The Effect of Hydrophobic Alkyl Silane Self-Assembled Monolayers on Adult Barnacle Adhesion

2017 ◽  
Vol 51 (2) ◽  
pp. 39-48
Author(s):  
Manuel A. Figueroa ◽  
Jennifer D. Schablik ◽  
Madison Mastroberte ◽  
Lovejot Singh ◽  
Gary H. Dickinson
Keyword(s):  
Shear Stress ◽  
Critical Shear Stress ◽  
Self Assembled Monolayers ◽  
Strong Positive Correlation ◽  
Cohesive Failure ◽  
Hydrophobic Surfaces ◽  
Glass Slides ◽  
Wide Range ◽  
Assembled Monolayers ◽  
Self Assembled

AbstractAlthough there exists a wide range of nonbiocidal and environmentally friendly surface coatings to reduce biofouling on marine structures, there is still not a fundamental understanding of barnacle adhesion upon reattachment. The purpose of this study is to assess the effect of hydrophobicity on adhesion in the barnacle Amphibalanus amphitrite, an abundant and widespread biofouler. Self-assembled monolayers were made on glass slides from alkyl silanes with methylated and fluorinated terminal groups to produce hydrophobic surfaces. Coated and uncoated glass slides underwent a 2-week barnacle reattachment assay. Barnacles were removed using a force gauge, and critical shear stress was calculated for each substrate. Following reattachment assays, a Coomassie Blue G250 protein stain was used to quantify the amount of glue remaining on substrates by measuring pixel density with ImageJ software on glue scans. Critical shear stress was found to be significantly higher for both hydrophobic surfaces as compared to the hydrophilic uncoated glass, and correspondingly, the density of residual glue was higher on hydrophobic surfaces. Given that hydrophobic substrates can exclude water from the surface, they may provide a protected environment for glue release that is favorable for adhesive bond formation with the substrate as well as inter- and intramolecular bonding within the glue layer. Critical shear stress showed a strong positive correlation with residual glue density, suggesting that barnacle release occurs primarily via cohesive failure. Scanning Electron Microscope (SEM) micrographs confirm morphological differences in the glue remnants, depending on the substrate coating. Among the hydrophobic substrates tested, results suggest that contact angle alone is not enough to predict the critical shear stress of barnacles. The chemical and physical properties of the coating become important parameters to consider in antifouling coating design.

In Situ Second Harmonic Generation Measurements of the Growth of Nonlinear Optical Ionically Self-Assembled Monolayers

2000 ◽  
Vol 660 ◽  
Author(s):  
C. Brands ◽  
P.J. Neyman ◽  
M.T. Guzy ◽  
S. Shah ◽  
K.E. Van Cott ◽  
...  
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Nonlinear Optical ◽  
Second Harmonic ◽  
Self Assembled Monolayers ◽  
Optical Polymer ◽  
Wide Range ◽  
Assembled Monolayers ◽  
Self Assembled

ABSTRACTIonically self-assembled monolayers (ISAMs) have recently been shown to spontaneously exhibit a polar ordering that gives rise to a substantial second order nonlinear optical (NLO) response. Here, the deposition of ISAMs has been studied in situ via second harmonic generation (SHG). We show that the adsorption and ordering of a noncentrosymmetric nonlinear optical polymer is constant over a wide range of concentrations. Upon immersion in the NLO-active polyelectrolyte solution, the SHG rises sharply over the first minute. Immersion in the NLO-inactive partner polyelectrolyte leads to a reduction in the SHG signal. Furthermore, when the film is removed from the NLO-active solution and allowed to dry, the SHG increases rapidly as the water evaporates. These studies provide greater understanding of the processes by which noncentrosymmetric order is formed in ISAM films and allows design of improved self- assembled nonlinear optical materials.

