Yong Soon Kong, Skinner William M, Bolan Nanthi S, Lombi Enzo, Kunhikrishnan Anitha, Ok Yong Sik
Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA, 5095, Australia.
Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor, Malaysia.
Environ Sci Pollut Res Int. 2016 Jan;23(2):1050-9. doi: 10.1007/s11356-015-5654-5. Epub 2015 Nov 4.
Pristine chitosan beads were modified with sulfur (S)-containing functional groups to produce thiolated chitosan beads (ETB), thereby increasing S donor ligands and crosslinks. The effect of temperature, heating time, carbon disulfide (CS2)/chitosan ratio, and pH on total S content of ETB was examined using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The total S content of ETB increased with increasing CS2/chitosan ratio and decreased with decreasing pH and increasing temperature (>60 °C) and heating time (at 60 °C). Spectroscopic analyses revealed the presence of thiol (-SH)/thione, disulfide (-S-S-), and sulfonate groups in ETB. The thiolation mechanism involves decomposition of dithiocarbamate groups, thereby forming thiourea crosslinks and trithiocarbonate, resulting in -SH oxidation to produce -S-S- crosslinks. The partially formed ETB crosslinks contribute to its acid stability and are thermodynamically feasible in adsorbing Cd and Cu. The S-containing functional groups added to chitinous wastes act as sorbents for metal remediation from acidic environments.
将纯净的壳聚糖珠用含硫（S）官能团进行改性，以制备硫醇化壳聚糖珠（ETB），从而增加硫供体配体和交联键。使用傅里叶变换红外光谱和X射线光电子能谱研究了温度、加热时间、二硫化碳（CS2）/壳聚糖比例和pH值对ETB总硫含量的影响。ETB的总硫含量随CS2/壳聚糖比例的增加而增加，随pH值的降低以及温度（>60°C）和加热时间（60°C时）的增加而降低。光谱分析表明ETB中存在硫醇（-SH）/硫酮、二硫键（-S-S-）和磺酸根基团。硫醇化机理涉及二硫代氨基甲酸盐基团的分解，从而形成硫脲交联键和三硫代碳酸盐，导致-SH氧化生成-S-S-交联键。部分形成的ETB交联键有助于其酸稳定性，并且在吸附镉和铜方面在热力学上是可行的。添加到含甲壳素废物中的含硫官能团可作为从酸性环境中修复金属的吸附剂。
