Zeta potential of microfluidic substrates: 2. Data for polymers

Kirby, Brian J.; Hasselbrink, Ernest F.

doi:10.1002/elps.200305755

Cited by 429 publications

(389 citation statements)

References 42 publications

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“…The maximum mass flux was 25 and 5 mg min −1 cm −2 for 1 mM NaCl and 10 mM NaCl, respectively, each at a current density J of 1.3 mA cm −2 . The flow rate increases linearly with increasing current density and decreases with increasing salt concentration, as expected (Kirby 2010). This setup generated easily measurable flow with 10 mM NaCl electrolyte, but not for 100 mM NaCl electrolyte.…”

Section: Resultssupporting

confidence: 78%

“…This equation is derived from the definition of electroosmotic mobility, assuming uniform and constant viscosity and electrical permittivity (Kirby 2010), and the value is proportional to the slope of the curve shown in Fig. 5a.…”

Section: Resultsmentioning

confidence: 99%

“…One published exception offers a fabric-like pump which electroosmotically controls water transport (Eidsnes et al 2004;Heldal and Lauper 2013). EOPs employ electroosmosis, where a liquid's movement, e.g., in a capillary, is driven by an externally applied electric field (Kirby 2010). The motion of the liquid stems from the coulombic forces on the ions in the so-called double layer-a thin layer of ions that forms near a charged wall in contact with an electrolyte.…”

Section: Introductionmentioning

confidence: 99%

“…Aside from the electrodes, an EOP needs a capillary or porous media through which ions near the media's surface, driven by the electric field, drag solvent (Kirby 2010). Traditionally, most EOPs have been constructed with beds of packed silica particles (Zeng et al 2001) or relatively rigid porous materials such as anodic aluminum oxide (Ai et al 2010;Miao et al 2007).…”

Section: Introductionmentioning

confidence: 99%

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A large-area, all-plastic, flexible electroosmotic pump

Bengtsson

Robinson

2017

Microfluid Nanofluid

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A large-area, fabric-like pump would potentially have applications, for example, in controlling water transport through a garment, such as a rain jacket, regardless of the external temperature and humidity. This paper presents an all-plastic, flexible electroosmotic pump, constructed from commercially available materials: A polycarbonate membrane combined with the electrochemically active polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate that actively transports water using an electric potential that can be supplied by a small battery. By using electrochemically active polymer electrodes instead of metal electrodes, the electrochemical reaction that drives flow avoids the oxygen and hydrogen gas production or pH changes associated with water electrolysis. We observe a water mass flux up to 23 mg min −1 per cm 2 polycarbonate membrane (porosity 10-15%), at an applied potential of 5 V, and a limiting operating pressure of 0.3 kPa V −1 , similar to previously reported membrane-based electroosmotic pumps.

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Section: Resultssupporting

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A large-area, all-plastic, flexible electroosmotic pump

Bengtsson

Robinson

2017

Microfluid Nanofluid

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“…Additionally, values for the zeta potential can be obtained from EOF data. 4,5 Traditionally, EOF can be measured by monitoring a neutral species moving on the microchannel through the application of an electric field. This method depends on the physicochemical properties of the species, such as high molar absorptivity, electroactivity, fluorescence, and so on.…”

Section: Introductionmentioning

confidence: 99%

Visible LED-Based Instrumentation for Photometric Determination of Electroosmotic Flow in Microchannels

