Electrification phenomena of pure water droplets dripping and sliding on a polymer surface

Self-cleaning hybrid energy harvester to generate power from raindrop and sunlight

“…Based on this mechanism, most research on TENGs has focused on harvesting ambient mechanical energy types such as vibrations [21][22][23], air flows [24,25] and the mechanical energy of water [26,27]. On the other hand, water-solid interaction also causes triboelectricity with the formation of an electrical double layer (EDL) [28][29][30][31][32]. Using water as a charging material directly, a TENG can harvest water energy (water-TENG) based on a fairly simple structure consisting of one electrode and one solid material [19,20].…”

Effect of moisture on the electrostatic charge properties of metered dose inhaler aerosols

“…Firstly, the added water may increase the electrical conductivity of the propellant, which would suppress charging. This inverse relationship between conductivity and charging has been reported for organic (Dacre & Hetherington, 1998) and aqueous (Rosell, Gonda, Schuster, & Liu, 2002;Vaaraslahti, Laitinen, & Keskinen, 2002;Yatsuzuka, Higashiyama, & Asano, 1996;Yatsuzuka et al, 1994) liquids. However, it is unlikely that the minute amounts of spiked water added would have affected the bulk properties sufficiently to produce the effects observed through this mechanism.…”

“…This might be the basis for the preferred charge polarity of the propellants. The anion attracting ability of fluorine atoms was also alluded to by Yatsuzuka, Mizuno, & Asano (1994) in the discussion on the negative charging of Teflon after contact with water droplets. Furthermore, HFA-134a is more polar than 227ea (dipole moment 2.058 vs. 0.93 debye; dielectric constant 9.5 vs. 4.1) (Jones et al, 2006;Solvay Fluor, 2004).…”

Electrostatics of pharmaceutical inhalation aerosols

“…The specific charge, expressed as the net charge per unit volume of sprayed liquid, was found to be inversely related to the electrical conductivity of, and hence the concentration of ionic species in, the liquid. [65] This effect of conductivity on charging was also observed by Yatsuzuka et al [61,62] The inverse relationship between ionic concentration and resultant charges on atomised droplets was exploited to suppress the charging of inhalation aerosols produced from a novel atomiser, AERx. [66] The rationale for reducing aerosol charging is to avoid premature droplet deposition in the oropharynx during inhalation.…”

“…This is because charge separation occurs when a liquid surface is disrupted during atomisation [57][58][59][60] or when a liquid flows against a solid surface. [61,62] Droplets of an unknown liquid nebulised from an Inspiron Mini-Neb nebuliser were found to contain bipolar charges using an ion mobility analyser. [63] The charge production rate and the ratio of positive-to-negative charges also increased with the compressed air flow rate.…”