%AKorpanty, Joanna%AParent, Lucas%AHampu, Nicholas%AWeigand, Steven%AGianneschi, Nathan%BJournal Name: Nature Communications; Journal Volume: 12; Journal Issue: 1; Related Information: CHORUS Timestamp: 2023-02-08 07:35:29 %D2021%INature Publishing Group %JJournal Name: Nature Communications; Journal Volume: 12; Journal Issue: 1; Related Information: CHORUS Timestamp: 2023-02-08 07:35:29 %K %MOSTI ID: 10305678 %PMedium: X %TThermoresponsive polymer assemblies via variable temperature liquid-phase transmission electron microscopy and small angle X-ray scattering %XAbstract

Herein, phase transitions of a class of thermally-responsive polymers, namely a homopolymer, diblock, and triblock copolymer, were studied to gain mechanistic insight into nanoscale assembly dynamics via variable temperature liquid-cell transmission electron microscopy (VT-LCTEM) correlated with variable temperature small angle X-ray scattering (VT-SAXS). We study thermoresponsive poly(diethylene glycol methyl ether methacrylate) (PDEGMA)-based block copolymers and mitigate sample damage by screening electron flux and solvent conditions during LCTEM and by evaluating polymer survival viapost-mortemmatrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS). Our multimodal approach, utilizing VT-LCTEM with MS validation and VT-SAXS, is generalizable across polymeric systems and can be used to directly image solvated nanoscale structures and thermally-induced transitions. Our strategy of correlating VT-SAXS with VT-LCTEM provided direct insight into transient nanoscale intermediates formed during the thermally-triggered morphological transformation of a PDEGMA-based triblock. Notably, we observed the temperature-triggered formation and slow relaxation of core-shell particles with complex microphase separation in the core by both VT-SAXS and VT-LCTEM.

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