PhD Defence Matus Kalina

Block copolymers are a specialized class of polymers in which two or more polymer segments, made from chemically distinct monomers, are arranged as separate blocks along the polymer backbone. These advanced materials can combine the properties of their individual segments, making them attractive for highly specialized applications such as drug delivery, membranes, and nanolithography. Because the different polymer blocks are inherently immiscible, but also covalently bonded and therefore unable to fully separate, block copolymers can organize themselves into ordered, periodic structures through a process known as self-assembly. During this process, the different blocks rearrange in order to minimize the contact area between incompatible segments.

Despite decades of research into block copolymer self-assembly, our ability to reliably predict, control and utilize the resulting structures remains limited. This work aims to improve the understanding of the factors that govern self-assembly, with particular emphasis on synthetic design and post-processing conditions. A major focus is placed on ABC star polymers, an architecture in which three chemically distinct polymer arms are connected at a common junction.

As part of this work, a novel PDMS-PB-PLA star polymer was designed and synthesized, although synthetic challenges prevented a full morphological characterization of the system. A more established PI-PS-PMMA star polymer system was also investigated, with particular focus on how the choice of casting solvent influences self-assembly.  A separate study on a simpler PS-PLA block copolymer architecture demonstrated that small amounts of residual homopolymer are responsible for stabilizing the Double Diamond network structure, making accessible a morphology that would otherwise not form under the same conditions.

Principal Supervisor: 
Professor Kristoffer Almdal, DTU Chemistry

Co-supervisor: 
Professor Robert Madsen, DTU Chemistry

Examiners:
Professor Esben Thormann, DTU Chemistry
Professor Anthony J. Ryan, University of Sheffield, UK
Professor Mogens Hinge, Aalborg University

Chairperson:
Ass. Professor Leo Gordon, DTU Chemistry