纤维素纳米晶须表面紫外光接枝丙烯酸及其吸附Cu^(2+)

Cellulose nanowhiskers' UV-grafted with acrylic acid and its adsorption performance for Cu^(2+)

利用紫外光接枝的方法,快速在纤维素纳米晶须(CNW)的表面接枝丙烯酸(AA),通过红外谱图(FT-IR)、核磁共振(NMR)等测试验证了接枝的成功,利用电导滴定测得接枝率为20.04%。透射电镜(TEM)观察到接枝前后颗粒均为纳米级的晶须。研究了接枝产物CNW-g-AA对Cu2+的吸附性能,考察了吸附时间、pH值、吸附温度和Cu2+初始浓度对吸附实验的影响。实验最佳吸附条件为吸附温度30℃、pH值为4、吸附时间为7h,且最大吸附量可达到66mg/g;同时该吸附剂经6次吸附-脱附循环后,吸附量仅降低15%。该吸附行为符合Langmuir准二级动力学模型。

Acrylic acid （AA）was fast grafted onto cellulose nanowhiskers （CNW）surface by UV-initiation.The characterization methods,such as infrared spectrum （FT-IR）and 13 C-CP/MAS nuclear magnetic resonance （NMR）,proved the successful grafting experiments.The graft yield of 20.04% was calculated by the conducto-metric titration method.TEM images showed that both CNW and CNW-g-AA had nano diameters.The adsorp-tion property of CNW-g-AA for copper ions was researched.The effects of adsorption time,pH value,tempera-ture and Cu2＋ initial concentration were studied.The optimum conditions for Cu2＋ adsorption was obtained when the adsorption temperature was 30 ℃,the pH value was 4 and the adsorption time was 7 h.The maxi-mum adsorption capacity was about 6 6 mg/g.After six adsorption-desorption cycles,the adsorption capacity de-creased only 1 5%.The Langmuir equation and the pseudo-second order kinetic could be fitted for the Cu2＋ ad-sorption on CNW-g-AA.