Ir prestige 21 ftir spectrometer

The infrared (IR) spectra were obtained in the fine films on the Shimadzu IR Prestige 21 FTIR spectrometer.

¹H NMR spectra were obtained from a Bruker ARX 400 MHz spectrometer at room temperature with tetramethylsilane (TMS) as the internal standard. The GPC analysis was conducted with a HLC-8320GPC (TOSOH, Japan) instrument at 30 °C at a flow rate of 0.3 mL/min. The solid-state ¹³C CP/MAS NMR measurements were carried out at 75 MHz with a spinning rate of 5 kHz at room temperature using a Bruker AV-300 NMR spectrometer. The chemical shifts were referred to an external adamantane standard. Wide angle X-ray diffraction (WXRD) patterns were recorded on a Shimadzu XD-D1 X-ray diffractometer with Ni-filtered Cu Kα (1.54 Å) radiation (20 kV, 40 mA). Powder samples were scanned from 2θ = 4.5–60° at a speed of 5°/min. FTIR spectra were measured using a Shimadzu IR Prestige-21 FTIR spectrometer at room temperature using the KBr pellet method. TGA analysis was performed with using a TA SDT 2960 instrument at a heating rate of 10 °C/min from room temperature to 500 °C in a nitrogen atmosphere. DSC measurements were measured on a SHIMADZU DSC-60 differential scanning calorimeter with a scanning temperature range from 20–80 °C at a scanning rate of 10 °C/min. The transmission electron microscopy image was observed using a JEM 1200EX (JEOL) transmission electron microscope operating at 120 KV.

FTIR was used to analyze the chemical interactions among PLGA, chitosan and DS. Absorbance spectra were recorded at 200 scans using IR Prestige21 FTIR Spectrometer (Shimadzu, Kyoto, Japan) from wavenumbers of 400 to 4000 cm⁻¹ with a resolution of 4 cm⁻¹. A pellet was made for FTIR measurement by dispersing the nanoparticles in KBr matrix and compressing at high pressure.