Suman Guddi, Pulikkathara Merlyn, Wilkins Richard, Treadwell LaRico J
Sandia National Laboratories, Albuquerque, NM 87106, USA.
Department of Chemistry and Physics, Prairie View A&M University, Prairie View, TX 77446, USA.
Nanomaterials (Basel). 2023 Sep 27;13(19):2653. doi: 10.3390/nano13192653.
This paper studies the ionizing radiation effects on functionalized single-walled carbon nanotube (SWCNT)/poly(methyl methacrylate) (PMMA) thin-film nanocomposites [SWNT/PMMA]. The functionalized thin-film devices are made of ferrocene-doped SWCNTs, SWCNTs functionalized with carboxylic acid (COOH), and SWCNTs coated/ modified with copper. The nanocomposite was synthesized by the solution blending method and the resulting nanocomposite was spin-cast on interdigitated electrodes (IDEs). A 160 kV X-ray source was used to irradiate the thin film and changes in the electrical resistance of the nanocomposites due to X-rays were measured using a semiconductor device analyzer. Carboxylic acid functionalized and copper-coated SWCNT/PMMA nanocomposite showed a reduced response to X-rays compared to unfunctionalized SWCNT/PMMA nanocomposite. Ferrocene-doped SWCNT showed a higher sensitivity to X-rays at lower dose rates. This is in contrast to a previous study that showed that similar nanocomposites using functionalized multi-walled CNTs (MWCNTs) had demonstrated an improved response to X-rays ionizing radiation compared to unfunctionalized MWCNTs for all dose rates. Electrical measurements were also performed using the Arduino Nano microcontroller. The result showed that a relatively economical, lightweight-designed prototype radiation sensor based on SWCNT/PMMA thin-film devices could be produced by interfacing the devices with a modest microcontroller. This work also shows that by encapsulating the SWCNT/PMMA thin-film device in a plastic container, the effect of ambient humidity can be reduced and the device can still be used to detect X-ray radiation. This study further shows that the sensitivity of SWCNT to X-rays was dependent on both the functionalization of the SWCNT and the dose rate.
本文研究了电离辐射对功能化单壁碳纳米管（SWCNT）/聚甲基丙烯酸甲酯（PMMA）薄膜纳米复合材料[SWNT/PMMA]的影响。功能化薄膜器件由二茂铁掺杂的SWCNT、用羧酸（COOH）功能化的SWCNT以及用铜包覆/改性的SWCNT制成。通过溶液共混法合成了纳米复合材料，并将所得纳米复合材料旋涂在叉指电极（IDE）上。使用160 kV的X射线源照射薄膜，并使用半导体器件分析仪测量由于X射线导致的纳米复合材料电阻变化。与未功能化的SWCNT/PMMA纳米复合材料相比，羧酸功能化和铜包覆的SWCNT/PMMA纳米复合材料对X射线的响应降低。二茂铁掺杂的SWCNT在较低剂量率下对X射线表现出更高的灵敏度。这与先前的一项研究形成对比，该研究表明，使用功能化多壁碳纳米管（MWCNT）的类似纳米复合材料在所有剂量率下对X射线电离辐射的响应均优于未功能化的MWCNT。还使用Arduino Nano微控制器进行了电学测量。结果表明，通过将器件与适度的微控制器连接，可以生产出基于SWCNT/PMMA薄膜器件的相对经济、设计轻便的原型辐射传感器。这项工作还表明，通过将SWCNT/PMMA薄膜器件封装在塑料容器中，可以降低环境湿度的影响，并且该器件仍可用于检测X射线辐射。这项研究进一步表明，SWCNT对X射线的灵敏度既取决于SWCNT的功能化，也取决于剂量率。
