Structural Analysis of Bottlebrush Block Copolymer Micelles Using Small-Angle X‑ray Scattering
journal contributionposted on 2020-08-18, 15:04 authored by Seyoung Kim, Yunshik Cho, Jee Hyun Kim, Sanghoon Song, Jeewoo Lim, Soo-Hyung Choi, Kookheon Char
We present structural analysis of spherical diblock copolymer micelles where core blocks have bottlebrush architecture. The dependence of the core radius (Rcore) and the corona thickness (Lcorona) on the core block length (Ncore) is investigated using small-angle X-ray scattering (SAXS) and discussed in terms of the stiffness of a core-forming polymer posed by its long fluoroalkyl side chains. The conformation of the core block is strongly stretched, and the measured exponents α and β from power-law correlations, Rcore ∼ Ncoreα and Lcorona ∼ Ncoreβ, respectively, are greater than those from any scaling predictions for block copolymer micelles with a flexible, linear core-block. Such deviations are attributed to the appreciable chain stiffness of the bottlebrush core block, and a simple model is suggested to understand how the core block stiffness influences both the dimensions of core and corona.
bottlebrush architecturebottlebrush core blockexponents αchain stiffnessblock copolymer micellesL coronafluoroalkyl side chainscore blockcorona thicknesscore blocksSAXSdiblock copolymer micellespower-law correlationssmall-angle X-raycore-forming polymerR corecore radiusN corecore block stiffness influencesSuch deviationsStructural AnalysisBottlebrush Block Copolymer Micellescore block length