Interaction of Hydroxypropyl-β-cyclodextrin Modified Multi-walled Carbon Nanotubes and Mandelic Acid
LI Sanqing1, LIU Yaochi2,3, YU Jingang2,3
1. Infectious Diseases Department, the PLA 425 Hospital, Sanya 572000, Hainan Province, China;2. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;3. Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha 410083, China
Abstract:Carboxyl groups are oxidized by nitric acid and introduced onto multi-walled carbon nanotubes (MWNTs). Catalyzed by ptoluenesulfonic acid (PTSA), the oxidized MWNTs (MWNTs-COOH) are reacted with hydroxypropyl-β-cyclodextrin (HP-β-CD) to obtain HP-β-CD-g-MWNTs with good dispersivity. The prepared composites are fully characterized by Transmission Electron Microscopy (TEM), Fourier Transform infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA), the results indicate that HP-β-CD is successfully grafted onto MWNTs. The dispersion performance test indicates that HP-β-CD-g-MWNTs are well-dispersed in the aqueous solutions, thus the composites are able to find their potential applications in biomedical materials or drug deliveries. The interactions between HP-β-CD-g-MWNTs and mandelic acid are investigated by using Ultraviolet-Visible light (Uv-Vis) absorption spectrum. The results indicate that mandelic acid is adsorbed on the surface of HP-β-CD-g-MWNTs by conjunct interactions, such as π-π stacking, polar interaction, and hydrogen bonding. Due to the molecular interactions, the absorbed molecules are able to realize controlled-releasing or sustained-releasing from the surface of MWNTs.