Triboelectric Energy Harvesting of the Superhydrophobic Coating from Dropping Water

In this paper, the superhydrophobic coating was prepared by spraying the composites of fluorocarbon emulsion and nanosized silica on the conductive glass sheet for the triboelectric energy harvesting from water droplets. The low surface energy of fluorine in the fluorocarbon emulsion and nanosilica renders the coating with the static contact angle and sliding angle of 156.2° and 6.74°, respectively. The conductive aluminum tape was attached on the surface of the superhydrophobic coating to complete the circuit constituted with the aluminum electrode, charged superhydrophobic coating, and the conductive glass sheet. During the contact electrification with the bouncing water droplet, the superhydrophobic coating with the aluminum electrode can obtain the electric energy with an open-circuit voltage of 20 V and short-circuit current of 4.5 μA, respectively. While the control device only produced an open-circuit voltage of 0.2 V. The generated power by one drop was enough to light up 16 commercial LEDs. Results demonstrate that the fluorocarbon/silica composite superhydrophobic coating is potentially a strong candidate for scavenging energy in sliding mode from raindrops.

Preparation and Characterization of Core-Shell Type Versatate-Fluorocarbon Emulsion

Versatate-fluorocarbon emulsion with core-shell structure was synthesized by seeded emulsion polymerization using versatate, organic fluorine and acrylate as raw materials. The influences of amount of organic fluorine and versatate, core-shell ratio on the properties of emulsion were discussed. The emulsion was characterized with contact angle analyzer, particle size, transmission electron microscopy (TEM), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The results showed that the emulsion had good properties while w(organic fluorine)=6%, w(versatate)=8%, soft core-hard shell and w(core):w(shell)=3:2. The particle size is 110nm and with core-shell structure. The contact angle of emulsion film to water is 98.1º. The synergistic effect of versatate and fluorocarbon based on core-shell structure improve the over-all properties effectively.

Microvascular gas embolization clearance following perfluorocarbon administration

Effective treatment of vascular gas embolism may be possible with emulsified fluorocarbon compounds. We tested the hypothesis that a fluorocarbon emulsion delivered before gas embolization would enhance bubble motion through the vasculature, favoring more rapid clearance. Air microbubbles were injected into the rat cremaster microcirculation in six groups of rats receiving Perftoran, an emulsified fluorocarbon, or saline immediately before, 2 h before, or after bubble injection. Embolism dimensions and dynamics were observed by using intravital microscopy. Surface area at lodging was equal between groups. Bubbles having smaller volume embolized smaller diameter vessels in the Perftoran pretreatment groups. A higher incidence of bubble dislodgement and larger distal displacement occurred in these two groups, with a 36% decrease in the time to bubble clearance and restoration of blood flow. Intravascular emulsified fluorocarbon administration before gas embolization affected initial bubble conformation, increased bubble dislodgement, and resulted in bubble displacement further into the periphery of the microcirculation. These dynamic events did not occur if embolization preceded fluorocarbon administration.

Ameliorating effects of fluorocarbon emulsion on sickle red blood cell–induced obstruction in an ex vivo vasculature

In sickle cell (SS) vaso-occlusion, the culminating event is blockage of blood vessels by sickled red blood cells (SS RBCs). As shown in animal models, SS RBC-induced vaso-occlusion is often partial, allowing for a residual flow, hence oxygen delivery to partially occluded vessels could reduce vaso-occlusion. The efficacy of an oxygenated perflubron-based fluorocarbon emulsion (PFE) was tested for its anti–vaso-occlusive effects in the ex vivo mesocecum vasculature of the rat. Microvascular obstruction was induced by the infusion of deoxygenated SS RBCs into ex vivo preparations with or without pretreatment with platelet-activating factor (PAF). PAF induced enhanced SS RBC–endothelium interactions, leading to greater vaso-occlusion. Microvascular blockage resulted in increased peripheral resistance units (PRU). Deoxygenated SS RBCs caused a persistent 1.5-fold PRU increase in untreated preparations and approximately a 2-fold PRU increase in PAF-treated preparations. The greater PRU in PAF-treated preparations was caused by widespread adhesion and postcapillary blockage. Oxygenated PFE, but not deoxygenated PFE, resulted in PRU decreases to baseline values in both groups of experiments (with or without PAF). The PRU decrease caused by oxygenated PFE infusion was caused by unsickling of SS RBCs in partially occluded vessels, with no antiadhesive effect on already adherent SS RBCs as assessed by intravital microscopy. PFE had no effect on vascular tone. The efficacy of PFE appears to result from its greater capacity to dissolve oxygen (10-fold higher than plasma). The dislodgement of trapped SS RBCs and an increase in wall shear rates will help reverse the partial obstruction. Thus, oxygenated PFE is capable of reducing SS RBC-induced vaso-occlusion, and further development of this approach is advisable.