Templated Crystallization of Calcite on Patterned Self-Assembled Monolayers

2000 ◽  
Vol 620 ◽  
Author(s):  
Joanna Aizenberg
Keyword(s):  
Functional Groups ◽  
Crystallographic Orientation ◽  
Crystallization Process ◽  
Inorganic Materials ◽  
Fine Tuning ◽  
Self Assembled Monolayers ◽  
Experimental Conditions ◽  
Wide Range ◽  
Assembled Monolayers ◽  
Self Assembled

ABSTRACTMicropatterned self-assembled monolayers (SAMs) that serve as substrates for nucleation provide a way of controlling various aspects of the crystallization process with a previously unreachable precision. We focus on crystallization of calcite (CaCO3) on SAMs of HS(CH2)nX (X = CO2H, CH3, SO3H, OH, N(CH3)3Cl) supported on Ag and Au. Fine-tuning of the crystallographic orientation of the forming crystals has been achieved by using different functional groups and metal substrates. By patterning SAMs with microregions having different nucleating activities and proper geometry, it is possible to confine crystallization to well defined, spatially delineated sites. This method provides means to fabricate arbitrarily patterned calcitic arrays with controlled density of nucleation, crystallographic orientation, and crystal sizes. The experimental conditions and the mechanisms discussed can be applied to the templated nucleation of a wide range of inorganic materials.

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.

Modulation of Biological Properties of Silicon Nitride for Biosensor Applications by Self-Assembled Monolayers

2006 ◽  
Vol 53 ◽  
pp. 122-127 ◽  
Author(s):  
J. Gustavsson ◽  
G. Altankov ◽  
A. Errachid ◽  
Josep Samitier ◽  
Josep A. Planell ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Silicon Nitride ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Self Assembled Monolayers ◽  
Total Protein Content ◽  
Wide Range ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Biosensor Applications

As a ceramic, silicon nitride (Si3N4) has been suggested as a biocompatible material in contact with bone. In another configuration, as a low pressure chemically vapor deposited (LPCVD) thin film, Si3N4 can also be used as the sensitive material in certain biosensor applications. With the latter in mind, the biocompatibility of such films was investigated after them being modified with silane based self-assembled monolayers (SAMs) bearing functional end groups of methyl (CH3), primary amine (NH2), and carboxyl (COOH) respectively. The SAM surface modifications provided a wide range of physiochemical properties including hydrophobic (CH3), hydrophilic (bare Si3N4), positively (NH2) and negatively charged (COOH). Specifically the cell adhesion and proliferation, as well as the levels of alkaline phosphatase activity and osteocalcin, have been evaluated using the human osteoblast-like MG-63 cell line. It was observed that attachment and spreading was pronounced on NH2 while suppressed on CH3. With time the cells grew to confluence on all chemistries, and the levels of osteocalcin normalized to total protein content varied as CH3 > Si3N4 > COOH > NH2, but without significant differences. The highest spontaneous alkaline phosphatase activity was observed from cells grown on Si3N4 substrata.

scholarly journals Self-Assembled Monolayers for Dental Implants

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Sidónio C. Freitas ◽  
Alejandra Correa-Uribe ◽  
M. Cristina L. Martins ◽  
Alejandro Pelaez-Vargas
Keyword(s):  
Dental Implants ◽  
Functional Groups ◽  
Complex Geometry ◽  
Self Assembled Monolayers ◽  
World Population ◽  
Research Strategies ◽  
Continuous Increase ◽  
Wide Range ◽  
Assembled Monolayers ◽  
Self Assembled

Implant-based therapy is a mature approach to recover the health conditions of patients affected by edentulism. Thousands of dental implants are placed each year since their introduction in the 80s. However, implantology faces challenges that require more research strategies such as new support therapies for a world population with a continuous increase of life expectancy, to control periodontal status and new bioactive surfaces for implants. The present review is focused on self-assembled monolayers (SAMs) for dental implant materials as a nanoscale-processing approach to modify titanium surfaces. SAMs represent an easy, accurate, and precise approach to modify surface properties. These are stable, well-defined, and well-organized organic structures that allow to control the chemical properties of the interface at the molecular scale. The ability to control the composition and properties of SAMs precisely through synthesis (i.e., the synthetic chemistry of organic compounds with a wide range of functional groups is well established and in general very simple, being commercially available), combined with the simple methods to pattern their functional groups on complex geometry appliances, makes them a good system for fundamental studies regarding the interaction between surfaces, proteins, and cells, as well as to engineering surfaces in order to develop new biomaterials.

