Shape Memory Behavior of Polyacrylamide/Multi‐Walled Carbon Nanotubes Nanocomposite Aerogel

ABSTRACT The development of lightweight, stimuli‐responsive materials remains a significant challenge in materials science. Shape memory aerogels represent a promising category of smart materials, yet their widespread application has been limited by performance constraints. This study explores the synthesis and characterization of polyacrylamide (PAAm) hydrogels enhanced with multi‐walled carbon nanotubes (MWCNTs) and transformed into aerogels through freeze‐drying. The obtained aerogels were characterized using mercury intrusion porosimetry, weighing method, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The results revealed that the aerogels possessed high porosity (over 80%), low density (0.098 g cm −3 ), high specific surface area (152 m 2 g −1 ), and an average pore diameter of 1280 nm. Electrical conductivity analysis demonstrated an electrical percolation threshold at 2.5 wt.% of MWCNTs. Furthermore, dynamic mechanical analysis indicated a 400% increase in the Young's modulus in the presence of nanoparticles. The mentioned aerogel exhibited shape memory behavior under direct thermal stimulation, and the results also showed that the shape recovery ratio and shape recovery speed of the nanocomposite aerogel were 14% and 74% higher than those of the PAAm aerogel, respectively. The enhancements in mechanical and shape memory properties, combined with inherent lightweight nature, suggest promising applications across various technical fields, from aerospace to biomedical engineering.