原位沉积酚醛树脂对椰壳活性炭孔隙结构的调控

Regulation of Pore Structure of Coconut Shell Activated Carbon by in situ Deposition of Phenolic Resin

为实现对活性炭孔隙结构的调控,以甲醛和苯酚为前驱体,在市售颗粒椰壳活性炭表面原位合成酚醛树脂,并于高温下炭化。实验结果表明:于850～900℃下炭化1 h得到的产物亚甲基蓝吸附值为60 mg/g,远低于原炭,而碘吸附值可超过1 000 mg/g,接近于原炭。这说明所沉积的聚合物的残留炭可有效地填充至活性炭的中大孔壁上,提高微孔比率。通过比表面积、元素分析、热重分析等表征方法可进一步证明聚合物残留炭的存在,与测定亚甲基蓝和碘吸附值所反映的结果相吻合。因此,采用酚醛树脂沉积炭化的方法可有效地对活性炭孔隙结构进行调控。

Phenolic resin was in-situ synthesized on the surface of commercial coconut shell activated carbon for the regulation of pore size distribution, using formaldehyde and phenol as the precursors. Then, the samples were carbonized under high temperature. The samples carbonized at 850-900℃ for lh hadmethyl blue （MB） adsorption capacity 60 mg/g, much lower than the original sample, while they had iodine adsorption capacity above 1 000 mg/g, close to the original sample. This result illustrated that the residual carbon from the polymer was efficiently adopted on the wall of meso- and macropores. It led to the in- creasing amount of micropores. The existence of residual carbon was further proved by surface area analysis, thermal gravimetric （TG） analysis, elemental analysis and other characterization methods. They coincided with the results of MB and iodine adsorption experiments. Hence, the pore size distribution is able to be efficiently regulated by the adoption and carbonization of phenolic resin.