Nanometer coating on aerosol particles

Kousaka, Yasuo; Endo, Yoshiyuki; Alonso, M.; Ichitsubo, Hirokazu; Fukui, Atsushi

doi:10.1016/s0921-8831(08)60544-0

Cited by 13 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The aggregates restructured only after the droplets were allowed to evaporate. Following a previous work, we speculate that for a nonwetting liquid with high surface tension, such as water, it is possible that at such high supersaturations vapor condensation on hydrophobic soot occurs as heterogeneous nucleation on a favorable location, such as a surface defect. Preferential condensation on the defect causes the water nucleus to grow rapidly outward from that point until the aggregate is engulfed.…”

Section: Resultssupporting

confidence: 61%

Vapor Condensation and Coating Evaporation Are Both Responsible for Soot Aggregate Restructuring

Enekwizu

Hasani

Khalizov

2021

Environ. Sci. Technol.

View full text Add to dashboard Cite

Fresh soot is made of fractal aggregates, which often appear collapsed in atmospheric samples. A body of work has concluded that the collapse is caused by liquid shells when they form by vapor condensation around soot aggregates. However, some recent studies argue that soot remains fractal even when engulfed by the shells, collapsing only when the shells evaporate. To reconcile this disagreement, we investigated soot restructuring under conditions ranging from capillary condensation to full encapsulation, also including condensate evaporation. In these experiments, airborne fractal aggregates were exposed to vapors of wetting liquids, and particle size was measured before and after coating loss, allowing us to isolate the contribution from condensation toward restructuring. We show the existence of three distinct regions along the path connecting the initial fractal and final collapsed aggregates, where minor restructuring occurs already at zero vapor supersaturation due to capillary condensation. Increasing supersaturation increases the amount of condensate, producing a more notable aggregate shrinkage. At even higher supersaturations, the aggregates become encapsulated, and subsequent condensate evaporation leaves behind fully compacted aggregates. Hence, for wetting liquids, minor restructuring begins already during capillary condensation and significant restructuring occurs as the coating volume increases. However, at this time, we cannot precisely quantify the contribution of condensate evaporation to the full aggregate compaction.

show abstract

Section: Resultssupporting

confidence: 61%

Vapor Condensation and Coating Evaporation Are Both Responsible for Soot Aggregate Restructuring

Enekwizu

Hasani

Khalizov

2021

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…For DEHS, the required temperature was between 90 and 115 • C for coating layers between 10 and 150 nm, respectively. A similar system for coating with organic substances has been tried and was found to be efficient and accurate (Kousaka et al, 1995).…”

Section: Coating Of Seed Aerosolmentioning

confidence: 99%

Extinction efficiencies of coated absorbing aerosols measured by cavity ring down aerosol spectrometry

et al. 2008

View full text Add to dashboard Cite

Abstract. In this study, we measure the extinction efficiency at 532 nm of absorbing aerosol particles coated with a nonabsorbing solid and liquid organic shell with coating thickness varying between 5 and 100 nm using cavity ring down aerosol spectrometry. For this purpose, we use nigrosin, an organic black dye, as a model absorbing core and two nonabsorbing organic substances as shells, glutaric acid (GA) and Di-Ethyl-Hexyl-Sebacate (DEHS). The measured behavior of the coated particles is consistent with Mie calculations of core-shell particles. Errors between measured and calculated values for nigrosin coated with GA and DEHS are between 0.5% and 10.5% and between 0.5% and 9%, respectively. However, it is evident that the calculations are in better agreement with the measured results for thinner coatings. Possible reasons for these discrepancies are discussed.

show abstract

“…Therefore, it appears to be more practical to coat the nanocrystals on commercially available particles such as alumina, silica, PMMA (poly-methylmethacrylate), which are core particles in this study with materials of interest to realize the desired nanofunctional properties. Moreover, the reproduction of the exact stoichiometry in the particulate coating is very difficult if more commonly used techniques such as sputtering, thermal evaporation, or e-beam evaporation are applied [15,16].…”

Section: Introductionmentioning

confidence: 99%

Quantum Confinement of GaAs Nanocrystals Deposited on PMMA Microspheres Using Pulsed Laser Ablation

Ryu

Kweon

Lee

et al. 2013

AMR

View full text Add to dashboard Cite

A modified pulsed laser deposition (PLD) was employed to deposit GaAs nanocrystals on the surface of PMMA microspheres. This novel approach is distinguished by the fact that laser ablated materials are deposited uniformly onto the surface of spherical particles that are held constantly in a particle fludization unit. The XRD, SEM, EDX, TEM, EDP and PL results confirmed that cubic structured GaAs nanocrystals were deposited uniformly on the surface of PMMA microspheres with an average diameter of about 15 nm.

show abstract

Nanometer coating on aerosol particles

Cited by 13 publications

References 7 publications

Vapor Condensation and Coating Evaporation Are Both Responsible for Soot Aggregate Restructuring

Vapor Condensation and Coating Evaporation Are Both Responsible for Soot Aggregate Restructuring

Extinction efficiencies of coated absorbing aerosols measured by cavity ring down aerosol spectrometry

Quantum Confinement of GaAs Nanocrystals Deposited on PMMA Microspheres Using Pulsed Laser Ablation

Contact Info

Product

Resources

About