scholarly journals The Impact of Sonication on the Surface Quality of Single-Walled Carbon Nanotubes

2015 ◽  
Vol 104 (8) ◽  
pp. 2594-2599 ◽  
Author(s):  
Byumseok Koh ◽  
Wei Cheng
2008 ◽  
Vol 58 (3) ◽  
pp. 623-628 ◽  
Author(s):  
Y. Yin ◽  
X. Zhang

This paper evaluated the impact of single-walled carbon nanotubes (SWCNTs) on the performance and activated sludge properties in an activated sludge wastewater reactor. The reactor was shock loaded with 270 mg/L of 90% purified SWCNTs after the reactor reached quasi-steady state and the reactor was monitored for 18 days after the shock loading. Various experimental parameters were measured and compared. Overall the addition of SWCNTs did not negatively impact the performance of the activated sludge reactor; on the other hand, SWCNTs improved sludge settleability and sludge dewaterability. The cake solids of the sludge were increased and the activated sludge flocs became less negatively charged. The positive impacts were more significant in Phase II (after running the reactor for one solids retention time, SRT) than that in Phase III (after running for additional 1.5 SRT).


2011 ◽  
Vol 6 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Sejin Youn ◽  
Randy Wang ◽  
Jie Gao ◽  
Anna Hovespyan ◽  
Kirk J. Ziegler ◽  
...  

Carbon ◽  
2018 ◽  
Vol 139 ◽  
pp. 609-613 ◽  
Author(s):  
Nathaniel E. Kallmyer ◽  
Trinh Huynh ◽  
Joseph Connor Graves ◽  
Joseph Musielewicz ◽  
Denis Tamiev ◽  
...  

2015 ◽  
Vol 42 ◽  
pp. 50-61 ◽  
Author(s):  
Messika Revel ◽  
Michel Fournier ◽  
Christian Gagnon ◽  
Pierre Yves Robidoux

The aim of this study was to assess the impact of single-walled carbon nanotubes (SWCNT) on the toxicity of cadmium (Cd) using the crustacean Daphnia magna. LC50 of Cd and SWCNT alone and combined were calculated and compared. Sorption of Cd on SWCNT was also quantified in separate batch experiments. Results showed that the maximum adsorption of Cd onto SWCNT calculated by the Langmuir equation was 24.4 mg kg-1. LC50s for Cd and SWCNT alone were 252.3 µg L-1 and 1400 µg L-1, respectively. In the presence of 500 and 1000 µg L-1 of SWCNT, Cd LC50s were 127.2 and 120.1 µg L-1 respectively. Therefore, Cd toxicity increased when organisms were exposed to both contaminants which indicated that SWCNT induces a synergistic toxic effect on the survival of D. magna. It appears that even if SWCNT had a low adsorption capacity for Cd, toxicity of the metal can be increased. Our study shows the complexity of SWCNT toxicity and how the understanding of their interactions with other contaminants is crucial to determine the consequences of their release into the environment.


Pesticides are useful in increasing the quantity and quality of agricultural products. However, over-application or misuse would accumulate their residues in the environments, which might pose threats to non-target organisms and humans. Therefore, this study investigated the sorption of herbicide, pendimethalin (PD) onto titanium dioxide nanoparticles (TiO2 NPs) and single-walled carbon nanotubes (SWCNTs) surfaces in aqueous solutions. Several experiments were conducted to study the contact time of the nanoparticles with different concentrations of PD under laboratory conditions. The experiments were done at 25 ºC and pH values 7.0. Sorption results were then fitted using Langmuir and Freundlich isotherm models. Quantities of 0.5 to 2.5 µg/ml of TiO2 NPs and 50.0 µg/ml of SWCNTs exhibited 100.0% and 99.8% removal of PD, respectively. Small amounts of PD (0.5-2.5 µg/ml) were completely removed (100%) by TiO2NPs and SWCNTs particles. Isotherms displayed adsorption capacities of 1.850 and 2.304 µg/g for TiO2NPs and SWCNTs, respectively, which highlight the elevated potential of cleaning the environment from pendimethalin residues.


Author(s):  
Mariana Ionita

Atomistic models of polyaniline (PANI)-single walled carbon nanotubes (CNTs) were built in order to assess the effect of quantity and quality of CNTs and temperature on the calculated mechanical properties of PANI. Three different types of CNTs were considered: single walled carbon nanotubes m-polyaminobenzene sulfonic acid functionalized (CNTs-PABS), single walled carbon nanotubes octadecylamine functionalized (CNTs-ODA) and single walled carbon nanotubes carboxylic acid functionalized (CNTs-CX). Atomistic models were built for PANI-functionalized CNTs with a range of CNTs content, contained within periodic boundary conditions and were subject of multistage equilibration procedure. In order to test the mechanical behaviour of the models virtual uniaxial traction tests along the three perpendicular edges of the models were performed. The Young’s moduli generally increased with increasing of CNTs content and values range from 0.48 GPa in the case of pure PANI to 1.35–1.83 GPa in the case of PANI-CNTs-PABS composite system.


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