Tensor 27 ir

The morphology and diameter of the nanofibers were examined by scanning electron microscopy (FESEM; Philips XL30) after coating with gold by gold sputtering apparatus. ImageJ software was used to measure the average diameter of nanofibers. X‐ray energy dispersive spectroscopy coupled to FESEM apparatus was used for elemental analysis of prepared nanofibrous mats to confirm nanoparticles' presence in the nanofibrous mats. The FTIR was performed in the 4000 to 400 cm⁻¹ region using Bruker Tensor 27 IR to investigate the characteristic bonds in the nanofibrous mats. A tensile strength test was used with SANTAM universal testing machine (STM‐1 model) to evaluate the tensile strength of scaffolds. For this purpose, 30 × 10 mm specimens were cut from scaffolds with a diameter of 200 ± 20 μm and used for this test. A tensile strength test was performed using three samples of each scaffold, and the results were presented as mean.

After being separated by filtration, the acid liquor was triple-concentrated by rotary vacuum evaporation (RV10, IKA, Germany), and the concentrated hydrolysate was then refrigerated overnight at 4 °C to allow FA to gradually crystallize and precipitate. The FA crystals were recovered by filtration through a glass fiber filter and were then compared with the crystals of the FA standard using Fourier transform infrared (FTIR) spectroscopy (Tensor 27-IR, Bruker, USA).

PLA films were analyzed using IR Fourier analysis with a NETZSCH TG 209 F1 (NETZSCH-Gerätebau GmbH, Selb, Germany) thermoanalytical balance and a Bruker Tensor 27 IR (Billerica, MA, USA) Fourier spectrometer with PIKE MIRacle™ accessory (PIKE Technologies, Madison, WI, USA) equipped with a germanium (Ge) crystal and an ATR attachment with a Teflon cell and cesium antimony electrode, which allows the measurements of solid samples. The sample was placed on the surface of the crystal and tightly clamped to ensure optical contact. IR spectra were recorded in the range of 4000–400 cm⁻¹ with a resolution of 4 cm⁻¹ and averaging over 16 successive scans.

A Bruker Optics (Tensor 27) IR (Bruker Corporation, Billerica, MA, USA) spectrometer equipped with a deuterated triglyceride sulfate detector was operated with Opus software from Bruker to obtain the spectra of ambient air samples. An ATR accessory with a germanium crystal flat plate was coupled with the spectrometer for data acquisition. Aerosol sample spectra were obtained over wavelengths between 4000 and 400 cm^–1 (mid-infrared region) with 2 cm^–1 resolution by averaging 32 scans. Each aerosol sample was scanned by placing the quartz fiber filter sample-side down on the ATR crystal and applying the pressure tower. Each IR spectrum was corrected for optical effects with the ATR correction algorithm in Opus. A blank quartz fiber spectrum was obtained with each set of daily samples to account for any changes in the absorbance bands due to instrument drift. Between each sample spectrum acquisition, the ATR crystal was cleaned with ethanol, and an air background spectrum was obtained. The FTIR operation method is explained in Doyle [35 ] and Simonescu [36 ].

The mineralogical phases were determined by X-Ray diffraction (XRD) using the Rigaku smart lab II diffractometer according to the diffraction powder method operating at 9 kW and 9 mA with oriented sample holders in polymethyl methacrylate or Si of diameters 25 and 20 mm depending on the amount of material (2–5 mg). The XRD patterns were obtained by scanning at the rate of 1º/minute from 5º to 90º (2 h) and steps of 0.05º (2 h)^{39 (link)}. Fourier transform infrared spectroscopy (FT-IR) was performed using the Bruker Tensor 27IR with KBr pellets to measure the samples' energy absorption. 5 mg of finely ground < 75 µm specimen powder was homogenously mixed with 250 mg of KBr powder until the mixture had the consistency of fine flour and then pressed into a thin 15 mm diameter disc with infrared spectra obtained at 4000–400 cm ^− 1 range, with a resolution of 4 cm⁻¹ 32 scans respectively^{40 –43 (link)}. The samples' morphology was observed with a Carl Zeiss Supra 55 FE-SEM. The elemental analyses were performed using an X-ray dispersive spectrometer (E-DAX) resolution of 0.8 nm coupled to F.E.S.E.M. Each sample was coated with gold sputter (90 s) in a vacuum evaporating system. The sample was observed at a magnification range of 3300–10,000 × with low vacuum mode at 20 kV (Izaguirre, Lanas, & Álvarez 2010; Macwilliam & Nunes, 2019; Pradeep & Selvaraj, 2019).

Fourier transform infrared spectroscopy ATR-FTIR (Bruker Tensor 27 IR, Germany) was used to investigate the functional chemical groups. The FTIR spectra of pure chitosan, pristine polycaprolactone, and different types of composite coating were recorded between (4000–500) cm⁻¹ regions using a universal ATR sampling accessory.

The FTIR spectrum of prepared rGO is presented in Figure 1. The Fourier transform infrared (FTIR) spectroscopy was carried out using Bruker Tensor 27 IR (Natick, MA, USA). According with the spectral illustration, the content dominant concentration is alcoholic hydroxyl (3400 cm⁻¹) [61 ]. The other two main peaks may be ascribed to carboxyl acid (1700 cm⁻¹) [62 (link)] and 1100 cm⁻¹ identified as C–O units [61 ]. The dissimilarity between the spectra of graphene oxide and reduced graphene oxide was reported [36 (link)]; it is relevant in the region around 3400 cm⁻¹, where rGO presents a very prominent peak like our material.