Permeation and tangential flow streaming potential measurements for electrokinetic characterization of track-etched microfiltration membranes

Lettmann, Christian; Möckel, Dirk; Staude, Eberhard

doi:10.1016/s0376-7388(99)00067-8

Cited by 69 publications

(38 citation statements)

References 19 publications

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“…Furthermore, in the case of the template zeta potential, it is possible that values at the outside surface and within the pore walls differ. However, values obtained by streaming potential measurements of PC membranes, as shown in literature [16], are quite similar to values obtained by our method, at least for membranes with 100-200 nm pores. In addition, the data measured for AAM samples show reasonable agreement with reports from the literature [17] as well.…”

Section: Zeta Potentialsupporting

confidence: 90%

“…Thus, the measured values for AAM zeta potential showed a reasonably close trend to the actual values. Similarly, the PC values were also quite close to those reported in the literature [16].…”

Section: Zeta Potentialsupporting

confidence: 89%

“…This may explain some of the difficulties that have been experienced in synthesizing nanorods. The PC membranes used in synthesizing nanorods have their isoelectric point (IEP) at about pH ∼4 [20,21], and thus have a positive surface charge at pHs below this value. Since all of the sols discussed above have pHs at or below 4, it is expected that growth will proceed as Wang et al proposed [18].…”

Section: Zeta Potentialmentioning

confidence: 99%

See 2 more Smart Citations

A Study on the Influences of Processing Parameters on the Growth of Oxide Nanorod Arrays by Sol Electrophoretic Deposition

Limmer

Chou

Cao

2005

J Sol-Gel Sci Technol

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Abstract.Template-based sol electrophoretic deposition has been demonstrated as an attractive method for the synthesis of oxide nanorod arrays, including simple and complex oxides in the forms of amorphous, polycrystalline, and single crystal. This paper systematically studied a number of processing parameters to control nanorod growth by sol electrophoretic deposition. The influences of particle and template zeta potentials, condensation rate, deposition rate (or externally applied electric field), the presence of organic additives, and sol concentration on the growth of nanorod arrays were studied. It was found that higher zeta potential or electric field resulted in higher growth rates but less dense packing. Templates with charge opposite to that of the sol particles prevented formation of dense nanorods, sometimes resulting in nanotubes, depending on the field strength during electrophoresis. In addition, the pH of the sol and chelating additives were also varied and likely affected the deposition process by affecting the condensation reactions.

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Section: Zeta Potentialsupporting

confidence: 90%

Section: Zeta Potentialsupporting

confidence: 89%

Section: Zeta Potentialmentioning

confidence: 99%

See 1 more Smart Citation

A Study on the Influences of Processing Parameters on the Growth of Oxide Nanorod Arrays by Sol Electrophoretic Deposition

Limmer

Chou

Cao

2005

J Sol-Gel Sci Technol

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“…The results from the limiting hydrodynamic pressure measurement can also be used to calculate µ eo , see (Zeng et al 2001): where Δp lim is the limiting hydrodynamic pressure and r the pore radius (0.2 µm), resulting in ζ = −1.9 ± 0.1 mV (corrected with α = 0.9), which is much smaller in magnitude than reported by others, e.g., −25 mV at pH = 6, for both pure polycarbonate and PVP-treated polycarbonate membranes (Kirby and Hasselbrink 2004;Lettmann et al 1999). Note that both ζ and eo should be calculated with the actual potential drop across the membrane, which we estimate to be about 75% of the actual applied potential, meaning that we have underestimated each by ~ 33%.…”

Section: Resultsmentioning

confidence: 88%

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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“…34,57 Previously reported data shows that the EOP using a polycarbonate should be able to produce even higher flow rates than what we reported; it was not determined if the difference in electroosmotic mobility was due to the coating of the membrane with residues from the PEDOT electrodes or whether it was caused by altering pH in the measuring chamber.…”

Section: Figure 8 Polyethylene Glycol (Peg)mentioning

confidence: 64%

Electrokinetic devices from polymeric materials

Bengtsson¹

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There are multiple applications for polymers: our bodies are built of them, plastic bags and boxes used for storage are composed of them, as are the shells for electronics, TVs, computers, clothes etc. Many polymers are cheap, and easy to manufacture and process which make them suitable for disposable systems. The choice of polymer to construct an object will therefore highly influence the properties of the object itself. The focus of this thesis is the application of commonly used polymers to solve some challenges regarding integration of electrodes in electrokinetic devices and 3D printing.The first part of this thesis regards electrokinetic systems and the electrodes' impact on the system. Electrokinetic systems require Faradaic (electrochemical) reactions at the electrodes to maintain an electric field in an electrolyte. The electrochemical reactions at the electrodes allow electron-to-ion transduction at the electrode-electrolyte interface, necessary to drive a current at the applied potential through the system, which thereby either cause flow (electroosmosis) or separation (electrophoresis). These electrochemical reactions at the electrodes, such as water electrolysis, are usually problematic in analytical systems and systems applied in biology. One solution to reduce the impact of water electrolysis is by replacing metal electrodes with electrochemically active polymers, e.g. poly(3,4-ethylenedioxythiophene) (PEDOT). Paper 1 demonstrates that PEDOT electrodes can replace platinum electrodes in a gel electrophoretic setup. Paper 2 reports an all-plastic, planar, flexible electroosmotic pump which continuously transports water from one side to the other using potentials as low as 0.3 V. This electroosmotic pump was further developed in paper 3, where it was made into a compact and modular setup, compatible with commercial microfluidic devices. We demonstrated that the pump could maintain an alternating flow for at least 96 h, with a sufficient flow of cell medium to keep cells alive for the same period of time.The second part of the thesis describes the use of 3D printers for manufacturing prototypes and the material requirements for 3D printing. Protruding and over-hanging structures are more challenging to print using a 3D printer and usually require supporting material during the printing process. In paper 4, we showed that polyethylene glycol (PEG), in combination with a carbonate-based plasticizer, functions well as a 3D printable sacrificial template material. PEG2000 with between 20 and 30 wt% dimethyl carbonate or propylene carbonate iv have good shear-thinning rheology, mechanical and chemical stability, and water solubility, which are advantageous for a supporting material used in 3D printing.The advances presented in this thesis have solved some of the challenges regarding electrokinetic systems and prototype manufacturing. Hopefully this will contribute to the development of robust, disposable, low-cost, and autonomous electrokinetic devices.v Populärvetenskaplig sammanfattning Polymera...

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Permeation and tangential flow streaming potential measurements for electrokinetic characterization of track-etched microfiltration membranes

Cited by 69 publications

References 19 publications

A Study on the Influences of Processing Parameters on the Growth of Oxide Nanorod Arrays by Sol Electrophoretic Deposition

A Study on the Influences of Processing Parameters on the Growth of Oxide Nanorod Arrays by Sol Electrophoretic Deposition

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

Electrokinetic devices from polymeric materials

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