Formation of Mesoporous BaSO4 Microspheres with a Larger Pore Size via Ostwald Ripening at Room Temperature

area: 25.6 m2/g), the radial arrangement of irregular BaSO4 nanorods, were successfully synthesized by the radiolysis of an aqueous solution of K2S2O8, Ba(NO3)2, and disodium ethylenediaminetetraacetate with an irradiation time of 1000 min (dose rate: 20 Gy/min) at room temperature. It was confirmed that the mesoporous microspheres with a larger pore size evolved from the mesoporous microspheres with a smaller pore size (diameter of pore: ca. 4 nm, BET surface area: 49.6 m2/g), which were generated at the early stage of the irradiation course and were mainly constructed by quasi-spherical nanoparticles, via Ostwald ripening at room temperature. In the current materials synthesis and nanodevice fabrication, complex architectures constructed by the self-assembly and highly ordered organization of one- and two-dimensional (1D, 2D) nano-scale building blocks have been of intense interest because of their uniqueproperties andpotential applications, andare of importance in understanding the regularity of self-assembly with artificial buildingblocks.1Asa result of rapid advancements in synthetic stra-tegies, highlyorganized1Dand2Dbuildingblocksofmetals,2metal oxides,1c,e,f,3 organic-inorganic hybrid materials,1d minerals,1a,4 and soon5 have been synthesized.Among the numerous syntheti