In situ quartz crystal microbalance

I. Vikholm, W.M. Albers, H. Valimaki, and H. Helle, In situ quartz crystal microbalance monitoring of Fab-fragment binding to hnker lipids in a phosphatidylcholine monolayer matrix application to immunosensors. Thin Solid Films 327, 643-646 (1998). 

Niwa et al. [297] prepared a mixed SAM from dithiols on gold which partly bears a dithiocarbamate group. The RAFT-SIP of methacrylic acid was monitored by in situ quartz crystal microbalance. The polymerization rate depended strongly on the composition of the SAM. 

Monoatomic copper vapor was generated by directly heating a tungsten-rod assembly around which copper wire was wrapped. The rate of metal atom deposition (10-12 K) was continuously monitored with use of an in situ quartz-crystal microbalance assembly. Cu(C2H2) and Cu(C2H2)2 were detected by spectroscopic methods. 

The initial formation of the monolayer is rapidly occurred within 30 minutes. If we assume that coverage is proportional to total amount of film material and all surface sites are equivalent, we can use Langmuir adsorption model. We compared experimental EPPI adsorption trend with theoretical Langmuir isotherm determined from ex-situ quartz crystal microbalance data that was indicated that the hypothetical Langmuir isotherm matches with the experimental isotherm in aspects of deposition time and trend of adsorption. The Langmuir isotherm dictates that fractional surface coverage is given by [17 -19]... 

Lincot D, Ortega-Borges R (1992) Chemical bath deposition of cadmium sulfide thin films. In situ growth and structural studies by Combined Quartz Crystal Microbalance and Electrochemical Impedance techniques. J Electrochem Soc 139 1880-1889... 

Buttry, D. A., The quartz crystal microbalance as an in situ tool in electrochemistry, in H. D. Abmna, Ed., Electrochemical Interfaces, VCH, Weinheim, Germany, 1991, p. 529. 

Leopold et al. and Nyholm et al. have investigated this oscillatory system by in situ confocal Raman spectroscopy [43], and in situ electrochemical quartz crystal microbalance [44], and in situ pH measurement [45] with the focus being on darification of the osdllation mechanism. Based on the experimental results, a mechanism for the oscillations was proposed, in which variations in local pH close to the electrode surface play an essential role. Cu is deposited at the lower potentials ofthe oscillation followed by a simultaneous increase in pH close to the surface due to the protonation... 

Bohannan, E. W., Huang, L. Y Miller, F. S., Shumsky, M. G. and Switzer, J. A. (1999) In situ electrochemical quartz crystal microbalance study of potential oscillations during the electrodeposition of CU/CU2O layered nanostructures. Langmuir, 15, 813—818. 

We have found new CO-tolerant catalysts by alloying Pt with a second, nonprecious, metal (Pt-Fe, Pt-Co, Pt-Ni, etc.) [Fujino, 1996 Watanabe et al., 1999 Igarashi et al., 2001]. In this section, we demonstrate the properties of these new alloy catalysts together with Pt-Ru alloy, based on voltammetric measurements, electrochemical quartz crystal microbalance (EQCM), electrochemical scanning tunneling microscopy (EC-STM), in situ Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). 

The first application of the quartz crystal microbalance in electrochemistry came with the work of Bruckenstein and Shay (1985) who proved that the Sauerbrey equation could still be applied to a quartz wafer one side of which was covered with electrolyte. Although they were able to establish that an electrolyte layer several hundred angstroms thick moved essentially with the quartz surface, they also showed that the thickness of this layer remained constant with potential so any change in frequency could be attributed to surface film formation. The authors showed that it was possible to take simultaneous measurements of the in situ frequency change accompanying electrolysis at a working electrode (comprising one of the electrical contacts to the crystal) as a function of the applied potential or current. They coined the acronym EQCM (electrochemical quartz crystal microbalance) for the technique. 

Given the efforts in this group and others (Table 1) to form the Cd based II-VI compounds, studies of the formation of Cd atomic layers are of great interest. The most detailed structural studies of Cd UPD have, thus far, been published by Gewirth et al. [270-272]. They have obtained in-situ STM images of uniaxial structures formed during the UPD of Cd on Au(lll), from 0.1 M sulfuric acid solutions. They have also performed extensive chronocoulometric and quartz crystal microbalance (QCM) studies of Cd UPD from sulfate. They have concluded that the structures observed with STM were the result of interactions between deposited Cd and the sulfate electrolyte. However, they do not rule out a contribution from surface reconstructions in accounting for the observed structures. 

In situ Characterization of Langmuir-Blodgett Films by using a Quartz Crystal Microbalance as a... 

The changes in the mass of the surface during cyclic polarization of the electrode provide information on the amounts of deposited or stripped substances, adsorption, and surface hydration. The first report on the in situ use of quartz crystal microbalances for determination of the mass change of an electrode was given by Nomura and lijima. The experimen-... 

On a pc-Au electrode in 1 M NaF vertically oriented pyridine molecules have been observed at 0.7 V (versus Ag/AgCl), applying in situ IR. In contrast, they have not been detected at this potential in electrochemical method [240]. Considering the fact that adsorption of pyridine on gold electrodes is a replacement reaction and taking into account the results obtained from quartz crystal microbalance experiments, the conclusion has been made that adsorption of one pyridine molecule is accompanied by the removal of 10-12 water molecules [241]. 

The application of novel in situ spectroscopic techniques for the study of Li electrodes in solutions should also be acknowledged. These include FTIR spectroscopy [108], atomic force microscopy (AFM) [109], electrochemical quartz crystal microbalance (EQCM) [110], Raman spectroscopy [111], and XRD [83],... 

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