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Visualization of Polymer Dynamics in a Cellulose Nanocrystal Matrices Using Fluorescence Lifetime



Huyen Vu, Jeremiah Woodcock, Ajay Krishnamurthy, Jan Obrzut, Jeffrey Gilman, Bryan Couglin


Polymer nanocomposites containing self-assembled cellulose nanocrystals (CNCs) are ideal for advanced applications requiring both strength and toughness, as their helicoidal structure deflects crack propagation and the polymer matrix dissipates impact energy. However, any adsorbed water layer surrounding the CNC rods may compromise interfacial adhesion between the polymer matrix and the CNCs, thus impacting stress transfer at that interface. Therefore, it is critical to study the role of water at the interface on the coupling between polymer dynamics and the resulting mechanical performance of the nanocomposite. Here, we explore the role of polymer confinement and water content on polymer dynamics in CNC nanocomposites by covalently attaching a fluorogenic water-sensitive dye to poly(diethylene glycol methyl ether methacrylate) (PMEO2MA), to provide insight into the observed mechanical performance. Utilizing fluorescence lifetime imaging microscopy (FLIM), the lifetime of the dye fluorescence decay was measured to probe polymer chain dynamics of PMEO2MA in the CNC nanocomposite films. The PMEO2MA chains experienced three different environments within the Bouligand structures. A correlation was observed between the average fluorescence lifetime and mechanical performance of CNCs films, indicating polymer chains with high mobility improved strain and toughness.These studies demonstrated FLIM as a method to investigate polymer nanosecond-dynamics in other composite
ACS Applied Materials and Interfaces


Cellulose nanocrystals, polymer dynamics, interfaces, thermoresponsive polymer, fluorescence lifetime imaging microscopy


Vu, H. , Woodcock, J. , Krishnamurthy, A. , Obrzut, J. , Gilman, J. and Couglin, B. (2022), Visualization of Polymer Dynamics in a Cellulose Nanocrystal Matrices Using Fluorescence Lifetime, ACS Applied Materials and Interfaces, [online],, (Accessed April 12, 2024)
Created February 18, 2022, Updated March 13, 2023