Aerosol Emission Monitoring and Assessment of Potential Exposure to Multi-walled Carbon Nanotubes in the Manufacture of Polymer Nanocomposites.
Aerosol Emission Monitoring and Assessment of Potential Exposure to Multi-walled Carbon Nanotubes in the Manufacture of Polymer Nanocomposites.
复制标题
聚合物纳米复合材料制造过程中气溶胶排放监测和多壁碳纳米管潜在暴露评估。
DOI：
10.1093/annhyg/mev044
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Pui,DavidYH
中科院分区：
文献类型：
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作者：
Thompson,Drew;Chen,Sheng-Chieh;Wang,Jing;Pui,DavidYH
最近的动物研究表明，碳纳米管（CNT）可能对工作场所暴露的人构成重大健康风险。为了进一步了解这种潜在的风险，必须采取措施来衡量职业暴露的碳纳米管。从潜在的暴露于多壁碳纳米管（MWCNTs）进行的工业设施，其中聚合物纳米复合材料的挤出工艺制造的评估结果。暴露于多壁碳纳米管量化的元素碳（EC）的个人采样收集的呼吸性粉尘的热光学分析。收集的所有个人可吸入样本（n= 8）的估计8小时时间加权平均（TWA）EC浓度低于分析的检测限，该检测限约为CNT推荐暴露限值的一半，即8小时TWA可吸入质量浓度为1 µg EC/m3。通过直接读数仪器和区域取样确定了潜在的接触源并进行了表征。EC分析的区域样品产生了可量化的质量浓度，其中未结合的多壁碳纳米管被处理的外壳内和附近的造粒机，其中纳米复合材料被切割，而那些通过电子显微镜分析检测到多壁碳纳米管的存在下，在整个设施的六个位置。通过尺寸选择性区域采样，确定了工作场所中存在的空气中的多壁碳纳米管以大团聚体的形式存在。这通过电子显微镜证实，其中观察到的大多数MWCNT结构是以微米尺寸的绳状团聚体的形式。然而，也观察到一小部分的单个游离MWCNT。结果发现，生产设施中存在的纳米颗粒的高数量浓度（约200000个颗粒/cm 3）可能归因于挤出工艺中产生的聚合物烟雾。
Recent animal studies have shown that carbon nanotubes (CNTs) may pose a significant health risk to those exposed in the workplace. To further understand this potential risk, effort must be taken to measure the occupational exposure to CNTs. Results from an assessment of potential exposure to multi-walled carbon nanotubes (MWCNTs) conducted at an industrial facility where polymer nanocomposites were manufactured by an extrusion process are presented. Exposure to MWCNTs was quantified by the thermal-optical analysis for elemental carbon (EC) of respirable dust collected by personal sampling. All personal respirable samples collected (n= 8) had estimated 8-h time weighted average (TWA) EC concentrations below the limit of detection for the analysis which was about one-half of the recommended exposure limit for CNTs, 1 µg EC/m3as an 8-h TWA respirable mass concentration. Potential exposure sources were identified and characterized by direct-reading instruments and area sampling. Area samples analyzed for EC yielded quantifiable mass concentrations inside an enclosure where unbound MWCNTs were handled and near a pelletizer where nanocomposite was cut, while those analyzed by electron microscopy detected the presence of MWCNTs at six locations throughout the facility. Through size selective area sampling it was identified that the airborne MWCNTs present in the workplace were in the form of large agglomerates. This was confirmed by electron microscopy where most of the MWCNT structures observed were in the form of micrometer-sized ropey agglomerates. However, a small fraction of single, free MWCNTs was also observed. It was found that the high number concentrations of nanoparticles, ~200000 particles/cm3, present in the manufacturing facility were likely attributable to polymer fumes produced in the extrusion process.