Self-healing polyacrylamide (PAAm) gels at room temperature based on complementary guanine and cytosine base pairs

The unique properties of self-healing materials hold great potential in many fields because they can repair themselves automatically and have an improved service time. In this study, polyacrylamide (PAAm) gels with complementary guanine and cytosine base pairs have been prepared. Herein, based on our previous research, cytosine (C) and guanine (G) (triple hydrogen) with biosafety were introduced to endow the PAAm with self-healing properties. Then, their self-healing properties were studied in detail and the results indicate that the optimized PAAm gel sample manifests a healing efficiency of 90% at room temperature. The excellent proportion of methacryloyloxyethyl isocyanate-cytosine/guanine (IEM-C/G) to AAm is 1 : 30, according to which the PAM-CG material exhibits enhanced stretchability and tensile strength. The major healing process occurs within 5 h at room temperature, and the material is completely healed after 20 h. Moreover, the healing time can be shortened at a higher temperature. The mechanical behaviors are tuned by changing the base pairs, and the gels exhibit recoverable mechanical performances. Therefore, this study provides a facile strategy for developing self-healing and biocompatible PAAm gels.