Molecular environment and reactivity in gels and colloidal solutions under identical conditions

Philip Groves, Jin Huang, Andreas Heise, Jennifer Marsh, Victor Chechik*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

A PEG-Tyr block copolymer forms a kinetically stable colloidal solution in water at room temperature which undergoes an irreversible conversion to a gel phase upon heating. A micellar solution and a gel can therefore be studied under identical experimental conditions. This made it possible to compare physical properties and chemical reactivity of micelles and gels in identical chemical environments and under identical conditions. EPR spectra of the spin-labelled copolymer showed that tyrosine mobility in gels was slightly reduced compared to micelles. Chemical reactivity was studied using photochemical degradation of tyrosine and tyrosine dimerization, in the absence and in the presence of an Fe(iii) salt. The reactivity trends were explained by reduced tyrosine mobility in the gel environment. The largest reactivity difference in gels and micelles was observed for bimolecular dityrosine formation which was also attributed to the reduction in molecular mobility.

Original languageEnglish
Pages (from-to)12267-12272
Number of pages6
JournalPhysical chemistry chemical physics
Volume22
Issue number21
DOIs
Publication statusPublished - 7 May 2020

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