Jayakumar Sangeetha, Saravanan T, Philip John
SMART Materials Section, Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, HBNI, Kalpakkam 603102, India.
Inspection Technology Section, Non Destructive Evaluation Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, HBNI, Kalpakkam 603102, India.
J Nanosci Nanotechnol. 2018 Jun 1;18(6):3969-3981. doi: 10.1166/jnn.2018.15237.
Nanocomposites containing α-Bi2O3, β-Bi2O3 and Bi nanoparticles as nanofillers in vulcanized silicone resin as a matrix are prepared and their diagnostic X-ray attenuation property is studied. The nanocomposites are prepared using a simple solution casting technique, with nanofiller concentration varying from 2-50 wt%. Thermogravimetric analysis and differential scanning calorimetry are performed to study the thermal stability of the nanocomposites. The attenuation property is studied by exposing the nanocomposites containing α-Bi2O3, β-Bi2O3 and Bi nanoparticles to X-rays of energy 30-60 keV. Nanocomposites containing β-Bi2O3 nanoparticles are found to exhibit the highest attenuation than nanocomposites of α-Bi2O3 and Bi nanoparticles of similar concentration. Nanocomposites containing 50 wt% of β-Bi2O3 nanoparticles exhibit an X-ray attenuation of 93, 86, 71, 45 and 10% at an X-ray photon energy of 40, 45, 50, 55 and 59 keV, respectively. Further increase in photon energy is found to saturate the flat panel detector owing to the lower thickness of the nanocomposites. Analysis of high resolution X-ray radiographs of the nanocomposites confirms the uniform distribution of nanofillers in the matrix. Thermal analysis confirms the structural integrity and thermal stability of the nanocomposites. Heat flow curves also confirm the interaction of nanofillers with the matrix, corroborated by a change in the peak position and its endothermic/exothermic nature, corresponding to the phase transition of the nanofillers. It is also interpreted from thermal analysis of nanocomposites that the nanofillers interact with the matrix either by intercalating in the bridging polymer chain of silicone resin network structure or by occupying the interchain space. Thermal analysis of X-ray exposed nanocomposites shows no significant change in heat flow rates, thus, confirming the stability of the nanocomposites. Our study shows that nanocomposites containing β-Bi2O3 nanofiller are potential candidates for radiopaque fabrics which can find application in diagnostic X-ray shielding in mammography, dental scan, etc.
制备了以硫化硅树脂为基体、含有α - Bi2O3、β - Bi2O3和Bi纳米颗粒作为纳米填料的纳米复合材料，并研究了它们的诊断X射线衰减性能。采用简单的溶液浇铸技术制备纳米复合材料，纳米填料浓度在2 - 50 wt%之间变化。进行热重分析和差示扫描量热法以研究纳米复合材料的热稳定性。通过将含有α - Bi2O3、β - Bi2O3和Bi纳米颗粒的纳米复合材料暴露于能量为30 - 60 keV的X射线下研究其衰减性能。发现含有β - Bi2O3纳米颗粒的纳米复合材料比浓度相似的α - Bi2O3和Bi纳米颗粒的纳米复合材料表现出最高的衰减。含有50 wt%β - Bi2O3纳米颗粒的纳米复合材料在X射线光子能量为40、45、50、55和59 keV时，X射线衰减分别为93%、86%、71%、45%和10%。由于纳米复合材料的厚度较低，发现光子能量的进一步增加会使平板探测器饱和。对纳米复合材料的高分辨率X射线射线照片的分析证实了纳米填料在基体中的均匀分布。热分析证实了纳米复合材料的结构完整性和热稳定性。热流曲线也证实了纳米填料与基体的相互作用，这由对应于纳米填料相变的峰位置及其吸热/放热性质的变化所证实。从纳米复合材料的热分析中还可以推断出，纳米填料通过插入硅树脂网络结构的桥连聚合物链中或占据链间空间与基体相互作用。对经X射线照射的纳米复合材料的热分析表明热流速率没有显著变化，因此，证实了纳米复合材料的稳定性。我们的研究表明，含有β - Bi2O3纳米填料的纳米复合材料是不透射线织物的潜在候选材料，可用于乳腺摄影、牙科扫描等诊断X射线屏蔽应用。
