Nicolet iz10 spectrometer

The hydrogels and their components were investigated for chemical interaction between KT and the polymer by Fourier transform infrared. The samples investigated were: KT alginate gel prior to reticulation, KT G15 gel, both placebos, and alginate and ketorolac powders. All the KT gels and placebos were dried in an oven at 55 °C. FTIR spectra were obtained using a Nicolet iZ10 spectrometer (Thermo Scientific, Waltham, MA, USA). The measurements were performed in the range of 4000–525 cm⁻¹ with a DTGS detector using a spectral resolution of 4 cm⁻¹, obtaining 32 scans per spectrum. The spectra were recorded using attenuated total reflectance (ATR) with a diamond crystal.

The Attenuated Total Reflectance-Fourier Transform Infrared Reflectance spectra (ATR-FTIR) were recorded with a Nicolet iZ10 spectrometer (Thermo Scientific, Waltham, MA, USA) equipped with a Smart iTR™ diamond ATR accessory. The spectra were acquired with a resolution of 4 cm⁻¹ in the range of 4000–550 cm⁻¹ (32 co-added scans).

The morphologies of the films were characterized by a JCM-5000 SEM (JEOL, Tokyo, Japan). The particle size (diameter) of about 1000 particles were measured from the SEM images using the Nano Measurer software. Meanwhile, the energy dispersive spectra (EDS) were recorded on an Oxford INCA X-Max 250 (High Wycombe, UK). XRD was measured on a PANalytical X’Pert X-ray diffractometer (Almelo, The Netherlands). 2θ was set from 10° to 80°. The FT-IR spectra were collected on a Thermofisher Nicolet iz10 spectrometer (Framingham, MA, USA). The wavenumber was from 4000 cm⁻¹ to 800 cm⁻¹ and the resolution was 2 cm⁻¹.

Gel permeation chromatography (GPC 515, Waters, Milford, MA, USA) was used to determine number- and weight-average molar masses (M_n and M_w) and dispersity (Ð) of the synthesized copolymers. The analyses were carried out using a Waters 1515 gel permeation chromatograph equipped with HR 1, HR 3, and HR 4 columns, thus covering a molecular weight range of 100–500,000 g mol⁻¹. Tetrahydrofuran was used as the eluent at a flow rate of 1.0 mL min⁻¹, at 30 °C. A differential refractive index detector was used and average molar masses (M_n and M_w), as well as dispersity (Ð), were calculated from a calibration curve based on polystyrene (PS) standards from Polymer Laboratories.
Copolymer composition was determined using ¹H NMR (Varian Mercury 300 MHz, Varian, Santa Clara, CA, USA). Copolymer samples were dissolved in deuterated chloroform and scanned 32 times at room temperature.
Chemical structures of the copolymers and modified PLA were analyzed by Fourier transform infrared spectroscopy. The FTIR spectra of samples were measured at room temperature with 32 scans at a resolution of 1 cm⁻¹ using a Nicolet IZ10 spectrometer (Thermo Fisher Scientific, Waltham, MA, USA) over the wavenumbers ranging from 4000 to 600 cm⁻¹.