In order to prepare excellent electro-responsive natural hydrogels, in this paper, soluble starch with large amount of hydroxyl groups was selected as raw material. For exploring the enhancement to electro-response of starch hydrogel, starch-Fe(III) composite hydrogels were successfully obtained by a combination of Fe(III) into starch hydrogel in this paper. The composite hydrogels were prepared as A-hydrogels cured in the presence of electric field and B-hydrogels which cured without electric field. The storage modulus of A-hydrogels and B-hydrogels was measured using a dynamic viscoelasticity spectrometer (DMA); the consequent modulus increment (ΔG = GA-GB) and modulus increment sensitivity (ΔG/GB) were analyzed for indicating electro-response of the hydrogels. The physical microstructure of the hydrogels was observed by scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) were used to study the chemical constitution and structure. The results show that there is a coordinate bond between Fe(III) with –OH of starch which leads to a stronger three-dimensional network structure and higher thermal stability of the starch-Fe(III) hydrogel. What’s more, the electro-response of the hydrogels can be affected according to the Fe3+ concentration. When the Fe3+ concentration is 0.15 ~ 0.25 M under the electric field of 0.8 kV mm−1, the starch-Fe(III) hydrogels have the strongest electro-response, the maximum value of modulus increment (ΔG) is 24 kPa, and the modulus increment sensitivity (∆G/GB) is about 90%, far more than pure starch hydrogel. Starch-iron (III) hydrogel can be obtained with the coordination of –OH and Fe(III) on starch in the presence of electric field or without electric field. The starch-iron (III) hydrogel prepared under the application of an external electric field has a more ordered structure and better mechanical properties. Starch-iron (III) hydrogel can be obtained with the coordination of –OH and Fe(III) on starch in the presence of electric field or without electric field. The starch-iron (III) hydrogel prepared under the application of an external electric field has a more ordered structure and better mechanical properties.

中文翻译：

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Fe(III)对淀粉水凝胶电响应的增强

为了制备优良的电响应性天然水凝胶，本文选择了含有大量羟基的可溶性淀粉为原料。为了探索淀粉水凝胶电响应的增强，本文通过将Fe(III)与淀粉水凝胶结合，成功获得了淀粉-Fe(III)复合水凝胶。复合水凝胶制备为在电场存在下固化的A-水凝胶和无电场固化的B-水凝胶。使用动态粘弹性光谱仪 (DMA) 测量 A-水凝胶和 B-水凝胶的储能模量；分析了随之而来的模量增量 (ΔG = GA-GB) 和模量增量灵敏度 (ΔG/GB) 以指示水凝胶的电响应。通过扫描电子显微镜（SEM）观察水凝胶的物理微观结构。傅里叶变换红外光谱（FT-IR）和热重分析（TGA）用于研究化学组成和结构。结果表明，Fe(III)与淀粉的-OH之间存在配位键，导致淀粉-Fe(III)水凝胶具有更强的三维网络结构和更高的热稳定性。此外，水凝胶的电响应会受到 Fe3+ 浓度的影响。Fe3+浓度为0.15~0.25 M，电场强度为0.8 kV mm-1时，淀粉-Fe(III)水凝胶电响应最强，模量增量(ΔG)最大值为24 kPa，模量增量灵敏度（ΔG/GB）约为90%，远超纯淀粉水凝胶。在有电场或无电场的情况下，淀粉-铁（III）水凝胶可以通过-OH和Fe（III）在淀粉上的配位获得。在外电场作用下制备的淀粉-铁(III)水凝胶结构更有序，力学性能更好。在有电场或无电场的情况下，淀粉-铁（III）水凝胶可以通过-OH和Fe（III）在淀粉上的配位获得。在外电场作用下制备的淀粉-铁(III)水凝胶结构更有序，力学性能更好。在外电场作用下制备的淀粉-铁(III)水凝胶结构更有序，力学性能更好。在有电场或无电场的情况下，淀粉-铁（III）水凝胶可以通过-OH和Fe（III）在淀粉上的配位获得。在外电场作用下制备的淀粉-铁(III)水凝胶结构更有序，力学性能更好。在外电场作用下制备的淀粉-铁(III)水凝胶结构更有序，力学性能更好。在有电场或无电场的情况下，淀粉-铁（III）水凝胶可以通过-OH和Fe（III）在淀粉上的配位获得。在外电场作用下制备的淀粉-铁(III)水凝胶结构更有序，力学性能更好。