Boric Acid Adsorption by Surface Modified Submicrometer Silica Spheres
Pure submicrometer silica spheres and eight kinds of surface modified submicrometer silica spheres were prepared through a one-step process. Scanning electron microscopy (SEM), nitrogen sorption, and the determination of point of zero charge (PZC) were used to characterize the modified and pure silica particles. Boric acid adsorption by the unacidified and acidified particles from its water solutions of deferent initial pH values was compared comprehensively. The SEM micrographs of the particles demonstrated that the modified particles are spherical particles with uniform size and shape. The particles modified with methacryloxypropyltrimethoxysilane and the pure silica particles have the largest size. And the particles modified with octadecyltrichlorosilane have the smallest size. All the particles are nonporous with a surface area smaller than 21 m2/g. The particles have a PZC between 8.25 and 8.93 depending on the surface modification groups. For the boric acid adsorption by the particles, in general, the surface modification does not improve the adsorption capacity of the particles obviously. The unacidified and acidified particles have a similar adsorption amount of boric acid from the solutions of the same composition. The adsorption decreases with the increase in solution pH. It is suggested that boron is adsorbed in both H3BO3 and B(OH)4 - forms through the interactions of hydrogen bonding, electrostatic and hydrophobic attractions with the particle surfaces.
Surface modification Silica sphere Boric acid Adsorption Adsorption mechanism
卿彬菊 叶秀深 郭敏 吴志坚
中国科学院青海盐湖研究所,中国 西宁 810008;中国科学院研究生院,中国 北京100049 中国科学院青海盐湖研究所,中国 西宁 810008;福建省高校功能材料重点实验室,华侨大学材料科学与工程学院,中国 泉州362021
国际会议
成都
英文
2007-11-19（万方平台首次上网日期，不代表论文的发表时间）