2.6. Characterization
The Ag NC composite polymer fibers were characterized by fluorescence spectra, UV–vis absorption spectra and XPS. The measurement of fluorescence emission spectra and life time was obtained on Edinburgh FLS980 fluorescence spectrometer. The absolute quantum yield was directly measured on Edinburgh FLS920 transient and steady-state fluorescence spectrometer. UV–vis absorption spectra were measured by a Shimadzu UV-3100 spectrophotometer. XPS measurements were conducted using an Omicron ESCA Probe spectrometer with monochromatized Mg Ka X-rays (hν = 1253.6 eV) and the signal of pollution carbon (C1S at 284.6 eV) was used as a reference. The fluorescence imaging experiments were performed with the system of Olympus Fluoview FV1000. Field-emission scanning electron microscopy (SEM) (HITACHI SU8000) with energy dispersive X-Ray spectroscopy (EDX) was employed to investigate the morphology of fibers and their element analysis. Infrared (IR) spectra of PMMA–PMAA fibers were measured at room temperature on a Bruker Vertex 80v Fourier transform (FT) spectrometer equipped with a liquid nitrogen-cooled mercury cadmium telluride detector. 0.0012 g of the Ag NC composite polymer fibers was dissolved into 2.0 mL of DMF for LDI-ToF-MS measurements. LDI-ToF-MS measurement was performed on a ShimadzuTM Kratos PC Axima CFR V2.3.1 system in a reflection mode using a nitrogen laser (337 nm).