Persulfate Chemical Functionalization of Carbon Nanotubes and Associated Adsorption Behavior in Aqueous Phase

Abstract

The chemical functionalization of carbon nanotubes (CNTs) using sodium persulfate (SPS) oxidation was designed to improve their dispersion stability in water. The test results indicated that base activated SPS oxidation of CNTs (BSPS/CNTs) adds a significant amount of oxygen functional groups to the surface of CNTs. The BSPS/CNTs dispersion is dependent on a solution within the pH range of 5−12. Experimental results obtained by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy demonstrated that CNTs were successfully modified and the carboxylic functional groups (e.g., −COO − Na + or −COO − H + ) were created. The BSPS/CNTs, which carry negative charges, enhance the dispersion characteristics of CNTs. The BSPS/CNTs adsorption capacities of inorganic ions (e.g., copper ion) and organic compounds (e.g., benzene) were higher than those obtained by raw CNTs mainly due to enhanced CNTs dispersion. Furthermore, Langmuir and Freundlich adsorption models were applied to examine both raw CNTs and BSPS/CNTs adsorption behaviors. Copper and benzene sorption onto BSPS/CNTs fit the Freundlich isotherm model well, while raw CNTs adsorption did not fit any model. The findings of this study are of great significance for the base activated persulfate oxidation process, indicating that the functionalization of CNTs enhances CNTs dispersivity in water.

Insights into the Electron-Transfer Regime of Peroxydisulfate Activation on Carbon Nanotubes: The Role of Oxygen Functional Groups

“…% after a heat treatment. 49 Therefore, the carbonaceous materials were gradually inactivated in persulfate activation after the introduction of a large number of oxygen groups, 10,50 whereas their activities could be restored by thermal decomposition of the oxygen moieties. 32,51,52 Figure 3b shows that the carbonyl and carboxyl groups present good linearity with ln k obs (eqs S2 and S3), that is, the more oxygen groups, the lower reaction rate.…”

Evaluation of the Engineering Properties of Powdered Activated Carbon Amendments in Porous Asphalt Pavement

“…A 21% voids design criterion was used for the porous pavement in this study. PAC was washed with hydrochloric acid and then rinsed with reverse osmosis (RO) water [11]. Thereafter, PAC was oven-dried at 105 • C (6 h) and then stored in a desiccator.…”

Investigation of thermal and tensile properties of poly(benzimidazole-imide) composites incorporating salicylic acid–functionalized multiwalled carbon nanotubes

“…These reactive groups on CNTs will very much increase the combination of CNTs with polymer matrix, so improving the stability of the composites. 32 –36…”

“…These reactive groups on CNTs will very much increase the combination of CNTs with polymer matrix, so improving the stability of the composites. [32][33][34][35][36] In the present investigation, in order to attain a new category of thermally stable and processable PIs, PBII, design and synthesis of a novel diacid (as an important monomer in fabrication of final polymer) containing imide and salicylic acid segments in the main chain were considered. Then, composites of the PBII filled with different contents of amino salicylic acid (ASA)-modified multiwalled CNTs (MWCNTs-ASA) were prepared by solution blending and ultrasonic dispersion method.…”