Metachromasy in clay dye systems: the adsorption of acridine orange by Na-beidellite

AbstractThe adsorption of the metachromic dye acridine orange (AO) by Na-beidellite was investigated by visible spectroscopy. Different types of clay-AO association were identified from the appearance and location of absorption bands α or β. The colloidal properties were determined from curves of the absorbance vs. the degree of saturation. Three regions were identified in the absorbance curve. In the first region beidellite is peptized with small amounts of AO and the dye penetrates into the interlayer space where it undergoes metachromasy due to π interactions between the aromatic entity and the oxygen plane of the clay. With larger amounts of AO (second region), the clay flocculates due to the aggregation of the dye cations in the interparticle space of the flocs. In excess AO (third region), beidellite is gradually peptized, forming small tactoids with monomeric AO in the interlayer space and at the same time adsorbing dimeric and polymeric AO cationic species at the solid-liquid interface. Compared with the other smectites, AO shows the greatest tendency to undergo metachromasy in the presence of beidellite.

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Metachromasy in clay-dye systems: the adsorption of acridine orange by Na-saponite

Clay Minerals ◽

10.1180/claymin.1997.032.4.15 ◽

1997 ◽

Vol 32 (4) ◽

pp. 653-663 ◽

Cited By ~ 22

Author(s):

D. Garfinkel-Shweky ◽

S. Yariv

Keyword(s):

Cation Exchange ◽

Acridine Orange ◽

Organic Cation ◽

Interlayer Space ◽

Aqueous Suspension ◽

Cationic Dye ◽

Visible Spectroscopy ◽

Π Interactions ◽

Colloidal Properties ◽

Clay Platelets

AbstractThe adsorption of the cationic dye acridine orange (AO) by Na-saponite and the colloidal properties of the aqueous suspension were investigated by visible spectroscopy and XRD. The organic cation is adsorbed by the mechanism of cation exchange. When small amounts of the dye are adsorbed, the system contains small tactoids and is peptized. At this stage the dye penetrates into the interlayer space and most of it undergoes metaehromasy due to interactions between the aromatic entity and the oxygen plane of the clay. When greater amounts of AO are adsorbed, the clay platelets flocculate to form book-house floes which, with excess AO, are transformed into card-house floes. At this stage metachromasy results from the aggregation of the dye in the interparticle space of the floes, in addition to the π interactions with the oxygen plane. In excess AO, the clay is gradually peptized. At this stage the dispersed clay platelets form small tactoids with monomeric AO in the interlayer space and at the same time adsorb dimerie and polymeric AO cationic species at the solidliquid interface.

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Determination of optical constants and vibrational band intensities of liquids in the infrared using attenuated total reflexion

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1967.0097 ◽

1967 ◽

Vol 298 (1453) ◽

pp. 160-177 ◽

Cited By ~ 15

Keyword(s):

Refractive Index ◽

Carbon Tetrachloride ◽

Working Conditions ◽

Optical Constants ◽

Carbon Disulphide ◽

Absorption Bands ◽

Total Reflexion ◽

Solid Liquid Interface ◽

Solid Liquid

The refractive index, and vibrational absorption band intensities, of some liquids have been determined by a new method involving attenuated total reflexion at a solid liquid interface. The principles of the method have been explained and the factors which determine a choice of optimal working conditions have been discussed. The method has been applied to absorption bands of benzene, carbon tetrachloride, chloroform, bromoform, sym -tetrabromo-ethane, and carbon disulphide. Data have been obtained on the variation of refractive index across the absorption bands, and the computed band intensities have been compared with those obtained previously by other methods.

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THE FORMATION OF STRIATION-TYPE SUBSTRUCTURE IN ALUMINUM

Canadian Journal of Physics ◽

10.1139/p62-091 ◽

1962 ◽

Vol 40 (7) ◽

pp. 850-858 ◽

Cited By ~ 6

Author(s):

J. T. McGrath ◽

G. B. Craig

Keyword(s):

Crystal Growth ◽

Crystallographic Orientation ◽

Complex Function ◽

Solute Concentration ◽

Growth Direction ◽

Average Concentration ◽

Rate Of Growth ◽

Different Types ◽

Solid Liquid Interface ◽

Solid Liquid

Striations are one type of substructure which can form in metals as they solidify from the melt. The formation of striations is dependent upon the rate of crystal growth, the purity, and the crystallographic orientation. In aluminum single crystals, it was found that striation boundaries tended to approach a preferred (100) growth direction with increasing rate of growth and with increasing solute concentration. With different types of solute, it appears that similar values of the average concentration of solute in the liquid at the solid–liquid interface (C0/k) produced the same effect on striation direction.The number of striations found in any sample appeared to be a complex function of the purity, the orientation, and the rate of growth.

