title: Post-polymerization of urease-induced calcified, polymer hydrogels.
abstract: Urease-induced calcification is an innovative method to artificially produce highly filled CaCO3-based composite materials by intrinsic mineralization of hydrogels. The mechanical properties of these hybrid materials based on poly(2-hydroxyethylacrylate) cross-linked by triethylene glycol dimethacrylate are poor. Increasing the degree of calcification to up to 94 wt% improves the Young's moduli (YM) of the materials from some 40 MPa to more than 300 MPa. The introduction of calcium carbonate affine groups to the hydrogel matrix by copolymerizing acrylic acid and [2-(methacryloyloxy) ethyl]trimethylammonium chloride, respectively, does not increase the stiffness of the composites. A Young's modulus of more than 1 GPa is achieved by post-polymerization (PP) of the calcified hydrogels, which proves that the size of the contact area between the matrix and calcium carbonate crystals is the most crucial parameter for controlling the stiffness of hybrid materials. Switching from low Tg to high Tg hydrogel matrices (based on poly(N,N-dimethyl acrylamide)) results in a YM of up to 3.5 GPa after PP.
authors.affiliation: TU Dortmund, Emil-Figge-Str. 66, 44227, Dortmund, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rauner
authors.forename: Lea
authors.initials: L
authors.lastname: Buenger
authors.forename: Stefanie
authors.initials: S
authors.lastname: Schuller
authors.forename: Joerg C
authors.initials: JC
authors.lastname: Tiller
mesh_terms: D000179:Acrylates / Q000737:chemistry; D002119:Calcium Carbonate / Q000737:chemistry* / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry; D055119:Elastic Modulus; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011109:Polymethacrylic Acids / Q000737:chemistry; D014510:Urease / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000179:Acrylates; D003432:Cross-Linking Reagents; D020100:Hydrogels; D011108:Polymers; D011109:Polymethacrylic Acids; C020946:triethylene glycol dimethacrylate; C035957:2-hydroxyethyl acrylate; D011092:Polyethylene Glycols; D014510:Urease; D002119:Calcium Carbonate; C036658:acrylic acid
keywords: Urease-induced calcification; artificial biomineralization; hydrogels; organic/inorganic hybrid materials; polymer conetworks