Combined Analysis of Polycation/ODN Polyplexes by Analytical Ultracentrifugation and Dynamic Light Scattering Reveals their Size, Refractive Index Increment, Stoichiometry, Porosity, and Molecular Weight

2014 ◽  
Vol 15 (3) ◽  
pp. 940-947 ◽  
Author(s):  
Yves Niebel ◽  
Michael D. Buschmann ◽  
Marc Lavertu ◽  
Gregory De Crescenzo
Keyword(s):  
Molecular Weight ◽  
Refractive Index ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Analytical Ultracentrifugation ◽  
Combined Analysis ◽  
Refractive Index Increment

LIGHT-SCATTERING STUDIES OF COPOLYMERS: I. EFFECT OF HETEROGENEITY OF CHAIN COMPOSITION ON THE MOLECULAR WEIGHT

1958 ◽  
Vol 36 (12) ◽  
pp. 1616-1626 ◽  
Author(s):  
W. Bushuk ◽  
H. Benoit
Keyword(s):  
Molecular Weight ◽  
Refractive Index ◽  
Light Scattering ◽  
Average Molecular Weight ◽  
Apparent Molecular Weight ◽  
Scattering Data ◽  
Refractive Index Increment ◽  
Molecular Weights ◽  
Chain Composition ◽  
Total Molecular Weight

The classical light-scattering theory for polymer solutions is extended to solutions of copolymers which may be polydisperse in chain composition as well as in molecular weight. It is shown that much too high molecular weights will result from light-scattering data for copolymers owing to fluctuations in chain composition; the magnitude of this effect increases rapidly as the absolute value of the refractive index increment approaches zero. The methods for determining the usual weight-average molecular weight and polydispersity of composition are described.The theory was tested with experimental results on: (1) a mixture of polystyrene and poly(methylmethacrylate), considered as a copolymer with the highest possible polydispersity of composition; (2) a high conversion, statistical copolymer of styrene and methylmethacrylate (copolymer I); and (3) a block copolymer of the same monomers (copolymer II). The apparent molecular weight for copolymer I (Mw = 1.83 × 105) varied markedly with refractive index increment in much the same way as the total molecular weight for the mixture. The molecular weight of copolymer II (Mw = 1.20 × 106) remained essentially constant in the same series of solvents. The polydispersities of composition obtained were 0.72 and 0.05 for copolymer I and II respectively compared with the maximum possible value equal to 1.0.

scholarly journals The molecular weight of Artemia ribosomes, as determined from their refractive-index increment and light-scattering intensity

1981 ◽  
Vol 197 (3) ◽  
pp. 689-693 ◽  
Author(s):  
Paul Nieuwenhuysen ◽  
Frank De Voeght ◽  
Julius Clauwaert
Keyword(s):  
Molecular Weight ◽  
Refractive Index ◽  
Light Scattering ◽  
Brine Shrimp ◽  
Artemia Salina ◽  
Refractive Index Increment ◽  
Scattering Intensity ◽  
A Value ◽  
Light Scattering Intensity ◽  
Cytoplasmic Ribosomes

Cytoplasmic ribosomes were isolated from the cryptobiotic embryos of the brine shrimp Artemia salina. Measurements of their refractive-index increments and light-scattering intensities give a value for their molecular weight of (3.4±0.2)×106.

Effect of small refractive index increment on light scattering molecular weight

1954 ◽  
Vol 14 (75) ◽  
pp. 310-312 ◽  
Author(s):  
Robert Tremblay ◽  
Yvon Sicotte ◽  
Marcel Rinfret
Keyword(s):  
Molecular Weight ◽  
Refractive Index ◽  
Light Scattering ◽  
Refractive Index Increment

scholarly journals COMPLEXATION OF POLYETHYLENE-GLYCOL WITH THE SODIUM SALTS OF CITRIC AND SUCCINIC ACIDS IN THE AQUEOUS SOLUTIONS. STUDIES BY DYNAMIC LIGHT SCATTERING AND UV/VIS SPECTROPHOTOMETRY

2015 ◽  
Vol 11 (8) ◽  
pp. 3866-3872
Author(s):  
E.A. Masimov ◽  
Etibar Hummat Ismailov ◽  
S.Y. Odzhaqverdiyeva
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Aqueous Solutions ◽  
Polyethylene Glycols ◽  
Hydrodynamic Diameter ◽  
Absorption Bands ◽  
Sodium Salts ◽  
And Diffusion ◽  
Formation Of Complexes

Dynamic light scattering (DLS) method in combination with the UV/VIS spectrophotometry is used to study the interaction of polyethylene- glycols with a molecular weight  6000 ( PEG6000 ) with sodium salts of citric and succinic acids in aqueous solutions. The values of density, viscosity, refractive and diffusion indexes, the values of the hydrodynamic diameter, wavelength electronic absorption bands for PEG6000 aqueous solutions, their mixtures with succinic and citric acids are determined. It was shown that depending on the composition of the solutions the values of hydrodynamic diameter for aqueous solutions containing 1-5 wt.% PEG6000 and their mixtures with succinic and citric acids (~ 1 wt%) ranges from 3.6 to 5.2 nm. It is assumed that the formation of complexes with the sizes  that are within the above range is due to the features of interaction  and the structure of the complexes formed in solution.

Study of stabilization of self-assembly processes in fullerene C60 solution

2021 ◽  
Vol 23 (3) ◽  
pp. 12-14
Author(s):  
U.K. Makhmanov ◽  
A.M. Kokhkharov ◽  
Sh.A. Esanov ◽  
B.A. Aslonov ◽  
B.A. Sindarov ◽  
...  
Keyword(s):  
Refractive Index ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Molecular Interactions ◽  
Self Assembly ◽  
Fullerene C60 ◽  
Self Organization ◽  
Final Size ◽  
Initial Concentration ◽  
Xylene Solution

The dynamics of changes in the values of the refractive index of solutions of C60 in xylene at various concentrations has been studied by the refractometric method. It was found that the deviation from the linear form of the dependence of the refractive index on the C60 concentration occurs at a C60 concentration of 1.8 mg/ml. The deviation is associated with the largest number of molecular interactions between C60−C60 and the formation of large nanoclusters on their basis in solution. It was found by the dynamic light scattering (DLS) that the final size of C60 nanoclusters in solution depends on the initial concentration of the solute. A higher initial concentration of C60 leads to the synthesis of nanoclusters with a larger diameter. Using the method of optical spectroscopy, the processes of self-organization of fullerene C60 molecules in a xylene solution in time are studied. The character of stability of synthesized fullerene nanoclusters in solution is discussed. The results obtained are of particular importance for numerous applications of nanotechnology for understanding self-assembly processes and the development of new nanomaterials.

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