Polydopamine-coated montmorillonite micro/nanoparticles enhanced pectin-based sprayable multifunctional liquid mulching films: Wind erosion resistance, water retention, and temperature increase/heat preservation properties

Natural biopolymer-based liquid mulching films (LMF) have received widespread attention, whereas the fragile structure and limited functionality have severely restricted their application. Herein, polydopamine-coated montmorillonite micro/nanoparticles enhanced pectin-based sprayable multifunctional liquid mulching films (P-MMT@PDA LMF) were prepared. Dopamine has abundant active sites, and its self-polymerization onto the surface of MMT improves the compatibility of MMT with pectin chains, facilitates the homogeneous dispersion of MMT@PDA in pectin polymers, and makes them more tightly entangled through hydrogen bonding. Therefore, P-MMT@PDA LMF exhibits better mechanical properties (improved by 64.94 N) and wind erosion resistance (wind speed 30 m/s, >60 min). Moreover, MMT@PDA micro/nanoparticles can fill the voids of pectin chains, thus increasing the densification and complexity of the network structure in LMF, enabling better water retention (improved by 14.67 %) and heat preservation (increased by 3.14 °C). Meanwhile, the photothermal effect of PDA endows P-MMT@PDA LMF with a warming effect (increased by 2.84 °C). Hence, this LMF promote wheat growth and demonstrate good biodegradability. These results suggest that the application of P-MMT@PDA LMF is an effective strategy in the environments of drought and cold, which is expected to provide a green solution for sustainable agricultural development and environmental protection in the future.