Gold Film Surface Preparation for Self-Assembled Monolayer Studies

Langmuir ◽  
2007 ◽  
Vol 23 (2) ◽  
pp. 509-516 ◽  
Author(s):  
Jing Kang ◽  
Paul A. Rowntree
Keyword(s):  
Gold Film ◽  
Film Surface ◽  
Surface Preparation ◽  
Self Assembled Monolayer ◽  
Self Assembled

Selective Surface Modification and Patterning on Self-Assembled Monolayers by a Micro-Plasma Discharge

2005 ◽  
Author(s):  
Jinan Chai ◽  
Baoming Li ◽  
Daniel Y. Kwok
Keyword(s):  
Gold Film ◽  
Argon Plasma ◽  
Plasma Discharge ◽  
Optical Microscope ◽  
Surface Patterning ◽  
Self Assembled Monolayers ◽  
Plasma Exposure ◽  
Self Assembled Monolayer ◽  
Assembled Monolayers ◽  
Self Assembled

In this paper, we will demonstrate a selective surface patterning method by a micro-plasma discharge. In this method, argon plasma is ignited through a hole of copper clad polyimide microstructure electrodes. As an illustration, experiments were performed in which an octadecanethiol (CH3(CH2)17SH) self-assembled monolayer (SAM) on a gold film is exposed to a microdischarge and subsequently followed by immersion into the 16-mercaptohexadecanoic acid (COOH(CH2)15SH) solution. The octadecanethiol SAM is desorbed upon Ar plasma exposure, allowing the formation of a second SAM on the damaged region [Chai et al, App. Phys. Lett., 86, 034107 (2005)]. The patterned samples are viewed by using optical microscope and scanning electron microscopy. The advantage of this approach is that it is noncontact and eliminates the need of photolithography. The patterned samples can be employed to microfluidic self-propelled movement.

scholarly journals An Easy Route to Wettability Changes of Polyethylene Terephthalate–Silicon Oxide Substrate Films for High Barrier Applications, Surface-Modified with a Self-Assembled Monolayer of Fluoroalkylsilanes

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 257 ◽  
Author(s):  
Paola Scarfato ◽  
Nicola Schiavone ◽  
Gabriella Rossi ◽  
Loredana Incarnato
Keyword(s):  
Contact Angle ◽  
Polyethylene Terephthalate ◽  
Silicon Oxide ◽  
Film Surface ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Self Assembled Monolayer ◽  
Water Contact ◽  
Oxide Substrate ◽  
Self Assembled

Inorganic–organic multilayer films consisting of polymers coated with thin inorganic oxidic layers (e.g., SiOx) ensure very high barrier performances against gas and vapor permeation, what makes them packaging materials suitable for sophisticated technical applications, including the encapsulation of photovoltaic devices or quantum dots, barrier films for optical displays, and transparent greenhouse screens. In these fields, surface coating or texturing of the multilayer protective films are effective technologies to improve their self-clean ability, thus reducing the required maintenance and ensuring longer durability and better performances. In this work, we used the self-assembled monolayer (SAM) technique to modify the surface and wetting properties of commercial polyethylene terephthalate-silicon oxide substrate (PET-SiOx) films developed for technical applications requiring a combined high barrier and transparency. The selected surface modifier was the 1H,1H,2H,2H-per-fluorodecyltrichlorosilane (FDTS). The reagent mixture composition was optimized for the lowest water and oil wettability, as well as the highest self-cleaning capacity and performance stability. In particular, for the used PET-SiOx film the best FDTS/film surface for both the lowest water and oil wettability was found to be equal to 26.5 mM/dm2, which changes the surface behavior from very hydrophilic (static water contact angle (CAw) = 21.5°) to hydrophobic (CAw = 101°), and gives a significant increment of the static oil contact angle (CAo) from 27° to 60°. Interestingly, the results demonstrated that the SAM reaction occurred also on the uncoated the PET side. After the SAM treatment, a small increase of the water vapor permeability is observed, probably due to a crack or defect onset of the SiOx coating of the SAM modified films. On this point, atomic force measurements demonstrated an increment of the SiOx coating layer roughness after the SAM treatment execution. Finally, the transparency changes of the SAM treated films, measured in the wavelength range 400–800 nm, were always small, so that the results were acceptable for the films’ use in applications where high transparency is required.

