Nanoporous 3D Polyurethane for Toosendanin Adsorption, Encapsulation, and High-Efficient Utilization

Nanoporous 3D-polyurethane (3D-PU) was prepared based on nano-CaCO3 templated controllably confined polymerization assembly and weak acid etching strategies. Nanopores with diameters ranging from 48 to 72 nm were distributed on 3D-PU, facilitating its high BET surface area of 468.0 m2/g. The 3D-PU exhibited enhanced adsorption selectivity to multi-H-bond donors and acceptors, multirings contained compounds based on pore filling, hydrogen-bonding, and π-π interactions; therefore, the novel 3D-PU had promising adsorption ability to toosendanin (TSN) with a maximum theoretical adsorption capacity of 361.6 mg/g. Adsorption isotherm, kinetic, and thermodynamic investigations revealed that the adsorption was heterogeneous and was supported by multiple adsorption sites, controlled by a chemical adsorption mechanism, endothermic, spontaneous, and with increased entropy. Based on the optimized adsorption, the loading capacity (LC) of 3D-PU toward TSN attained 23.4%. After encapsulation, the effective period of TSN was extended to 11 days, the photolysis half-life of TSN was increased 3.2 times, and the LC50 for Aphis citricola was reduced approximately 6.0 times, indicating that 3D-PU effectively improved the performance of TSN. The porous 3D-PU can serve as a promising carrier for more pesticide adsorption, encapsulation, safe, highly efficient, and environmentally friendly utilization.