Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384, People's Republic of China.
Nanotechnology. 2020 Apr 9;31(26):265603. doi: 10.1088/1361-6528/ab7aa4. Epub 2020 Feb 27.
Single-walled carbon nanotubes (SWCNTs) are potential antibacterial material, and their antibacterial activity in aqueous solutions depends on efficient surfactants to create strong interactions between well-dispersed SWCNTs and bacterial cells. Here, we designed and synthesized a new family of cationic surfactants by introducing different positively charged hydrophilic heads, i.e. -(CH)N(CH)Br, -(CH)N(CH)Br and -(CH)NPyridineBr, to cardanol obtained from cashew nut shell liquid. These surfactants can efficiently disperse SWCNTs in aqueous solutions because benzene rings and olefin chains in cardanol enable their strong π-stacking on SWCNTs. A much higher fraction of SWCNTs can be dispersed individually compared to the commonly used surfactant, dodecylbenzene-sulfonate sodium (SDBS). SWCNTs dispersed in the cardanol-derived surfactants demonstrate significantly improved antibacterial activity. At the concentration of 0.5 wt%, their minimum inhibitory concentration is 0.33 and 0.02 μg ml against E. coli and S. aureus, respectively, which is only 0.8%-1.5% of that of SDBS-dispersed SWCNTs. The strong antibacterial activity can be attributed to both better dispersion of SWCNTs and positive charges introduced by hydrophilic heads, which are attracted to negatively charged bacterial cell surfaces. These cardanol-derived surfactants are promising as sustainable surfactants for enabling various SWCNT applications.
单壁碳纳米管（SWCNTs）是一种有潜力的抗菌材料，其在水溶液中的抗菌活性取决于高效的表面活性剂，以在分散良好的 SWCNTs 和细菌细胞之间产生强烈的相互作用。在这里，我们通过引入不同的带正电荷的亲水基团，即 -(CH)N(CH)Br、-(CH)N(CH)Br 和 -(CH)NPyridineBr，设计并合成了一系列新型阳离子表面活性剂，这些亲水基团接枝到腰果壳油中的腰果酚上。这些表面活性剂可以有效地在水溶液中分散 SWCNTs，因为腰果酚中的苯环和烯烃链使它们能够与 SWCNTs 形成强烈的π堆积。与常用的表面活性剂十二烷基苯磺酸钠（SDBS）相比，SWCNTs 可以以更高的比例分散在这些表面活性剂中。分散在腰果酚衍生的表面活性剂中的 SWCNTs 表现出显著提高的抗菌活性。在 0.5wt%的浓度下，它们对大肠杆菌和金黄色葡萄球菌的最小抑菌浓度分别为 0.33 和 0.02μg/ml，仅为 SDBS 分散的 SWCNTs 的 0.8%-1.5%。这种强抗菌活性可以归因于 SWCNTs 的更好分散和亲水基团引入的正电荷，这些正电荷被吸引到带负电荷的细菌细胞表面。这些腰果酚衍生的表面活性剂有望成为可持续的表面活性剂，以实现各种 SWCNT 应用。
