Sta 449f5 thermoanalyzer

The thermal properties of unmodified and cross-linked gelatin materials were studied using the Simultaneous TGA-DTA NETZSCH Thermal Analysis TA Instruments type STA 449F5 Thermoanalyzer (NETZSCH, Selb, Germany) in the temperature range from 30 °C to 650 °C. Samples weighing about 10 mg were tested. The measurement was performed under a nitrogen atmosphere with a gas flow rate of about 50.0 mL/min. The heating speed was 10 K/min. The research program that was used to determine the loss of mass during material degradation and the temperature values at the maximum speed of the entire process was the NETZSCH Proteus software (Version 6.1.0).

UV–VIS absorption spectra were recorded in chloroform, acetone, DMSO, acetonitrile, and methanol (3.323 × 10⁻⁶ M) solutions on a Hitachi spectrophotometer. The fluorescence spectra were recorded on a spectrofluorometer Gildenpλotonics 700 (Dublin, Ireland) in the range 900–200 nm (grating 1, bandpass 5 and 8, integration time 100 ms, chloroform, acetone, DMSO, acetonitrile, and methanol solution of compounds the same as in the case of the UV–VIS studies or silicon slides). The elemental analysis was carried out using a Vario EL III Elemental analyzer. The thermal analysis (TG, DTG, DTA) was performed on an SDT 2960 TA analyzer under air, a heating rate of 10 °C min⁻¹, and a heating range of up to 1000 °C and a Jupiter STA 449 F5 thermoanalyzer from Netzsch (Selb, Germany) with an automatic sample feeder coupled to a Vertex 70V FT-IR spectrometer from Bruker Optik (Ettlingen, Germany). After combustion, the residue of the sample was analyzed by an XRD analysis performed with a Philips X’Pert equipped with an X’Celerator Scientific detector. The IR spectra were recorded on the Bruker instrument using the ATR technique in the range of 70–4000 cm⁻¹. Circular dichroism spectra were recorded with a Jasco J-815 spectropolarimeter (Jasco Inc.) in the range of 310–700 nm wavelengths. The solution of K1 and K2 complexes (≈1 × 10⁻⁴ M) was prepared by dissolving it in a CHCl₃ solution.