scholarly journals Adsorption of benzyldimethyldodecylammonium chloride onto stainless steel using the quartz crystal microbalance and the depletion methods: an optimisation study

Author(s):  
Ibrahim E. Salama ◽  
Bernard P. Binks ◽  
Paul D.I. Fletcher ◽  
David I. Horsup
2020 ◽  
Vol 34 (8) ◽  
pp. 9283-9295 ◽  
Author(s):  
Fang Liu ◽  
Scott Hickman ◽  
Tabish Maqbool ◽  
Vincent Pauchard ◽  
Sanjoy Banerjee

2005 ◽  
Vol 71 (5) ◽  
pp. 2705-2712 ◽  
Author(s):  
Ann-Cathrin Olofsson ◽  
Malte Hermansson ◽  
Hans Elwing

ABSTRACT The reduction of bacterial biofilm formation on stainless steel surfaces by N-acetyl-l-cysteine (NAC) is attributed to effects on bacterial growth and polysaccharide production, as well as an increase in the wettability of steel surfaces. In this report, we show that NAC-coated stainless steel and polystyrene surfaces affect both the initial adhesion of Bacillus cereus and Bacillus subtilis and the viscoelastic properties of the interaction between the adhered bacteria and the surface. A quartz crystal microbalance with dissipation was shown to be a powerful and sensitive technique for investigating changes in the applied NAC coating for initial cell surface interactions of bacteria. The kinetics of frequency and dissipation shifts were dependent on the bacteria, the life cycle stage of the bacteria, and the surface. We found that exponentially grown cells gave rise to a positive frequency shift as long as their cell surface hydrophobicity was zero. Furthermore, when the characteristics of binding between the cell and the surface for different growth phases were compared, the rigidity increased from exponentially grown cells to starved cells. There was a trend in which an increase in the viscoelastic properties of the interaction, caused by the NAC coating on stainless steel, resulted in a reduction in irreversibly adhered cells. Interestingly, for B. cereus that adhered to polystyrene, the viscoelastic properties decreased, while there was a reduction in adhered cells, regardless of the life cycle stage. Altogether, NAC coating on surfaces was often effective and could both decrease the initial adhesion and increase the detachment of adhered cells and spores. The most effective reduction was found for B. cereus spores, for which the decrease was caused by a combination of these two parameters.


Author(s):  
Samuel Erzuah ◽  
Ingebret Fjelde ◽  
Aruoture Voke Omekeh

Wettability is an indispensable parameter in multiphase flow due to its profound effect in fluid phase distribution and flow properties in the oil reservoirs. One approach of unravelling the enigma associated with wettability characterization is to investigate oil adhesion onto reservoir rock surface during crude oil accumulation. This was accomplished using Quartz Crystal Microbalance with Dissipation (QCM-D) device. The QCM-D is a microbalance device that hinges on the changes in the frequency of a resonating crystal due to changes in the mass on sensor surface, precipitation, adsorption and desorption. However, this technique was confronted with numerous challenges during its early try-out. The objective of this study is to enumerate these challenges and how they were resolved. The piston-cell, valves, flow-lines and most of the experimental set-up were made from stainless steel. Hence, the high temperature coupled with high salinity brine resulted in the formation and deposition of corroded materials on the sensor. Due to the high sensitivity of the QCM-D technique, these corrosion deposits were detected via the high attenuation of the frequency signal as time elapsed during Formation Water (FW) injection. The second challenge was related to the dissolution of the thin sensor coatings (sensor etching) depicted by the relatively high increase in frequency signal with negligible changes in Dissipation (D). The third challenge was related to the trapping of fluids such as Stock Tank Oil (STO) inside the flow-cell. Finally, salt precipitation resulting from temperature variation during the initial experimental set-up was also observed. To resolve the corrosion challenge, all the stainless-steel components in the experimental set-up were replaced with titanium and non-metallic component such as peek materials. The sensor etching was also averted by injecting the brine through a packed column filled with similar mineral as the coatings on the sensor to attain equilibrium prior to injecting it onto the sensor. Geochemical simulation of the sensor etching was also confirmed using the geochemical simulator PHREEQ-C. Furthermore, the trapping of fluids inside the flow-cell was overcome by rotating the flow-cell to optimize the fluid displacement via capitalizing on their density contrast. Finally, the salt precipitation was avoided by conducting the experiment in a constant temperature experimental set-up. The QCM-D technique can be employed to estimate wettability by evaluating the tendency of the various minerals to adhere oil. The beauty of the QCM-D technique is that the surface interactions can be monitored on a real-time.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Eiji Yoshida ◽  
Tohru Hayakawa

It is postulated that biofilm formation in the oral cavity causes some oral diseases. Lactoferrin is an antibacterial protein in saliva and an important defense factor against biofilm development. We analyzed the adsorbed amount of lactoferrin and the dissociation constant (Kd) of lactoferrin to the surface of different dental materials using an equilibrium analysis technique in a 27 MHz quartz crystal microbalance (QCM) measurement. Four different materials, titanium (Ti), stainless steel (SUS), zirconia (ZrO2) and polymethyl methacrylate (PMMA), were evaluated. These materials were coated onto QCM sensors and the surfaces characterized by atomic force microscopic observation, measurements of surface roughness, contact angles of water, and zeta potential. QCM measurements revealed that Ti and SUS showed a greater amount of lactoferrin adsorption than ZrO2and PMMA. Surface roughness and zeta potential influenced the lactoferrin adsorption. On the contrary, theKdvalue analysis indicated that the adsorbed lactoferrin bound less tightly to the Ti and SUS surfaces than to the ZrO2and PMMA surfaces. The hydrophobic interaction between lactoferrin and ZrO2and PMMA is presumed to participate in better binding of lactoferrin to ZrO2and PMMA surfaces. It was revealed that lactoferrin adsorption behavior was influenced by the characteristics of the material surface.


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