Department of Chemical Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh, 11421 Saudi Arabia.
Department of Chemical Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh, 11421 Saudi Arabia.
Carbohydr Polym. 2018 Nov 1;199:406-414. doi: 10.1016/j.carbpol.2018.07.026. Epub 2018 Jul 10.
A novel step wise synthetic route was developed to prepare amine grafted nanofibers (AGNFs) affinity membrane. The chemical structure of the nanofibers (NFs) after grafting was studied by acquiring Fourier Transform Infrared (FT-IR) spectra and Carbon, Hydrogen and Nitrogen (CHN) data. The morphology of the NFs before and after grafting was studied by Field Emission Scanning Electron Microscope (FE-SEM). FT-IR and CHN data confirmed the introduction of new functional groups into the primary structure of chitosan (CH). FE-SEM showed denser membrane with no deterioration of the NFs morphology after grafting. The aqueous stability of the membranes was studied in distilled water. The AGNFs membranes showed good aqueous stabilities (with only ∼ 6% loss in weight until 24 h and remained stable thereafter) which was less than the weight loss by glutaraldehyde treated nanofibers (GNFs) (∼44% loss in weight until 24 h) and pristine NFs (100% loss in weight as soon as the NFs were immersed in distilled water). The maximum adsorption (q) capacity of AGNFs for Cu (II) and Pb (II) was observed to be 166.67 mg.g and 94.34 mg.g. The adsorption capacity of the present systems was much higher for Cu (II) when compared to the already existing conventional and chitosan adsorbents. This increased might be related not just to the size, but more potentially to the increase in the number of nitrogen binding sites (chelating sites). Nitrogen donates lone-pair of electrons for chelation. The combination of processing into nano size and amine grafting (AG) has significantly increased the adsorption capacity of CH NFs membrane.
开发了一种新颖的逐步合成路线，用于制备接枝胺的纳米纤维（AGNFs）亲和膜。通过获取傅里叶变换红外（FT-IR）光谱和碳、氢和氮（CHN）数据来研究纳米纤维（NFs）接枝后的化学结构。通过场发射扫描电子显微镜（FE-SEM）研究了接枝前后 NFs 的形态。FT-IR 和 CHN 数据证实了新官能团已引入壳聚糖（CH）的主链结构中。FE-SEM 表明，接枝后膜的密度更大，NFs 的形态没有恶化。研究了膜在蒸馏水中的水稳定性。AGNFs 膜表现出良好的水稳定性（在 24 小时内仅损失约 6%的重量，此后保持稳定），小于戊二醛处理的纳米纤维（GNFs）（在 24 小时内损失约 44%的重量）和原始 NFs（NFs 一浸入蒸馏水就会损失 100%的重量）。AGNFs 对 Cu（II）和 Pb（II）的最大吸附（q）容量分别观察到为 166.67mg·g 和 94.34mg·g。与现有的常规和壳聚糖吸附剂相比，本系统对 Cu（II）的吸附容量要高得多。这种增加不仅与尺寸有关，而且更可能与氮结合位点（螯合位点）数量的增加有关。氮提供孤对电子进行螯合。将处理成纳米尺寸与胺接枝（AG）相结合，显著提高了 CH NFs 膜的吸附容量。
