Stimuli responsive polymers (SRPs) have the ability to change their chemical and physical properties at a specific location and time in response to external stimuli. As a result of the stimuli, the polymer structure transforms and therefore these polymers could offer great advantages for numerous applications such as drug delivery, tissue engineering, sensors and lithography. SRPs modification can be reversible or irreversible. Most of the irreversible SRPs were studied in solution or in gel phase but only a few examples in solid phase were published.
In this work, we present stimuli responsive polymeric films that contain degradable cross-linkers fabricated by straightforward synthesis and polymerization processes. UV-responsive cross-linkers were copolymerized with acrylate and methacrylate monomers to receive standalone films. The response of the films to UV was studied in solid phase and in solution. Complete degradation was observed in solution by thermogravimetric analysis (TGA), high-performance liquid chromatography (HPLC), UV-Vis and FTIR-ATR spectroscopy. For solid films, atomic force microscopy (AFM), UV-Vis and FTIR-ATR spectroscopy indicated changes only on the surface of the film. The responsive cross-linkers were compared to the non-responsive ones, which did not indicate any structural change.
Figure 1: FTIR-ATR spectra after UV exposure indicate film degradation.