Mira3 lmu sem

SEM images were evaluated using a Mira3 LMU SEM (Tescan, Brno, The Czech Republic) with a vacuum set to below 5 × 10⁻³ Pa, accelerating voltage was 20 kV, and spot size was 5.5–6.5 nm. Platinum was used as the gold-spraying material and the gold-spraying time was set to 120 s to increase the conductivity of the samples. The differential thermal analysis was analyzed using the STA449C (NETZSCH Machinery and Instruments, Selb, Germany), which ranged from 30 to 600 °C under constant argon purging with 10 °C/min rate of rise. The zeta potential values were measured using a Malvern Zetasizer Nano S90 (Malvern Instruments, Malvern, UK). The gel precursor, dissolved in buffer solutions with varying pH levels, was placed in a quartz cuvette. The values of zeta potential were obtained from three measurements. The diffuse reflectance spectrum was measured using a Fourier transform infrared spectrometer (Shimadzu FTIR 8120 spectrometer, SHIMADZU, Kyoto, Japan) in the range from 400 to 4000 cm⁻¹.

The CTS-g-P(AM-DMC) flocculants were characterized by ¹H NMR, FTIR, XRD, SEM, and TG/DSC, respectively. The ¹H NMR and FTIR spectra of the polymers were conducted with an Avance-500 NMR spectrometer (Bruker Company, Karlsruhe, Germany) with standard pulse procedures in deuterium oxide (D₂O) and a 550-Series II infrared spectrometer (Burker Company, Zurich, Switzerland) using KBr (Potassium bromide) as pellets, respectively. XRD patterns of the polymers were obtained by an X-ray diffractometer (SmartLabTM 3 KW, Tokyo, Japan) equipped with graphite monochromatized Cu Kα radiation (λ = 1.54056 Å). The morphological features of CTS-g-P(AM-DMC) were inspected by a MIRA 3 LMU SEM (TES-CAN, Brno, Czech Republic). TG/DSC was performed on a synchronal thermal analyzer (DTG-60H, Shimadzu, Japan) to inspect the thermal stability of copolymers under a nitrogen atmosphere from a temperature of 20 °C to 600 °C. In this section, chitosan (CTS), a copolymer of AM and DMC (P(AM-DMC)), and CTS-g-P(AM-DMC) were selected for the comparative analysis.