Mahendar Chinthakuntla, Kumar Yeeshu, Dixit Manish Kumar, Dubey Mrigendra
Soft Materials Research Laboratory, Discipline of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Simrol, Indore 453552, India.
Soft Matter. 2020 Apr 14;16(14):3436-3442. doi: 10.1039/c9sm02544h. Epub 2020 Mar 20.
An alkali base and counterion-selective red metallogel (1% w/v) has been synthesized by mixing the adipic acid-derived ligand HAL with LiOH, followed by the addition of 1 equivalent of Co(OAc) in DMF. The addition of Co(OAc) not only resulted in the formation of a 2 : 2 (M : L) complex, but also led to the consecutive steps of aggregation, fiber creation, entrapment of the solvent and eventually gelation. The metallogel formation and the mechanism behind gelation have been well characterized and established using various instrumental techniques such as FTIR spectroscopy, UV-vis spectroscopy, FE-SEM, TEM, PXRD, ESI-mass spectrometry, Job's plot and rheology analysis. Nyquist plots suggested a large decrease in the resistance value from 11.3 kΩ to 4.2 kΩ for the solution obtained from the ligand deprotonated by LiOH (AL) and Co(OAc) containing the metallogel. The Nyquist plot and resistance of the metallogel have also been studied under the influence of temperature and ultrasound stimuli. The extensive rheological measurements provide information about the strength of the gel network and the highly reversible nature and thixotropic behaviour of the metallogel.
通过将己二酸衍生的配体HAL与LiOH混合，随后在DMF中加入1当量的Co(OAc)，合成了一种碱金属阳离子和抗衡离子选择性红色金属凝胶（1% w/v）。Co(OAc)的加入不仅导致形成2:2（M:L）配合物，还引发了连续的聚集步骤、纤维形成、溶剂捕获并最终凝胶化。使用FTIR光谱、UV-vis光谱、FE-SEM、TEM、PXRD、ESI-质谱、Job曲线和流变学分析等各种仪器技术，对金属凝胶的形成及其凝胶化背后的机制进行了充分表征和确定。奈奎斯特图表明，对于由LiOH去质子化的配体（AL）和含有金属凝胶的Co(OAc)得到的溶液，电阻值从11.3 kΩ大幅降至4.2 kΩ。还研究了温度和超声刺激影响下金属凝胶的奈奎斯特图和电阻。广泛的流变学测量提供了有关凝胶网络强度以及金属凝胶高度可逆性质和触变行为的信息。
