High-performance polyimides (PIs) with ether linkages and trifluoromethyl (–CF3) groups based on xanthene were designed and synthesized via a polycondensation reaction of novel diamine monomers with available aromatic dianhydrides. The structure of the synthesized compounds was confirmed by the 1H-NMR, FT-IR and elemental analysis techniques, and their photophysical attributes were studied by UV-vis and fluorescence spectroscopy. All the PIs demonstrated excellent thermal stability, glass transition temperatures (Tg) from 249 to 263 °C, char yields of greater than 37.9%, and 10% weight loss temperatures in a nitrogen atmosphere from 430 to 508 °C. Also, the inherent viscosities of the resulting polymers were in the range of 0.49–0.66 dL g−1. The PIs were completely soluble in polar amide-type organic solvents (NMP, DMAc, DMSO, and DMF) at ambient temperature. A polymeric nanocomposite (PI-a2/GO-HBP NC) was prepared by linking a polyimide (PI-a2) and hyperbranched aromatic polyamide-coated GO nanoparticles (GO-HBP NPs). The thermal stability, photoluminescence intensity, and antibacterial properties of the nanocomposite are higher than the neat polyimide due to powerful chemical links between the GO-HBP and PI-a2 chains. Also, all components were applied as efficient adsorbents for the elimination of chromium metal ions from aqueous solutions.
