1H NMR, Surface Tension, Viscosity, and Volume Evidence of Micelle−Polymer Hydrophobic Interactions:  LiPFN−PVP System†

1997 ◽  
Vol 101 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Bianca Sesta ◽  
Anna Laura Segre ◽  
Alessandro D'Aprano ◽  
Noemi Proietti
Keyword(s):  
Surface Tension ◽  
1H Nmr ◽  
Hydrophobic Interactions

scholarly journals Jetting Performance of Polyethylene Glycol and Reactive Dye Solutions

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 739 ◽  
Author(s):  
Zhiyuan Tang ◽  
Kuanjun Fang ◽  
Yawei Song ◽  
Fuyun Sun
Keyword(s):  
Surface Tension ◽  
Polyethylene Glycol ◽  
Production Efficiency ◽  
Hydrophobic Interactions ◽  
Reactive Dye ◽  
Droplet Formation ◽  
Visible Absorption ◽  
Fluid Behavior ◽  
Spherical Droplets ◽  
Dye Solutions

The jetting performance of dye inks determines the image quality, production efficiency, and lifetime of the print head. In the present study, we explored the jetting performance of mixed solutions of polyethylene glycol (PEG) and reactive dye by testing the visible absorption spectra, rheological properties, and surface tension, in addition to the observation of droplet formation. The results indicate that PEG macromolecules could change the aggregate groups of Red 218 molecules into smaller ones through hydrophobic interactions and separation effect. The addition of PEG into the dye solution increased the viscosity and decreased the surface tension. In the whole shear rate range tested, the 10% and 20% PEG400, as well as the 30% PEG200 dye solutions, showed good Newtonian fluid behavior. PEG macromolecules improved the droplet formation of the dye solutions. Increasing the PEG400 concentration to 30% and 40% resulted in elimination of the formation of satellites and the formation of ideal droplets at 10,000 Hz jetting frequency. A 30% PEG600-dye solution with the Z value of 4.6 formed the best spherical droplets at 10,000 Hz and produced perfect color images on cotton fabrics.

Aggregation behavior of pyridinium based ionic liquids in water – Surface tension, 1H NMR chemical shifts, SANS and SAXS measurements

2012 ◽  
Vol 371 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Nandhibatla V. Sastry ◽  
Nilesh M. Vaghela ◽  
Pradip M. Macwan ◽  
Saurabh S. Soni ◽  
Vinod K. Aswal ◽  
...  
Keyword(s):  
Surface Tension ◽  
Ionic Liquids ◽  
1H Nmr ◽  
Water Surface ◽  
Chemical Shifts ◽  
Aggregation Behavior ◽  
Nmr Chemical Shifts

scholarly journals Production of biosurfactant by hydrocarbon degrading Rhodococcus ruber and Rhodococcus erythropolis

1999 ◽  
Vol 30 (3) ◽  
pp. 231-236 ◽  
Author(s):  
Flávio Correa Bicca ◽  
Leonardo Colombo Fleck ◽  
Marco Antônio Záchia Ayub
Keyword(s):  
Surface Tension ◽  
Oil Spills ◽  
Hydrophobic Interactions ◽  
Rhodococcus Erythropolis ◽  
Medium Composition ◽  
Biosurfactant Production ◽  
Rhodococcus Ruber ◽  
Biotechnological Production ◽  
Reduce Surface Tension ◽  
Production Strain

There is world wide concern about the liberation of hydrocarbons in the environment, both from industrial activities and from accidental spills of oil and oilrelated compounds. Biosurfactants, which are natural emulsifiers of hydrocarbons, are produced by some bacteria, fungi and yeast. They are polymers, totally or partially extracellular, with an amphipathyc structure, which allows them to form micelles that accumulate at the interface between liquids of different polarities such as water and oil. This process is based upon the ability of biosurfactants to reduce surface tension, blocking the formation of hydrogen bridges and certain hydrophilic and hydrophobic interactions. The ability of biosurfactant production by five strains of Rhodococcus isolated from oil prospecting sites was evaluated. Surface tension measurement and emulsifying index were used to quantify biosurfactant production. The influence of environmental conditions was also investigated - pH, temperature, medium composition, and type of carbon source - on cell growth and biosurfactant production. Strain AC 239 was shown to be a potential producer, attaining 63% of emulsifying index for a Diesel-water binary system. It could be used, either directly on oil spills in contained environments, or for the biotechnological production of biosurfactant.

