Journal of Aerosol Science最新文献_第5页

Size-segregated chemical composition and oxidative potential of ambient quasi-ultrafine and accumulation mode particles in Los Angeles 洛杉矶环境准超细颗粒和堆积模式颗粒的尺寸分离化学成分和氧化电位

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-15 DOI: 10.1016/j.jaerosci.2025.106696

Yashar Aghaei , Mohammad Mahdi Badami , Mohammad Aldekheel , Ramin Tohidi , Yousef Alramzi , P.S. Ganesh Subramanian , Vishal Verma , Leonidas Ntziachristos , Constantinos Sioutas

Quasi-ultrafine particles (q-UFPs; 30 nm < d_p < 170 nm) are increasingly recognized as potent contributors to air pollution-related health effects due to their physicochemical characteristics and deep lung penetration. This study investigated the size-segregated chemical composition and oxidative potential of ambient particles in the q-UFPs and accumulation mode ranges (30 nm - 2.5 μm) in central Los Angeles. A Low-Pressure Impactor (LPI), coupled with a Versatile Aerosol Concentration Enrichment System (VACES), was employed alongside a Sioutas Personal Cascade Impactor (PCIS) to collect size-fractionated PM for mass, elemental, ionic, carbonaceous, and toxicological analysis. Mass concentrations in q-UFPs (30–170 nm) were significantly lower than those in the accumulation mode (250–2500 nm), with the latter mode contributing >83 % of total PM mass. Dithiothreitol (DTT) activity was observed to increase across q-UFP size bins, peaking in the 108–170 nm range at 25.98 pmol/min/m³ in winter and 44.31 pmol/min/m³ in summer/fall. In the accumulation mode, slightly lower DTT activity levels were measured (23.95 and 39.98 pmol/min/m³, respectively). Strong positive correlations were identified between DTT activity and elemental carbon (r = 0.95), organic carbon (r = 0.94), ammonium (r = 0.93), and sulfate (r = 0.91), suggesting contributions from both primary emissions and secondary atmospheric processes. Respiratory deposition modeling using the International Commission on Radiological Protection (ICRP) method showed that although q-UFPs comprised a smaller fraction of the total mass, they were found to contribute 29 % of the cumulative alveolar-region dose, with the 108–170 nm fraction alone delivering 31.5 pmol/min. These results highlight the toxicological importance of UFPs and support the need for continued monitoring and research, consistent with the World Health Organization's good practice statements, which recommend the integration of UFP metrics into air quality monitoring frameworks in the absence of formal guideline values.

准超细颗粒（q- ufp; 30 nm < dp < 170 nm）由于其物理化学特性和深肺穿透性，越来越被认为是空气污染相关健康影响的有力贡献者。本研究调查了洛杉矶中部q- ufp和积累模式范围（30 nm - 2.5 μm）内环境颗粒的尺寸分离化学成分和氧化电位。低压冲击器（LPI）与多功能气溶胶浓度富集系统（VACES）相结合，与Sioutas个人级联冲击器（PCIS）一起收集大小分级的PM，用于质量、元素、离子、碳质和毒理学分析。q- ufp （30-170 nm）的质量浓度显著低于积累模式（250-2500 nm）的质量浓度，后者占PM总质量的83%。双硫苏糖醇（DTT）活性随着q-UFP大小的变化而增加，在108-170 nm范围内达到峰值，冬季为25.98 pmol/min/m3，夏秋季节为44.31 pmol/min/m3。在累积模式下，DTT活性水平略低（分别为23.95和39.98 pmol/min/m3）。DTT活性与元素碳（r = 0.95）、有机碳（r = 0.94）、铵（r = 0.93）和硫酸盐（r = 0.91）呈显著正相关，表明主要排放过程和二次大气过程都对DTT活性有贡献。使用国际放射防护委员会（ICRP）方法的呼吸沉积模型显示，尽管q- ufp占总质量的比例较小，但它们占肺泡区累积剂量的29%，仅108-170 nm部分就提供31.5 pmol/min。这些结果突出了超细颗粒的毒理学重要性，并支持按照世界卫生组织良好做法声明继续进行监测和研究的必要性。世界卫生组织良好做法声明建议，在没有正式指导值的情况下，将超细颗粒指标纳入空气质量监测框架。

