ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Study on the aqueous dispersibility of multi-walled carbon nanotubes bearing modified corn starch

Pei Zhan, Shengyuan Liang, Shi Li, Jiwen Hu, Shudong Lin, Xuefeng Gui, and Cailin Liu

Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou, People’s Republic of China

E-mail: linsd@gic.ac.cn

Received: 30 March 2021  Accepted: 31 August 2021

Abstract:

A novel type of poly(St–SSS–APEG) (SAS) copolymer was prepared by graft polymerization with corn starch (St) as the backbone chain and with sodium p-styrene sulfonate (SSS) and allyl polyethylene glycol (APEG-1000) as side chains in aqueous solution. This graft copolymer can serve as an effective dispersing agent for multi-walled carbon nanotubes (MWCNTs) and offers excellent dispersion performance. The primary focus of this investigation was the dispersing behavior of the graft copolymer and the optimization of the ratio between SAS and MWCNTs. For comparisons, poly(St–SSS) (SS) and poly(St–APEG) (SA) were, respectively, synthesized under the same conditions. The structures of SAS, SS, and SA were characterized via Fourier-transform infrared (FT-IR) spectroscopy. The morphologies of corn starch and modified corn starch were characterized by scanning electron microscopy (SEM), while the crystal form of the starch before and after this modification reaction was evaluated by X-ray diffraction (XRD). In addition, the morphology of the dispersed MWCNTs was observed by transmission electron microscopy (TEM). In addition, the dispersion properties and the optimum mass ratio between SAS and MWCNTs were analyzed by zeta potential measurements and ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy. It was found that the SAS was more effective in decreasing the aggregative tendency of MWCNTs in water than SS and SA.

Graphic abstract

Based on a simple graft polymerization reduction, we have successfully prepared a novel type of poly(St–SSS–APEG) (SAS) copolymer with corn starch (St) as the backbone chain and with sodium p-styrene sulfonate (SSS) and allyl polyethylene glycol (APEG-1000) as side chains in aqueous solution, which can serve as an effective dispersing agent for multi-walled carbon nanotubes (MWCNTs) and offer excellent dispersion performance. It was demonstrated that the dispersion ability of SAS is due to the synergic effects of electrostatic repulsion and steric hindrance.

Keywords: Modified corn starch; Graft polymerization; Dispersion; Multi-walled carbon nanotubes

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01851-0

Chemical Papers 76 (2) 691–700 (2022)