Suspension stability and aggregation of multi-walled carbon nanotubes as affected by dissolved organic matters extracted from agricultural wastes.
Suspension stability and aggregation of multi-walled carbon nanotubes as affected by dissolved organic matters extracted from agricultural wastes.
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DOI：
10.1016/j.envpol.2016.01.029
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发表时间：
2016-03
影响因子：
8.9
通讯作者：
Helian Li;Yanhua Qiu;Xiaonuan Wang;Wenhao Liu;Guangcai Chen;Yibing Ma;B. Xing
中科院分区：
文献类型：
--
作者：
Helian Li;Yanhua Qiu;Xiaonuan Wang;Wenhao Liu;Guangcai Chen;Yibing Ma;B. Xing
以小麦秸秆和牛粪中提取的溶解性有机物（DOM）为原料，研究了其对多壁碳纳米管（MWCNTs）悬浮稳定性和聚集性的影响。两种类型的DOM可以有效地分散和稳定多壁碳纳米管。在初始MWCNT浓度为500 mg/L时，当溶解性有机碳（DOC）在50 ~ 200 mg/L范围内变化时，悬浮MWCNT浓度在8.0 ~ 17.9 mg/L范围内变化。在不存在DOM的情况下，临界混凝浓度（CCC）值估计为41.4 mM NaCl和5.3 mM CaCl 2。SDOM和MDOM的存在显着延缓了MWCNTs的聚集速率。当SDOM浓度为20 mg/L DOC时，CCC值增加到120 mM NaCl和14.8 mM CaCl 2。由于其较高的芳香度和分子量，MDOM显示出更高的稳定MWCNTs的能力，在20 mg/L DOC时CCC值为201 mM和15.8 mM。这些结果表明，来自农业废弃物的DOM将对多壁碳纳米管的分散和稳定性产生重大影响，从而影响其在水环境中的归宿。
Dissolved organic matters (DOMs) extracted from wheat straw (SDOM) and cow manure (MDOM) were used to investigate their effects on the suspension stability and aggregation of multi-walled carbon nanotubes (MWCNTs). Two types of DOM can effectively disperse and stabilize the MWCNTs. At initial MWCNT concentration of 500 mg/L, suspended MWCNT concentration ranged from 8.0 to 17.9 mg/L as DOM were varied from 50 to 200 mg/L dissolved organic carbon (DOC). The critical coagulation concentration (CCC) values were estimated to be 41.4 mM NaCl and 5.3 mM CaCl2in the absence of DOM. The presence of SDOM and MDOM significantly retarded the aggregation rate of MWCNTs. The CCC values increased to 120 mM NaCl and 14.8 mM CaCl2at SDOM concentration of 20 mg/L DOC. Due to its higher aromaticity and molecular weight, MDOM showed higher ability to stabilize MWCNTs, with CCC values of 201 mM and 15.8 mM at 20 mg/L DOC. These findings revealed that DOMs originated from agricultural wastes will have great impact on the dispersion and stabilization of MWCNTs, thus their fate in the aquatic environment.