Stanojev Jovana, Armaković Stevan, Joksović Sara, Bajac Branimir, Matović Jovan, Srdić Vladimir V
BioSense Institute, University of Novi Sad, Dr Zorana Djindjica 1, 21000 Novi Sad, Serbia.
Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia.
Nanomaterials (Basel). 2022 Jun 1;12(11):1901. doi: 10.3390/nano12111901.
Single-walled carbon nanotubes (SWCNTs) are well-known for their excellent electrical conductivity. One promising application for SWCNT-based thin films is as transparent electrodes for uncooled mid-IR detectors (MIR). In this paper, a combination of computational and experimental studies were performed to understand the chemistry behind the stability of carboxylic SWCNTs (SWCNTs-COOH) dispersions in different solvents. A computational study based on the density functional tight-binding (DFTB) method was applied to understand the interactions of COOH-functionalized carbon nanotubes with selected solvents. Attention was focused on understanding how the protonation of COOH groups influences the binding energies between SWCNTs and different solvents. Thin film electrodes were prepared by alternately depositing PEI and SWCNT-COOH on soda lime glass substrates. To prepare a stable SWCNT dispersion, different solvents were tested, such as deionized (DI) water, ethanol and acetone. The SWCNT-COOH dispersion stability was tested in different solvents. Samples were prepared to study the relationship between the number of depositions, transparency in the MIR range (2.5-5 µm) and conductivity, looking for the optimal thickness that would satisfy the application. The MIR transparency of the electrode was reduced by 20% for the thickest SWCNT layers, whereas sheet resistance values were reduced to 150-200 kΩ/sq.
单壁碳纳米管（SWCNT）以其优异的导电性而闻名。基于SWCNT的薄膜的一个有前景的应用是作为非制冷中红外探测器（MIR）的透明电极。在本文中，进行了计算和实验研究相结合的工作，以了解羧基化SWCNT（SWCNTs-COOH）在不同溶剂中分散稳定性背后的化学原理。应用基于密度泛函紧束缚（DFTB）方法的计算研究来理解COOH功能化碳纳米管与选定溶剂之间的相互作用。重点关注理解COOH基团的质子化如何影响SWCNT与不同溶剂之间的结合能。通过在钠钙玻璃基板上交替沉积PEI和SWCNT-COOH来制备薄膜电极。为了制备稳定的SWCNT分散体，测试了不同的溶剂，如去离子（DI）水、乙醇和丙酮。测试了SWCNT-COOH在不同溶剂中的分散稳定性。制备样品以研究沉积次数、中红外范围（2.5 - 5 µm）的透明度和导电性之间的关系，寻找满足应用的最佳厚度。对于最厚的SWCNT层，电极的中红外透明度降低了20%，而薄层电阻值降低到150 - 200 kΩ/sq。
