Simple Process for Sidewall Modification of Multi-Walled Carbon Nanotubes with Polymer Side Chain Radicals Generated by Ultraviolet-Induced C–Cl Bond Dissociation of Polystyrene Derivatives

Abstract

Abstract:In this work, we investigated a simple one-step process for the formation of chemical bonds between multi-walled carbon nanotubes (MWCNTs) and benzyl-type side chain radicals generated by UV photolysis of polystyrene derivatives containing the chloromethyl (-CH 2 Cl) group. Poly(4-chloromethyl)styrene, or styrene/4-(chloromethyl)styrene random copolymer, was mixed with MWCNTs in 1-methyl-2-pyrrolidone and irradiated with ultraviolet (UV) light. Films of polymer/MWCNT mixtures before and after UV irradiation were fabricated, and then examined by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. According to the XPS analysis, the amount of Cl atoms in the mixture was found to decrease upon UV irradiation, indicating that the Cl atoms generated by photolysis of chloromethyl groups escaped from the reaction system in the form of gaseous Cl 2 . The structural change of CNTs after UV irradiation was also observed by comparing the G/D ratios (the intensity ratio of the G to D bands) of the Raman spectra obtained before and after UV irradiation. Similar phenomena were also confirmed in the case of the polymer/MWCNT mixture containing hydroxylammonium chloride as a dispersant of MWCNTs. These results confirmed the UV-induced covalent bond formation between polymer side chains and MWCNTs.

Zwitterionic Polymer Modified Porous Carbon for High-Performance and Antifouling Capacitive Desalination

“…The Raman spectra of PC and PC-SBMA-24 (Figure A) show two prominent peaks, the D and G bands at 1581 and 1349 cm –1 , respectively. It is universally acknowledged that the G band is due to the in-plane vibration of the sp 2 carbon atoms, whereas the D band is a defect-induced Raman feature representing the imperfect crystalline structure of the material. , The ratio of the intensities ( I G / I D ) is a measure of the degree of structural disorder. − Compared with pristine PC, the G/D ratio calculated for PC-SBMA-24 decreased considerably from 1.08 to 0.88, indicating that the carbon surface defects increased with the grafting of PSBMA zwitterionic polymer brushes through SI-ATRP modification. − The I G / I D of PC-PDA and PC-Br also decreased to 0.97 and 0.92 (Figure S6), respectively, which may be caused by the successful coating with PDA and immobilization of the ATRP initiator.…”

The Ultraviolet-Induced Functionalization of Multi-Walled Carbon Nanotubes with Polymer Radicals Generated from Polyvinyl Benzoate Derivatives

“…The bond formation process is depicted in Scheme 1. Recently, we reported the photoinduced chemical bond formation between CNTs and poly(pchloromethyl)styrene [23]. We found that the C-Cl bonds of the chloromethyl side chains (-CH2Cl) of the polymer dissociated with ultraviolet (UV) irradiation to form benzyl-type side chain radicals.…”