Aging mechanisms of perfluorocarbon emulsions using image analysis

Freire, Mara G.; Dias, Ana M.A.; Coelho, Maria Alice Zarur; Coutinho, João A. P.; Marrucho, Isabel M.

doi:10.1016/j.jcis.2004.12.036

Cited by 73 publications

(123 citation statements)

References 33 publications

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“…14 PFH (56°C boiling point) was used instead of the more commonly used perfluoropentane (PFP, 29°C boiling point) as micron-scale PFH droplets are more stable and are less likely to spontaneously vaporize at the temperatures used in these experiments compared to PFP droplets. 35,36 Moreover, the sound speed of bulk PFP could not be measured at 36°C as it is over the boiling point of 29°C, and it would be difficult to use the theoretical photoacoustic equations. The sound speed of bulk PFH has been previously measured at the frequencies and temperatures used.…”

Section: Pfc Emulsionsmentioning

confidence: 99%

Acoustic and photoacoustic characterization of micron-sized perfluorocarbon emulsions

et al. 2012

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Abstract. Perfluorocarbon droplets containing nanoparticles (NPs) have recently been investigated as theranostic and dual-mode contrast agents. These droplets can be vaporized via laser irradiation or used as photoacoustic contrast agents below the vaporization threshold. This study investigates the photoacoustic mechanism of NPloaded droplets using photoacoustic frequencies between 100 and 1000 MHz, where distinct spectral features are observed that are related to the droplet composition. The measured photoacoustic spectrum from NP-loaded perfluorocarbon droplets was compared to a theoretical model that assumes a homogenous liquid. Good agreement in the location of the spectral features was observed, which suggests the NPs act primarily as optical absorbers to induce thermal expansion of the droplet as a single homogenous object. The NP size and composition do not affect the photoacoustic spectrum; therefore, the photoacoustic signal can be maximized by optimizing the NP optical absorbing properties. To confirm the theoretical parameters in the model, photoacoustic, ultrasonic, and optical methods were used to estimate the droplet diameter. Photoacoustic and ultrasonic methods agreed to within 1.4%, while the optical measurement was 8.5% higher; this difference decreased with increasing droplet size. The small discrepancy may be attributed to the difficulty in observing the small droplets through the partially translucent phantom.

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Section: Pfc Emulsionsmentioning

confidence: 99%

Acoustic and photoacoustic characterization of micron-sized perfluorocarbon emulsions

et al. 2012

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“…6 In biomedical applications, they are used as agents for drug delivery, anti-tumural agents, diagnostic imaging agents, and as in vivo gas carriers in liquid ventilation or blood substitute formulations. [7][8][9] The perfluorooctylbromide and perfluorodichlorooctane are replacing the perfluorinated compounds in the formulation of artificial blood substitutes. They are currently used on the Oxygent from Alliance Pharmaceutical Corporation and Oxyfluor from Hemogen, since both allow the development of emulsions with higher concentrations of fluorocarbon compounds, thus increasing their oxygencarrying capability.…”

Section: Introductionmentioning

confidence: 99%

“…8,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] The study of water solubility is of particular interest, since the solvation properties and the molecular interactions of fluorocompounds with water are important to understand the FC-in-water or reversed emulsions formation and aging. 9,[25][26][27][28] The objective of the present work is to provide experimental and theoretical information about the unlike water-FC compound molecular interactions and to evaluate the effect of R-(ω-)fluorine substitution by H, Cl, Br, and I on this interaction. For that purpose, experimental solubility data were precisely measured by Karl Fischer titration of the water in saturated fluorocarbon-rich phases, in a sufficiently large temperature range in order to allow the calculation of the thermodynamic quantities associated with the dissolution.…”

Section: Introductionmentioning

confidence: 99%

Water Solubility in Linear Fluoroalkanes Used in Blood Substitute Formulations

et al. 2006

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The interactions between water and n-perfluoroalkanes or substituted R-(ω-)fluoroalkanes used in blood substitute formulations were investigated experimentally and using ab initio calculations. The solubility of water in C 6 -C 9 perfluoroalkanes and five C 8 analogues of substituted fluoroalkanes was measured in the temperature range between 288 and 318 K at atmospheric pressure, using a Karl Fischer coulometer. From these data, the thermodynamic functions and partial molar solvation quantities such as Gibbs energy, enthalpy, and entropy were determined and compared with the interaction energies in 1:1 water-fluoroalkane complexes in vacuum, obtained using B3LYP/6-311++G(d,p). The experimental solubility data indicates a significant specific interaction between the water and the R-(ω-)substitute atom (H, I, Br, or Cl) in the fluoroalkanes.

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“…Besides, traditionally polymerization of HIPEs was initiated by heating the emulsion system. However, high temperature would destabilize the HIPE by enhancing the Ostwald ripening and coalescence in the emulsion [6].…”

Section: Introductionmentioning

confidence: 99%

Aligned Porous Beads Prepared by Frozen Polymerization of Emulsion-Templates Involving Tiny Emulsifier

et al. 2016

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Abstract. High internal phase emulsion (HIPE) templated porous materials are attracting increasing interests due to its high porosity and tunable structure. However, large amounts (5-50 vol%) of suitable non-ionic surfactants are commonly required to stabilize conventional HIPE due to the high internal volume fraction of HIPE. In this work, applying frozen polymerization in HIPE, aligned porous beads were prepared with tiny surfactant (~0.1 wt%). These interconnected aligned porous beads were prepared through directional freezing, and frozen ultraviolet (UV) initiation of an oil-in-water (o/w) HIPE. The HIPEs are extruded by needle, and then directionally frozen in liquid nitrogen to form beads. The frozen beads were exposed under UV irradiation in a -20 ºC ethanol bath to initiate the monomers in the aqueous phase. Moreover, the morphology of the resulting porous beads were tailored by vary the ratio of oil/water and the amount of emulsifier.

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Aging mechanisms of perfluorocarbon emulsions using image analysis

Cited by 73 publications

References 33 publications

Acoustic and photoacoustic characterization of micron-sized perfluorocarbon emulsions

Acoustic and photoacoustic characterization of micron-sized perfluorocarbon emulsions

Water Solubility in Linear Fluoroalkanes Used in Blood Substitute Formulations

Aligned Porous Beads Prepared by Frozen Polymerization of Emulsion-Templates Involving Tiny Emulsifier

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