Lamellar Dilation in (AB)-g-A Copolymacromer Melts: A Dissipative Particle Dynamics Study

Area of Science:

• Polymer Science
• Materials Science
• Computational Chemistry

Background:

• Homopolymer addition is a common method to increase spacing in block copolymer microdomains.
• Conventional blends face macrophase separation at high homopolymer concentrations, limiting dilation.

Purpose of the Study:

• Investigate a novel covalently hybridized bottlebrush copolymer (CH-BBC) architecture.
• Compare the phase behavior of CH-BBC with conventional blends using simulations.

Main Methods:

• Dissipative particle dynamics (DPD) simulations were employed.
• Phase behavior of CH-BBC melts was directly compared to blends of AB diblocks and homopolymers.
• Lamellar analysis and 1D density profiles were used.

Main Results:

• CH-BBC exhibited microphase morphologies without macrophase separation.
• Conventional blends showed significant two-phase coexistence at high homopolymer loading.
• CH-BBC achieved larger microphase dilation and selective swelling of the A-rich domain.

Conclusions:

• The CH-BBC architecture effectively suppresses macrophase separation.
• This approach allows for greater homopolymer-driven microdomain dilation.
• Tethered homopolymer segments preferentially swell the A-rich domains in CH-BBC.