AC Electrowetting Modulation of Low-Volatile Liquids Probed by XPS : Dipolar vs Ionic Screening

X-ray photoelectron spectroscopic (XPS) data have been recorded for a low-molecular-weight poly(ethylene glycol) microliter-sized sessile liquid drops sitting on a dielectric covered planar electrode while imposing a ±6 V square-wave actuation with varying frequencies between 10-1 and 105 Hz to tap...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 35(2019), 9 vom: 05. März, Seite 3319-3326
1. Verfasser: Aydogan Gokturk, Pinar (VerfasserIn)
Weitere Verfasser: Ulgut, Burak, Suzer, Sefik
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2019
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
LEADER 01000naa a22002652 4500
001 NLM293937508
003 DE-627
005 20231225080412.0
007 cr uuu---uuuuu
008 231225s2019 xx |||||o 00| ||eng c
024 7 |a 10.1021/acs.langmuir.8b04099  |2 doi 
028 5 2 |a pubmed24n0979.xml 
035 |a (DE-627)NLM293937508 
035 |a (NLM)30768276 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Aydogan Gokturk, Pinar  |e verfasserin  |4 aut 
245 1 0 |a AC Electrowetting Modulation of Low-Volatile Liquids Probed by XPS  |b Dipolar vs Ionic Screening 
264 1 |c 2019 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Revised 20.11.2019 
500 |a published: Print-Electronic 
500 |a Citation Status PubMed-not-MEDLINE 
520 |a X-ray photoelectron spectroscopic (XPS) data have been recorded for a low-molecular-weight poly(ethylene glycol) microliter-sized sessile liquid drops sitting on a dielectric covered planar electrode while imposing a ±6 V square-wave actuation with varying frequencies between 10-1 and 105 Hz to tap into the information derivable from (AC) electrowetting. We show that this time-varying XPS spectra reveal two distinct behaviors of the device under investigation, below and above a critical frequency, measured as ∼70 Hz for the liquid poly(ethylene glycol) with a 600 Da molecular weight. Below the critical frequency, the liquid complies faithfully to the applied bias, as determined by the constant shift in the binding energy position of the XPS peaks representative of the liquid throughout its entire surface. The liquid completely screens the applied electrical field and the entire potential drop takes place at the liquid/dielectric interface. However, for frequencies above the critical value, the resistive component of the system dominates, resulting in the formation of equipotential surface contours, which are derived from the differences in the positions of the twinned O 1s peaks under AC application. This critical frequency is independent of the size of the liquid drop, and the amplitude of the excitation, but increases when ionic moieties are introduced. The XP spectra under AC actuation is also faithfully simulated using an equivalent circuit model consisting of only resistors and capacitors and using an electrical circuit simulation software. Moreover, a mimicking device is fabricated and its XP spectra are recorded using the Sn 3d peaks of the solder joints at different points on the circuit to confirm the reliability of the measured and simulated AC behaviors of the liquid. These new findings indicate that in contrast to direct current case, XPS measurements under variable frequency AC actuation reveal (through differences in the frequency response) information related to the chemical makeup of the liquid(s) and brings the laboratory-based XPS as a powerful complimentary arsenal to electrochemical analyses of liquids and their interfaces 
650 4 |a Journal Article 
700 1 |a Ulgut, Burak  |e verfasserin  |4 aut 
700 1 |a Suzer, Sefik  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1992  |g 35(2019), 9 vom: 05. März, Seite 3319-3326  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnns 
773 1 8 |g volume:35  |g year:2019  |g number:9  |g day:05  |g month:03  |g pages:3319-3326 
856 4 0 |u http://dx.doi.org/10.1021/acs.langmuir.8b04099  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 35  |j 2019  |e 9  |b 05  |c 03  |h 3319-3326