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引用次数: 0

Engineered Pd-Ga alloy nanoparticles through spark ablation and in-flight metal-organic precursor decomposition 通过火花烧蚀和飞行中的金属有机前驱体分解来设计Pd-Ga合金纳米颗粒

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-15 DOI: 10.1016/j.jaerosci.2025.106698

Marie Bermeo , Markus Snellman , Linnéa Jönsson , Thomas Krinke , Zhongshan Li , Knut Deppert , Maria E. Messing

Pd-Ga alloy nanoparticles with tunable compositions were produced by combining spark ablation with a downstream injection of a metal-organic precursor. This dual-process approach enables control over nanoparticle composition and morphology by adjusting precursor flow rate and sintering temperature. At lower precursor flows, uniform Pd-Ga nanoparticles form, exhibiting stable Pd₅Ga₂ and Pd₂Ga phases. HRTEM and STEM-EDX analyses reveal that as precursor supply increases, Ga incorporation intensifies, leading to structural transitions, phase segregation, and the formation of PdGa dominated phases with amorphous Ga-rich domains, influencing nanoparticle shape and crystallinity. This process unlocks pathways for tailoring alloy compositions in-flight with low-melting point materials.

采用火花烧蚀与下游注入金属有机前驱体相结合的方法制备了具有可调成分的Pd-Ga合金纳米颗粒。这种双工艺方法可以通过调节前驱体流速和烧结温度来控制纳米颗粒的组成和形态。在较低的前驱体流量下，形成均匀的Pd-Ga纳米颗粒，表现出稳定的Pd5Ga2和Pd2Ga相。HRTEM和STEM-EDX分析表明，随着前驱体供应的增加，Ga掺入加剧，导致结构转变，相偏析，形成具有非晶富Ga域的PdGa主导相，影响纳米颗粒的形状和结晶度。这一过程为在飞行中使用低熔点材料定制合金成分开辟了途径。

引用次数: 0

Numerical simulation of aerosolised medicine delivery through tracheostomy airways 气管造口气管雾化给药的数值模拟

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-15 DOI: 10.1016/j.jaerosci.2025.106694

Monica Gumulya , Natalie V.E. Anderson , Ryan Mead-Hunter , Britta S. von Ungern-Sternberg , Benjamin J. Mullins

The administration of inhaled antibiotics to patients with upper or lower respiratory infections is sometimes conducted via a tracheostomy airway. However, precise dosing via this route remains uncertain, especially in spontaneously breathing paediatric patients. This study uses computational fluid dynamics (CFD) to explore the delivery of aerosolised medicine through an idealised tracheostomy tube, focussing on how droplet size distribution (polydispersity) and breathing flow conditions affect drug delivery efficiency. Unlike previous studies that incorporate elongated inlet and outlet sections to minimise flow disturbances, this work considers the compact geometry of tracheostomy tubes, demonstrating an earlier vortex formation around the inlet, resulting in an increased droplet deposition along the outer wall, closer to the inlet. As a result, the transfer efficiency,

η

(i.e. mass percentage of particles exiting the tracheostomy tube relative to the inlet rate), which decreases with increasing velocity, is found to be lower than those shown in other studies of 90° pipes. This efficiency further decreases with increased polydispersity of the inlet particles. The proportion of respirable droplets in the outlet stream is strongly influenced by the Mass Median Diameter (MMD) of the inlet. When the inlet MMD is 3.5 μm, the net transfer efficiency of respirable droplets,

η_{r e s p i r a b l e}

, is 50.3 %, with minimal variation across flow conditions. A lower inlet MMD of 2.2 μm yields higher

η_{r e s p i r a b l e}

values (64.9–87.7 %), although with greater sensitivity to flow and polydispersity. These findings offer new insights into optimising aerosol drug delivery through tracheostomy airways.

