Study of Frequency Response of Quartz Crystal Microbalance to Different Wetting States of Micropillar Surfaces

2017 ◽  
Author(s):  
Junwei Su ◽  
Hamed Esmaeilzadeh ◽  
Hongwei Sun
Keyword(s):  
Quartz Crystal Microbalance ◽  
Nanoimprint Lithography ◽  
Quartz Crystal ◽  
Beam Theory ◽  
Frequency Shifts ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Potential Applications ◽  
Order Of Magnitude

Enhanced wettability, known as superhydrophobicity or superhydrophilicity has drawn extensive attention in the past for wide range potential applications such as superhydrophobic surfaces for self-cleaning, anti-icing, dropwise condensation, and drag reduction. This research focuses on the investigation of the frequency responses of quartz crystal microbalance (QCM) devices coated with micropillars to the different wetting states of drops. A theoretical model was developed to correlate the resonant frequency shifts of QCMs with the penetrated (Wenzel state) and suspended (Cassie state) states based on the Euler-Bernoulli beam theory. In the experimental validation of the theory, Poly(methyl methacrylate) (PMMA) micropillars were fabricated on the QCMs using nanoimprint lithography (NIL) method and the different wetting states were generated by plasma treatment and chemical coating. The frequency shifts of the QCM device were measured by a network analyzer. A good agreement between experimental measurements and theoretical predictions was obtained. It was found that the micropillars operating in the penetrated state results in one order of magnitude higher frequency shift of QCM than the micropillars in suspended state. There exists a highly nonlinear vibrating behavior of micropillars with different heights in both penetrated and suspended states. The QCM based technology is a valuable tool for studying the wettability of different superhydrophobic or superhydrophilic surfaces.

Effect of Current Distribution on Quartz Crystal Microbalance Measurements

1997 ◽  
Vol 502 ◽  
Author(s):  
James J. Kelly ◽  
Christopher J. Durning ◽  
Alan C. West
Keyword(s):  
Quartz Crystal Microbalance ◽  
Current Distribution ◽  
Quartz Crystal ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Sensitivity Factor ◽  
A Posteriori ◽  
Frequency Shifts ◽  
Point To Point ◽  
Measured Mass

ABSTRACTSpatially nonuniform electrodeposition can cause discrepancies between predicted and experimentally measured mass loadings on an electrochemical quartz crystal microbalance (EQCM) since the sensitivity of the quartz crystal varies significantly from point to point. These discrepancies can be significant even if the current distribution is nearly uniform. These effects were examined experimentally by varying the conductivity of the electrolyte and the current density during the electrodeposition of copper on an EQCM, effecting changes in the spatial, deposited-mass distribution in a controlled manner. The resulting frequency shifts are in agreement with results predicted by current distribution simulations, validated a posteriori with profilometry measurements. Our results permit determination of the spatial variation of the quartz crystal sensitivity factor or of the current distribution on the EQCM.

scholarly journals Effect of a Non-Newtonian Load on SignatureS2for Quartz Crystal Microbalance Measurements

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jae-Hyeok Choi ◽  
Kay K. Kanazawa ◽  
Nam-Joon Cho
Keyword(s):  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Volume Concentration ◽  
Interfacial Interaction ◽  
Quartz Resonator ◽  
Measurement Analysis ◽  
Wide Range ◽  
Experimental Subjects ◽  
Newtonian Liquids ◽  
Newtonian Behavior

The quartz crystal microbalance (QCM) is increasingly used for monitoring the interfacial interaction between surfaces and macromolecules such as biomaterials, polymers, and metals. Recent QCM applications deal with several types of liquids with various viscous macromolecule compounds, which behave differently from Newtonian liquids. To properly monitor such interactions, it is crucial to understand the influence of the non-Newtonian fluid on the QCM measurement response. As a quantitative indicator of non-Newtonian behavior, we used the quartz resonator signature,S2, of the QCM measurement response, which has a consistent value for Newtonian fluids. We then modified De Kee’s non-Newtonian three-parameter model to apply it to our prediction ofS2values for non-Newtonian liquids. As a model, we chose polyethylene glycol (PEG400) with the titration of its volume concentration in deionized water. As the volume concentration of PEG400 increased, theS2value decreased, confirming that the modified De Kee’s three-parameter model can predict the change inS2value. Collectively, the findings presented herein enable the application of the quartz resonator signature,S2, to verify QCM measurement analysis in relation to a wide range of experimental subjects that may exhibit non-Newtonian behavior, including polymers and biomaterials.

