Characterization of Nano-/Micro-Fibrous Materials

The morphologies of the nano-/micro-fibrous materials were characterized by SEM (HITACHI SU800), laser scanning confocal microscope (Leica TCS SP5 II) and fluorescent microscope (Nikon Eclipse Ni-U). The crystallinity of the PVA sample was characterized by wide angle X-ray diffraction (WAXD, D/Max 2550 VB PC, Rigaku). UV absorption measurements were performed on a Shimadzu UV 3600. PL spectra were collected on a PTI QM/TM. The quantum yields were measured on a HAMAMASTU fluorescence spectrometer. For demonstrating the fluorescence sensitivity of the AIE/polymer fibers, the samples were placed in a self-made moisture chamber and incubated for 1 h before characterization. The moisture (RH) was adjusted by saturated salt solutions. The RH from 11% to 95% was adjusted by saturated salt solutions of LiCl, MgCl₂, NaBr, NaCl and KNO₃, respectively. Fluorescent and optical images were collected on a Cannon digital camera. A MATLAB program was used to convert the optical images from RGB color space into CIE x and y chromaticity values [50 (link)].