Optimization of light-curing ionogels by response surface methodology

Abstract

Because of their unique properties, ionogels are very suitable for wide application in fields such as energy storage devices and wearable devices, but poor mechanical strength limits their practical use. Polyols or compounds containing multiple unsaturated double bonds are typically used as cross-linking agents in the construction of gels, but it is difficult to balance mechanical strength with flexibility because these compounds mainly form linear or simple reticular structures. It is, therefore, important to design ionogels with improved mechanical properties. Here, response surface methodology was used to optimize the preparation of light-curing ionogels, using the biomass-derived polymer rutin as an antioxidant cross-linking agent. The prepared ionogels had a tensile strength as high as 639.15 kPa, which was attributed to the three-dimensional cross-linked network structure formed by esterified rutin and to the sacrificial hydrogen bond energy dissipation mechanism. After light curing of the esterified rutin by free radical polymerisation, the structure retained the intact conjugated system and thus provided good UV protection (light transmission in UVB region = 0%). This study offers a new way to rapidly prepare high-performance UV-resistant polymer coatings, which show promise for applications in sunscreen coatings, such as parasols and automotive/architectural sunscreen glass.