Flash 2000 elemental analyzer

IR spectra were recorded on a Thermo Fisher Scientific Nicolet iS10 FT-IR spectrometer with a Monolithic Diamond ATR accessory and absorption in cm⁻¹. ¹H- and ¹³C-NMR spectra were recorded at 400 MHz on a Bruker Avance 400 instrument. Chemical shifts are reported in ppm, by using the solvent residual signal. The elemental analysis for carbon and hydrogen was carried out using a Thermo Flash 2000 Elemental Analyzer.

C, H, N, S were analysed by combustion at 1200°C and subsequent gas chromatography in a Flash 2000 Elemental Analyzer (Thermo Fisher Scientific, Waltham, MA, USA). Oxygen was determined through an oxygen‐specific pyrolysis at 1060°C. Ash content was determined by subtraction of the C, H, N, O, S fractions as remaining component.

A Thermo Scientific FLASH 2000 Elemental Analyzer (OEA, Thermo Fisher Scientific, Waltham, MA, USA) was employed to establish the elemental composition of the precursor and biochars. The standard test method for ash was performed according to the ASTM D2866-94 Standard (2004).

The samples of control and heat-treated wood were ground in a Fritsch type 15 laboratory mill (IKA Werke, Staufen im Breisgau, Germany) to sawdust with a particle size below 0.50 mm and used for all chemical analyses.
The chemical composition of wood was assayed according to the TAPPI standards. The content of extractives in the wood samples was determined in accordance with TAPPI T 204 cm-07 [29 ]. The cellulose content in the wood samples was assayed according to Seifert [30 ], the lignin content by applying the TAPPI T 222 om-06 standard [31 ], and the holocellulose content was assayed based on TAPPI T 9 wd-75 [32 ]. The content of hemicelluloses was calculated from the difference between holocellulose and cellulose.
The elemental composition (contents of carbon, nitrogen, hydrogen and oxygen) of the wood samples was determined using a Flash 2000 elemental analyzer (Thermo Fisher Scientific, Waltham, MA, USA).
The attenuated total reflectance Fourier transform infrared spectroscopy (ATR–FTIR) was applied to analyze changes in the wood structure after heat treatment using a Nicolet iS5 spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). The obtained spectra were used to calculate the total crystalline index (TCI, H₁₃₇₂/H₂₈₈₅) [33 (link)]; the lateral order index (LOI, A₁₄₂₇/A₈₉₆) [34 (link)]; and the hydrogen bond intensity (HBI, A₃₄₀₀/A₁₃₂₀) [35 (link)].

The produced NPs were characterized using various characterization techniques to confirm the functionalization and to explore its effects on GO properties. XPS measurements were conducted over a 0–1200 eV range on a Kratos AXIS Ultra DLD (Kratos Analytical Ltd, Manchester, UK) with Al-Kα source and X-ray power of 15 Kv and 20 mA. The elemental compositions of GO and GO-PDA were analyzed using FLASH 2000 elemental analyzer (Thermo Scientific™, Waltham, MA, USA). XRD measurements were carried out using EMPYREAN PANalytical diffractometer (Malvern Panalytical B.V., Eindhoven, Netherlands) equipped with a Cu-Kα radiation source (λ = 1.5406 Å). FTIR-UATR spectra were determined using FTIR Perkin Elmer 2000 in the range of 400–4000 cm⁻¹ to study the surface functional groups of pristine GO and GO-PDA.
Raman spectra of the prepared NPs were obtained with DXR Raman Spectrometer operated with a 532 nm laser and a 10× objective (Thermo Scientific™). Moreover, the morphological structure of GO and GO-PDA NPs was investigated using SEM analysis that was conducted using the JEOL model JSM-6390LV. TGA analysis was conducted to assess the thermal stability of both samples using Pyris 6 TGA (PerkinElmer, Waltham, MA, USA) under nitrogen gas at a 10 °C/min heating rate and over a temperature range of 30–800 °C.