Dma q800

Dynamic mechanical properties of collagen network and the resultant collagen/HA hybrid scaffolds (n = 5), under dry and wet conditions, were measured using a DMA Q800 (PerkinElmer, Waltham, MA, USA). Cylindrical samples (d = 15 mm, h = 15 mm) were subjected to cyclic forces (0 and 10% compressive strain) in the frequency range 0.01–100 Hz at 37 °C. For wet testing, samples were tested under same conditions while immersed in PBS bath.

¹H, ¹³C, and ¹⁹F NMR spectra were all created via Bruker DRX-600 spectrometer (Karlsruhe, Germany) with chloroform-d (CDCl₃), dichloromethane-d₂ (CD₂Cl₂), and dimethylsulfoxide (DMSO-d₆) as deuterated solvents. IR spectra were all measured by PerkinElmer SP one FT-IR (Waltham, MA, USA). Wide-angle X-ray diffraction (WAXD) measurement were carried out on Bruker Bede XRD Di (Karlsruhe, Germany). The optical properties of PI films were recorded on Shimadzu UV-2450 (Kyoto, Japan) from 300 to 800 nm. The refractive index of PI films was measured by ME-Lellipsometer (Wuhan, China). Thermogravimetric analysis (TGA) measurements were performed on PerkinElmer TGA-2 (Waltham, MA, USA) under nitrogen conditions at rate of 10 °C min⁻¹ from room temperature to 800 °C. Dynamic mechanical analyses (DMA) were carried out on PerkinElmer DMA Q800 using tensile mode at a frequency of 1 Hz. Coefficient of thermal expansion (CTE) values were measured by thermal mechanical analysis (TMA) Q400 (USA). Mechanical properties were all measured by stretching machine. Contact angles were measured at room temperature with deionized water as the solvent. According to the stability of the droplets, the measurements were taken over a period of 120 s.