Constant-current corona charging of biaxially stretched PVDF films in humidity-controlled atmospheres

Ribeiro, Paulo A.; Raposo, Maria; Marat-Mendes, J.N.; Giacometti, J.A.

doi:10.1109/14.155791

Cited by 24 publications

(15 citation statements)

References 23 publications

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“…3 but hold the following constant: RH = 70 %; T = 298 K; NO 2 = 0.3 ppb; NO = 0.05 ppb; isoprene = 5 ppb; OH = 1.5 × 10 6 molec. cm −3 ; CO = 135 ppb; O 3 = 37 ppb; and HO 2 = 25 ppt (Sanchez et al, 2018;Feiner et al, 2016;Pajunoja et al, 2016). Then gas-phase HMML and the gas-phase dinitrate SOA precursors are simulated as done for the experimental results in Fig.…”

Section: Estimating the Atmospheric Contribution Of The LV Versus 2mgmentioning

confidence: 99%

“…Thus, based on the simple calculations summarized above, the LV pathway may produce moderately more SOA mass than the 2MGA pathway in the atmosphere and consequently deserves equal attention. The conditions chosen here represent average atmospheric conditions around noon as measured during the Southern Oxidant and Aerosol Study (SOAS) field campaign, which occurred in the isoprenerich southeastern United States (Sanchez et al, 2018;Feiner et al, 2016;Pajunoja et al, 2016). A more complete assessment using global and regional modeling is needed to more definitively determine the fraction of SOA formed via the LV versus 2MGA pathways as location, time of day, season, ambient aerosol concentration, and composition, etc.…”

Section: Estimating the Atmospheric Contribution Of The LV Versus 2mgmentioning

confidence: 99%

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Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NOx conditions

et al. 2019

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Abstract. Recent advances in our knowledge of the gas-phase oxidation of isoprene, the impact of chamber walls on secondary organic aerosol (SOA) mass yields, and aerosol measurement analysis techniques warrant reevaluating SOA yields from isoprene. In particular, SOA from isoprene oxidation under high-NOx conditions forms via two major pathways: (1) low-volatility nitrates and dinitrates (LV pathway) and (2) hydroxymethyl-methyl-α-lactone (HMML) reaction on a surface or the condensed phase of particles to form 2-methyl glyceric acid and its oligomers (2MGA pathway). These SOA production pathways respond differently to reaction conditions. Past chamber experiments generated SOA with varying contributions from these two unique pathways, leading to results that are difficult to interpret. This study examines the SOA yields from these two pathways independently, which improves the interpretation of previous results and provides further understanding of the relevance of chamber SOA yields to the atmosphere and regional or global modeling. Results suggest that low-volatility nitrates and dinitrates produce significantly more aerosol than previously thought; the experimentally measured SOA mass yield from the LV pathway is ∼0.15. Sufficient seed surface area at the start of the reaction is needed to limit the effects of vapor wall losses of low-volatility compounds and accurately measure the complete SOA mass yield. Under dry conditions, substantial amounts of SOA are formed from HMML ring-opening reactions with inorganic ions and HMML organic oligomerization processes. However, the lactone organic oligomerization reactions are suppressed under more atmospherically relevant humidity levels, where hydration of the lactone is more competitive. This limits the SOA formation potential from the 2MGA pathway to HMML ring-opening reactions with water or inorganic ions under typical atmospheric conditions. The isoprene SOA mass yield from the LV pathway measured in this work is significantly higher than previous studies have reported, suggesting that low-volatility compounds such as organic nitrates and dinitrates may contribute to isoprene SOA under high-NOx conditions significantly more than previously thought and thus deserve continued study.

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Section: Estimating the Atmospheric Contribution Of The LV Versus 2mgmentioning

confidence: 99%

Section: Estimating the Atmospheric Contribution Of The LV Versus 2mgmentioning

confidence: 99%

Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NOx conditions

et al. 2019

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“…PTFE Teflon has fluoride atoms bound to carbon atoms; FEP Teflon has both fluoride atoms and trifluoromethyl groups bound to carbon atoms, whereas PVDF films consist of hydrogen and fluoride atoms bound to carbon atoms. Therefore, while it is possible that the relative humidity effect is unique to PVDF films, the Ribeiro et al (1992) study suggests that it is possible, if not probable, that increasing the relative humidity surrounding a chamber will decrease the chamber's surface charge. Figure 10a shows dynamics of the total number concentration of inorganic particles subject to simultaneous coagulation and wall deposition for experiments that began with approximately the same number distribution and are aligned at a common number concentration (as verified in the displayed size distribution in Figure 10b).…”

