Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Schematic illustration of preparation process and the formation mechanism of the PVA/CaCO3-Na2SO4 hybrid hydrogels.

ABSTRACT
Recently, hydrogels with desirable mechanical properties and multi-functionality have displayed great potential in the fields of biomedicine, health monitoring, and artificial intelligence. However, it remains a challenge to fabricate multifunctional hydrogels with both sufficient mechanical strength and toughness. In this work, inspired by biomineralization in nature and the Hofmeister effect, CaCO3 whiskers enhanced PVA (PVA/CaCO3-Na2SO4) hybrid hydrogels with excellent mechanical properties, freezing-tolerance, high ionic conductivity, and good cyto-compatibility were successfully developed by in situ CaCO3 mineralization and subsequent Na2SO4 solution immersion strategies. The CaCO3 whiskers formed mechanisms, physiochemical properties, mechanical performances, freezing-tolerance, conductivity, and in vitro cyto-compatibility of PVA/CaCO3-Na2SO4 hybrid hydrogels were investigated. The resultant PVA/CaCO3-Na2SO4 hybrid hydrogels exhibited excellent tensile strength (13.01 ± 1.56 MPa with elongation at break of 306.58% ± 4.70%), compression strength (6.64 ± 0.05 MPa at 80% compressive strain), good freezing-tolerance at −20°C, high ionic conductivity (4.18 ± 0.04 S/m), and good cyto-compatibility. Furthermore, the resultant PVA/CaCO3-Na2SO4 hybrid hydrogels exhibit sensitive and reliable responses to deformations, which demonstrate promising applications in the detection of human motions and human–machine cooperation. Therefore, this work provided a new strategy for the design and development of multi-functionality hydrogels with tunable mechanical properties.