Gelber Chen, Margel Shlomo
The Institute of Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel.
ACS Omega. 2020 Feb 21;5(8):4004-4013. doi: 10.1021/acsomega.9b03529. eCollection 2020 Mar 3.
Synthetic organic dyes constitute a major pollutant in wastewater. Here, we describe the synthesis and characterization of -halamine nanoparticles (NPs) for decomposition of organic dyes from contaminated wastewater. Cross-linked poly(methacrylamide) (PMAA) NPs of hydrodynamic diameters ranging from 11 ± 1 to 161 ± 31 nm were synthesized at room temperature by redox surfactant-free dispersion copolymerization of methacrylamide and the cross-linking monomer ,'-methylenebis(acrylamide) in an aqueous continuous phase. The effect of various polymerization parameters on the diameter and size distribution of the formed NPs was studied. Additionally, thin coatings composed of cross-linked PMAA NPs were grafted onto oxidized corona-treated polypropylene (PP) films by redox graft polymerization of the monomers in the presence of oxidized PP films. The free and grafted NPs were converted to -halamine species by chlorination with sodium hypochlorite. The decomposition kinetics of two model organic dyes, methylene blue (MB) and crystal violet (CV), was evaluated for both free and grafted PMAA-Cl NPs. Free cross-linked PMAA-Cl NPs at room temperature, with concentrations of 5 and 0.5 mg/mL, illustrated full decomposition of CV and approximately 90% decomposition of MB after 42 and 97 h. In order to enhance the dye decomposition, the mixtures were heated to 70 °C. Complete decomposition of CV and MB at PMAA-Cl NP concentrations of 5 and 0.5 mg/mL required 60 and 240 min for CV, respectively, and 180 and 420 min for MB, respectively. Similarly, the PP/PMAA-Cl films also demonstrated a high reduction in the MB concentration after 150 min. Due to the highly efficient dye decomposition, these free and immobilized chlorinated NPs may be utilized as new reagents for decomposition of organic materials from contaminated wastewater.
合成有机染料是废水中的主要污染物。在此，我们描述了用于分解受污染废水中有机染料的卤胺纳米颗粒（NPs）的合成与表征。通过甲基丙烯酰胺与交联单体N,N'-亚甲基双丙烯酰胺在水连续相中进行氧化还原无表面活性剂分散共聚，在室温下合成了流体动力学直径范围为11±1至161±31nm的交联聚（甲基丙烯酰胺）（PMAA）纳米颗粒。研究了各种聚合参数对所形成纳米颗粒直径和尺寸分布的影响。此外，在氧化的电晕处理聚丙烯（PP）薄膜存在下，通过单体的氧化还原接枝聚合将由交联PMAA纳米颗粒组成的薄涂层接枝到氧化的PP薄膜上。通过用次氯酸钠氯化将游离和接枝的纳米颗粒转化为卤胺物种。评估了两种模型有机染料亚甲基蓝（MB）和结晶紫（CV）在游离和接枝的PMAA-Cl纳米颗粒中的分解动力学。室温下浓度为5和0.5mg/mL的游离交联PMAA-Cl纳米颗粒在42和97小时后分别显示出CV的完全分解和MB的约90％分解。为了增强染料分解，将混合物加热至70°C。对于浓度为5和0.5mg/mL的PMAA-Cl纳米颗粒，CV和MB的完全分解分别需要60和240分钟（CV）以及180和420分钟（MB）。同样，PP/PMAA-Cl薄膜在150分钟后也显示出MB浓度的大幅降低。由于高效的染料分解，这些游离和固定的氯化纳米颗粒可作为分解受污染废水中有机物质的新试剂。
