Surface Modification of a MXene by an Aminosilane Coupling Agent
Surface Modification of a MXene by an Aminosilane Coupling Agent
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DOI：
10.1002/admi.201902008
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发表时间：
2020-02-03
影响因子：
5.4
通讯作者：
Soroush, Masoud
中科院分区：
文献类型：
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作者：
Riazi, Hossein;Anayee, Mark;Soroush, Masoud
MXene，二维（2D）过渡金属碳化物和/或氮化物，具有可用于表面官能化的表面终止基团，例如羟基、氧和氟。它们的表面化学在许多应用中至关重要。本文报道了用[3-（2-氨基乙基氨基）-丙基]三甲氧基硅烷（AEAPTMS）胺官能化Ti 3C 2 Tx MXene表面。X射线光电子能谱等表征技术验证了表面功能化的成功，并证实了硅烷偶联剂在物理和化学上与Ti 3C 2 Tx表面结合。官能化在中性pH下将MXene表面电荷从-35 mV改变到+25 mV，这允许原位制备自组装膜。此外，在不同pH值下官能化的MXene的表面电荷测量显示官能化的MXene在约10.7的pH下具有等电点，并且在2.58的pH下具有+62mV的最高报道的正表面电荷。此外，AEAPTMS的不同取向的混合物的存在和质子化和游离胺基团的同时存在的表面上的Ti 3C 2 Tx被证明。表面上游离胺基的可用性潜在地允许制造交联的导电MXene/环氧复合材料、染料吸附剂、高性能膜和药物载体。这种类型的表面改性适用于许多其他MXene。
MXenes, two-dimensional (2D) transition metal carbides and/or nitrides, possess surface termination groups such as hydroxyl, oxygen, and fluorine, which are available for surface functionalization. Their surface chemistry is critical in many applications. This article reports amine functionalization of Ti3C2Tx MXene surface with [3-(2-aminoethylamino)-propyl]trimethoxysilane (AEAPTMS). Characterization techniques such as X-ray photoelectron spectroscopy verify the success of the surface functionalization and confirm that the silane coupling agent bonds to Ti3C2Tx surface both physically and chemically. The functionalization changes the MXene surface charge from -35 to +25 mV at neutral pH, which allows for in situ preparation of self-assembled films. Further, surface charge measurements of the functionalized MXene at different pH values show that the functionalized MXene has an isoelectric point at a pH around 10.7, and the highest reported positive surface charge of +62 mV at a pH of 2.58. Furthermore, the existence of a mixture of different orientations of AEAPTMS and the simultaneous presence of protonated and free amine groups on the surface of Ti3C2Tx are demonstrated. The availability of free amine groups on the surface potentially permits the fabrication of crosslinked electrically conductive MXene/epoxy composites, dye adsorbents, high-performance membranes, and drug carriers. Surface modifications of this type are applicable to many other MXenes.