Axs d8 advance powder diffractometer

The degree of substitution (DS) of the CSLG was measured by determining the nitrogen content of the CSLG with a Kjeldahl method [23 (link)]. Briefly, CSLG (1 g), CuSO₄·5H₂O (0.7179 g), and K₂SO₄ (6.2821 g) were mixed and hydrolyzed in the concentrated sulfuric acid (12 mL) at 420 °C for 1 h. When the digestive liquid turned clear, it was taken out and cooled to room temperature before measurement on a Kjeltec-2300 autoanalyzer. The DS was calculated using the following equation:
where N is the amount of nitrogen measured by using the Kjeldahl method, 162 is the average molecular weight of the anhydroglucose unit, 1400 is 10 times the value of the atomic weight of nitrogen, and 151.5 is the molecular weight of CHPTAC without chloride group.
The structure analysis of the SLG and CSLG were performed using a proton nuclear magnetic resonance (¹H NMR) spectrometer (AVANCE NEO 600 MHz, Bruker, Switzerland), and the chemical shifts were expressed in ppm. The chemical structures of SLG and CSLG were measured by a Fourier transform infrared (Thermo Fisher Co., Waltham, Massachusetts, USA) spectrum, and the FTIR spectra were collected in the range of 500–4000 cm⁻¹. The XRD spectra of SLG and CSLG were measured by a Bruker-AXS D8 ADVANCE powder diffractometer. In addition, a Zetasizer Nano Series measured the zeta potential of SLG and CSLG at 25 °C.

The magnetic nanoparticles were characterized using several conventional methods^{41 (link),44 (link)}. An IFS 66 v/s Fourier transform infrared (FTIR) spectrophotometer from Brucker (USA) was used to obtain infrared spectra. The samples were first powdered and the spectra were recorded in the 400–4000 cm⁻¹ range. The FTIR spectrophotometer was equipped with MCT detector (125 scans, resolution 2 cm⁻¹). Bruker AXS D8 Advance powder diffractometer (Germany) was used for collecting of X-ray diffraction (XRD) patterns. The diffractometer was equipped with Johansson monochromator (λCu K_α1 = 1.5406 Å). Transmission electron microscope (TEM) images of the samples were recorded on a Hitachi HT7700 microscope (Japan), while EDX patterns were obtained using energy dispersive X-ray (EDX) spectroscopy.