期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：10
页码：5168-5175
DOI：10.1073/pnas.1916362117
出版社：The National Academy of Sciences of the United States of America
摘要：Uncharged bottlebrush polymer melts and highly charged polyelectrolytes in solution exhibit correlation peaks in scattering measurements and simulations. Given the striking superficial similarities of these scattering features, there may be a deeper structural interrelationship in these chemically different classes of materials. Correspondingly, we constructed a library of isotopically labeled bottlebrush molecules and measured the bottlebrush correlation peak position q * = 2 π / ξ by neutron scattering and in simulations. We find that the correlation length scales with the backbone concentration, ξ ∼ c B B − 0.47 , in striking accord with the scaling of ξ with polymer concentration c P in semidilute polyelectrolyte solutions ( ξ ∼ c P − 1 / 2 ) . The bottlebrush correlation peak broadens with decreasing grafting density, similar to increasing salt concentration in polyelectrolyte solutions. ξ also scales with sidechain length to a power in the range of 0.35–0.44, suggesting that the sidechains are relatively collapsed in comparison to the bristlelike configurations often imagined for bottlebrush polymers.
