Dilute gels with exceptional rigidity from self-assembling silk-collagen-like block copolymers

作者：Martens Aernout A^*; van der Gucht Jasper; Eggink Gerrit; de Wolf Frits A; Stuart Martien A Cohen

来源：Soft Matter, 2009, 5(21): 4191-4197.

DOI：10.1039/b907537b

Rheological data on monodisperse block copolymer hydrogels are rare because the amounts produced with various methods usually are not sufficient for materials testing. By biotechnological means, expression of a block copolymer encoding gene in the yeast Pichia pastoris, we produced enough protein block copolymer for a study of the macroscopic properties of several gels. To study the effect of block order on the mechanical properties of self-assembling block copolymer hydrogels, we tested gels of two molecules with complementary triblock organization: CS(E)S(E)C and S(E)CCS(E), in which the S(E) block self assembles at low pH while the C block remains a random coil. Dynamic mechanical spectroscopy revealed differences in gelling kinetics and mechanical properties. The gels displayed non-linear elasticity comparable to that of actin gels and other networks of cross-linked semiflexible polymers. Moreover, exceptionally high storage moduli, exceeding 40 kPa, were reached already at concentrations as low as 1.5 wt%, without any additional crosslinking agent. Increasing the temperature of a CS(E)S(E)C gel led to stiffening until 50 degrees C, above which it melted.

• 出版日期2009