Multifunctional sustainable quercetin polyphenol/functionalized carbon nanotubes; semi-transparent conductive films and 3D printing inks

Semi-transparent conductive films (semi-TCFs) were fabricated from sustainable onion quercetin polyphenol and functionalized carbon nanotubes (F-CNTs) in presence of different metal ion crosslinking agents via layer-by-layer technique. Layer-by-layer semi-TCFs were fabricated in presence of metal ion crosslinking agents of Ca2+, Ti2+, Sn2+, and Fe3+ ions. Optical transmittance values was in the range of 41%-67%, sheet resistance in 17-1567 k omega/sq, and sigma(dc)/sigma(op) in 0.0005-0.02 range, which confirm their semi-TCFs characteristics. Optimum performance of single-layer F-CNTs semi-TCFs was as follows; transmittance = 46.6%, sheet resistance = 6.5 k omega/sq, and sigma(dc)/sigma(op) = 0.06. 3D printing inks and injectable hydrogels were also fabricated from multifunctional sustainable onion/F-CNTs in presence gelatin. Proposed mechanism of gelation was established for the 3D printing ink, and the semi-Interpenetrating network hydrogel was verified using spectroscopic ATR-FTIR technique. The injectable hydrogel showed promising characteristics of robustness, elasticity, anti-microbial activity, biocompatibility, and stretchable low cost multifunctional materials that adapt them to be successfully employed in biomedical and surgical applications. Characteristic peaks that demonstrate chemical structure of quercetin and successful functionalization of F-CNTs were observed in H-1-NMR and ATR-FTIR spectra. High thermal stability of F-CNTs was observed (694 degrees C) in TGA and DTG thermograms, and two C(002) and C(100) crystal structures of F-CNTs were result. Topologic nanostructure of F-CNTs and spherical shape clusters of quercetin were demonstrated using optical and scanning electron microscope images.