上呼吸道或下呼吸道感染患者吸入抗生素的管理有时是通过气管切开术进行的。然而，通过这种途径的精确给药仍然不确定，特别是在自主呼吸的儿科患者中。本研究使用计算流体动力学（CFD）来探索雾化药物通过理想的气管造口管的输送，重点关注液滴大小分布（多分散性）和呼吸流动条件如何影响药物输送效率。与之前的研究不同，该研究考虑了气管切开术管的紧凑几何形状，证明了在入口周围形成较早的涡流，导致液滴沿外壁沉积增加，靠近入口。因此，与其他90°管道的研究结果相比，随着速度的增加，传递效率η（即离开气管造口管的颗粒相对于入口速率的质量百分比）降低。该效率随着进口颗粒多分散性的增加而进一步降低。出口流中可呼吸飞沫的比例受进口质量中值直径（MMD）的强烈影响。当入口MMD为3.5 μm时，可呼吸飞沫的净传递效率为50.3%，不同流动条件下的变化最小。入口MMD为2.2 μm时，η呼吸值较高（64.9 ~ 87.7%），但对流动和多分散性的敏感性较高。这些发现为优化气管造口气道的气溶胶给药提供了新的见解。

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引用次数: 0

Quantification of human aerosol emission by measuring different breathing patterns 通过测量不同的呼吸方式来量化人类的气溶胶排放

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-13 DOI: 10.1016/j.jaerosci.2025.106680

Carl Firle , Asmus Meyer-Plath , Dierk-Christoph Pöther , Peter Kujath

The pandemic of SARS-CoV-2 asked for airborne transmission risk assessments in occupational and daily life situations. Some physical activities (singing, wind instrument playing, sport) seem to have higher infection risk than speaking or breathing.

We conducted an exploratory human study (n = 30; n_female = 13, n_male = 17) that assessed the aerosol emission per breath depending on breathing volume and inspiratory duration. The PExA instrument, “Particles in Exhaled Air 2.1” (PExA AB, Gothenburg, Sweden), was customized to measure inhalation flow rate. The instrument allows to simultaneously quantify breathing volumes and emitted aerosol particle concentrations using a Grimm 11-D aerosol spectrometer with size range 0.31 to >3.42 μm.

The results revealed a non-linear correlation of emitted aerosol particles on both breathing volume and inspiratory duration (

R_{V}^{2} = 0.55

). The logarithmised particle counts exhibit a sigmoidal dependence on breathing volume and a decay-like dependence on inspiratory duration. Error-weighted data fitting was used to determine the parameters of our model function and enables to predict the aerosol emission per breath.

The interpretation of the aerosol emission data strengthens the theory of bronchiole fluid film burst. It suggests that fluid film burst starts not in respiratory bronchioles as is generally assumed, but in upper bronchioles. The increase of intrathoracic pressure for higher breathing volume leads to dynamic compression of upper and terminal bronchioles, and thus to an increase in particle emission. Its exponential increase that became evident in our data can be explained by the bifurcative branching along the respiratory tree. This interpretation further refines the theory of particle formation in human respiratory tract. Our model provides a functional parametrization as a tool to predict human aerosol emission for a wide range of breathing conditions. It is considered a valuable tool for airborne risk assessments.