Wet Chemical Cleaning of Organosilane Monolayers

2021 ◽  
Vol 314 ◽  
pp. 54-59
Author(s):  
Adam P. Hinckley ◽  
Anthony J. Muscat
Keyword(s):  
Self Assembly ◽  
Surface Preparation ◽  
Ammonium Hydroxide ◽  
Silicon Surfaces ◽  
Particle Removal ◽  
Chemical Cleaning ◽  
Self Assembled Monolayer ◽  
Metal Oxide Surfaces ◽  
Aqueous Mixture ◽  
Self Assembled

Thin organic self-assembled monolayer films are used to promote adhesion and seal the pores of metal oxides as well as direct the deposition of layers on patterned surfaces. Defects occur as the self-assembled monolayer forms, and the number and type of defects depend on surface preparation, deposition solvent, temperature, time and other parameters. Particles commonly deposit during organosilane self-assembly on metal oxide surfaces. The particles are defects because they are prone to react in subsequent processing, which may not be desirable if the organosilane serves as a pore sealant or passivation layer. Cleaning the organosilane by solvent extraction to remove non-polar agglomerates followed by an aqueous mixture of ammonium hydroxide and hydrogen peroxide, which is Standard Clean 1, a common particle removal step for silicon surfaces, produced monolayers with few agglomerates based on atomic force microscopy without etching the layer. The combined cleaning sequence contained fewer particles than separate cleaning steps, showing that the cleans removed particles with different compositions. The thickness and contact angle of cleaned monolayers was comparable to those made using a costlier solvent.

CURRENT RECTIFICATION IN NEMATIC LIQUID CRYSTAL CELL WITH ALKANETHIOL SELF-ASSEMBLED MONOLAYER

2008 ◽  
Vol 17 (04) ◽  
pp. 495-501
Author(s):  
FENGFENG YAO ◽  
YANBO PEI ◽  
XIUDONG SUN
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Gold Film ◽  
Glass Slide ◽  
Self Assembled Monolayer ◽  
Coated Glass ◽  
Voltage Bias ◽  
Current Rectification ◽  
Self Assembled ◽  
Coated Glass Slide

Asymmetric current–voltage (I/V) behaviors with respect to the polarity of the voltage bias were observed in the nematic liquid crystal (NLC) cells constructed with the gold film on the silicon wafer as one substrate and an indium-tin-oxide (ITO)-coated glass slide as the other substrate. A little smaller current resulted at the positive bias corresponding to the positive voltage bias being applied to the gold film relative to the ITO-coated glass slide. When the alkanethiol self-assembled monolayer (SAM) was introduced into the above NLC cell as the aligning layer, it was able to enhance the forward current significantly, but suppress the reverse current. A current rectification ratio of ~20 was obtained at 1.5 V in the NLC cell with SAM as the aligning layer. Besides, we also characterized the effect of the optical power of 632.8 nm on the asymmetric I/V behaviors in the NLC cells without SAM and with SAM as the aligning layer.

Self-Assembled Fluid Phase Floating Membranes with Tuneable Water Interlayers

2019 ◽  
Author(s):  
Luke Clifton ◽  
Nicoló Paracini ◽  
Arwel V. Hughes ◽  
Jeremy H. Lakey ◽  
Nina-Juliane Seinke ◽  
...  
Keyword(s):  
Fluid Phase ◽  
Interlayer Thickness ◽  
Supported Bilayers ◽  
Self Assembled Monolayer ◽  
High Coverage ◽  
Nano Technology ◽  
Surface Distance ◽  
Potential Applications ◽  
Self Assembled ◽  
Coated Surfaces

<p>We present a reliable method for the fabrication of fluid phase unsaturated bilayers which are readily self-assembled on charged self-assembled monolayer (SAM) surfaces producing high coverage floating supported bilayers where the membrane to surface distance could be controlled with nanometer precision. Vesicle fusion was used to deposit the bilayers onto anionic SAM coated surfaces. Upon assembly the bilayer to SAM solution interlayer thickness was 7-10 Å with evidence suggesting that this layer was present due to SAM hydration repulsion of the bilayer from the surface. This distance could be increased using low concentrations of salts which caused the interlayer thickness to enlarge to ~33 Å. Reducing the salt concentration resulted in a return to a shorter bilayer to surface distance. These accessible and controllable membrane models are well suited to a range of potential applications in biophysical studies, bio-sensors and Nano-technology.</p><br>

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