Evanescent wave excitation of palladium metalated porphyrins as self-assembled monolayers and phosphorescence quenching by oxygen

2012 ◽  
Vol 16 (11) ◽  
pp. 1186-1195 ◽  
Author(s):  
Zhenxin Wang ◽  
Shaya Y. Al-Raqa ◽  
Isabelle Chambrier ◽  
David A. Russell ◽  
Michael J. Cook
Keyword(s):  
Luminescence Spectroscopy ◽  
Self Assembled Monolayers ◽  
The Novel ◽  
Self Assembled Monolayer ◽  
Phosphorescence Quenching ◽  
Glass Slides ◽  
Assembled Monolayers ◽  
Phosphorescence Emission ◽  
Self Assembled ◽  
Derivatives Of

The novel palladium metalated derivatives of 5,5′-[8,8′-di(thiooctyloxy)-4,4′-phenyl)]-10,10′,15,15′,20,20′-hexakis(4,4′-t-butylphenyl)diporphyrin and 5,5′-[8,8′-di(thiooctyloxy)-4,4′-phenyl)]- 10,10′,15,15′,20,20′-hexakis(3,3′,4,4′,5,5′-hexakisdecyloxyphenyl)diporphyrin, 1 and 2 respectively, have been synthesized and deposited to form self-assembled monolayer (SAM) films on gold-coated glass slides that served as substrates. The SAM films have been characterised by RAIR spectroscopy. Excitation of the molecules within the films has been achieved using the evanescent field arising when the glass substrate was used as a waveguide. Luminescence spectroscopy detected both fluorescence and phosphorescence emission from the SAM films under an argon atmosphere. Quenching of the phosphorescence emission by dioxygen was investigated for both films. Greater reproducibility of data was achieved from the SAM films of compound 2. The phosphorescence quenching from these films followed the Stern–Volmer relationship.

scholarly journals Antifouling Studies of Unsymmetrical Oligo(ethylene glycol) Spiroalkanedithiol Self-Assembled Monolayers

Micro ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 151-163
Author(s):  
Lydia R. St. Hill ◽  
Hung-Vu Tran ◽  
Pawilai Chinwangso ◽  
Han Ju Lee ◽  
Maria D. Marquez ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Critical Role ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Ex Situ ◽  
Self Assembled Monolayers ◽  
Resonance Spectroscopy ◽  
Wide Range ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Complementary Techniques

The antifouling properties of self-assembled monolayers (SAMs) on gold generated from custom-designed bidentate unsymmetrical spiroalkanedithiols containing both oligo(ethylene glycol) and hydrocarbon tailgroups (EG3C7-C7 and EG3C7-C18) were evaluated and compared to SAMs derived from analogous monodentate octadecanethiol (C18SH) and the tri(ethylene glycol)-terminated alkanethiol EG3C7SH. Complementary techniques, including in situ surface plasmon resonance spectroscopy (SPR), ex situ electrochemical quartz crystal microbalance (QCM) measurements, and ex situ ellipsometric thickness measurements, were employed to assess the protein resistance of the SAMs using proteins having a wide range of sizes, structures, and properties: protamine, lysozyme, bovine serum albumin (BSA), and fibrinogen. The studies found that SAMs generated from the bidentate adsorbates EG3C7-C7 and EG3C7-C18, which contain a 1:1 mixture of OEG and hydrocarbon tailgroups, exhibited a diminished capacity to resist protein adsorption compared to the EG3C7SH SAMs, which possess only OEG tailgroups. The data highlight the critical role of hydration of the OEG matrix for generating antifouling OEG-based surface coatings.

Electrochemical behavior of self-assembled monolayers based on functionalized oligothiophenes

1998 ◽  
Vol 95 (6) ◽  
pp. 1339-1342 ◽  
Author(s):  
R. Michalitsch ◽  
A. El Kassmi ◽  
P. Lang ◽  
A. Yassar ◽  
F. Garnier
Keyword(s):  
Electrochemical Behavior ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled
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