Single-Chain Conformation of Poly(α-olefins) in Dilute Solutions at the Crossover between Linear and Bottlebrush Architectures

2021 ◽  
Author(s):  
Carlos R. López-Barrón ◽  
Fernando Vargas-Lara ◽  
Shuhui Kang
Keyword(s):  
Chain Conformation ◽  
Single Chain ◽  
Dilute Solutions

Multiscale modeling of polymers closely coupled to Broad Q neutron scattering from NIMROD

2013 ◽  
Vol 1524 ◽  
Author(s):  
Thomas Gkourmpis ◽  
Daniel Lopez ◽  
Geoffrey R. Mitchell
Keyword(s):  
Structure Factor ◽  
Chain Structure ◽  
Distribution Functions ◽  
Chain Conformation ◽  
Coarse Grained ◽  
Lamellar Thickness ◽  
Single Chain ◽  
Crystal Unit Cell ◽  
Key Length ◽  
Using Data

ABSTRACTWe use data over an extended Q range from 0.01 to 100Å-1 from the recently commissioned NIMROD instrument at the ISIS pulsed neutron source to develop a multi-scale inverse modeling procedure which will provide insight in to the phase transformations of polymer systems. The first level of our procedure is atomistic and we use internal coordinates (bond length, bond angles and torsion angles) to define the polymer chain in full atomistic detail. Values were assigned to each internal coordinate within the chain using a stochastic Monte Carlo method in which the probabilities were drawn from distributions representing the possible range of values. Using this approach, random chain configurations could be rapidly built and the intrachain structure factor calculated utilizing a small set of parameters and compared with the experimental function. Parameters representing the probability distribution functions were systematically varied using a grid search to find the values which gave the best fit to the structure factor for Q > 3Å-1 in order to determine the details of the chain conformation in the molten phase. This process was repeated for data over the same extended Q range obtained at lower temperatures where the polymer was expected to crystallize. Polymers crystallize via chainfolded thin lamellae crystals. Such crystals give rise to an intense peak at Q ∼ 0.03Å-1. This scattering can be calculated using a lamellar stack model, coarse-grained from the single chain structure. We describe this approach using data obtained on the crystallization from the melt phase of perdeuterated polymers. The objective here is to follow the three key length scales; the chain folded lamellar thickness of ∼ 10nm, the crystal unit cell ∼ 1nm and the detail of the chain conformation is ∼ 0.1nm.

Properties of Solutions of Rodlike Chains from Dilute Solutions to the Nematic State

1988 ◽  
Vol 134 ◽  
Author(s):  
Guy C. Berry
Keyword(s):  
Physical Chemistry ◽  
Intrinsic Viscosity ◽  
Rheological Behavior ◽  
Nematic Phase ◽  
Infinite Dilution ◽  
Chain Conformation ◽  
Dilute Solutions ◽  
Concentrated Solutions ◽  
Nematic State ◽  
Rodlike Polymers

ABSTRACTCertain aspects of the physical chemistry of solutions rodlike polymers are reviewed. The range of concentrations includes infinite dilution ([ŋ]c<<l), dilute solutions ([ŋ,]c<l), moderately concentrated solutions (l<[ŋ]c<[ŋ]cNI), and concentrated solutions (c<cN,), where [ŋ] is the intrinsic viscosity and cNI. is the concentration required for a stable nematic phase. Studies of chain conformation are emphasized at infinite dilution, and rheological behavior is emphasized for more concentrated isotropic and nematic solutions. Both theoretical and experimental considerations are included.

scholarly journals Single-chain conformation of carboxylated schizophyllan, a triple helical polysaccharide, in dilute alkaline aqueous solution

Polymer ◽  
2019 ◽  
Vol 185 ◽  
pp. 121944 ◽  
Author(s):  
Yu Tomofuji ◽  
Kazuto Yoshiba ◽  
Bjørn E. Christensen ◽  
Ken Terao
Keyword(s):  
Aqueous Solution ◽  
Chain Conformation ◽  
Single Chain ◽  
Alkaline Aqueous Solution

Chain stiffness and chain conformation of poly(α-methylene-γ-butyrolactone) in dilute solutions

Polymer ◽  
2014 ◽  
Vol 55 (25) ◽  
pp. 6539-6545 ◽  
Author(s):  
Yuji Higaki ◽  
Ryosuke Okazaki ◽  
Tatsuya Ishikawa ◽  
Moriya Kikuchi ◽  
Noboru Ohta ◽  
...  
Keyword(s):  
Chain Conformation ◽  
Dilute Solutions ◽  
Chain Stiffness

Relating Substitution to Single-Chain Conformation and Aggregation in Poly(p-phenylene Vinylene) Films

Nano Letters ◽  
2003 ◽  
Vol 3 (9) ◽  
pp. 1191-1196 ◽  
Author(s):  
M. Kemerink ◽  
J. K. J. van Duren ◽  
P. Jonkheijm ◽  
W. F. Pasveer ◽  
P. M. Koenraad ◽  
...  
Keyword(s):  
Chain Conformation ◽  
Phenylene Vinylene ◽  
Single Chain

Chain conformation of block copolymers in dilute solutions measured by small-angle neutron scattering

Polymer ◽  
1992 ◽  
Vol 33 (11) ◽  
pp. 2412-2415 ◽  
Author(s):  
Yushu Matsushita ◽  
Kunio Shimizu ◽  
Ichiro Noda ◽  
Taihyun Chang ◽  
Charles C. Han
Keyword(s):  
Block Copolymers ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Chain Conformation ◽  
Dilute Solutions
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