Maio 2014 vol. 1 num. 1 - 10th World Congress on Computational Mechanics
Full Article - Open Access.
Numerical Computation of Cone-Jet Formation and Deposition Characteristics in Electrostatic Spray
Wei Wei, Sheng Wang*; Kase, Kiwamu; Tajima, Yusuke; Orii, Takaaki; Takaku, Hideaki; Imai, Noboru; Yamagata, Jungmyoung Ju Andamp; Yutaka;
Electrospray deposition (ESD) is a method to fabricate thin films of micro/nanoparticles directly from solution. It has been used in various processes including sample preparation in mass spectrometry, polymer coatings, organic film formation in solar cells, fuel cells and ink-jet printing. In this study a comprehensive ESD simulation methodology consisting of two solvers, i.e., Solver 1 for cone-jet formation and droplet generation modeling, and Solver 2 for droplet trajectory tracking and deposition characteristic calculations was developed. Without the assumption of the initial cone shape, the fluid flow equation and electric field distribution equation were solved simultaneously to obtain the evolution of cone-jet and droplets emitted from the cone-jet tip under different operation conditions. Based on the droplet characteristics from Solver 1, the trajectory and deposition characteristics of droplet/particle were investigated by using Solver 2 with a three dimensional Lagrangian model. In order to verify the validity of the proposed simulation methodology, ESD experiments were carried out. Various organic solvents were sprayed by using the ESD technique to investigate the effects of the applied voltage and the properties of the solvent to the deposition characteristics. The deposition area of the sprayed organic droplets was observed by using a CCD camera. The experimental data and the numerical results are consistent in the deposition characteristics. The method proposed in this study will be very helpful for fabricating thin films of micro/nanoparticles with ESD.
Palavras-chave: Electrospray deposition, Cone-jet formation, Deposition characteristics, Numerical simulation,
-  Fenn J., et al., "Electrospray ionization for mass spectrometry of large biomolecules". Science.246, 64-71, 1989.
-  Guerrero I., et al., "Ion evaporation from Taylor cones of propylene carbonate mixed with ionic liquids". J. Fluid. Mech.591, 437-459, 2007.
-  Rezvanpour A. and C.-H. Wang, "Computational and experimental studies of electrospray deposition process in pharmaceutical micro-pattern formation". Chem. Eng. Sci.66, 3836-3849, 2011.
-  Ju J., Y. Yamagata, and T. Higuchi, "Thin-Film Fabrication Method for Organic Light- Emitting Diodes Using Electrospray Deposition". Adv. Mater.21, 4343-4347, 2009.
-  Kim J. H., et al., "Direct pattern formation of bacterial cells using micro-droplets generated by electrohydrodynamic forces". Microfluidics and Nanofluidics.7, 829-839, 2009.
-  Barletta M. and A. Gisario, "Electrostatic spray painting of carbon fibre-reinforced epoxy composites". Prog. Org. Coat.64, 339-349, 2009.
-  Oh H., K. Kim, and S. Kim, "Characterization of deposition patterns produced by twinnozzle electrospray". J. Aerosol. Sci.39, 801-813, 2008.
-  Wilhelm O., L. Madler, and S. E. Pratsinis, "Electrospray evaporation and deposition". J. Aerosol. Sci.34, 815-836, 2003.
-  Hirt C. W. and B. D. Nichols, "Volume of fluid(VOF) method for the dynamics of free boundaries". J. Comput. Phys.39, 201-225, 1981.
-  Saville D. A., "Electrohydrodynamics: The Taylor-Melcher leaky dielectric model". Annu. Rev. Fluid. Mech.29, 27-64, 1997.
-  GananCalvo A. M., "Cone-jet analytical extension of Taylor''s electrostatic solution and the asymptotic universal scaling laws in electrospraying". Phys. Rev. Lett.79, 217-220, 1997.
-  Ganan-calvo A. M., et al., "The electrostatic spray emitted from an electrified conical meniscus". J. Aerosol. Sci.25, 1121-Andamp;, 1994.
-  Kim H., et al., "Parallel patterning of nanoparticles via electrodynamic focusing of charged aerosols". Nat Nano.1, 117-121, 2006.
-  Hartman R. P. A., et al., "Electrohydrodynamic atomization in the cone-jet mode physical modeling of the liquid cone and jet". J. Aerosol. Sci.30, 823-849, 1999.
-  Gomez A. and K. Q. Tang, "Charge and fission of droplets in electrostatic sprays". Phys. Fluids.6, 404-414, 1994.
-  Tang K. and A. Gomez, "On the structure of an electrostatic spray of monodisperse droplets". Phys. Fluids.6, 2317-2332, 1994.
Wei Wei, Sheng Wang*; Kase, Kiwamu; Tajima, Yusuke; Orii, Takaaki; Takaku, Hideaki; Imai, Noboru; Yamagata, Jungmyoung Ju Andamp; Yutaka; "Numerical Computation of Cone-Jet Formation and Deposition Characteristics in Electrostatic Spray", p. 3166-3173 . In: In Proceedings of the 10th World Congress on Computational Mechanics [= Blucher Mechanical Engineering Proceedings, v. 1, n. 1].
São Paulo: Blucher,
ISSN 2358-0828, DOI 10.5151/meceng-wccm2012-19215
últimos 30 dias | último ano | desde a publicação