Contact Angle Analysis During the Electro-oxidation of Self-Assembled Monolayers Formed by n-Octadecyltrichlorosilane

2010 ◽  
Vol 20 (19) ◽  
pp. 3252-3259 ◽  
Author(s):  
Nicole Herzer ◽  
Jurriaan H. K. van Schaik ◽  
Stephanie Hoeppener ◽  
Ulrich S. Schubert
Keyword(s):  
Contact Angle ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Electro Oxidation ◽  
Self Assembled ◽  
Contact Angle Analysis

Reconfigurable Hydrophobic/Hydrophilic Surfaces Based on Self-Assembled Monolayers

2003 ◽  
Vol 774 ◽  
Author(s):  
Joanne Deval ◽  
Teodoro A. Umali ◽  
Brandee L. Spencer ◽  
Esther H. Lan ◽  
Bruce Dunn ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Water ◽  
Water Contact Angle ◽  
Self Assembled Monolayers ◽  
Ionic Surfactant ◽  
Initial Surface ◽  
Lauryl Sulfate ◽  
Water Contact ◽  
Assembled Monolayers ◽  
Self Assembled

AbstractThe fabrication of micron-scale channels and reaction chambers using micromachining techniques has created devices with large surface to volume ratios. As a result, surface properties play a major role in determining the behavior of micromachined devices. In this work, we present strategies that can be used to reconfigure surfaces from hydrophobic to hydrophilic or from hydrophilic to hydrophobic. The reversible nature of the surface is made possible by using deposition and removal of biomolecules or amphiphiles on self-assembled monolayers (SAMs). When the initial surface was hydrophobic (using a CH3-terminated SAM on the surface, water contact angle ∼100), it was rendered hydrophilic (water contact angle ≤60°) using monolayer adsorption of avidin protein. To retrieve the hydrophobicity, the avidin was subsequently removed using non-ionic surfactant octyl-β-D-glucopyranoside. Moreover, by incorporating a biotinylated poly(ethyleneglycol), the avidin-coated surface was resistant to further non-specific adsorption. If the initial surface was hydrophilic (using a CO2H-terminated SAM on the surface, water contact angle ≤20°), it was rendered hydrophobic (water contact angle >90°) using monolayer amphiphilic octadecylamine adsorption. The hydrophilicity was restored after subsequently removing the amphiphile using anionic surfactant sodium lauryl sulfate. Both types of surfaces showed excellent reversibility and demonstrated the ability to control surface wettability.

Origin of the Contact Angle Hysteresis of Water on Chemisorbed and Physisorbed Self-Assembled Monolayers

Langmuir ◽  
2012 ◽  
Vol 28 (41) ◽  
pp. 14609-14617 ◽  
Author(s):  
Nataly Belman ◽  
Kejia Jin ◽  
Yuval Golan ◽  
Jacob N. Israelachvili ◽  
Noshir S. Pesika
Keyword(s):  
Contact Angle ◽  
Contact Angle Hysteresis ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

scholarly journals Use of Self-Assembled Monolayers of Different Wettabilities To Study Surface Selection and Primary Adhesion Processes of Green Algal (Enteromorpha) Zoospores

2000 ◽  
Vol 66 (8) ◽  
pp. 3249-3254 ◽  
Author(s):  
Maureen E. Callow ◽  
J. A. Callow ◽  
Linnea K. Ista ◽  
Sarah E. Coleman ◽  
Aleece C. Nolasco ◽  
...  
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Self Assembled Monolayers ◽  
Use Of Self ◽  
Oh Groups ◽  
X Ray ◽  
Green Algal ◽  
Assembled Monolayers ◽  
Self Assembled

ABSTRACT We investigated surface selection and adhesion of motile zoospores of a green, macrofouling alga (Enteromorpha) to self-assembled monolayers (SAMs) having a range of wettabilities. The SAMs were formed from alkyl thiols terminated with methyl (CH3) or hydroxyl (OH) groups or mixtures of CH3- and OH-terminated alkyl thiols and were characterized by measuring the advancing contact angles and by X-ray photoelectron spectroscopy. There was a positive correlation between the number of spores that attached to the SAMs and increasing contact angle (hydrophobicity). Moreover, the sizes of the spore groups (adjacent spores touching) were larger on the hydrophobic SAMs. Video microscopy of a patterned arrangement of SAMs showed that more zoospores were engaged in swimming and “searching” above the hydrophobic sectors than above the hydrophilic sectors, suggesting that the cells were able to “sense” that the hydrophobic surfaces were more favorable for settlement. The results are discussed in relation to the attachment of microorganisms to substrata having different wettabilities.

