D max2200 x ray diffractometer

A D/MAX 2200 X-ray diffractometer (Rigaku Corporation, Tokyo, Japan) was used to measure the WXRD patterns of the fiber samples before and after modification [17 ]. Prior to the measurement, the samples were placed onto the supporter and pressed compactly. Over the angular range of 2θ = 5° to 40° and a step size of 5°/min, the WXRD data was generated by a diffractometer with Cu Kα radiation (λ = 1.542 Å) at 40 kV and 30 mA. The degree of crystallinity, or crystallinity index (CI %), was evaluated for each sample using Equation (1),
$CI\%=(A_{\mathrm{c}}/A_{\mathrm{a}})\times 100$
where A_c is the area of the crystalline reflection and A_a is the area subtending the whole diffraction profile. The WXRD jade software (MDI JADE 6.5, Materials Data, Inc., Livermore, CA, USA) was adopted to calculate the diffraction peaks (002), the crystalline reflection, and the area subtending the whole diffraction profile.

Powder X-ray diffraction (XRD) patterns were recorded on a Rigaku D/max 2200 X-ray diffractometer using Ni-filtered Cu Kα radiation (λ = 0.15418 nm) operating at 40 kV and 40 mA. Transmission electron microscopy (TEM) images were measured on a JEOL JEM-2010 transmission electron microscope equipped with an Oxford energy-dispersive X-ray (EDX) spectrometer attachment operating at 200 kV. Nitrogen adsorption-desorption isotherms were measured on a Micromeritics ASAP 2020M analyzer at liquid nitrogen temperature (77 K). Prior to determination of the isotherm, the samples were degassed at 423 K in vacuum for 5 h. The Brunauer-Emmett-Teller (BET) specific surface area was calculated using the adsorption data in the relative pressure (P/P₀) range from 0.05 to 0.3, and the total pore-volume was determined from the amount adsorbed at P/P₀ = 0.98. The pore-size distribution curve was calculated based on the desorption branch of the isotherm using the Barrett-Joyner-Halenda (BJH) method. The pore diameter was defined as the position of the maximum in the pore-size distribution.

In order to understand the synthesis mechanism of L/C, the chemical structure, thermal stability, and crystalline structure of L/C were characterized. Fourier-transform infrared (FTIR) spectroscopy (ThermoFisher, Waltham, MA, USA) was used to analyze the functional groups in chitosan, sodium lignosulfonate, and L/C with a Nicolet Magna-IR560 E.S.P. using KBr method, in the spectral range of 650 to 4000 cm⁻¹. The spectra were recorded with a resolution of 4 cm⁻¹ by accumulating 32 scans. X-ray diffraction (XRD) patterns of chitosan, sodium lignosulfonate, and L/C were collected with a Rigaku D/max 2200 X-ray diffractometer (Rigaku, Tokyo, Japan). The X-ray diffractometer used a Cu Kα radiation source and its scan rate was set to 4° min⁻¹. It works at 40 kV and 30 mA, in the 2θ range of 5–40°. The thermal stabilities of chitosan, sodium lignosulfonate, and L/C were measured with a NET-ZSCH-TGA209 thermogravimetric analyzer (NETZSCH, Selb, Germany). The samples (5 mg each in a 70 μL alumina pan) were heated from 40 °C to 800 °C at 10 °C/min and 30 mL/min nitrogen flow rates.

XRD patterns were obtained by a D/max2200 X-ray diffractometer (Rigaku, Tokyo, Japan) with Cu Kα as the radiation source. It was operated at 40 KV and 30 mA, and the scanning range was 10–30° (2θ) at a step size of 2°/min. The crystal size was calculated via the Scherrer Equation [35 (link)]:
$D=\frac{\mathrm{k}\mathsf{\lambda }}{\mathrm{\beta }\cos \mathrm{\theta }},$
where D represents the crystal size (nm), k is a constant (0.9), λ represents the X-ray wavelength (0.154059 nm), β represents the half-width (rαd), and θ represents the diffraction angle (°).