Infiltration of laponite: An effective approach to improve the mechanical properties and thermostability of collagen hydrogel

摘要

Rapid aggregate precipitation of collagen and laponite in solution restricted the development of corresponding hybrid materials. Herein, a facile method of immerging collagen hydrogel into laponite dispersion was adopted to prepare hybrid collagen/laponite hydrogel, avoiding the precipitation. Collagen hydrogel shrunk and water content decreased dramatically after laponite solution treatment. According to the images of Scanning electron microscopy and energy dispersive system, the uniformly dispersed laponite in collagen hydrogel was observed, demonstrating infiltration of laponite into collagen hydrogel. X-ray photoelectron spectroscopy results revealed that coordination bonds generated between magnesium in laponite and collagen. Thermogravimetric analysis and Differential scanning calorimetry results displayed thermal decomposition temperature of collagen hydrogel increased from 321 to 342 degrees C, and denaturation temperature rose from 43.8 to 50.8 degrees C after laponite infiltration. Rheological and compressive tests showed the elastic modulus, fracture stress, compressive modulus and rupture point of hydrogel treated by 10 laponite were 695.2 Pa, 253.3 kPa, 13.5 kPa and 76.7, respectively, which were about 3.5, 5.5, 45.0, and 1.4 times larger than those of pristine collagen hydrogel. Besides, enzyme degraded rate of collagen was decelerated, and the hydrogel was still nontoxic with the infiltration of laponite. The promising data demonstrated infiltration of laponite was an effective way to fabricate collagen/laponite hybrid materials with desirable properties.