新型tempo 氧化聚乙烯醇/纤维素纳米晶基纳米复合膜用于孔雀石绿染料的去除。
Novel tempo oxidized polyvinyl alcohol/ cellulose nanocrystal-based nanocomposite membrane for malachite green dye removal.
机构信息
Department of Environmental Science, Graphic Era Hill University, Dehradun, Uttarakhand, India.
Department of Chemistry, Graphic Era (Deemed to Be) University, Dehradun, Uttarakhand, India.
出版信息
Environ Monit Assess. 2024 Oct 11;196(11):1045. doi: 10.1007/s10661-024-13196-8.
In this study, in-situ modification by TEMPO oxidation was performed after nanocomposite synthesis to improve its properties toward dye molecule removal. The unoxidized and oxidized polymeric-based nanocomposite was denoted as PNC and PNCO respectively. The nanocomposites were characterized using FESEM, FTIR, contact angle, XRD and BET analysis. Measurements of swelling ratio and chemical stability were also performed to provide insight into the durability of the nanocomposites. The effects of changing variables included contact duration, pH of aqueous solution, initial pollutant concentration, and temperature were observed. The kinetic study showed that the experimental data is best fitted with pseudo-second-order kinetics (R = 0.988 and 0.997 respectively), whereas on observing isotherm data, in both unoxidized and oxidized nanocomposite it fits well with Langmuir isotherm (R = 0.951 and 0.993 respectively). In addition, the effects on Gibb's free energy, Enthalpy, and Entropy were measured in terms of thermodynamic characteristics, it was established that dye molecules adsorption mechanism is endothermic and spontaneous in behaviour. To check regeneration tendency of the nanocomposite seven consecutive adsorption desorption cycles were run and about 90% and 80%, regeneration ability could be seen in an unoxidized state (PNC) and an oxidized state (PNCO) respectively upto 5th cycle after that the tendency get reduced. This study suggests that this novel polymeric nanocomposite can be employed as an efficient and relatively inexpensive adsorbent for dye removal from aqueous solutions.
在这项研究中,在纳米复合材料合成后进行了 TEMPO 氧化原位改性,以改善其去除染料分子的性能。未氧化和氧化的聚合基纳米复合材料分别表示为 PNC 和 PNCO。使用 FESEM、FTIR、接触角、XRD 和 BET 分析对纳米复合材料进行了表征。还进行了溶胀比和化学稳定性测量,以深入了解纳米复合材料的耐用性。观察了变量变化的影响,包括接触时间、水溶液的 pH 值、初始污染物浓度和温度。动力学研究表明,实验数据最好用伪二阶动力学拟合(分别为 R = 0.988 和 0.997),而在观察等温线数据时,在未氧化和氧化纳米复合材料中,它都很好地符合朗缪尔等温线(分别为 R = 0.951 和 0.993)。此外,根据热力学特性测量了吉布斯自由能、焓和熵的影响,确定了染料分子吸附机制是吸热和自发的。为了检查纳米复合材料的再生趋势,进行了七次连续的吸附解吸循环,在未氧化状态(PNC)和氧化状态(PNCO)中,分别可以看到约 90%和 80%的再生能力,在第 5 次循环后,这种趋势有所降低。这项研究表明,这种新型聚合物纳米复合材料可以用作从水溶液中去除染料的高效且相对廉价的吸附剂。