Dma q800 dynamic mechanical analyzer

A compression test was performed by using the submersion compression clamp on the DMA Q800 dynamic mechanical analyzer (TA Instrument). Seven square-shaped samples (16 × 16 mm²) with a thickness of 6 mm were tested for each type of composite. During the measurement samples were immersed in distilled water. The following testing conditions were applied in a quasi-static compression test: a compressive ramp of up to 60% strain and a strain rate of 10% per min, a preload of 0.05 N was used. In a cyclic loading/unloading test 10 cycles were continuously repeated. A relaxation time of 10 min was used in between each loading/unloading cycle.

Mechanical testing was conducted using single silk fiber spun by the bimolters and the control trimolters. The cocoons were harvested and degummed as described in Section 2.6. The degummed silks were used as samples for characterization of the mechanical properties of the silk fibers. In this case, two fibroin brins were completely separated [23 (link),25 (link),34 (link)]. A single brin was used to test the mechanical properties. To ensure the accuracy of the data, we also used the remainder of the same brin for SEM to calculate the diameter for mechanical testing. A minimum of 25 tensile deformation tests were performed for each silk type on fibers from five separate cocoons. The tensile properties of individual brins were measured using a DMA-Q800 dynamic mechanical analyzer (TA, New Castle, DE, USA). Mechanical tests were performed according to a previously reported method [9 (link)]. For each tensile test, the fiber diameter was measured using JCM-5000 SEM (JEOL, Shoshima, Japan). The experimental data obtained relating to the mechanical properties were analyzed using the TA Universal Analysis software. Subsequently, the raw data were used to calculate the mechanical performance parameters using the ORIGIN8.0 software (OriginLab, Northampton, MA, USA).

The compressive stress-strain measurements were performed on cylindrical bulk discs of 300 μL of volume (diameter 8mm, height 6mm). Two solutions of PF (5 mg/mL or 8 mg/mL supplemented with 1% of PEG-DA) were cross-linked using a UV light at 365 nm (intensity 4–5 mW/cm²) for 5 min. Compression tests were performed with a DMA Q800 Dynamic Mechanical Analyzer (TA Instruments, New Castle, DE, USA) in the strain rate mode. All tests were performed at 25 °C with the following parameters: 0.003 N preloaded force, 5% min—1 strain rate and final deformation was set at 30%. Young’s modulus was calculated from the initial linear regions (0–5% of strain) of obtained stress-strain curves. Each measurement was performed in triplicate and results are reported as the mean ± standard deviation.