Efficient reclamation phosphate by alginate-g-BMOF using poly(N-isopropyl acrylamide-co-acrylamide) as coating for temperature-responsive slow-release P-fertilizer

Poly(N-isopropyl acrylamide) and its derived copolymer, as a temperature-responsive material, are widely used in the field of anticancer drug carrier. And it also plays an important role as carrier in slow-release fertilizer in recent years. In this paper, a smart poly(N-isopropyl acrylamide-co-acrylamide)-coated Alg-BMOF (PABMOF) was fabricated in ionic liquids microemulsion ([Bmim]PF6/TX-100/water) as nano-reactor. The structure and morphology of PABMOF were characterized by FT-IR, XRD, XPS, SEM, TG and BET. The resultant PABMOF was used as a adsorbent for H2PO4- adsorption. The adsorption kinetics, isotherms and mechanism of H2PO4- onto the resultant PABMOF were studied. The adsorption kinetic data was well suitable for pseudo-second-order kinetic model, and adsorption isotherm results demonstrated that the equilibrium data was fitted for Freundlich model. The water-holding and water-retention capacity of soil with TRSRFs addition of 2 wt% were74.3% and 52.13% at 30th day, respectively. Moreover, the release behavior of TRSRFs in water show that the cumulative release rate (Cr%) were 81.4% at 45 °C and 97.6% at 25 °C within 172 h, which displayed the excellent temperature-responsive property. The effect of TRSRFs on the growth of Chinese cabbage was investigated, which was indexed with the germination rate, plant height and root length of the crop.