University of Johannesburg, Department of Applied Chemistry, PO Box 17011, Doornfontein 2028, Johannesburg, South Africa.
Carbohydr Polym. 2013 Oct 15;98(1):470-6. doi: 10.1016/j.carbpol.2013.06.034. Epub 2013 Jun 26.
Multiwalled carbon nanotubes were synthesised by the nebulised spray pyrolysis method and purified to remove amorphous carbon and fullerenes. The purified multiwalled carbon nanotubes were oxidised using a 3:1 H2SO4/HNO3 mixture to introduce carboxylic groups and to a smaller extent hydroxyl groups on the walls of the carbon nanotubes. Subsequently, the oxidised carbon nanotubes were chlorinated using oxalyl chloride to generate acyl chloride groups through which phosphorylation took place. 4-Aminophenyl methylphosphonate was attached to the multiwalled carbon nanotubes via an amidation reaction. FT-IR and XPS confirmed the presence of PO, PO and PCP functional groups in the phosphorylated carbon nanotubes. Polymerisation of the phosphorylated carbon nanotubes with cyclodextrins was achieved using hexamethylene diisocyanate as a bifunctional linker. Surface morphology of the polymer was investigated by SEM while FT-IR was used to confirm the polymerisation reaction. Moreover, the thermal stability of the polymer was probed using TGA while BET was employed to determine the surface area and pore volume of the polymer. Furthermore, the polymer was tested for the removal of cobalt and 4-chlorophenol from synthetic aqueous solutions of the pollutants. The polymer displayed potential as an adsorbent for both cobalt and 4-chlorophenol.
多壁碳纳米管通过雾化喷雾热解法合成，并进行纯化以去除无定形碳和富勒烯。纯化后的多壁碳纳米管使用 3:1 的 H2SO4/HNO3 混合物氧化，在碳纳米管的壁上引入羧酸基团，并在较小程度上引入羟基。随后，使用草酰氯将氧化后的碳纳米管氯化，通过酰氯基团发生磷酸化反应。4-氨苯基甲基膦酸通过酰胺化反应连接到多壁碳纳米管上。FT-IR 和 XPS 证实了在磷酸化碳纳米管中存在 PO、PO 和 PCP 官能团。使用六亚甲基二异氰酸酯作为双功能连接剂，使磷酸化碳纳米管与环糊精聚合。通过 SEM 研究了聚合物的表面形态，通过 FT-IR 确认了聚合反应。此外，使用 TGA 探测了聚合物的热稳定性，而 BET 用于确定聚合物的表面积和孔体积。此外，还测试了聚合物对钴和 4-氯苯酚从污染物合成水溶液中的去除效果。该聚合物显示出作为钴和 4-氯苯酚吸附剂的潜力。
