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Hydrogels are commonly used in research and energy, manufacturing, agriculture, and biomedical applications. These uses typically require hydrogel mechanics and internal water transport, described by the poroelastic diffusion coefficient, to be characterized. Sophisticated indentation-based approaches are typically used for this purpose, but they require expensive instrumentation and are often limited to planar samples. Here, we present Sha pe Re laxation (SHARE), an alternative way to assess the poroelastic diffusion coefficient of hydrogel particles that is cost-effective, straightforward, and versatile. This approach relies on first indenting a hydrogel particle via swelling within a granular packing, and then monitoring how the indented shape of the hydrogel relaxes after it is removed from the packing. We validate this approach using experiments in packings with varying grain sizes and confining stresses; these yield measurements of the poroelastic diffusion coefficient of polyacrylamide hydrogels that are in good agreement with those previously obtained using indentation approaches. We therefore anticipate that the SHARE approach will find broad use in a range of applications of hydrogels and other swellable soft materials.
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Nanostructured Surface Functionalization of Polyacrylamide Hydrogels Below the Length Scale of Hydrogel Heterogeneity
Hydrogels are broadly used in applications where polymer materials must interface with biology. The hydrogel network is amorphous, with substantial heterogeneity on length scales up to hundreds of nanometers, in some cases raising challenges for applications that would benefit from highly structured interactions with biomolecules. Here, we show that it is possible to generate ordered patterns of functional groups on polyacrylamide hydrogel surfaces. We demonstrate that when linear patterns of amines are transferred to polyacrylamide, they pattern interactions with DNA at the interface, a capability of potential importance for preconcentration in chromatographic applications, as well as for the development of nanostructured hybrid materials and supports for cell culture.
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- Award ID(s):
- 2108966
- PAR ID:
- 10467282
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- ACS Applied Materials & Interfaces
- Volume:
- 14
- Issue:
- 38
- ISSN:
- 1944-8244
- Page Range / eLocation ID:
- 43937 to 43945
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1021/acsami.2c12034
