LIGHT-SCATTERING STUDIES ON ALUMINUM DISTEARATE

1958 ◽  
Vol 36 (11) ◽  
pp. 1584-1595 ◽  
Author(s):  
A. E. Leger ◽  
J. C. Hyde ◽  
H. Sheffer
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Intrinsic Viscosity ◽  
Benzene Solution ◽  
Unit Length ◽  
Random Coil ◽  
Linear Molecule ◽  
Radius Of Gyration ◽  
Average Unit ◽  
Scattering Study

A light-scattering study of aluminum distearate in dilute benzene solution suggests that it is a linear molecule of random coil shape. This is further substantiated by intrinsic viscosity – molecular weight data, the constancy of the ratio of the molecular weight to the square of the radius of gyration (Rg), the value of Φ in Flory's intrinsic viscosity – molecular weight relationship, and the close agreement between the theoretical and experimental results found for the unit length of the polymer chain. This average unit length has been calculated to be 4.46 Å.

scholarly journals The supramolecular organization of ovomucin. Biophysical and morphological studies

1990 ◽  
Vol 266 (3) ◽  
pp. 697-706 ◽  
Author(s):  
C Rabouille ◽  
M A Aon ◽  
G Muller ◽  
J Cartaud ◽  
D Thomas
Keyword(s):  
Light Scattering ◽  
Spatial Organization ◽  
Unit Length ◽  
Random Coil ◽  
Radius Of Gyration ◽  
Supramolecular Organization ◽  
Linear Character ◽  
Morphological Studies ◽  
Exclusion Chromatography

Ovomucin participates in the ovomucin-gel-forming properties because of its shape and its ability to interact in a specific spatial organization. Purified from chicken egg-white by exclusion chromatography with Sephacryl S-300 and Sepharose CL-2B and analysed by light-scattering, it exhibited an Mr of about 40 x 10(6). This large Mr can be explained by the aggregation of polymers that can be degraded into 3 x 10(6)-Mr fragments by reduction with dithiothreitol. The values for hydrodynamic parameters such as Mr, radius of gyration, hydrodynamic radius, mass per unit length and combinations of them suggested that ovomucin is a linear and highly flexible molecule conferring upon it a random-coil-like structure in 0.2 M-NaCl solution. Analysis of the ovomucin molecules by electron microscopy revealed its linear character but also indicated a lower Mr than that obtained in the light-scattering experiments. By temperature-induced non-specific aggregation of an ovomucin solution containing other globular egg proteins, an attempt was made to find out what conditions are required for gel formation and to examine the quality of aggregation that is obtained under these conditions. Results show that the viscosity of the solution did not increase after heat treatment. Apparently, in the ovomucin gel, specific spatial organization of the ovomucin molecules is required for hydrogel formation.

scholarly journals MOLECULAR SIZE AND CONFIGURATION OF CELLULOSE TRINITRATE IN SOLUTION

1958 ◽  
Vol 36 (6) ◽  
pp. 952-969 ◽  
Author(s):  
M. M. Huque ◽  
D. A. I. Goring ◽  
S. G. Mason
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Ethyl Acetate ◽  
Average Molecular Weight ◽  
Molecular Size ◽  
Random Coil ◽  
Radius Of Gyration ◽  
Molecular Weight Range ◽  
Scattering Measurements ◽  
The Relationship

Viscosity and light-scattering measurements were made on several fractions and two unfractionated samples of cellulose trinitrate. The samples were prepared from bleached ramie, unbleached ramie, and cotton linters. The solvents were acetone and ethyl acetate. Viscosity was measured in a multishear viscometer designed for the purpose. Light-scattering measurements were made in a Brice-Phoenix Light-scattering Photometer modified to accommodate a cell which could be ultracentrifuged.The range of molecular weight investigated was from 6.5 × 105 to 25.0 × 105 The relationship between the z-average mean-square radius of gyration, [Formula: see text] and the z-average molecular weight was approximately linear in both solvents. The ratio of [Formula: see text] (where [Formula: see text] is the value of [Formula: see text] in the unperturbed state) was found constant in acetone but to increase with [Formula: see text] in ethyl acetate. This indicated that, whereas in acetone random coil configuration was attained, a configurational transition occurred in ethyl acetate in the molecular weight range investigated.The value of the exponent a in the relationship between intrinsic viscosity and molecular weight was found to be lower than unity but approximately equal in both solvents.The significance of the experimental data is discussed.