Silva¹,

Deblire²,

Jesus³

et al. 2011

J. Braz. Chem. Soc.

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A instrumentação para a determinação fotométrica do fluxo eletrosmótico (EOF) em dispositivos microfluídicos é descrita neste trabalho. A instrumentação é baseada em componentes acessíveis e consiste em um microscópio trinocular e no fotodiodo integrado OPT101. Um diodo emissor de luz (LED) de alta intensidade foi utilizado como fonte de radiação. Para as determinações foram utilizadas soluções aquosas dos corantes azul patente V e azul de metileno. O sistema foi utilizado no monitoramento do EOF em microdispositivos de poli(dimetilsiloxano) (PDMS) e híbridos de toner/vidro. As mobilidades do EOF determinadas em pH 7,0 foram (5,75 ± 0,01)10 -4 cm 2 V -1 s -1 e (3,2 ± 0,1)10 -4 cm 2 V -1 s -1 para os dispositivos de toner/vidro e PDMS, respectivamente. Medidas reprodutíveis foram obtidas em todos os experimentos, levando a uma alta precisão na determinação. O método proposto foi comparado com o método tradicional de determinação do EOF que envolve a medida da corrente nos microcanais.An instrumental setup for electroosmotic flow (EOF) determination in microfluidic devices is described. The system is based on a trinocular microscope and an integrated photodiode OPT101. The radiation was provided by a high-intensity white LED. For the determinations, patent blue V and methylene blue aqueous solutions were used. The setup was applied for EOF monitoring in hybrid toner/glass and PDMS microchips. For the toner/glass device, the EOF mobility was determined to be (5.75 ± 0.01) 10 -4 cm 2 V -1 s -1 at pH 7.0. For PDMS devices the measured EOF mobility was (3.2 ± 0.1) 10 -4 cm 2 V -1 s -1 . Reproducible measurements were obtained in all experiments, which produced results with small errors. The proposed method was compared to the conventional current monitoring method.Keywords: electroosmotic flow, mTAS, Lab-on-a-chip, photometric methods, microfluidic devices IntroductionElectroosmotic flow (EOF) is the movement of solvent molecules caused by an applied voltage in a capillary system. EOF plays an essential role in electromigration separation techniques, such as capillary zone electrophoresis (CZE or free solution capillary electrophoresis, FSCE) or microchip electrophoresis, 1 since the velocity of the ions is influenced by the magnitude of the EOF. As an example, both positively and negatively charged species can be simultaneously analyzed due to the EOF. Moreover, the EOF magnitude could bring some information about the condition of the surface of the capillary or microchannel wall. In particular, the knowledge about the surface charge density (including not only the EOF magnitude but also the zeta potential) can be of paramount importance for preventing adsorption of analyte to the wall.It is well accepted that EOF has its origin on the unbalanced charge distribution in the region closer to the capillary/microchannel wall, the so called electrical double layer (EDL). More precisely, the flow is caused by the movement of excess ions in the diffuse portion of the EDL. Mathematical treatment of the EOF combines the Newto...

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Hydrodynamic coupling in microbially mediated fracture mineralization: Formation of self-organized groundwater flow channels

et al. 2014

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[1] Evidence of fossilized microorganisms embedded within mineral veins and mineralfilled fractures has been observed in a wide range of geological environments. Microorganisms can act as sites for mineral nucleation and also contribute to mineral precipitation by inducing local geochemical changes. In this study, we explore fundamental controls on microbially induced mineralization in rock fractures. Specifically, we systematically investigate the influence of hydrodynamics (velocity, flow rate, and aperture) on microbially mediated calcite precipitation. Our experimental results demonstrate that a feedback mechanism exists between the gradual reduction in fracture aperture due to precipitation, and its effect on the local fluid velocity. This feedback results in mineral-fill distributions that focus flow into a small number of self-organizing channels that remain open, ultimately controlling the final aperture profile that governs flow within the fracture. This hydrodynamic coupling can explain field observations of discrete groundwater flow channeling within fracture-fill mineral geometries where strong evidence of microbial activity is reported.

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Zeta potential of microfluidic substrates: 2. Data for polymers

Cited by 429 publications

References 42 publications

A large-area, all-plastic, flexible electroosmotic pump

A large-area, all-plastic, flexible electroosmotic pump

Visible LED-Based Instrumentation for Photometric Determination of Electroosmotic Flow in Microchannels

Hydrodynamic coupling in microbially mediated fracture mineralization: Formation of self-organized groundwater flow channels

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