Fluorescent Self-Assembled Monolayers of Umbelliferone: A Relationship between Contact Angle and Fluorescence

Langmuir ◽  
2013 ◽  
Vol 29 (33) ◽  
pp. 10423-10431 ◽  
Author(s):  
Luc Séro ◽  
Lionel Sanguinet ◽  
Séverine Derbré ◽  
Frank Boury ◽  
Guillaume Brotons ◽  
...  
Keyword(s):  
Contact Angle ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

Mixed Self-Assembled Monolayers of Alkanethiolates on Ultrasmooth Gold Do Not Exhibit Contact-Angle Hysteresis

2005 ◽  
Vol 127 (1) ◽  
pp. 4-5 ◽  
Author(s):  
Pooja Gupta ◽  
Abraham Ulman ◽  
Stephanie Fanfan ◽  
Alexander Korniakov ◽  
Katja Loos
Keyword(s):  
Contact Angle ◽  
Contact Angle Hysteresis ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

scholarly journals Differences in ITO Surfaces According to the Formation of Aromatic Rings and Aliphatic Self-Assembled Monolayers for Organic Light-Emitting Diode Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2520
Author(s):  
Myung-Gyun Baek ◽  
Sang-Geon Park
Keyword(s):  
Contact Angle ◽  
Work Function ◽  
Light Emitting Diode ◽  
Substrate Surface ◽  
Self Assembled Monolayers ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Assembled Monolayers ◽  
Self Assembled

In this study, we investigated the effects on the characteristic changes in OLED devices of using self-assembled monolayers with different functional groups as the hole injection layer, resulting in changes in their performance. Thus, we confirmed that it is possible to control the wetting properties, surface roughness, and work function of the indium tin oxide (ITO) surface by introducing self-assembled monolayers (SAMs). The contact angle measurements confirmed that the substrate surface contact angle tended to increase with SAM deposition. In addition, AFM measurements confirmed that the substrate surface roughness tended to decrease when SAM was deposited on the surface. Finally, it was confirmed through the work function measurement results that the work function increased when the ITO surface was modified by SAM. Furthermore, compared to OLEDs using only the ITO anode, the SAM-modified device showed a higher current density (359.68 A/cm2), improved brightness (76.8 cd/cm2), and a smaller turn-on voltage (7 V). This approach provides a simple route for fabricating organic light-emitting diode applications.

scholarly journals The influence of surface lubricity on the adhesion of Navicula perminuta and Ulva linza to alkanethiol self-assembled monolayers

2006 ◽  
Vol 4 (14) ◽  
pp. 473-477 ◽  
Author(s):  
J Bowen ◽  
M.E Pettitt ◽  
K Kendall ◽  
G.J Leggett ◽  
J.A Preece ◽  
...  
Keyword(s):  
Contact Angle ◽  
Shear Stress ◽  
Marked Change ◽  
Self Assembled Monolayers ◽  
Surface Adhesion ◽  
Ulva Linza ◽  
Structure Changes ◽  
Hydrodynamic Shear ◽  
Assembled Monolayers ◽  
Self Assembled

The settlement and adhesion of Navicula perminuta and Ulva linza to methyl-terminated alkanethiol self-assembled monolayers (SAMs) of increasing chain length has been investigated. Organisms were allowed to settle onto the monolayers and were subsequently exposed to hydrodynamic shear stress in order to determine their adhesion strength. Results show that as the SAM structure changes from amorphous to crystalline (C14), there is a marked change in the adhesion of N. perminuta and U. linza . Given that the SAMs in the series all exhibit similar contact angle behaviour and surface energy, it is hypothesized that the lubricity of the surface plays a role in determining the surface adhesion.

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