In a new paper published in the journal Advanced Functional Materials, professor Rosa Espinosa Marzal and co-authors explore the microstructures of hydrogels, including ways to tailor their nanostructures for use in different applications. Hydrogels - materials that are mainly composed of water - are promising candidates for applications in biomedical devices, tissue engineering and soft robotics because of their ability to mimic biological materials and to tune their properties via synthesis.
In this work, the researchers demonstrate that incorporating a charged component into a polyacrylamide hydrogel, while partially restricting the expansion of the network in water, reorganizes the disordered microstructure of the hydrogel into an ordered microstructure. From microscopy imaging of the interface with water, the researchers discovered microscopic structures with either spherical or lamellar shapes, which have a direct impact on the surface structure and on adhesive and frictional properties of the hydrogels. The authors also show that it is possible to dynamically modulate the properties of a hydrogel by changing the ionic content of water.
This work advances the knowledge necessary to design functional and responsive hydrogels with control over their nano-scale structure to tailor hydrogel properties for engineered applications. By revealing the origin for the structural ordering, they also make it possible to apply these principles to similar materials in order to engineer specific properties.
The paper, Charge-Induced Structural Changes of Confined Copolymer Hydrogels for Controlled Surface Morphology, Rheological Response, Adhesion, and Friction, is available online at https://onlinelibrary.wiley.com/doi/10.1002/adfm.202111414