TY  - JOUR
A1  - Seifert, Annika
A1  - Gruber, Julia
A1  - Gbureck, Uwe
A1  - Groll, Jürgen
T1  - Morphological control of freeze‐structured scaffolds by selective temperature and material control in the ice‐templating process
JF  - Advanced Engineering Materials
N2  - Herein, it is aimed to highlight the importance of the process parameter choice during directional solidification of polymer solutions, as they have a significant influence on the pore structure and orientation. Biopolymer solutions (alginate and chitosan) are directionally frozen, while systematically varying parameters such as the external temperature gradient, the temperature of the overall system, and the temperatures of the cooling surfaces. 

In addition, the effect of material properties such as molecular weight, solution concentration, or viscosity on the sample morphology is investigated. By selecting appropriate temperature gradients and cooling surface temperatures, aligned pores ranging in size between (50 ± 22) μm and (144 ± 56) μm are observed in the alginate samples, whereas the pore orientation is influenced by altering the external temperature gradient. 

As this gradient increases, the pores are increasingly oriented perpendicular to the sample surface. This is also observed in the chitosan samples. However, if the overall system is too cold, that is, using temperatures of the lower cooling surface down to −60 °C combined with low temperatures of the upper cooling surface, control over pore orientation is lost. This is also found when viscosity of chitosan solutions is above ≈5 Pas near the freezing point.
KW  - unidirectional freezing
KW  - anisotropic porous structures
KW  - morphology controls
KW  - systematic investigations
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256330
VL  - 24
IS  - 3
ER  -