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Morphology of poly(lactide)‐ block ‐poly(dimethylsiloxane)‐ block ‐polylactide high‐ χ triblock copolymer film studied by grazing incidence small‐angle X‐ray scattering
Author(s) -
Freychet Guillaume,
Maret Mireille,
FernandezRegulez Marta,
Tiron Raluca,
Gharbi Ahmed,
Nicolet Celia,
Gergaud Patrice
Publication year - 2020
Publication title -
journal of polymer science
Language(s) - English
Resource type - Journals
eISSN - 2642-4169
pISSN - 2642-4150
DOI - 10.1002/pol.20200196
Subject(s) - grazing incidence small angle scattering , materials science , copolymer , scattering , volume fraction , morphology (biology) , composite material , polymer , polymer chemistry , crystallography , optics , small angle neutron scattering , chemistry , physics , neutron scattering , biology , genetics
The morphologies of poly(lactide)‐ block ‐poly(dimethylsiloxane)‐ block ‐polylactide (PLA‐ b ‐PDMS‐ b ‐PLA) triblock copolymer films were studied using a combination of grazing‐incidence small‐angle X‐ray scattering, X‐ray reflectivity and scanning electron microscopy. This block copolymer is characterized by a high Flory–Huggins interaction parameter which leads to the self‐assembly of periodic high‐resolution nanodomains. In this article, we performed a detailed analysis of GISAXS patterns, in the frame of the Distorted Wave Born Approximation, in order to determine the morphology of blocks and their spatial arrangement. For a low volume fraction of PLA (17%), a three‐dimensional hexagonal lattice of PLA spherical blocks is revealed, while, for a PLA fraction twice larger, in‐plane (parallel) PLA lying cylinders adopt a two‐dimensional centered rectangular lattice. Moreover, the in‐depth electron density profile of the polymer film for the cylindrical morphology was extracted from the XRR data, revealing the presence of interfacial layers at the top surface and at the interface with the Si substrate.