4.4.2 Printability of carrageenan/MCNTs hydrogel
As shown in Figure 6, the printability of kc-sa-c-0.3 hydrogel was simulated similar to that of kc-sa-1.0. As for the printability of binary composite hydrogel, the following observations were made:
Printing pressure should be coordinated with the printing rate, and lower pressure with high rate can destroy the integrity of printed structure
The broken line graph of printability lined by a known printing pressure and rate can simulate the printability of unknown pressure and rate.
The above summarised rules apply to the ternary composite hydrogel. In view of the more complex interaction within the ternary composite hydrogel, we added 15 kPa,25 kPa, and 35 kPa pressures for kc-sa-c-0.3.
As shown in Figure 6a, the diameter of the samples No. 5, 9, 10, and 14 was <1.1 mm, that is, the value of printability was <0.1. As shown in Figure 6d, the diameter of the most printed gel filament was 0.8–1.2 mm. Our results demonstrated that the printability of kc-sa-c-0.3 was better than that of kc-sa-1.0.
The printability value of samples No. 13, 18, 19, 22, and 23 was close to zero. These results have been simulated from Figure 6b before printing. These results demonstrated that in the range of the allied printing pressure, the higher is the printing pressure and rate, better is the stability of the filament shape.