Preparation of high tenacity bilayer hydrogel with rapid thermal response based on the introduction of sodium alginate and porogen

ABSTRACT

Bilayer hydrogels composed of poly(N-isopropylacrylamide) (PNIPAm) and poly(acrylic acid-co-acrylamide) (P(AAc-co-AAm)) are commonly utilized as anisotropic hydrogels with temperature and pH sensitivity. Nonetheless, PNIPAm is known to possess poor mechanical properties, a slow thermal response, and brittleness, which greatly restricts its application for temperature sensitivity. In order to overcome these limitations, a semi-interpenetrating network (semi-IPN) structure was created by combining PNIPAm with sodium alginate. This structure effectively addressed the issue of PNIPAm’s brittleness, increased its tensile stress, and improved its tensile strain. Notably, a porogen such as sodium carbonate was incorporated to increase the porosity of the thermo-sensitive layer hydrogel, resulting in a faster thermal response rate. The bilayer hydrogel obtained can be used as a bidirectional hydrogel driver with both temperature and pH sensitivity. Mechanical manipulation through temperature changes or pH shifts can cause significant deformation in the hydrogel, making it a promising material for soft actuator applications.

KEYWORDS:

• Bilayer hydrogel
• tensile property
• thermal response rate
• porogen
• sodium alginate

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Authors’ Contributions

In this study, Chengao Li conducted the main experiments, wrote the manuscript, and edited the images. Licheng Wang carried out the initial investigation of the rapid response and mechanical properties of the bilayer hydrogel. Liuyun Wei conducted the preliminary exploration of the bilayer hydrogel. Mingqing Yuan performed the microstructure analysis of the bilayer hydrogel and provided funding for the completion of the experiment. Hua Yang is the corresponding author of this article.

Data Availability Statement

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This research was supported by Research, development and industrialization of frontier new material medical silicone gel and its products [Guike AA23023002, Program Leader: Pingchuan Jiang], The sub leader of this project is Yuan Mingqing.