Huang Siqi, Wang Jing, Zhang Yang, Yu Zhiming, Qi Chusheng
Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China.
MOE Key Laboratory of Wooden Material Science and Application, Beijing Forestry University, Beijing 100083, China.
Nanomaterials (Basel). 2016 Jun 17;6(6):118. doi: 10.3390/nano6060118.
A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs) was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC) as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR) and ¹H nuclear magnetic resonance (NMR). The formation, size distribution, and dispersion of the Ag NPs in the QCMC matrix were determined using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-Vis), transmission electron microscopy (TEM), and field emission scanning electron microscope (FESEM) analysis, and the thermal stability and antibacterial properties of the synthesized QCMC-based Ag NPs composite (QCMC-Ag) were also explored. The results revealed that (1) QCMC was successfully prepared by grafting quaternary ammonium groups onto carboxymethyl chitosan (CMC) chains under microwave irradiation in water for 90 min and this substitution appeared to have occurred at -NH₂ sites on C2 position of the pyranoid ring; (2) uniform and stable spherical Ag NPs could be synthesized when QCMC was used as the reducing and stabilizing agent; (3) Ag NPs were well dispersed in the QCMC matrix with a narrow size distribiution in the range of 17-31 nm without aggregation; and (4) due to the presence of Ag NPs, the thermal stability and antibacterial activity of QCMC-Ag were dramatically improved relative to QCMC.
开发了一种简便、高效且环保的制备均匀银纳米颗粒（Ag NPs）的方法。该合成在暴露于微波辐射8分钟的水性介质中进行，使用实验室制备的水溶性季铵化羧甲基壳聚糖（QCMC）作为化学还原剂和稳定剂，硝酸银作为银源。使用傅里叶变换红外光谱（FT-IR）和¹H核磁共振（NMR）对制备的QCMC的结构进行了表征。使用X射线衍射（XRD）、X射线光电子能谱（XPS）、紫外可见光谱（UV-Vis）、透射电子显微镜（TEM）和场发射扫描电子显微镜（FESEM）分析确定了Ag NPs在QCMC基质中的形成、尺寸分布和分散情况，并且还探索了合成的基于QCMC的Ag NPs复合材料（QCMC-Ag）的热稳定性和抗菌性能。结果表明：（1）通过在水中微波辐射90分钟将季铵基团接枝到羧甲基壳聚糖（CMC）链上成功制备了QCMC，并且这种取代似乎发生在吡喃环C2位置的-NH₂位点上；（2）当使用QCMC作为还原剂和稳定剂时，可以合成均匀且稳定的球形Ag NPs；（3）Ag NPs在QCMC基质中分散良好，尺寸分布狭窄，在17-31 nm范围内且无聚集；（4）由于Ag NPs的存在，QCMC-Ag的热稳定性和抗菌活性相对于QCMC有显著提高。
