加速受损植物修复的压电水凝胶制备与性能研究

In ecological restoration projects such as wetland reconstruction and revegetation of degraded mining areas, seedlings often heal slowly after transplanting or mechanical damage, leading to decreased vegetation survival and weakened carbon sequestration and soil conservation functions. To address the issue of secondary pollution caused by traditional chemical treatments, this study aimed to develop an environmentally-friendly self-powered piezoelectric hydrogel to provide green electrical stimulation for plant wound healing and explore physical stimulation pathways for the restoration of rare and endangered plant species. Using polyacrylamide/polyethylene glycol (PAM/PEG) as the matrix, calcium chloride (CaCl₂) was introduced to prepare a piezoelectric hydrogel with a microporous network and locally ordered piezoionic domains. The microstructure, piezoionic response, and water retention properties were characterized. The mass retention rate was examined under 30 °C and 55% relative humidity conditions. Using tomato seedling stems as a model, the hydrogel was attached to high-strain areas, and the wound healing process was quantitatively analyzed by measuring the callus area fraction and healing progression at different treatment times. The prepared PAM/PEG/CaCl₂ piezoelectric hydrogel, without using heavy metals or poorly degradable components, achieved millivolt-level force-to-electric conversion, with a peak voltage of approximately 6 mV. After 80 h of water loss at 30 °C and 55% RH, the hydrogel still retains~70% of its mass, showing good anti-drying ability and holding promise for long-term outdoor operation under appropriate encapsulation and protection. The results with the tomato stem model showed that, when the hydrogel was attached and driven by environmental forces, the callus area fraction at 3, 5, and 10 days was approximately 49.50%, 64.87%, and 86.13%. The PAM/PEG/CaCl₂ piezoelectric hydrogel can convert ambient mechanical energy into gentle electrical signals, effectively promoting plant wound healing. This enhances the health and survival rate of vegetation while reducing the use of external chemicals, providing a low-carbon, environmentally-friendly functional material pathway for ecological restoration and urban green space management.