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In this article, an easy, effective, π-π conjugation non-covalent surface functionalization of multi-walled carbon nanotubes (MWCNTs) was achieved by using ball grinding technology between pristine MWCNTs and esterified styrene-maleic anhydride ester (ESMA) copolymer, resulting in the formation of modified E-MWCNTs dispersion with excellent dispersibility and long storage stability in N-methylpyrrolidone (NMP). The analysis of transmittance spectroscopy, absorption spectroscopy, sedimentation photo, and transmittance electron microscopy (TEM) confirms that the modified E-MWCNT dispersion has a homogeneous dispersion in NMP. Results obtained from thermogravimetry analysis (TGA) and Raman spectroscopy reveal that ESMA copolymer is successfully coated on pristine MWCNTs surface. Compared with the bad dispersibility of MWCNTs in NMP, the physically modified E-MWCNTs-3 dispersion mixed with 0.12wt% ESMA copolymer under the condition of total 6 h ball grinding time using paint shaker can be easily well-dispersed and has good storage stability, and no sedimentation is observed more than 3 months. Furthermore, the method is simple and economical to operate in industry. An easy, effective, π-π conjugation non-covalent surface functionalization of multi-walled carbon nanotubes (MWCNTs) was achieved by using ball grinding technology between pristine MWCNTs and esterified styrene-maleic anhydride ester (ESMA) copolymer, resulting in the formation of modified E-MWCNTs dispersion with excellent dispersibility and long storage stability reported firstly in N-methylpyrrolidone. [ABSTRACT FROM AUTHOR]

Although graphene oxide (GO) has been used in multidisciplinary areas due to its excellent physicochemical properties, its environmental behavior and fate are still largely unclear. In this study, batch experiments, spectroscopy analysis and theoretical calculations were addressed to promote a more comprehensive understanding toward the coagulation behavior of GO onto TiO2 under various environmental conditions (pH, co-existing ions, temperature, etc.). The results indicated that neutral pH was beneficial to the removal of GO due to the electrostatic interaction. The presence of cations accelerated GO coagulation significantly owing to the influence of electrical double layer compression. On the contrary, the presence of anions improved the stability of GO primarily because of electrostatic repulsion and steric hindrance. Results of XRD, FTIR and XPS analysis indicated that the coagulation of GO on TiO2 was mainly dominated by electrostatic interactions and hydrogen bonds, which were further evidenced by DFT calculations. The high binding energy further indicated the stability of GO + TiO2 system, suggesting that TiO2 can be used as an effective coagulant for the efficient elimination and coagulation of GO from aqueous solutions. These findings might likely lead to a better understanding of the migration and transformation of carbon nanomaterials in the natural environment. [ABSTRACT FROM AUTHOR]

In this work, an easy, green, π-π conjugation non-covalent surface modification of pristine single-walled carbon nanotubes (SWCNT) was carried out by using ultrasonic technology between pristine SWCNT and anionic surfactant (sodium dodecyl benzene cyclate (SDBS) and sodium polynaphthalene sulfonate (SPS)), resulting in the formation of modified SWCNT dispersion with good dispersibility and long storage stability in water. Results obtained from transmittance spectroscopy, absorption spectroscopy, zeta potential analyzer, sedimentation photo, and transmittance electron microscopy (TEM) reveals that the modified SWCNT dispersion has a high degree of dispersion. The analysis of thermogravimetry analysis (TGA) and scanning electron microscope (SEM) confirm that two kinds of dispersants are successfully decorated on pristine SWCNT surface. More importantly, the pristine SWCNT is insoluble, while the modified S2-SWCNT dispersion mixed with 1.25 wt% SDBS and 1.00 wt% SPS correspondingly under the condition of total 3 h ultrasonic time can be easily well-dispersed in water and has good storage stability, and no sedimentation is observed more than 3 months. More importantly, this strategy is green and economical owing to its easy operation in industry. [ABSTRACT FROM AUTHOR]

Abstract: Lead contamination is a threat for the environment and human health due to lead non-degradability and non-detoxification. Therefore, methods for efficient removal of lead from contaminated waters are needed. Here, a novel material has been synthesised by surface functionalization of magnesium-aluminum layered double hydroxide with citrate (citric-LDH) and applied to the efficient removal of lead from aqueous solutions. Effects of ionic strength and temperature on the adsorption have been evaluated. Results show that lead adsorption by citric-LDH can be used for lead pollution cleanup. Adsorption kinetics were simulated using a revised model. Simulation results show that citric-LDH adsorb lead ions through a more efficient and time-dependent pathway, leading to the rapid and efficient removal of lead ions. [ABSTRACT FROM AUTHOR]