Unnervik David, Harada Takuya
Department of Chemical Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan.
ACS Appl Mater Interfaces. 2023 Nov 29;15(47):54667-54676. doi: 10.1021/acsami.3c12788. Epub 2023 Nov 14.
This paper reports on the structural changes occurring within the lithium-sodium orthoborate crystal lattice during the solid-state absorption of CO. Results derived from Fourier transform infrared measurements indicate that the CO-saturated mixed-alkali metal orthoborate and its CO-lean metaborate counterpart essentially present the same spectral profile, suggesting that CO capture results in a fundamental shift of the orthoborate composition to the metaborate one. The implications of such a structural transformation were examined in the molten state at elevated temperatures through rheological measurements, and although confirming that the CO-lean metaborate exhibits a higher viscosity than the CO-lean orthoborate, the results suggest that incorporation of CO in the orthoborate ionic lattice dilutes the melt, leading to a remarkable reduction in its overall viscosity, despite causing a structural transformation from the less viscous orthoborate form to the more viscous metaborate one.
本文报道了正硼酸锂晶格在固态吸收CO过程中发生的结构变化。傅里叶变换红外测量结果表明，CO饱和的混合碱金属正硼酸盐及其贫CO的偏硼酸盐基本上呈现相同的光谱特征，这表明CO捕获导致正硼酸盐组成向偏硼酸盐发生根本性转变。通过流变学测量在高温熔融状态下研究了这种结构转变的影响，尽管证实贫CO的偏硼酸盐比贫CO的正硼酸盐具有更高的粘度，但结果表明，将CO掺入正硼酸盐离子晶格中会稀释熔体，导致其整体粘度显著降低，尽管会引起从粘度较小的正硼酸盐形式到粘度较大的偏硼酸盐形式的结构转变。
