Drop shape analyzer dsa25

For determination of the surface wettability of treated and untreated seeds, contact angle measurements were performed using a Drop Shape Analyzer DSA25 (Krüss GmbH, Germany) with Software ADVANCE for intelligent image evaluation algorithm. For each seed, the contact angle was measured between the surface of the seed and liquid by placing 1 µL of distilled water at 0.1 µL/s at 26.0 °C. This was performed on three seeds for each condition.

Contact-angle measurements were done at room temperature using a 10 µl droplet of deionized water addition on the surface of the samples using Drop Shape Analyzer DSA25, Kruss GmbH, Germany. Ten readings per sample were measured.

Surface free energies of the substrate/air interface and WCA were determined by the sessile drop method using the Drop Shape Analyzer—DSA25 (Krüss, Hamburg, Germany) (Staehlke et al., 2018 (link)). One μl drops of distilled water and diiodomethane (Sigma-Aldrich Chemie, Taufkirchen, Germany) were deposited on the sample surface (n = 3 at 3 drops each). WCA values were calculated with the supplied software (ADVANCE, V.1.7.2.1, Krüss, Hamburg, Germany) via the Young’s equation and the SFE according to Owens, Wendt, Rabel und Kaelble (OWRK).

For the determination of surface free energy, contact angle measurements were performed: 1 µL of distilled water and 1 µL of methylene iodide were applied to the specimen’s surface. Within 30 s after application, a computer-aided measurement device (Drop Shape Analyzer DSA25, Krüss, Hamburg, Germany) performed ten contact angle measurements for each liquid. The surface free energy was calculated using the formula introduced by Owens and Wendt [36 (link)].

Powdered samples were compacted into 4.5 cm in diameter disks and placed on the lifting table of a Drop Shape Analyzer DSA 25 (Krüss, Hamburg, Germany). Then, an automated dosing syringe containing water at 20 °C was used to deposit a single drop of 14 µL on the surface of the disks. The images of the water drop on the surface of the disks were recorded for 10 min by a high-resolution camera and processed by ADVANCE software ver. 1.9 (Krüss) to calculate the contact angle. Each sample had the contact angle measured in duplicate.

Scanning electron microscopy (SEM) was used to test surfaces of the materials, including fibers diameter and pore sizes, as earlier described [23 (link)]. The contact angle was determined with a Drop Shape Analyzer DSA 25 (Kruss GmbH, Hamburg, Germany), as described in the manufacturer’s instructions.
A Universal Zwick/Roell Z100 (Zwick Roell AG, Ulm, Germany) test bench was used to study mechanical properties of scaffolds, as described in ISO 7198:1998 (4 replicates for every scaffold) [23 (link)]. A “wet” sample was obtained after incubation of a matrix in water for 30 min at 20–23 °C to moisten the 3D matrix completely. The strength and elongation of matrices were determined from the constructed tensile curves in four replicates. Young’s modulus was determined in experiments with statistical loading. Before testing, the material was conditioned by loading the test specimen 5 times (each for 10–20 s) using 30–50% of the elastic limit load determined in the preliminary test. The static load was increased in steps of 10 g (to 60–70% of the elastic limit) that were applied for 20 s with a subsequent measuring of the deformation after unloading. The load that induced more than 5% elongation after unloading was considered the elastic limit.