ◽  
Vol 54 (4) ◽  
pp. 613-617 ◽  
Author(s):  
T. K. Sue ◽  
L. B. Jaques ◽  
E. Yuen
Keyword(s):  
Gastrointestinal Tract ◽  
Citric Acid ◽  
Blood Clotting ◽  
Molecular Size ◽  
Systemic Circulation ◽  
Anticoagulant Effect ◽  
Distilled Water ◽  
Simultaneous Administration ◽  
Factor X ◽  
Molecular Weight Fractions

Heparin was introduced into the stomach or duodenum of mice separately in doses of ca, 250 mg/kg. A slight anticoagulant effect in the systemic circulation was detected in whole blood clotting times and factor X inhibition. In contrast to most drugs, more heparin was absorbed from the stomach than from the intestine. Suppressing ionization of heparin by simultaneous administration of acid resulted in improved absorption of heparin from the small intestine. Heparin was separated with ethanol into five molecular weight fractions: I, 17 000; II, 13 200; III, 10 800, IV, 8 700; and V, 6 700. Each was introduced into the duodenum of mice with citric acid. The maximum hypocoagulability was produced with fraction IV. When administered in distilled water instead of in citric acid, this heparin fraction did not produce an anticoagulant effect. These studies demonstrated that improvement of heparin absorption from the gastrointestinal tract can be obtained by the combination of suppressing ionization and selecting molecular size.

Lead Oxide Plate Precipitates from Lead Nitrate Solution

2010 ◽  
Vol 123-125 ◽  
pp. 1243-1246
Author(s):  
Gang Qiang Yang ◽  
Xiao Ping Zou ◽  
Xiang Min Meng ◽  
Jin Cheng ◽  
Xue Ming Lü ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Sodium Chloride ◽  
Lead Oxide ◽  
Nitrate Solution ◽  
Lead Nitrate ◽  
Chloride Anion ◽  
Distilled Water ◽  
Lead Monoxide ◽  
Reaction Solution ◽  
Nitrate Solutions

In this paper, a simple and controllable method to fabricate - and -PbO is reported. Lead nitrate as precursor was dissolved in 50ml distilled water, and was heated to 80oC. Sodium chloride was added into the lead nitrate aqueous solution. During the process, -PbO deposition will be obtained when we add lead nitrate solutions with KOH pellets without chloride anion. When we add lead nitrate solutions with KOH pellets with a little chloride anion, there will produce -PbO deposition. Our results indicate that the concentration of chloride anion and temperature of reaction solution affects the crystal morphologies and modifications of lead monoxide plate precipitates from lead nitrate solution and we can selectively and controllably produce - or -PbO by this way.

Measurement of the Molecular Mass Dependence of the Mass Diffusion Coefficient in Protein Aqueous Solutions

2012 ◽  
Vol 326-328 ◽  
pp. 452-458 ◽  
Author(s):  
Juan F. Torres ◽  
Atsuki Komiya ◽  
Junnosuke Okajima ◽  
Shigenao Maruyama
Keyword(s):  
Molecular Structure ◽  
Diffusion Coefficient ◽  
Molecular Size ◽  
Mass Diffusion ◽  
Phase Shifting ◽  
Distilled Water ◽  
Concentration Profiles ◽  
Mass Dependence ◽  
Free Diffusion ◽  
Wide Range

This paper reports the measurement of the binary mass diffusion coefficient for proteins with a wide range of molecular size. The diffusion coefficient is obtained by conducting diffusion experiments in the dilute region. Transient concentration profiles were measured by a phase shifting interferometer and subsequently compared with a numerical calculation based on Ficks law to determine the diffusion coefficient. Distilled water was used as solvent in free diffusion experiments conducted at T = (25 ± 1.0)°C. The method was validated by measuring the diffusion coefficient of aqueous NaCl, Sucrose, and BSA, which values have been extensively reported in the literature. The values of the diffusion coefficient for seven proteins: aprotinin (6.5 kDa), α-lactalbumin (14.2 kDa), lysozyme (14.3 kDa), trypsin inhibitor (20.1 kDa), ovalbumin (44.2 kDa), bovine serum albumin (66.7 kDa), and phosphorylase b (97.2 kDa), were determined in the dilute region of 0-3 mg/ml. The results are compared with the Stokes-Einstein equation. The influence of the molecular structure and pH on the diffusion coefficient is discussed.

