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首页> 外文期刊>Environmental Science & Technology >Manipulating the Size and Dispersibility of Zerovalent Iron Nanoparticles by Use of Carboxymethyl Cellulose Stabilizers
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Manipulating the Size and Dispersibility of Zerovalent Iron Nanoparticles by Use of Carboxymethyl Cellulose Stabilizers

机译：通过使用羧甲基纤维素稳定剂操纵零价铁纳米粒子的大小和分散性

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摘要

Zerovalent iron (ZVI) nanoparticles of various sizes were synthesized by applying various types of carboxymethyl cellulose (CMC) as a stabilizer. At an initial Fe~(2+) concentration of 0.1 g/L and with 0.2% (w/w) of CMC (M_r = 90 000), nanoparticles with a hydrodynamic diameter of 18.6 nm were obtained. Smaller nanoparticles were obtained as the CMC/Fe~(2+) molar ratio was increased. When the initial Fe~(2+) concentration was increased to 1 g/L, only 1/4 of the CMC was needed to obtain similar nanoparticles. On an equal weight basis, CMC with a greater M_r or higher D.S. (degree of substitution) gave smaller nanoparticles, and lower the synthesizing temperature favored the formation of smaller nanoparticles. It is proposed that CMC stabilizes the nanoparticles through the accelerating nucleation of Fe atoms during the formation of ZVI nanoparticles and, subsequently, forms a bulky and negatively charged layer via sorption of CMC molecules on the ZVI nanoparticles, thereby preventing the nanoparticles from agglomeration through electrosteric stabilization. In agreement with the classical coagulation theory, the presence of high concentrations of cations (Na~+ and Ca~(2+)) promoted agglomeration of the nanoparticles. The strategy for manipulating the size of the ZVI nanoparticles may facilitate more effective applications of ZVI nanoparticles for in situ dechlorination in soils and groundwater.
机译：通过应用各种类型的羧甲基纤维素（CMC）作为稳定剂，合成了各种尺寸的零价铁（ZVI）纳米粒子。在最初的Fe〜（2+）浓度为0.1 g / L且含0.2％（w / w）的CMC（M_r = 90 000）时，获得的流体动力学直径为18.6 nm。随着CMC / Fe〜（2+）摩尔比的增加，纳米粒子的粒径减小。当最初的Fe〜（2+）浓度增加到1 g / L时，仅需要1/4的CMC即可获得相似的纳米颗粒。在等重的基础上，具有更大的M_r或更高的D.S.（取代度）的CMC产生较小的纳米颗粒，而较低的合成温度有利于形成较小的纳米颗粒。提出CMC通过在ZVI纳米颗粒形成过程中加速Fe原子的成核作用来稳定纳米颗粒，随后通过CMC分子在ZVI纳米颗粒上的吸附形成大体积且带负电荷的层，从而防止纳米颗粒通过静电位聚结稳定。与经典的凝聚理论一致，高浓度阳离子（Na〜+和Ca〜（2+））的存在促进了纳米颗粒的团聚。操纵ZVI纳米粒子尺寸的策略可能有助于ZVI纳米粒子在土壤和地下水中就地脱氯的更有效应用。

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  • 来源
    《Environmental Science & Technology》 |2007年第17期|6216-6221|共6页
  • 作者

    FENG HE; DONGYE ZHAO;

  • 作者单位

    Environmental Engineering Program, Department of Civil Engineering, 238 Harbert Engineering Center, Auburn University, Auburn, Alabama 36849;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 环境化学;
  • 关键词

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