Preparation and photoluminescence of functionalized cotton fabric by double luminescent guests-encapsulated ZnBDC metal-organic framework

Abstract A series of functionalized cotton fabrics (LG-ZnBDC-CCtn) were prepared by attachment of ZnBDC metal-organic framework with LbL deposition method on carboxylated cotton fabric (CCtn) and further encapsulation of ZnBDC with different luminescent guests (LG = Tb3+, La3+, Rhodanmine B or/and acridine orange). The characterization of LG-ZnBDC-CCtn by XRD, SEM and EDS showed that the structural integrity and morphology of ZnBDC on the CCtn surface were not destroyed after encapsulation. The photoluminescence behavior of sample LG-ZnBDC-CCtn was investigated by fluorescence excitation and emission spectra. After encapsulated with different luminescent guests, samples LG-ZnBDC-CCtn emitted different fluorescence. Although sample Tb/RhB-ZnBDC-CCtn with double LGs (Tb3+ and RhB) showed almost same visible color with RhB-ZnBDC-CCtn under sunlight, the orange yellow fluorescence of sample Tb/RhB-ZnBDC-CCtn was quite different with that of the single LG encapsulated sample Tb-ZnBDC-CCtn (green) or RhB-ZnBDC-CCtn (rose). A similar phenomenon was also observed in La/AO-ZnBDC-CCtn system. The fluorescence change of sample Tb/RhB-ZnBDC-CCtn could be due to a two-step fluorescence resonance energy transfer (FRET) among ZnBDC framework and luminescent guests. The visible color-change properties and technical performance of sample LG-ZnBDC-CCtn were evaluated with LAB color space and color strength.