| 单层硅烷负载磁铁矿纳米颗粒的制备及除磷性能 |
| 摘要点击 1572 全文点击 584 投稿时间：2018-04-26 修订日期：2018-06-20 |
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| 中文关键词 磁铁矿纳米颗粒(MNPs) 硅烷 单分子层 吸附 磷 |
| 英文关键词 magnetite nanoparticles(MNPs) silane monolayer adsorption phosphate |
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| 中文摘要 |
| 研究了N-氨乙基-γ-氨丙基三甲氧基硅烷在水溶液中以单层形式负载于磁铁矿纳米颗粒表面的方法，并研究了单分子层硅烷负载磁铁矿纳米颗粒吸附剂（monolayer of silane on magnetite nanoparticles，MSMNPs）的除磷性能.结果表明，在低浓度下（平衡浓度小于300mg·L-1）硅烷在磁铁矿纳米颗粒表面产生单层吸附，而反应温度90℃以上或离子强度0.1mol·L-1 NaCl以上可以使单层硅烷在磁铁矿纳米颗粒表面的覆盖度达到~100%.FTIR和XPS图谱显示负载的硅烷以化学键的形式与磁铁矿纳米颗粒表面相结合.单层硅烷负载不引起磁性强度的明显变化.MSMNPs对磷的吸附等温线更符合Langmuir模型，拟合得到的最大吸附量为7.59mg·g-1.由于磷吸附位位于MSMNPs的最外面，磷的吸附及脱附均很快，30 min内达到90%以上，1 h内达到平衡.因此，MSMNPs是一种易分离因而可反复使用，并且可快速吸附与脱附污染物的新型吸附剂. |
| 英文摘要 |
| We studied the loading of N-(2-Aminoethyl)-3-aminopropyl trimethoxy silane from aqueous solution as a monolayer on magnetite nanoparticles and examined the phosphate removal performance of the generated adsorbent (silane monolayer on magnetite nanoparticles, abbreviated as MSMNPs). The results indicate that silane monolayer adsorption on magnetite nanoparticles occurred at low concentrations (equilibrium silane concentration <300 mg·L-1) and a~100% surface monolayer coverage by silane could be established at a temperature ≥ 90℃ or a NaCl concentration ≥ 0.1 mol·L-1. The FTIR and XPS spectra indicate that hydrolyzed silane and magnetite nanoparticles are chemically linked. The loading of silane as a monolayer did not significantly change the saturation magnetization. The adsorption isotherm of phosphate based on MSMNPs fit the Langmuir model better, with a calculated maximum adsorption capacity reaching 7.59 mg·g-1. The adsorption and desorption of phosphate by MSMNPs are very fast, exceeding 90% within 30 min and reaching an equilibrium within 1 h. In conclusion, MSMNPs are novel adsorbents with easy separability, which enables the repeated use, and rapid adsorption and desorption of pollutants. |
