The role of the elemental carbon (EC), in synergy with hygroscopic ionic species, was investigated to study the formation of electrical bridging phenomena once the aerosol deliquescence is achieved. Ambient aerosol samples were collected on hydrophobic surfaces in urban and rural sites in Northern Italy; their conductance was measured in an Aerosol Exposure Chamber (AEC) while varying the relative humidity. An electric signal was detected on 64% of the collected samples with conductance values (11.20 ± 7.43 μS) above the failure threshold (1 μS) of printed circuit boards. The ionic content was higher for non-electrically conductive samples (43.7 ± 5.6%) than for electrically conductive ones (37.1 ± 5.6%). Conversely, EC was two times higher for electrically conductive samples (26.4 ± 4.1 μg cm⁻²; 8.4 ± 1.7%) than for non-electrical ones (12.0 ± 4.1 μg cm⁻²; 5.2 ± 1.9%) suggesting that the synergy between the ionic and carbonaceous fractions is necessary to promote a bridging phenomenon. Synthetic aerosols (EC only, saline only, mixed saline and EC) were generated in laboratory and their conductance was measured in the AEC to verify the ambient results. Only in case of a contemporary presence of both EC and ionic components the bridging phenomenon occurred in keeping with the theoretical deliquescence values of each salt (R² = 0.996).

中文翻译：

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在确定沉积的气溶胶的电导特性时元素碳和无机离子之间的协同作用：对能源应用的启示

研究了碳元素与吸湿性离子物种协同作用的作用，以研究气溶胶潮解后电桥现象的形成。在意大利北部城市和乡村地区的疏水表面上收集了环境气溶胶样品；在改变相对湿度的同时，在气溶胶暴露室（AEC）中测量其电导率。在64％的采样样品上检测到电信号，其电导值（11.20±7.43μS）高于印刷电路板的故障阈值（1μS）。非导电样品的离子含量（43.7±5.6％）比导电样品的离子含量（37.1±5.6％）高。相反，导电样品的EC值高出两倍（26.4±4.1μgcm ^-2; 8.4±1.7％）比非电的（12.0±4.1μgcm ^-2； 5.2±1.9％）提示离子级和碳级分之间的协同作用对于促进桥接现象必不可少。在实验室中生成了合成气雾剂（仅EC，仅盐水，混合盐水和EC），并在AEC中测量了其电导率以验证环境结果。仅在同时存在EC和离子成分的情况下，才出现与每种盐的理论潮解值一致的桥接现象（R ² = 0.996）。