scholarly journals Lateral association and elongation of vimentin intermediate filament proteins: A time-resolved light-scattering study

2016 ◽  
Vol 113 (40) ◽  
pp. 11152-11157 ◽  
Author(s):  
Carlos G. Lopez ◽  
Oliva Saldanha ◽  
Klaus Huber ◽  
Sarah Köster
Keyword(s):  
Light Scattering ◽  
Quantitative Model ◽  
Radius Of Gyration ◽  
Time Resolved ◽  
Intermediate Filament Proteins ◽  
Hierarchical Assembly ◽  
Lateral Association ◽  
Cytoskeletal Filament ◽  
Longitudinal Association ◽  
Scattering Study

Vimentin intermediate filaments (IFs) are part of a family of proteins that constitute one of the three filament systems in the cytoskeleton, a major contributor to cell mechanics. One property that distinguishes IFs from the other cytoskeletal filament types, actin filaments and microtubules, is their highly hierarchical assembly pathway, where a lateral association step is followed by elongation. Here we present an innovative technique to follow the elongation reaction in solution and in situ by time-resolved static and dynamic light scattering, thereby precisely capturing the relevant time and length scales of seconds to minutes and 60–600 nm, respectively. We apply a quantitative model to our data and succeed in consistently describing the entire set of data, including particle mass, radius of gyration, and hydrodynamic radius during longitudinal association.

Sorption of GR-S Type of Polymer on Carbon Black. III. Sorption by Commercial Blacks

1953 ◽  
Vol 26 (1) ◽  
pp. 102-114 ◽  
Author(s):  
I. M. Kolthoff ◽  
R. G. Gutmacher
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Intrinsic Viscosity ◽  
Benzene Solution ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Molecular Weights ◽  
Bound Rubber ◽  
Flow Through ◽  
Peculiar Behavior

Abstract The sorption capacities toward GR-S five commercial carbon blacks are in decreasing order: Spheron-6, Vulcan-1, Philblack-0, Sterling-105, Philblack-A. Apparently, the sorption is not related to surface area. The sorption on Vulcan-1 of GR-S from its solutions in seven different solvents or mixtures of solvents increases with decreasing solvent power for the rubber. The sorption curves of two “cold rubbers,” polymerized at −10 and +5° respectively, showed little difference from that of 50° GR-S. Previous heating of carbon black in nitrogen at 500 or 1100° increased the sorption by about 20 per cent over unheated carbon. Air-heating of carbon black at 425° did not cause a difference in the sorption from benzene solution, but produced an increase in the sorption of rubber from n-heptane solution. In the range 75% butadiene-25% styrene to 5% butadiene-95% styrene, there is practically no effect of the degree of unsaturation on the sorption. Polystyrene of high intrinsic viscosity exhibits a peculiar behavior with furnace blacks. Vulcan-1 sorbed microgel as well as the sol fraction from n-heptane solutions of GR-S containing microgel (conversion 74.7 and 81.5 per cent). There was no appreciable difference in the amount of sorption of rubber fractions having average molecular weights varying from 433,000 to 85,000. There is little change in the amount sorbed after two hours of shaking, but the intrinsic viscosity of the residual rubber decreases with time. The low molecular-weight rubber is sorbed more rapidly, but is slowly replaced by the more tightly sorbed high molecular weight fraction. Partial fractionation of a rubber sample can be achieved by allowing the rubber solution to flow through a column of weakly sorbing carbon black. A large portion of the sorbed rubber can be recovered from the column by washing it with a good solvent such as xylene. Bound rubber is produced by intimate mixing of equal parts of carbon black and rubber swollen in chloroform, when the mixture is dried in vacuum at 80° or at room temperature. Milling is not essential to get bound rubber.

A light-scattering study of the effect of calcium chloride on the molecular weight of busycon hemocyanin

1978 ◽  
Vol 8 (2) ◽  
pp. 133-138 ◽  
Author(s):  
M.Constance Loeffler ◽  
Shian-shi Su ◽  
Norman C. Li ◽  
Edward F. Casassa
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Calcium Chloride ◽  
Scattering Study

Light-scattering study of the effect of sodium chloride on the molecular weight of human adult hemoglobin

Biochemistry ◽  
1971 ◽  
Vol 10 (17) ◽  
pp. 3222-3229 ◽  
Author(s):  
Chien Ho ◽  
Ingrid B. E. Noren ◽  
Edward F. Casassa
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Sodium Chloride ◽  
Human Adult ◽  
Adult Hemoglobin ◽  
Scattering Study
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