Using external stimuli to design responsive supramolecular systems with predictable properties - PhD thesis

Aug 21, 2026

Uploaded by Theodora

Supramolecular gels formed by peptide-based LMWG constitute soft materials with broad application potential, enabled by non-covalent interactions that confer stimuli-responsive behavior. This PhD thesis develops strategies to harness external triggers to produce predictable and reversible structural and rheological changes with controlled temporal and spatial resolution. It demonstrates pH-cycle-driven and mechanically stimulated gel–sol–gel transitions, including aligned-domain formation under shear and magnetic fields. It further uses light-driven photoacid switching to reproducibly modulate viscosity and enables location-specific flow arrest. Finally, peptide-gel design is evaluated for drug storage and release, linking mechanical properties, morphology, trigger choice, and stability under realistic conditions.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages240

Reading Time10 h 5 min

AccessFree to download

Abstract

pH-cycle controlled gel–sol–gel transitions

Mechanical and alignment control (shear, magnetic field)

Light-triggered multicomponent systems and viscosity switching

Mechanical-stimulus drug storage and release applications

Stability under real-world conditions

Bianco, Simona (2025) Using external stimuli to design responsive supramolecular systems with predictable properties. PhD thesis. [https://theses.gla.ac.uk/85169/](https://theses.gla.ac.uk/85169/) Copyright and moral rights for this work are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This work cannot be reproduced or quoted extensively from without first obtaining permission from the author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Enlighten: Theses [https://theses.gla.ac.uk/](https://theses.gla.ac.uk/) [research-enlighten@glasgow.ac.uk](research-enlighten@glasgow.ac.uk) Using external stimuli to design responsive supramolecular systems with predictable properties Simona Bianco Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy School of Chemistry College of Science and Engineering University of Glasgow February 2025 Declaration of Authorship I declare that, except where explicit reference is made to the contributions of others, that this dissertation is the result of my own work and has not been submitted for any other degree atthe University of Glasgow or any other institution. Simona Bianco Abstract Supramolecular gels formed by the self-assembly of peptide-based LMWG are a class of soft materials that have attracted significant interest for a vast range of applications. Due to the non-covalent nature of the interactions underpinning the gel networks, these materials can exhibit stimuli-responsive behaviour to external triggers. By introducing this aspect in their design, a wide variety of new materials can be accessed with pre-determined properties with a high level of temporal and spatial control. In this Thesis, we describe how to harness external stimuli to induce predictable and reversible changes in supramolecular systems, achieving materials with desirable properties for different potential applications. First, we show a dipeptide-based LMWG system undergoing pre-programmable gel-to-solto-gel transitions obtained by means of a pH cycle. We investigate the effect of mechanical stimuli applied during rheological measurements on the properties of these evolving materials, highlighting how varying parameters of strain and frequency can be used to obtain a wide range of gels with different properties starting from the same material. Building on these results, we then design a new system undergoing gel-to-sol-to-gel transitions capable of aligning under unidirectional shear in the solution phase. Using a novel combined technique of rheology, polarised light imaging and SAXS, we show the potential of this system to prepare gels with aligned domains using mechanical stimuli. We further highlight the versatility of this approach by inducing alignment using a magnetic field. We then describe the use of a non-invasive light trigger to design a multicomponent system based on a LMWG and a photoacid molecule capable of switching pH under irradiation. We show how this approach yields a light-responsive system that reproducibly changes viscosity under irradiation. Using a variety of combined in situ techniques (rheology, NMR and SAXS), we elucidate the way these changes occur on a variety of length scales. We finally show how this stimuli-responsive system can be used to stop flow at specific locations using light and discuss potential applications. Finally, we focus on the design of peptide-based gels for applications in drug storage and release by taking advantage of their unique response to mechanical stimulus. By using rheology, SAXS and release tests we show how gel mechanical properties, network morphology and choice of trigger can affe

FAQs

What external stimuli strategies are investigated in this thesis?

The thesis studies pH cycling, mechanical stimuli during rheology, magnetic field alignment, and a non-invasive light trigger using a photoacid to switch pH under irradiation.

How does the work ensure the material responses are predictable and reversible?

It focuses on design rules that translate specific external triggers into controlled, reversible gel–sol or alignment outcomes, supported by multi-technique measurements.

What is the main application direction besides fundamental supramolecular behavior?

Peptide-based gels are assessed for drug storage and release, including how gel mechanical properties, network morphology, and trigger selection affect cargo release, plus stability under realistic conditions.

Aug 21, 2026

Uploaded by Theodora