羟丙基壳聚糖纳米微粒的制备及其对Ni2+的吸附研究

摘要

通过在碱性条件下将羟丙基引入到壳聚糖分子上,再利用离子凝胶法制备羟丙基壳聚糖(HCS)纳米微粒.结果表明,HCS溶液的质量浓度为0.8～2.0 mg/mL、多聚磷酸钠(TPP)的质量浓度为0.4～1.5 mg/mL时,均可以生成HCS纳米微粒.粒径分布表明,HCS纳米微粒主要粒径约为200～300 nm,粒径分布较窄.HCS纳米微粒对工业电镀废水中的Ni2+吸附性能研究表明,粒径小的HCS纳米微粒对Ni2+的吸附容量要大于粒径大的吸附容量；HCS取代度越高,则对Ni2+吸附容量就越大,吸附能力越强.脱附实验表明,4种脱附剂的脱附能力总体为H2SO4＜ HCl＞H NO3＜ EDTA,前3种酸的脱附能力相当,都较EDTA脱附能力强,重现性较好,且使用H2SO4时,脱附时间只需30 min便能达到87％以上的脱附率.%Hydroxypropyl was introduced into chitosan under the alkaline condition, the hydroxypropyl-chitosan (HCS) nanoparticles was prepared through the ion-gel technologies. Results showed when HCS concentration was 0. 8-2. 0 mg/mL and sodium tripolyphosphate (TPP) concentration was 0. 4-1. 5 mg/mL, HCS nanoparticle could be generated. The nanoparticle size was mainly ranged from 200 nm to 300 nm, the size distribution was narrow. Applying the obtained HCS nanoparticles to removal the Ni2+ from industrial electroplating wastewater, results showed the smaller nanoparticles had a better adsorption capacity for Ni2+ . The higher substitution degrees of HCS, the greater adsorption capacity of HCS nanoparticles to Ni2+. The desorption experiment demostrated that the performance of 4 desorption agents follow the order of H2SO4>HC1>HNO3>EDTA. Appling H2SO4as desorption reagent and desorption for 30 min, the desorption rate could achieve over 87%.