Design and fabrication of photoactive imidazole-based poly(ether-imide)s and a polyimide/HBP-modified SiO2 composite: toward high heat-resistance, antimicrobial activity and removal of heavy metal ions

This article describes the synthesis and properties of novel imidazole-based aromatic polyimides (PIs) containing bulky groups from direct polycondensation of two diamines with 3,3 ',4,4 '-benzophenone tetracarboxylic dianhydride (BTDA) and (hexafluoroisopropylidene)diphthalic anhydride (6FDA). The structure-property relationship of the prepared samples was fully determined via FT-IR, H-1 and C-13 NMR and elemental analysis (CHN) techniques. The inherent viscosity values of the polyimides ranged from 0.51 to 0.73 dL g(-1). These PIs showed glass transition temperatures ranging from 273 to 306 degrees C, and 10% mass loss temperatures within the range of 478-504 degrees C in a N-2 atmosphere. High transparency with a UV-visible absorption cut-off wavelength was found to range between 285 and 300 nm. Good antimicrobial activity can be correlated with the presence of xanthene and imidazole units into the main structure of PIs. Next, SiO2 nanoparticles as inorganic nanoparticles were added to one of the synthesized polyimides (BTDA-PIb), causing changes in the attributes of both the nanoparticles and PI. The data obtained from examining the properties of the prepared BTDA-PIb/HBP@SiO2 demonstrated increased heat resistance, photoluminescence intensity, and antimicrobial inhibition compared to pure PI. Also, in this article, the polymeric samples as adsorbents were evaluated for extraction of heavy metal ions (Hg2+ and Co2+) from water sources.

Automated summary

This study synthesized novel imidazole-based aromatic polyimides and characterized their properties using various techniques, establishing the structure-property relationship. Addition of SiO2 nanoparticles to one of the polyimides led to improved heat resistance, photoluminescence intensity, and antimicrobial activity. Furthermore, the study explored the potential of these polymeric samples as adsorbents for extracting heavy metal ions from water sources.