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Well-dispersed BaSO_4 nanoparticles were synthesized in the presence of sodium polyacrylate(PAAS) by a simple precipitation method,with BaCl_2 and(NH_4)_2SO_4 as reactants.The different roles performed by PAAS in the synthesis of BaSO_4 nanoparticles were investigated using X-ray diffractometry,Fourier transform infrared spectroscopy,and transmission electron microscopy.The results indicate that the assynthesized BaSO_4 nanoparticles were spheres with an average diameter of 30 nm and that their surfaces were affected by the PAAS.Under a typical procedure employed,PAAS reacted with BaCl_2 to yield an intermediate,serving as a control releasing agent and separating the nucleation and crystal growth processes of the BaSO_4 nuclei.During formation of the BaSO_4 nanospheres,the intermediate slowly dissolved and released barium and polyacrylate ions,inhibiting the growth and aggregation of newly formed BaSO_4seeds and resulting in particles of narrow diameter distribution and improved dispersibility.Moreover,these polyacrylate ions further modified the surfaces of the BaSO_4 nanoparticles.
Well-dispersed BaSO_4 nanoparticles were synthesized in the presence of sodium polyacrylate (PAAS) by a simple precipitation method, with BaCl_2 and (NH_4) _2SO_4 as reactants. The different roles performed by PAAS in the synthesis of BaSO_4 nanoparticles were investigated using X-ray diffractometry, Fourier transform infrared spectroscopy, and transmission electron microscopy. Results indicative of the assynthesized BaSO 4 nanoparticles were spheres with an average diameter of 30 nm and that their surfaces were affected by the PAAS. Under a typical procedure employed, PAAS reacted with BaCl_2 to yield an intermediate, serving as a control releasing agent and separating the nucleation and crystal growth processes of the BaSO_4 nuclei. Preparation of the BaSO_4 nanospheres, the intermediate slowly dissolved and released barium and polyacrylate ions, inhibiting the growth and aggregation of newly formed BaSO_4seeds and resulting in particles of narrow diameter distribution and improved disper sibility. Moreover, these polyacrylate ions further modified the surfaces of the BaSO 4 nanoparticles.