Section: Wall Deposition Methods 2: Humidity Effects On Static Chargementioning

confidence: 98%

“…A study of the effect of humidity on the corona charging of polyvinylidenefluoride (PVDF) films, similar in structure to FEP Teflon, shows a linear decrease in the maximum voltage generated with an increase in relative humidity and, furthermore, that increasing the relative humidity decreases the surface potential even for a film that is already charged (Ribeiro et al 1992). Ribeiro et al (1992) postulate this is a result of dissociated absorbed water on the film surface.…”

Section: Wall Deposition Methods 2: Humidity Effects On Static Chargementioning

confidence: 99%

Effect of particle charge on aerosol dynamics in Teflon environmental chambers

Charan

Kong

Flagan

et al. 2018

Aerosol Science and Technology

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The contribution of particle charge to the rate of particle wall deposition has been a persistent source of uncertainty for experiments performed in environmental chambers. By tracking the preferential deposition of positively charged particles; by comparing experiments carried out under standard, humid, and highly statically charged conditions; and by performing two-parameter optimizations for the chamber eddy-diffusion coefficient (k e) and the average magnitude of the electric field (E), the effect of charge on the rate of particle-wall deposition is isolated. A combined experimental and computational method is also developed for determining values for k e and E within a FEP Teflon chamber. To fully account for the effects of charge on particle dynamics in environmental chambers, studies of the effect of air ion concentration on the rate of particle coagulation over a typical 20 h experiment are performed and demonstrated, in general, that particle charge is negligible for characteristic chamber ion concentrations. While the effect of particle charge on aerosol dynamics in an environmental chamber must be addressed for each specific chamber, we demonstrate experimentally that for the Caltech 19 m 3 Environmental Chamber, charge effects on the rate of particle-wall deposition are negligible.

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“…Temperature variations at poling affect the corona onset voltage, ion mobility, and, as a result, the V gap responsible for inaccuracies of the value of sample surface potential measured by this method. Versions of constant current corona triode poling setups [29][30][31][32][33][34][35][36][37] have been used in studies of polymer orientation, and their possible usage for poling NLO and HGP samples is still being examined [38,39]. As far as we know, the first system for measuring potential difference across a thin insulating film during the corona discharge has been reported by Weinberg [40].…”

Section: Methods and Techniques For Positive Corona Poling Of Polymermentioning

confidence: 99%

Chromofore Poling in Thin Films of Organic Glasses. 1. Overview of Corona Discharge Application

Vilitis¹,

Fonavs²,

Rutkis³

2011

Latvian Journal of Physics and Technical Sciences

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The introductory article in a series of works on the chromofore poling in thin films of organic glasses presents an overview of corona discharge applications, with a brief excursion into physics of the phenomenon. The authors consider this technique as related to the nonlinear optical (NLO) polymers. Its key points are as follows.In the ambient air such discharge is strongly affected by variable humidity and, consequently, uncertain concentration of the predominant charge carrier ((H 2 O) n H + ). To realize a repeatable poling process the composition of discharge atmosphere should be controlled (e.g. for pure nitrogen gas). In the case of discharge in N 2 the highly reactive ozone production could be avoided. To obtain second-order nonlinear activity of polymeric materials, a simple point/plane (two-electrode) technique of corona charging is successfully applied, which however does not provide information about the sample surface charge buildup and the efficiency of poling process. To study the dynamics of both the poling and the charge transport processes a three-electrode charging system -the corona triode − should be used.

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Constant-current corona charging of biaxially stretched PVDF films in humidity-controlled atmospheres

Cited by 24 publications

References 23 publications

Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NO<sub><i>x</i></sub> conditions

Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NO<sub><i>x</i></sub> conditions

Effect of particle charge on aerosol dynamics in Teflon environmental chambers

Chromofore Poling in Thin Films of Organic Glasses. 1. Overview of Corona Discharge Application

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Constant-current corona charging of biaxially stretched PVDF films in humidity-controlled atmospheres

Cited by 24 publications

References 23 publications

Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; conditions

Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; conditions

Effect of particle charge on aerosol dynamics in Teflon environmental chambers

Chromofore Poling in Thin Films of Organic Glasses. 1. Overview of Corona Discharge Application

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Product

Resources

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Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NO<sub><i>x</i></sub> conditions

Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NO<sub><i>x</i></sub> conditions