Ta q200 differential scanning calorimeter

Differential scanning calorimetry measurements were used to determine the glass transition temperature (T_g) of wet and dry samples. Measurement were obtained using a TA Q200 Differential Scanning Calorimeter (TA Instruments, New Castle, DE, USA). Hermetically sealed aluminum Tzero (Switzerland) pans with a hole poked in the top were used for all samples and goal foam sample weight was 5–10 mg. The cycle used for dry samples (Dry T_g) was first equilibrated at −40 °C for 5 min, heated to 120 °C (40 °C/min) and cooled to −40 °C. It was then reheated again at 10 °C/min to 120 °C. The second heating curve was analyzed using TA Universal Analysis software to determine dry T_g. Wet T_g foam samples were incubated in a 50 °C water bath for 30 min and pressed between Kimwipes to remove moisture prior to running. The cycle for wet samples was equilibrated at −40 °C for 5 min, with a single heating cycle that ramps to 100 °C at 10 °C/min. The wet T_g was determined from the inflection point on the heating curve using TA Universal Analysis software.

¹H-NMR spectrum was measured on Bruker Avance 400 M NMR spectrometer. Lambda 35 spectrophotometer from Perkin–Elmer was used to record UV-vis absorption. Fluorescence emission and excitation spectra were measured on HITACHI F-4500 fluorescence spectrometer. The morphology of the nanofibrous membrane was investigated by SEM (JSM-6700F) and CLSM (OLYMPUS, FV1000-IX81). Thermogravimetric analyzer TGA 8000 from Perkin–Elmer was used to record the TGA curves of CA-FITC and CA-PpIX under nitrogen atmosphere. The FTIR spectra were measured by NICOLET 6700 from Thermo-Fisher Scientific. Differential scanning calorimetry (DSC) was conducted on TA-Q200 differential scanning calorimeter (TA Instruments, USA) under nitrogen atmosphere. The total volatile basic nitrogen (TVBN) was measured by K-375 Kjeldahl apparatus from BUCHI Corporation.