利用动态光散射技术研究了环境因素对水中多壁碳纳米管（ Multi?walled carbon nanotubes，MWNTs）颗粒凝聚过程的影响．结果表明，投加一价、二价电解质均可使水中MWNTs颗粒Zeta电位减小、水合动力学半径增大，促进颗粒间凝聚的发生；水中MWNTs颗粒的凝聚过程可分为反应控制和扩散控制两个不同阶段，符合经典的胶体稳定性（DLVO）理论．经计算，Na＋、K＋、Ca2＋和 Mg2＋的临界凝聚浓度分别为221、251、8．0、8．4 mmol·L－1．腐殖酸存在可通过空间位阻效应显著增强水中MWNTs的分散性，表明MWNTs可稳定存在于典型的水环境中．
The aggregation kinetics of multi?walled carbon nanotubes ( MWNTs ) in water were examined through time?resolved dynamic light scattering measurements. The results showed that both monovalent ( NaCl) and divalent ( CaCl2 and MgCl2 ) electrolytes induced dramatic decrease in the hydrodynamic surface zeta potential and increase in the particle size of MWNTs, thus promoting the aggregation between particles. The aggregation process of MWNTs in water was divided into two phases, reaction limited aggregation and diffusion limited aggregation, which was found to be consistent with the classic Derjaguin?Landau?Verwey?Overbeek ( DLVO) theory on colloidal stability. The critical coagulation concentration ( CCC ) of MWNTs was 221 mmol·L-1 Na+, 251 mmol·L-1 K+, 8.0 mmol·L-1 Ca2+ and 8.4 mmol·L-1 Mg2+. The enhanced stability of MWNTs in the presence of humic acid was due to steric repulsion. MWNTs can be relatively stable in typical aquatic environments.
参考文献
| [1] | Shouping Li;Wei Wu;Stephane Campidelli .Adsorption of carbon nanotubes on active carbon microparticles[J].Carbon: An International Journal Sponsored by the American Carbon Society,2008(7):1091-1095. |
| [2] | Zhu L;Chang D W;Dai L et al.DNA damage induced by multiwalled carbon nanotubes in mouse embryonic stem cells[J].NANO LETTERS,2007,7(12):3592-3597. |
| [3] | Matthew M. Alloy;Aaron P. Roberts .Effects of suspended multi-walled carbon nanotubes on daphnid growth and reproduction[J].Ecotoxicology and Environmental Safety,2011(7):1839-1843. |
| [4] | Hyung H;Fortner JD;Hughes JB;Kim JH .Natural organic matter stabilizes carbon nanotubes in the aqueous phase[J].Environmental Science & Technology: ES&T,2007(26):179-184. |
| [5] | AARON P. ROBERTS;ANDREW S. MOUNT;BRANDON SEDA;JUSTIN SOUTHER;RUI QIAO;SIJIE LIN;PU CHUN KE;APPARAO M. RAO;STEPHEN J. KLAINE .In vivo Biomodification of Lipid-Coated Carbon Nanotubes by Daphnia magna[J].Environmental Science & Technology: ES&T,2007(8):3025-3029. |
| [6] | NAVID B. SALEH;LISA D. PFEFFERLE;MENACHEM ELIMELECH .Aggregation Kinetics of Multiwalled Carbon Nanotubes in Aquatic Systems: Measurements and Environmental Implications[J].Environmental Science & Technology: ES&T,2008(21):7963-7969. |
| [7] | Lin M Y;Lindsay H M;Weitz D A et al.Universality of fractal aggregates as probed by light scattering[J].Proceedings of the Royal Society of London Series A,1989,423(1864):71-87. |
| [8] | Chen KL;Elimelech M .Aggregation and deposition kinetics of fullerene (C-60) nanoparticles[J].Langmuir: The ACS Journal of Surfaces and Colloids,2006(26):10994-11001. |
| [9] | Clougherty D P;Zhu X .Stability and Teller′s theorem:Fullerenes in the march model[J].Physical Review A,1997,56(1):632-635. |
| [10] | Vaisman, L;Wagner, HD;Marom, G .The role of surfactants in dispersion of carbon nanotubes[J].Advances in Colloid and Interface Science,2006(0):37-46. |
| [11] | Masahito Sano;Junko Okamura;Seiji Shinkai .Colloidal Nature of Single-Walled Carbon Nanotubes in Electrolyte Solution: The Schulze-Hardy Rule[J].Langmuir: The ACS Journal of Surfaces and Colloids,2001(22):7172-7173. |
| [12] | Derjaguin B;Landau L .Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes[J].Progress in Surface Science,1993,43(1/4):30-59. |
| [13] | 张宝贵.环境化学[M].武汉:华中科技大学出版社,2009 |
| [14] | Adsorption Of Fulvic Acid By Carbon Nanotubes From Water[J].Environmental Pollution,2009(4):1095-1100. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%