Conformational analysis of poly (N-vinyl caprolactam) using 2D MXene nanomaterials for efficiently tuning the phase transition behaviour of the polymer

The advancement of smart polymers is pivotal in the evolution of drug delivery systems. The alteration in characteristic properties of the polymer in response to physiological stimuli has emerged as a promising strategy. Herein, we report a significant step forward by studying the effect of 2D MXene nanomaterials as stimuli in particular Ti₃C₂ single layered (SL), Ti₃C₂ stack, and V₂C stack on the lower critical solution temperature (LCST) of a biocompatible polymer; poly (N-vinyl caprolactam) (PVCL) in aqueous solution. An array of spectroscopic, imaging, and size-determining techniques were employed to probe into the intricate dynamics of phase transitions of PVCL. Our findings reveal the altered morphology and a discernible reduction in LCST of polymer in the presence of all three MXene nanomaterials, attributed primarily to the creation of a more hydrophobic microenvironment facilitated by MXenes and subsequent premature hydrophobic collapse of PVCL. Importantly, LCST was found to be tunable with an observed shift of 3 °C for Ti₃C₂ SL and 2 °C for Ti₃C₂ stack as well as V₂C stack. This study is of immense importance, as the nanoconjugates formed align with green practices of resource and energy efficiency. These nanoconjugates can be harnessed to design smart drug delivery systems where exact thermal control is required at a temperature below the LCST of the polymer.