论文部分内容阅读
以可溶性淀粉做原料,用N,N′—亚甲基双丙烯酰胺交联,过硫酸铵引发聚合得到微孔交联淀粉(MCS),并研究了其对Zn~(2+)的静态吸附行为;用红外光谱仪和X射线衍射仪对MCS及其吸附产物进行了对照分析。结果表明:MCS对Zn~(2+)的吸附符合Freundlich等温方程,吸附量达到2.36 mmol/g;MCS在1536 cm~(-1)处出现酰胺Ⅱ带N-H弯曲振动吸收峰,表明了淀粉与MBAA成功交联;MCS在3445cm~(-1)附近的N—H、O—H伸缩振动偶合而增宽的多重峰在吸附产物中变宽,且向低波数位移,而1536cm~(-1)处的酰胺Ⅱ带N—H弯曲振动吸收峰则移至1543cm~(-1)处,说明在吸附过程中,MCS的酰胺基团上的N、O原子可能与Zn~(2+)发生了配位反应;XRD显示,可溶性淀粉经交联后结晶度降低至6.4%左右,MCS上的酰胺基和—OH与Zn~(2+)形成配位键使MCS的晶形结构被进一步破坏,结晶度约为0.5%左右,已基本处于无序的非晶态。
The soluble starch was used as raw material, crosslinked by N, N’-methylenebisacrylamide and polymerized by ammonium persulfate to obtain microporous crosslinked starch (MCS). The static adsorption on Zn 2+ Behavior of MCS and its adsorption products were analyzed by infrared spectroscopy and X-ray diffractometer. The results showed that the adsorption of Zn 2+ by MCS conformed to the Freundlich isotherm equation and the adsorption capacity reached 2.36 mmol / g. The NHB vibrational absorption peak of amide Ⅱ band appeared at 1536 cm -1 in MCS, MBAA was successfully cross-linked. The widened multiple peaks of MCS near N-H and O-H stretching vibration near 3445cm ~ (-1) broadened in the product of adsorption and shifted to low wavenumbers, while the bands of 1536cm ~ (-1) ), The N-H bending vibration absorption peak shifted to 1543cm -1, indicating that the N and O atoms on the amide group of MCS may be related to Zn 2+ during the adsorption process XRD showed that the crystallinity of the soluble starch reduced to about 6.4% after crosslinking. The amide group and the coordination bond between -OH and Zn ~ (2+) formed on the MCS further destroyed the crystal structure of MCS. The degree of crystallinity is about 0.5%, has been basically in a disorderly amorphous.