scholarly journals Adsorption of Polycomplexes at Solution/Air Interface

2017 ◽  
Vol 4 (4) ◽  
pp. 259
Author(s):  
E.M. Shaikhutdinov ◽  
K.Zh. Abdiyev ◽  
M.B. Zhursumbayeva ◽  
S.Kh. Khussain
Keyword(s):  
Surface Tension ◽  
Relaxation Time ◽  
Complex Formation ◽  
Surface Activity ◽  
Kinetic Data ◽  
Hydrophobic Interactions ◽  
Standard Free Energy ◽  
Free Energy Of Adsorption ◽  
Air Interface ◽  
Potentiometric Measurements

<p>The effect of complex formation of polyacids (polyacrylic (PAAc) and polymethacrylic (PMAAc)) with polyacrylamide (PAA) on their surface properties at solution/air interface has been studied by surface tension, electric conductivity and potentiometric measurements at 293±0.2 K. The relaxation time and surface activity of polycomplexes were calculated from kinetic data on the surface tension. It was found that during complex formation the relaxation time of a surface layer has a maximum and the surface activity of macromolecules is increased. Also the standard free energy of adsorption for PAA and polyacid-PAA polycomplexes were calculated. They are equal DadsG°<sub>293</sub> = - 19.1±0.1 kJ/base-mol. for PAA, DadsG°<sub>293</sub> = -21.2±0.1 kJ/basemol. for PMAAc-PAA polycomplex and DadsG°<sub>293</sub> = -23.0±0.1 kJ/base-mol. for PAAc-PAA polycomplex (calculation per base-mole of PAA monomer link). It is shown that the surface activity and ability to decrease of the water surface tension is less for PMAAc-PAA than for PAAc-PAA. Such anomalous behaviour of PMAAc-PAA polycomplex probably is caused by an excessive strengthening of inner- and intermolecular hydrophobic interactions in macromolecules of PMAAc- PAA polycomplexes due to the presence of α-methyl groups in PMAAc macromolecules. Because of the rebuilding of macromolecule segments of complex by polarity at the interface is becoming a difficult one.</p>

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

The Use of Styrenes as Embedding Media for Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 488-489
Author(s):  
Edward D. De-Lamater ◽  
Eric Johnson ◽  
Thad Schoen ◽  
Cecil Whitaker
Keyword(s):  
Electron Microscopy ◽  
Surface Tension ◽  
Ultraviolet Light ◽  
Methyl Ethyl Ketone Peroxide ◽  
Methyl Ethyl ◽  
Styrene Polymerization ◽  
Radical Initiation ◽  
Tertiary Butyl ◽  
Low Viscosity ◽  
Free Radical Initiation

Monomeric styrenes are demonstrated as excellent embedding media for electron microscopy. Monomeric styrene has extremely low viscosity and low surface tension (less than 1) affording extremely rapid penetration into the specimen. Spurr's Medium based on ERL-4206 (J.Ultra. Research 26, 31-43, 1969) is viscous, requiring gradual infiltration with increasing concentrations. Styrenes are soluble in alcohol and acetone thus fitting well into the usual dehydration procedures. Infiltration with styrene may be done directly following complete dehydration without dilution.Monomeric styrenes are usually inhibited from polymerization by a catechol, in this case, tertiary butyl catechol. Styrene polymerization is activated by Methyl Ethyl Ketone peroxide, a liquid, and probably acts by overcoming the inhibition of the catechol, acting as a source of free radical initiation.Polymerization is carried out either by a temperature of 60°C. or under ultraviolet light with wave lengths of 3400-4000 Engstroms; polymerization stops on removal from the ultraviolet light or heat and is therefore controlled by the length of exposure.

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