二醛淀粉的光化学反应。
Photochemical Reactions in Dialdehyde Starch.
机构信息
Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100 Torun, Poland.
出版信息
Molecules. 2018 Dec 18;23(12):3358. doi: 10.3390/molecules23123358.
In this study potato and corn starch were subjected to oxidation, using sodium periodate, to obtain dialdehyde starch (DAS) containing different amount of aldehyde groups. The obtained modified starch samples have been characterized with chemical analysis, scanning electron microscopy (SEM) and ATR-FTIR spectroscopy. Then, the samples were exposed to polychromatic UV radiation and the course of photochemical reaction has been monitored with ATR-FTIR spectroscopy. The surface properties of the native and dialdehyde starch before and after UV-irradiation have been determined by contact angle measurements and calculation of surface free energy. The crystallinity of the samples has been estimated with X-ray diffraction (XRD). It has been proved that the dialdehyded corn starch contained a higher amount of functional groups was more photostable than the oxidized potato starch. Sodium iodide(V), firmly bound to DAS macromolecules, has been found to have a significant effect on the photooxidative degradation of the tested systems. In addition, the mechanism of photoinduced reactions in the dialdehyde starch has been proposed.
在这项研究中，马铃薯淀粉和玉米淀粉分别用过氧化氢钠进行氧化，得到含有不同醛基数量的双醛淀粉（DAS）。通过化学分析、扫描电子显微镜（SEM）和衰减全反射傅里叶变换红外光谱（ATR-FTIR）对所得的改性淀粉样品进行了表征。然后，将这些样品暴露在多色紫外辐射下，并通过 ATR-FTIR 光谱监测光化学反应过程。通过接触角测量和表面自由能计算，测定了天然和经 UV 照射后的 DAS 的表面性质。用 X 射线衍射（XRD）估计了样品的结晶度。结果表明，双醛化玉米淀粉比氧化马铃薯淀粉含有更多的官能团，具有更高的光稳定性。发现牢固结合到 DAS 大分子上的碘化钠（V）对测试体系的光氧化降解有显著影响。此外，还提出了 DAS 中光诱导反应的机制。
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