The purified MWCNTs with an average diameter of 10nm used in this work were provided by the Department of Chemical Engineering, Tsinghua University, and synthesized from ethylene and propylene gas via catalytic (Fe/Al2O3 as the catalyst) chemical vapor deposition . Anionic dye methyl orange (MO) and cationic dye methylene blue (MB) were provided by Tianjin Benchmark Chemical Reagent Co., Ltd. All other reagents were commercially available and of analytical grade.
- Preparation of MWCNT-COOH and MWCNT-starch
MWCNTs were dried at 130 ◦C for 3 h, and ground for 20 min. The MWCNTs were refluxed in concentrated hydrochloric acid for 5 h, washed to neutrality, and then dried. The purified MWCNTs (1.2 g) were stirred in 120mL concentrated nitric acid for 14 h at 120 ◦C. Subsequent washing, drying and grinding led to the production of MWCNT-COOH.
多层碳纳米管在130◦C的温度下干燥 3 h,然后在地面干燥20分钟。热合回流在浓盐酸5 h,洗中立,然后晒干。碳管(1.2 g)在 120◦C的条件下搅拌在120毫升浓硝酸为14 h。随后的洗涤、干燥和研磨产生了化碳纳米管。
MWCNT-COOH was added to 30mL thionyl chloride and 1mL N,N-dimethylformamide, and allowed to react for 24 h at 70 ◦C. The MWCNTs were filtered, washed with anhydrous tetrahydrofuran, and then dried to produce the acyl chloride-functionalized MWCNTs which were then added, along with dried soluble starch, to a solution of 50mL N,N-dimethylformamide and 1mL pyridine. The reaction continued for 16 h at 110 ◦C before the mixture was cooled to room temperature, filtered, and washed four times with N,N-dimethylacetamide/LiCl (95 wt%/5 wt%) solution to remove the soluble starch. The samples were further washed with distilled water and then dried to obtain MWCNT-starch.