Abstract: A composition of matter including a mother solution; an organic ester; an additive agent and deionized water. The mother solution includes a rare earth compound or a metal compound, an organic acid, an organic amine, and deionized water. Also provided is a method of preparing the composition of matter. The method includes: 1) heating deionized water to a temperature of 50-60° C.; adding an organic acid to the deionized water, allowing to dissolve, followed by addition of a rare earth compound or a metal compound, 2-4 hours later, adding an organic amine, heating to a temperature of 70-80° C. and holding; cooling and filtering to yield a mother solution; 2) mixing the mother solution, deionized water, and a catalyst; vacuumizing a resulting mixture, heating the mixture to a temperature of 95-125° C. and holding, following by addition of a polymerization inhibitor and an organic ester; 2-4 hours later, cooling, standing, separating.