Dr Karen Johnston

Reader

Chemical and Process Engineering

Contact

Personal statement

My group models a range of materials using multiscale simulations including sustainable plastics, polymer thin films and composites, molecular crystals, solid-liquid interfaces and oxide materials. In these systems the interfacial properties are crucial in understanding and controlling the system, for example, heterogeneous crystal nucleation of polymer or small molecule systems. We have a broad interest in materials science and engineering and enjoy collaborating with experimentalists and industrial partners.  For more information please visit my group webpage.

 

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Area of Expertise

Density functional theory (DFT): electronic structure, adsorption and surface energies, vibrational frequencies etc.

Molecular dynamics (MD) simulations: structure and dynamics of thin films, liquids, solutions, solids etc. using all-atom and/or coarse-grained force fields.

Prize And Awards

Strathclyde Team Award
Recipient
2019

More prizes and awards

Qualifications

Member of the Institute of Physics

Fellow of the Higher Education Academy

Member of the Scottish Plastics and Rubber Association

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Teaching

My teaching philosophy is to provide the best learning environment by challenging students through providing questions related to everyday exampes, that develop student's understanding and problem solving skills.

I am the course organiser and a lecturer for CP102 Introduction to Chemical Engineering: Fundamentals, Techniques and Tools, and the distance learning course CP108 Mathematics for Chemical Engineers. I also supervise CP407 design projects and 18350 MEng projects.

 

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Research Interests

Polymers

The properties of polymer composites are dependent on the interface between the polymer and surface. We have developed multiscale models to explore how surfaces affect the polymer properties, such as melt structure, glass transition and crystallisation. We also study sustainably-sourced and compostable polymers including polyhydroxyalkanoates, alginates and chitin/chitosan. We are investigating how the addition of filler particles and plasticisers may help to improve the properties, leading to uptake of sustainable plastics in applications such as food packaging.

Heterogeneous Nucleation

Nucleation mainly occurs via heterogeneous mechanisms, with the nucleus forming on a surface or interface, rather than in bulk solution. We use molecular dynamics simulations to study the composition, structure and dynamics of the solution at the interface region, which can have significantly different properties than in the bulk region.

Adsorption and self-assembly

​Adsorption of molecules to surfaces is important in a wide range of systems, including soft-hard matter interfaces, and self-assembly. We use quantum density functional theory to study the adsorption of molecules onto surfaces.

Force field optimisation

​To model systems using classical MD it is crucial to have a force field that accurately describes the behaviour of the system. In interfacial systems the interaction at the interface is particularly important but experimental information is not often available. We use quantum density functional theory calculations to optimise interface force fields. For crystallising systems the force field should describe both crystal and amorphous/solution phases. We validate force field to describe both phases based on available data.

Professional Activities

Departmental Seminar
Speaker
5/2/2025
External examiner for PhD thesis defence
Examiner
22/11/2024
Institute of Physics (External organisation)
Advisor
1/10/2024
Physical Aspects of Polymer Science 2024
Speaker
9/9/2024
CCP5 Annual General meeting
Speaker
4/9/2024
ScotCHEM Polymer & Soft Materials Conference III
Participant
13/6/2024

More professional activities

Projects

Modelling polylactone crystallisation (AKT Ingevity)
Johnston, Karen (Principal Investigator) Mulheran, Paul (Academic)
25-Jan-2024 - 23-Jan-2024
Sustainable plastics for bathroom products
Zhang, Xiaolei (Principal Investigator) Johnston, Karen (Principal Investigator)
01-Jan-2022 - 30-Jan-2022
IBioIC CTP PhD studentship Optimisation of alginate films for sustainable food packaging applications
Johnston, Karen (Principal Investigator) Mulheran, Paul (Co-investigator)
01-Jan-2021 - 30-Jan-2025
ISCF - Biocomposite design for food packaging
Johnston, Karen (Principal Investigator) Liggat, John (Co-investigator) Mulheran, Paul (Co-investigator) Magueijo, Vitor (Researcher)
01-Jan-2020 - 30-Jan-2024
Doctoral Training Partnership 2020-2021 University of Strathclyde | Anker, Samira
Johnston, Karen (Principal Investigator) Sefcik, Jan (Co-investigator) Anker, Samira (Research Co-investigator)
01-Jan-2020 - 14-Jan-2025
Design of functional chitosan films: antimicrobial and heavy metal capture applications
Mulheran, Paul (Principal Investigator) Ferro, Valerie (Co-investigator) Johnston, Karen (Co-investigator)
01-Jan-2020 - 30-Jan-2024

More projects

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Contact

Dr Karen Johnston
Reader
Chemical and Process Engineering

Email: karen.johnston@strath.ac.uk
Tel: Unlisted