Juan Pablo Segovia-Gutiérrez , José Alberto Rodríguez Agudo , Nicolas Binder , Peter Georg Weidler , Frank Kirschhöfer , Claudia Fink-Straube , Jürgen Utz , Natalie Germann
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引用次数: 0
Abstract
Hydrogels are natural/synthetic polymer-based materials with a large percentage of water content, usually above 80 %, and are suitable for many application fields such as wearable sensors, biomedicine, cosmetics, agriculture, etc. However, their performance is susceptible to environmental changes in temperature, relative humidity, and mechanical deformation due to their aqueous and soft nature. We investigate the mechanical response of both filled and unfilled alginate/gellan hydrogels using a combined axial-torsional rheometric approach with cylindrical samples of large length/diameter ratio under controlled temperature and relative humidity. Dynamic Mechanical Analysis (DMA) is performed on the same specimen in both torsion and extension under identical experimental conditions. This rheometric approach ensures consistent initial and boundary conditions, which are essential for a reliable estimation of viscoelastic moduli G* and E*, and their dependence on temperature, frequency, and relative humidity. Our findings indicate that humidity critically affects the mechanical response of the material due to sample volume shrinkage, necessitating corrections to the viscoelastic moduli. We also find temperature plays a role only at low/medium relative humidity values. The inclusion of fillers leads to a modest increase in the elasticity of the hydrogel, probably due to restricted water diffusion out of the sample. In connection with the latest, unfilled samples in breaking tests present only slippage due to twist-induced surface water excess, opposite to breakage events shown by filled samples, probably linked to restricted water diffusion.
期刊介绍:
Carbohydrate Polymers stands as a prominent journal in the glycoscience field, dedicated to exploring and harnessing the potential of polysaccharides with applications spanning bioenergy, bioplastics, biomaterials, biorefining, chemistry, drug delivery, food, health, nanotechnology, packaging, paper, pharmaceuticals, medicine, oil recovery, textiles, tissue engineering, wood, and various aspects of glycoscience.
The journal emphasizes the central role of well-characterized carbohydrate polymers, highlighting their significance as the primary focus rather than a peripheral topic. Each paper must prominently feature at least one named carbohydrate polymer, evident in both citation and title, with a commitment to innovative research that advances scientific knowledge.