Public defence in Chemistry, M.Sc. Kourosh Hasheminejad

Title of the thesis: Computational modelling of block copolymer surface coatings at multiple length scales

Thesis defender: Kourosh Hasheminejad
Opponent: Professor Philip J. Camp, University of Edinburgh, Scotland 
Custos: Prof. Maria Sammalkorpi, Aalto University School of Chemical Engineering

This doctoral thesis investigates how block copolymer coatings form on hydrophilic surfaces and how effectively they prevent water penetration. Such coatings are important for applications where moisture resistance and durability are required, including packaging and surface protection.

The purpose of the study was to understand how the molecular structure of block copolymers and the composition of coating mixtures influence coating structure, stability, and water-barrier performance. The research contributes to polymer and materials science by providing molecular-level explanations for coating behaviors that are difficult to access experimentally.

Using multiscale computer simulations, the study shows that block copolymers with balanced hydrophilic and hydrophobic segments form continuous, well-organized coatings, while strongly asymmetric polymers lead to defective structures. The results also demonstrate that stable, defect-free coatings are obtained only within a limited range of material compositions.

In addition, the chemical nature of the hydrophobic polymer segments was found to control how well coatings retain their barrier properties under mechanical strain. Certain chemical designs help maintain structural integrity and limit water penetration.

Overall, the thesis provides new insights into the relationship between polymer molecular design and coating performance. The findings can be applied to the rational design of improved moisture-barrier coatings for practical uses such as sustainable packaging and surface protection technologies.

Key words: Polymer coating, Di-block copolymers, Amphiphilic self-assembly, Surface functionalization, Moisture barrier

Thesis available for public display 7 days prior to the defence at Aalto University's public display page.