Hydrophobicity of Nanostructured Films Characterized by a Quartz Crystal Microbalance

2012 ◽  
Author(s):  
Pengtao Wang ◽  
Majid Charmchi ◽  
Mengyan Shen ◽  
Hongwei Sun
Keyword(s):  
Quartz Crystal Microbalance ◽  
Nanoimprint Lithography ◽  
Quartz Crystal ◽  
Mechanical Impedance ◽  
Hydrophobic Surface ◽  
Electrospinning Process ◽  
Polymer Surfaces ◽  
Double Layers ◽  
Pmma Film ◽  
Nanostructured Polymer

The hydrophobicity of two types of nanostructured polymer films were fabricated and characterized with a novel quartz crystal microbalance (QCM) technique to investigate their static and dynamic hydrophobic properties. The nanofibrous films of polymethylmethacrylate (PMMA), PMMA/Polydimethylsiloxane (PDMS) and Polyacrylonitril (PAN) were prepared with an electrospinning process and a PMMA film with nanoscale roughness was fabricated using nanoimprint lithography (NIL) technique. Significantly different static and dynamic hydrophobicities (wettability) were found among these films and the correlation between hydrophobicity and the mechanical impedance of QCM to these films were developed both experimentally and theoretically. It was shown that QCM is capable of quantitatively characterizing the hydrophobicity of these nanostructured polymer surfaces. For nanofibrous films, the double layers — a viscoelastic nanofiber film and a liquid layer result in a nonlinear combination of mechanical impedances of QCM. To simplify the analysis, an apparent viscosity was introduced in the analysis to take into account the interactions between liquid and polymer surfaces. For NIL PMMA film, the hydrophobicity was altered by coating nano-roughened surface with a Teflon layer. The reduction in the mechanical impedance of QCM clearly demonstrates the enhancement of hydrophobicity. The experimental results showed that the hydrophobic surface lead to a small mechanical impedance while the hydrophilic surface resulted in a large mechanical impedance of QCM.

Deliquescence Phase Transition Measurements by Quartz Crystal Microbalance Frequency Shifts

2012 ◽  
Vol 116 (29) ◽  
pp. 7658-7667 ◽  
Author(s):  
Kathleen Jane L. Arenas ◽  
Steven R. Schill ◽  
Ammaji Malla ◽  
Paula K. Hudson
Keyword(s):  
Phase Transition ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Frequency Shifts

scholarly journals Using Quartz Crystal Microbalance for Field Measurement of Liquid Viscosities

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Qingsong Bai ◽  
Xianhe Huang
Keyword(s):  
Field Measurement ◽  
Quartz Crystal ◽  
Newtonian Liquid ◽  
Viscous Damping ◽  
Frequency Shifts ◽  
Viscous Liquids ◽  
Sensor Applications ◽  
Potential Applications ◽  
Quartz Crystal Microbalances ◽  
Large Frequency

The field measurement of liquid viscosities, especially the high viscous liquids, is challenging and often requires expensive equipment, long processing time, and lots of reagent. We use quartz crystal microbalances (QCMs) operating in solution which are also sensitive to the viscosity and density of the contacting solution. QCMs are typically investigated for sensor applications in which one surface of QCM completely immersed in Newtonian liquid, but the viscous damping in liquids would cause not only large frequency shifts but also large losses in the quality factorQleading to instability and even cessation of oscillation. A novel mass-sensitivity-based method for field measurement of liquid viscosities using a QCM is demonstrated in this paper and a model describing the influence of the liquid properties on the oscillation frequency is established as well. Two groups of verified experiments were performed and the experimental results show that the presented method is effective and possesses potential applications.

Positive Frequency Shifts Observed Upon Adsorbing Micron-Sized Solid Objects to a Quartz Crystal Microbalance from the Liquid Phase

2010 ◽  
Vol 82 (6) ◽  
pp. 2237-2242 ◽  
Author(s):  
Agata Pomorska ◽  
Dmitry Shchukin ◽  
Richard Hammond ◽  
Matthew A. Cooper ◽  
Guido Grundmeier ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Frequency Shifts ◽  
Solid Objects ◽  
Positive Frequency

scholarly journals Investigating the Prospect of Copper-Histidine Complex Modified Gold Electrode for Histidine and Human Serum Albumin Recognition

2020 ◽  
Vol 6 (1) ◽  
pp. 33-40
Author(s):  
Irena Kereković ◽  
Sandra Domjanić Drozdek
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Modified Electrode ◽  
Quartz Crystal Microbalance ◽  
Gold Electrode ◽  
Quartz Crystal ◽  
Correlation Coefficients ◽  
Electrode Response ◽  
Wide Range

Histidine monolayer was adsorbed on the surface of the gold electrode and further tailored with Cu2+ cation with the aim to investigate adsorption of histidine (His) and human serum albumin (HSA). Formation of the layer on the surface of the gold electrode was confirmed with quartz crystal microbalance. Binding of the His and HSA onto the modified electrode was successfully done for a wide range of tested concentrations. Electrode response was linearly proportional to the concentration of His and HSA with the correlation coefficients R2 = 0.9895 and R2 = 0.9952 respectively.

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