Dimensions of branched macromolecules in good solvents

Kron, A.K.; Ptitsyn, Oleg B.

doi:10.1016/0032-3950(63)90329-0

Cited by 5 publications

(3 citation statements)

References 15 publications

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“…In refs. [4][5][6][7] it was assumed that the backbone and side chains obey the same random-flight (Gaussian) statistics and they have the same stiffness as for isolated chains. On the other hand, numerous experimental data 8,9) demonstrate that even at H-conditions the mean dimensions of a comb copolymer are much greater than the unperturbed dimensions of the homopolymer used as a backbone.…”

Section: Theoretical Background and Overviewmentioning

confidence: 99%

“…In the literature, there are different interpretations of this important observation, e. g., (i) at the theta point for the corresponding unbranched linear polymer, the expansion factor of the branched macromolecule, a, is essentially larger than unity and the osmotic second virial coefficient B is larger than zero, whereas according to the Flory-type theory [4][5][6][7] it should be a = 1 and B = 0 under these conditions (in other words, the dimensions of the comb polymer determined for theta conditions are not unperturbed) [10][11][12][13][14] ; (ii) the equilibrium stiffness of chains increases markedly when they are consolidated in a comblike structure 15) . At this stage it is worth-while to remind the concept of quasimonomers, introduced by one of us in ref.…”

Section: Theoretical Background and Overviewmentioning

confidence: 99%

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Conformational properties and dynamics of molecular bottle-brushes: A cellular-automaton-based simulation

Khalatur¹,

Shirvanyanz²,

Starovoitova³

et al. 2000

Macromol. Theory Simul.

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Extensive computer simulation was performed using the bond‐fluctuation model and cellular‐automaton (CA)‐based simulation technique to probe the equilibrium structure and dynamical behavior of comb‐branched polymers in which the flexible side chains of a given length are placed regularly along the backbone and the number of branches increases linearly with total molecular weight. By applying very efficient CA algorithm – the “lattice molecular dynamics” (LMD) method – we have been able to study the properties of sufficiently large structures (up to 5880 monomeric units). Depending on the length of main and side chains as well as on interbranch spacing, we have calculated mean chain dimensions, local fractal dimensionalities, particle scattering functions, time autocorrelation functions, etc. The following main conclusions may be drawn from the results presented in our study: (i) The critical exponent, governing the mean size of the main chain, remains unchanged from its value known for a 3d self‐avoiding walk (SAW). On the other hand, two‐dimensional branched macromolecules with one‐sided branches are effectively in a collapsed state even under conditions of a good solvent, forming specific helical superstructures. (ii) Comparison of the simulated data with the predictions of the scaling model indicates that the latter is valid in describing the mean dimensions of the backbone as a function of side‐chain length and interbranch spacing. (iii) The excluded volume interaction between side chains dramatically slows down the relaxation of the backbone chain.

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Section: Theoretical Background and Overviewmentioning

confidence: 99%

Section: Theoretical Background and Overviewmentioning

confidence: 99%

Conformational properties and dynamics of molecular bottle-brushes: A cellular-automaton-based simulation

Khalatur¹,

Shirvanyanz²,

Starovoitova³

et al. 2000

Macromol. Theory Simul.

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“…'2t giq) . (13) and determining giq) by extremizing the entropy of the branched polymer, we get (see section III of ref 15 for details)…”

Section: Uniform Starsmentioning

confidence: 99%

Extrapolation formulas for dimensions of branched polyelectrolytes

Muthukumar¹

1993

Macromolecules

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We have derived simple extrapolation formulas for the mean-square radius of gyration and structure factor of any branched polyelectrolytes for arbitrary values of molecular weight and various parameters of the screened electrostatic and excluded-volume interactions. In general, the mean-square radius of gyration < S2) b is proportional to (r*/5Le/5 and L2 in the strong and weak Coulombic screening limits, respectively, where is the inverse Debye length, L is the total chain length, and the proportionality coefficients depend on the nature and details of the branching. For uniform stars with f (»1) branches,

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