SARS-CoV-2大流行要求在职业和日常生活环境中进行空气传播风险评估。一些体力活动（唱歌、吹奏管乐器、运动）似乎比说话或呼吸有更高的感染风险。我们进行了一项探索性人体研究（n = 30; n = 13, n = 17），评估了每次呼吸的气溶胶排放取决于呼吸量和吸气时间。PExA仪器，“呼出空气中的颗粒2.1”（PExA AB，哥德堡，瑞典），是为测量吸入流速而定制的。该仪器可以同时量化呼吸量和排放的气溶胶颗粒浓度，使用格林11-D气溶胶光谱仪，尺寸范围为0.31至3.42 μm。结果表明，气溶胶颗粒的排放与呼吸量和吸气时间呈非线性相关（RV2=0.55）。对数粒子计数对呼吸量呈s型依赖性，对吸气时间呈衰减依赖性。误差加权数据拟合用于确定模型函数的参数，并能够预测每次呼吸的气溶胶排放。气溶胶发射数据的解释加强了细支气管液膜破裂理论。提示液膜破裂并非像一般认为的那样始于呼吸性细支气管，而是始于上细支气管。高呼吸量的胸内压力增加，导致上末细支气管的动态受压，从而导致颗粒排放增加。它的指数增长在我们的数据中变得明显，可以用呼吸树的分岔分支来解释。这一解释进一步完善了人类呼吸道颗粒形成的理论。我们的模型提供了一个功能参数化的工具，以预测人类气溶胶排放在大范围的呼吸条件。它被认为是空中风险评估的宝贵工具。

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引用次数: 0

Structural evolution during combustion of carbon nanoparticles generated by spark discharge 火花放电产生的碳纳米颗粒燃烧过程中的结构演变

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-11 DOI: 10.1016/j.jaerosci.2025.106690

A. Raiolo , N.P. Ivleva , C. Stockinger , U. Nieken

The oxidation behaviour of carbon nanoparticles generated by electrical discharge between two graphite electrodes (commonly referred to as spark discharge soot, SDS) is investigated and compared to that of nanoparticles originating from the incomplete combustion of organic fuels. Soot generated via a Combustion Aerosol Standard (CAST) soot generator and carbon black (CB) samples are taken as reference materials for the latter. By changing the carrier gas composition of the spark generator, carbon particles with varying reactivity and nanostructure can be obtained. SDS nanoparticles are considerably smaller, have much higher specific surface areas, and display a distinct nanostructure arrangement compared to CAST soot and CB. The evolution of the surface area with the extent of oxidation is tracked, showing that the surface area development of SDS is fundamentally different from that of CAST soot and CB. While the latter shows an extreme increase in the specific surface area during combustion, in comparison, the specific surface area increase of SDS is marginal. This information is crucial for anticipating the specific surface area gain achievable through partial oxidation, based on the initial morphology of the carbonaceous particles. The reactivity was found to correlate with Raman features. When analysing the evolution of the Raman spectra with oxidation, more reactive SDS showed a substantial increase in nanostructure order compared to the less reactive SDS and CAST soot.

研究了两个石墨电极之间放电产生的碳纳米颗粒（通常称为火花放电烟尘，SDS）的氧化行为，并将其与源自有机燃料不完全燃烧的纳米颗粒的氧化行为进行了比较。通过燃烧气溶胶标准（CAST）烟尘发生器产生的烟尘和炭黑（CB）样品作为后者的参考材料。通过改变火花发生器的载气组成，可以得到具有不同反应性和纳米结构的碳颗粒。与CAST烟尘和炭黑相比，SDS纳米颗粒体积更小，比表面积更高，并具有独特的纳米结构排列。跟踪了SDS的表面积随氧化程度的演变，表明SDS的表面积发展与CAST烟灰和CB的表面积发展有着根本的不同。后者在燃烧过程中比表面积急剧增加，相比之下，SDS的比表面积增加是微乎其微的。根据碳质颗粒的初始形态，这一信息对于预测通过部分氧化获得的比表面积增益至关重要。发现反应性与拉曼特征有关。当分析拉曼光谱随氧化的演变时，与活性较低的SDS和CAST烟灰相比，活性较高的SDS显示出纳米结构有序度的显著增加。

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引用次数: 0

Flash atomisation of saltwater through convergent-divergent nozzles: implications for marine cloud brightening 通过会聚-发散喷嘴的盐水闪蒸雾化：对海洋云增亮的影响

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-11 DOI: 10.1016/j.jaerosci.2025.106677