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Atom-probe analysis of the solid-liquid interface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139755 ◽

1995 ◽

Vol 53 ◽

pp. 676-677

Author(s):

J.A. Panitz

Keyword(s):

Molecular Level ◽

Selective Adsorption ◽

Electronic Devices ◽

Atom Probe ◽

Chemical Agent ◽

Hostile Environment ◽

Solid Interface ◽

Solid Liquid Interface ◽

Solid Liquid ◽

Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

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Structure of weakly charged polyelectrolytes at a solid-liquid interface

Journal de Physique II ◽

10.1051/jp2:1993186 ◽

1993 ◽

Vol 3 (7) ◽

pp. 1097-1108 ◽

Cited By ~ 24

Author(s):

R. Varoqui

Keyword(s):

Liquid Interface ◽

Solid Liquid Interface ◽

Solid Liquid

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THERMAL RESISTANCE OF NANOPARTICLE LAYER DEPOSITED SOLID-LIQUID INTERFACE

10.1615/ihtc16.tpm.022135 ◽

2018 ◽

Author(s):

Yoshitaka Ueki ◽

Tomoya Oyabu ◽

Masahiko Shibahara

Keyword(s):

Thermal Resistance ◽

Liquid Interface ◽

Nanoparticle Layer ◽

Solid Liquid Interface ◽

Solid Liquid

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THERMAL BOUNDARY MODULATION EFFECT ON THE FLOW AND CONCENTRATION FIELD ADJACENT TO THE SOLID-LIQUID INTERFACE

Equipment ◽

10.1615/ihtc13.p3.60 ◽

2006 ◽

Author(s):

E. Semma ◽

Mohammed El Ganaoui ◽

Victoria Timchenko ◽

Eddie Leonardi

Keyword(s):

Concentration Field ◽

Liquid Interface ◽

Modulation Effect ◽

Solid Liquid Interface ◽

Solid Liquid

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The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

Water Science & Technology ◽

10.2166/wst.1999.0336 ◽

1999 ◽

Vol 39 (7) ◽

pp. 91-98 ◽

Cited By ~ 3

Author(s):

Ryan N. Jordan ◽

Eric P. Nichols ◽

Alfred B. Cunningham

Keyword(s):

Mass Transfer ◽

Cell Membrane ◽

Substrate Concentration ◽

Water Interface ◽

Industrial Systems ◽

Solid Liquid Interface ◽

Solid Liquid ◽

Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

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Wetting of glass surface using natural surfactants

Micro and Nanosystems ◽

10.2174/1876402912666200219111447 ◽

2020 ◽

Vol 12 ◽

Author(s):

Nihar Ranjan Biswal

Keyword(s):

Contact Angle ◽

Glass Surface ◽

Pure Water ◽

Amyl Alcohol ◽

Synthetic Surfactant ◽

Wide Range ◽

Different Types ◽

Natural Surfactants ◽

Triton X ◽

Solid Liquid

Background: Surfactant adsorption at the interfaces (solid–liquid, liquid–air, or liquid–liquid) is receiving considerable attention from a long time due to its wide range of practical applications. Objective: Specifically wettability of solid surface by liquids is mainly measured by contact angle and has many practical importances where solid–liquid systems are used. Adsorption of surfactants plays an important role in the wetting process. The wetting behaviours of three plant-based natural surfactants (Reetha, Shikakai, and Acacia) on the glass surface are compared with one widely used nonionic synthetic surfactant (Triton X-100) and reported in this study. Methods: The dynamic contact angle study of three different types of plant surfactants (Reetha, Shikakai and Acacia) and one synthetic surfactant (Triton X 100) on the glass surface has been carried out. The effect of two different types of alcohols such as Methanol and amyl alcohol on wettability of shikakai, as it shows little higher value of contact angle on glass surface has been measured. Results: The contact angle measurements show that there is an increase in contact angle from 47° (pure water) to 67.72°, 65.57°, 68.84°, and 68.79° for Reetha, Acacia, Shikakai, and Triton X-100 respectively with the increase in surfactant concentration and remain constant at CMC. The change in contact angle of Shikakai-Amyl alcohol mixtures are slightly different than that of methanol-Shikakai mixture, mostly there is a gradual increase in contact angle with the increasing in alcohol concentration. Conclusion: There is no linear relationship between cos θ and inverse of surface tension. There was a linear increase in surface free energy results with increase in concentration as more surfactant molecules were adsorbing at the interface enhancing an increase in contact angle.

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