scholarly journals Electrification of water by splashing and spraying

1914 ◽  
Vol 90 (621) ◽  
pp. 531-543 ◽  
Keyword(s):  
Negative Charge ◽  
Positive Charge ◽  
Pure Water ◽  
Distilled Water ◽  
Dilute Solutions ◽  
Precise Data ◽  
The Subject ◽  
Vertical Jet ◽  
Made In ◽  
Complete Account

The experiments of Lenard and Sir J. J. Thomson on the electrification produced by the splashing of pure water and other liquids are well known. It was found that distilled water when splashed at a metal obstacle took up a positive charge, giving a negative charge to the air. Very dilute solutions of different substances gave very remarkable results, the sign and magnitude of the charge on the liquid depending on the dissolved substance and the degree of concentration of the solution. In all cases the electrification ultimately approached zero as the strength of the solution increased, so that for solutions of quite moderate strength the effect was inappreciable. Simpson has shown that if drops of distilled water are allowed to fall into a vertical jet of air of sufficient velocity, the drops are broken up and acquire a positive charge. Investigations of the electrification produced in the air when splashing takes place have been made by Kähler, Aselmann and Simpson. Similar investigations have been made in connection with bubbling and spraying of liquids by Townsend, Sir J. J. Thomson, Kosters, Eve and M. Bloch. A complete account of the subject will be found in a memoir by J. J. Rey. The work described in this paper was undertaken with a view to obtaining some precise data from which it might be possible to establish a connection between the charge produced on the liquid and the extent to which it had been broken up.

Interaction of monomeric and polymeric species of metal ions with clay surfaces. IV. Mixed system of aluminium(III) and iron(III)

Soil Research ◽  
1979 ◽  
Vol 17 (1) ◽  
pp. 141 ◽  
Author(s):  
P Rengasamy ◽  
JM Oades
Keyword(s):  
Positive Charge ◽  
Mixed System ◽  
Pure Aluminium ◽  
X Rays ◽  
Soil Systems ◽  
Mixed Solutions ◽  
Polymeric Species ◽  
Starting Solutions ◽  
End Members ◽  
Indifferent Electrolyte

Polymerization of aluminium(III) and iron(III), in mixed solutions of the nitrates, by dialysis against distilled water resulted in polycations having higher Fe/(Fe+Al) mole ratios than those of the starting solutions. A maximum of 25 mole per cent aluminium(III) entered probably into the structure of the po1y[Fe(III)-OH] cation. Ferric aquo-ions polymerized quickly and slower polymerization of aluminium(III) led to the exclusion of the monomeric aluminium(III) during hydrolysis. A more complete polymerization of both aluminium(III) and iron(III) in mixed solutions was initiated by adding sodium hydroxide up to a OH/(Fe+Al) mole ratio of 2.5 and then removing the monomers by dialysis. The resultant polycations had Fe/(Fe+Al) mole ratios close to the original solutions. The pH values and positive charge of these products were higher than any obtained with either pure aluminiurn(III) or iron(III) systems, suggesting that these are copolycations of aluminium(III) and iron(III) rather than a mixture of separate aluminium(III) and iron(III) species. The infrared spectra of these copolycations were different from the pure end members, viz. po1y[Fe(III)-OH] and poly[Al(III)-OH] cations prepared under similar conditions, confirming that they were copolymers rather than a physical mixture of individual polymers. The copolycations coagulated by adding an indifferent electrolyte, sodium nitrate, were amorphous to X-rays. Electron micrographs showed that the morphology of particles in these solutions of copolycations became regular hexagons as the aluminium(III) content increased. The pure aluminium(III) sample showed regular hexagonal particles. In general the particle size decreased with increasing aluminium(III) content. The results obtained for critical coagulation concentration and maximum adsorption for sodium-kaolinite were consistent with the earlier reports for pure aluminium(III) or iron(III) system. Both were related to the positive charge on the copolycations. Maximum adsorption of copolycations on sodium-kaolinite caused charge reversal. The pzc of the copolycation treated kaolinites were between 6.40 and 8.65, the PZC increasing with a1uminium(III) content. The significance of the possible existence of copolycations of aluminium(III) and iron(III) in soil systems is discussed.

Characterization of partially neutralized ferric nitrate solutions

1976 ◽  
Vol 56 (2) ◽  
pp. 270-283 ◽  
Author(s):  
P.J Murphy ◽  
A.M Posner ◽  
J.P Quirk
Keyword(s):  
Ferric Nitrate ◽  
Nitrate Solutions
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