Chris Medcraft , Mohammadreza Sedighi , Luke Harrison , Wayne A. Davies , Zoran Ristovski , Daniel P. Harrison

The potential feasibility of Marine Cloud Brightening (MCB) is currently limited by the efficiency and practicalities of technologies to generate the required flux of correctly sized aerosol particles. We studied the aerosols formed by the spray from superheated salt water through two convergent-divergent (de Laval) nozzles between 5 nm and 50 μm dry aerosol diameter. We found that they do not produce more particles useful for MCB (30-100 nm) than currently deployed effervescent nozzles. A significant portion of the mass flow through these nozzles was contained in particles larger than 2 μm. However, the production rate from these de Laval nozzles appeared unaffected by the reduction of throat diameter despite a fourfold reduction in water flow and thus power usage.

海洋云增亮（MCB）的潜在可行性目前受到产生正确大小的气溶胶颗粒所需通量的技术的效率和实用性的限制。我们研究了过热盐水通过两个直径在5 nm到50 μm之间的聚散式（de Laval）喷嘴喷射形成的气溶胶。我们发现，与目前部署的泡腾喷嘴相比，它们不会产生更多对MCB （30-100 nm）有用的颗粒。通过这些喷嘴的质量流中有很大一部分包含在大于2 μm的颗粒中。然而，这些de Laval喷嘴的产量并未受到喉道直径减小的影响，尽管水流减少了四倍，从而减少了电力消耗。

引用次数: 0

Experimental investigation of aerosol separation in a rising Taylor bubble 上升泰勒气泡中气溶胶分离的实验研究

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-09 DOI: 10.1016/j.jaerosci.2025.106675

Rhandrey Maestri , Clemens Bilsing , Lars Büttner , Jürgen Czarske , Uwe Hampel , Gregory Lecrivain

Aerosol transport in rising air bubbles finds application in the removal of micro-pollutants from gases. Its theoretical investigation is mostly limited to small air bubbles because they remain spherical. For bubbles larger than a few centimeters, the gas-liquid interface oscillates in an unpredictable way. This affects the flow on both sides of the interface and ultimately the aerosol-to-liquid capture. We presently investigate aerosol separation in rising Taylor bubbles. Such bubbles have a highly reproducible elongated shape, easily extending to 20 cm in length, and are ideal candidates for model validation. Over one hundred separation experiments with an aerosol size ranging from 1 to

5 μ m

are presented. This regime, known as inertia-dominated, is of particular scientific interest because the aerosol transport is strongly dependent on the air flow inside the bubble. A simple and semi-analytical formulation reducing all our experimental results is proposed.

在上升的气泡中进行气溶胶输送，可用于去除气体中的微污染物。它的理论研究主要局限于小气泡，因为它们是球形的。对于大于几厘米的气泡，气液界面以不可预测的方式振荡。这影响了界面两侧的流动，并最终影响了气溶胶到液体的捕获。我们目前研究上升泰勒气泡中的气溶胶分离。这种气泡具有高度可复制的细长形状，很容易延伸到20厘米的长度，是模型验证的理想候选者。在1 ~ 5μm的气溶胶粒径范围内进行了一百多次分离实验。这种被称为惯性主导的状态具有特殊的科学意义，因为气溶胶的传输强烈依赖于气泡内的气流。提出了一个简化所有实验结果的简单半解析公式。

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引用次数: 0

Initial size distribution of cough particles for CFD simulations based on particle sizer measurements and evaporation model 基于粒径测量和蒸发模型的咳嗽颗粒初始粒径分布CFD模拟

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-07 DOI: 10.1016/j.jaerosci.2025.106678

