Study on the synthesis of Fe2O3-, MgO-cored glass by sol-gel method and their application in agricultural chemistry

Fe 2 O 3 - and MgO-cored materials with SiO 2 –P 2 O 5 binary shells were synthesized using the sol-gel method and the influence of P 2 O 5 content on their release characteristics was evaluated. In the Fourier transform infrared (FT-IR) spectrum of the Fe 2 O 3 -cored sample, the peak corresponding to the P–O–P bond was not observed. In addition, the peaks associated with P=O and HPO 4− were clearly observed in contrast to the MgO-cored sample. It is possible that the Fe 3+ ion reacted with phosphoric acid to form a FeH 2 PO 4 2+ complex, and it was assumed that the release characteristics of the Fe 2 O 3 -cored sample would be less affected by the shell composition. From the X-ray diffraction (XRD) measurements, it was confirmed that amorphous shells were obtained, and the transmission electron microscopy (TEM) images showed that the Fe 2 O 3 -cored samples exhibited a spherical shape irrespective of the shell composition, whereas the MgO-cored sample exhibited the spherical shape only for the MS8P2 sample. The inductively coupled plasma (ICP) measurements showed that the MS8P2 sample exhibited controlled-release characteristics. As the phosphate content of the shell was increased, the release start time was shortened. A comprehensive review of the results of this study showed that the MS8P2 sample could be grafted as a nanopowder for use as a controlled-release fertilizer. The release test results of MgO-cored samples (If the results are in the box, the requirements are met) Highlights In this study, the core–shell sample of Fe 2 O 3 or MgO@(100 − x )SiO 2 – x P 2 O 5 (mol%) (where x = 0, 20, 40) was synthesized using the sol-gel process. By changing the SiO 2 /P 2 O 5 ratio, the chemical durability could be controlled to modify release characteristics. It is considered that the MS10 and MS8P2 samples and the core components can be completely released as time elapses. It is considered that the MS8P2 sample can be applied as CRF based on the associated requirements.