Yunchen Bu , Hideki Kikumoto , Wonseok Oh , Chao Lin , Ryozo Ooka

Expiratory particles are known to be capable of carrying viruses that cause respiratory diseases. To predict exposure to these particles, computational fluid dynamics (CFD) simulations can be used, with the initial size distribution of particles as an important input parameter. This study aims to explore the appropriate initial size distribution of cough particles to enhance the prediction accuracy. A novel inference method is proposed, based on experimental measurements with an optical particle sizer and a CFD simulation. The CFD simulation employs the Lagrangian method to track the dispersion of cough particles, incorporating an evaporation model; thus, the response relationship between the initial size distribution and measurements can be established. In the previous experiment by the authors, the number concentration of cough particles (0.3–10 μm) was measured at distances ranging from 1 to 60 cm from the mouth. The CFD results provided the response relationship for particle size (shrinkage factor) and particle number (relative number) at different distances. Under the current model, particles with initial diameters less than 32 μm reached a quasi-equilibrium size at all distances, and the shrinkage factors were 0.26–0.27 under a relative humidity of 34 %. Consequently, the initial size distribution for cough particles can be determined using measurements at 30–60 cm from the mouth, along with CFD derived response relationships. This distribution has been verified for reliability and can be used to predict particle size distributions at interpersonal conversation distances. In addition, this study further investigates the necessity of integrating the evaporation model into predictions of particle exposure. The results show that adding the evaporation model in CFD simulations has little impact on the predicted exposed particle number concentration. However, it significantly affects the predicted exposed particle size, which in turn influences the exposure to cough particles.

众所周知，呼气颗粒能够携带导致呼吸道疾病的病毒。为了预测这些颗粒的暴露，可以使用计算流体动力学（CFD）模拟，将颗粒的初始尺寸分布作为重要的输入参数。本研究旨在探索合适的咳嗽颗粒初始大小分布，以提高预测精度。基于光学粒度仪的实验测量和CFD模拟，提出了一种新的推断方法。CFD模拟采用拉格朗日方法跟踪咳嗽颗粒的扩散，并结合蒸发模型；由此可以建立初始尺寸分布与测量值之间的响应关系。在作者之前的实验中，在距离口腔1到60厘米的距离上测量了咳嗽颗粒（0.3-10 μm）的数量浓度。CFD计算结果给出了不同距离下颗粒尺寸（收缩系数）和颗粒数量（相对数量）的响应关系。在当前模型下，初始直径小于32 μm的颗粒在所有距离上均达到准平衡尺寸，相对湿度为34%时，收缩系数为0.26 ~ 0.27。因此，咳嗽颗粒的初始大小分布可以通过距离口腔30-60 cm的测量以及CFD推导的响应关系来确定。这种分布的可靠性已得到验证，并可用于预测人际交谈距离的粒径分布。此外，本研究进一步探讨了将蒸发模型整合到粒子暴露预测中的必要性。结果表明，在CFD模拟中加入蒸发模型对预测暴露粒子数浓度影响不大。然而，它显著影响预测的暴露颗粒大小，这反过来又影响咳嗽颗粒的暴露。

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引用次数: 0

In situ and on-line measurement of soot size using the light-based method 利用光基法对煤烟粒径进行原位和在线测量

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-04 DOI: 10.1016/j.jaerosci.2025.106679

Jingjing Xia , Chaohao Yang , Jin Zeng

In situ and on-line measurement of soot's particle size distribution (PSD) is crucial for comprehending its physical and chemical properties. The non-contact nature and high sensitivity of optical techniques have led to their widespread adoption in soot characterization. To overcome the computational burden associated with modeling fractal structures, this study utilizes the discrete dipole approximation (DDA) to represent soot as ellipsoids. Meanwhile, a miniaturized prototype sensor was utilized to collect the light scattering phase function (LSPF), providing sufficient optical information to retrieve soot's PSD. Experiments with Di-Ethyl-Hexyl-Sebacate (DEHS) demonstrated that the prototype sensor can accurately collect the LSPF, with a maximum relative error (RE) below 15 %. The Kullback-Leibler divergence (D_KL) of the PSD retrieved by the hybrid iterative inversion algorithm that was proposed in this study is no larger than 0.05. Further testing with open-flame combustion confirmed that the method proposed in this study can accurately sense soot's PSD and decouple its ovality parameter (OP). The method proposed in this study exhibits significant potential for in situ and on-line measurement of soot's PSD and provides a reliable framework for characterizing irregular particles.

现场和在线测量煤烟的粒径分布对了解煤烟的物理化学性质至关重要。光学技术的非接触性质和高灵敏度使其在烟灰表征中得到广泛应用。为了克服分形结构建模的计算负担，本研究利用离散偶极子近似（DDA）将烟灰表示为椭球。同时，利用小型化原型传感器采集光散射相位函数（LSPF），为提取烟尘的PSD提供充分的光学信息。用二乙基己基癸酸酯（DEHS）进行的实验表明，该传感器能够准确地采集LSPF，最大相对误差（RE）在15%以下。本文提出的混合迭代反演算法反演的PSD的Kullback-Leibler散度（DKL）不大于0.05。明火燃烧实验进一步验证了该方法能够准确地感知烟尘的PSD并解耦其椭圆度参数（OP）。本研究提出的方法在现场和在线测量烟尘的PSD方面具有重要的潜力，并为表征不规则颗粒提供了可靠的框架。

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引用次数: 0

Correlation of optical properties with particle size, morphology, and polymorph of fine- and nano-particle formulations of titanium dioxide powders 二氧化钛粉末的光学性质与颗粒大小、形貌和多晶型的关系

IF 2.9 3区环境科学与生态学 Q2 ENGINEERING, CHEMICAL

Journal of Aerosol Science

Pub Date : 2025-09-04 DOI: 10.1016/j.jaerosci.2025.106676

Schuyler P. Lockwood, Zezhen Cheng, Valentina Sola, Nurun Nahar Lata, Tanya L. Myers, Timothy J. Johnson, Mark E. Bowden, Alla Zelenyuk

Titanium dioxide (TiO₂) particulates are known to exhibit different visible and infrared optical properties compared to the bulk material, showing strong dependence on particle size, crystal structure, and morphology. In this study, the optical properties, sizes, and morphologies of TiO₂ particles from two different sources (nano and fine powders) having a) nominally different particle sizes and b) various crystal polymorph mixture fractions are compared using a combination of single particle mass spectrometry, optical spectroscopies, and aerosol characterization methods. The nano sample was found to be largely particles of the anatase polymorph (88% by mass), while the fine sample was found to consist largely of rutile particles (95% by mass). Two distinct particle morphologies (fractal and compact) were found in each powder sample and could be identified and separated in-situ based on particle aerodynamic properties. The attenuation of near-infrared, visible and ultraviolet light by TiO₂ particles shows strong dependence on particle morphology. While the fine particles were found to have larger near-infrared (675–800 nm) extinction coefficients by mass than the nanoparticles, the reverse was true in the ultraviolet and visible regions (370–675 nm). However, for polydisperse particles with different sizes and shapes, the optical behaviors are not straightforward to directly correlate to a combination of physical parameters.

众所周知，二氧化钛（TiO2）颗粒与大块材料相比，具有不同的可见光和红外光学性能，对颗粒大小、晶体结构和形貌有很强的依赖性。在本研究中，采用单粒子质谱、光谱学和气溶胶表征方法，比较了a)名义上粒径不同的两种不同来源（纳米粉末和细粉末）和b)不同晶体多晶混合物组分的TiO2颗粒的光学性质、尺寸和形貌。纳米样品主要由锐钛矿多晶颗粒组成（88%的质量），而细样品主要由金红石颗粒组成（95%的质量）。每个粉末样品中都有两种不同的颗粒形态（分形和致密），可以根据颗粒的空气动力学特性进行原位识别和分离。TiO2粒子对近红外光、可见光和紫外光的衰减与粒子形态有很强的依赖性。细颗粒在近红外波段（675-800 nm）的消光系数比纳米颗粒大，而在紫外和可见光波段（370-675 nm）的消光系数则相反。然而，对于不同尺寸和形状的多分散粒子，光学行为并不是直接与物理参数的组合相关联的。

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引用次数: 0