Contact angle anomalies indicate that surface-active eluates from silicone coatings inhibit the adhesive mechanisms of fouling organisms

Biofouling ◽  
2006 ◽  
Vol 22 (6) ◽  
pp. 411-423 ◽  
Author(s):  
Anne Meyer ◽  
Robert Baier ◽  
Christina Darkangelo Wood ◽  
Judith Stein ◽  
Kathryn Truby ◽  
...  
Keyword(s):  
Contact Angle ◽  
Silicone Coatings ◽  
Surface Active ◽  
Fouling Organisms

scholarly journals Adhesion of acorn barnacles on surface-active borate glasses

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190203 ◽  
Author(s):  
Kenan P. Fears ◽  
Andrew Barnikel ◽  
Ann Wassick ◽  
Heonjune Ryou ◽  
Janna N. Schultzhaus ◽  
...  
Keyword(s):  
Field Tests ◽  
Borate Glasses ◽  
Local Concentration ◽  
High Concentration ◽  
Marine Biofouling ◽  
Microbial Biofilms ◽  
Concentration Of Ions ◽  
Surface Active ◽  
Fouling Organisms ◽  
Aluminoborate Glass

Concerns about the bioaccumulation of toxic antifouling compounds have necessitated the search for alternative strategies to combat marine biofouling. Because many biologically essential minerals have deleterious effects on organisms at high concentration, one approach to preventing the settlement of marine foulers is increasing the local concentration of ions that are naturally present in seawater. Here, we used surface-active borate glasses as a platform to directly deliver ions (Na + , Mg 2+ and BO 4 3− ) to the adhesive interface under acorn barnacles ( Amphibalanus ( =Balanus ) amphitrite ). Additionally, surface-active glasses formed reaction layers at the glass–water interface, presenting another challenge to fouling organisms. Proteomics analysis showed that cement deposited on the gelatinous reaction layers is more soluble than cement deposited on insoluble glasses, indicating the reaction layer and/or released ions disrupted adhesion processes. Laboratory experiments showed that the majority (greater than 79%) of adult barnacles re-attached to silica-free borate glasses for 14 days could be released and, more importantly, barnacle larvae did not settle on the glasses. The formation of microbial biofilms in field tests diminished the performance of the materials. While periodic water jetting (120 psi) did not prevent the formation of biofilms, weekly cleaning did dramatically reduce macrofouling on magnesium aluminoborate glass to levels below a commercial foul-release coating. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.

Designing biomimetic antifouling surfaces

2010 ◽  
Vol 368 (1929) ◽  
pp. 4729-4754 ◽  
Author(s):  
Maria Salta ◽  
Julian A. Wharton ◽  
Paul Stoodley ◽  
Simon P. Dennington ◽  
Liam R. Goodes ◽  
...  
Keyword(s):  
Detrimental Effect ◽  
Hydrodynamic Drag ◽  
Biologically Inspired ◽  
Marine Life ◽  
Marine Biofouling ◽  
Surface Active ◽  
Fouling Organisms ◽  
Operational Range ◽  
Fuel Costs ◽  
Naval Fleets

Marine biofouling is the accumulation of biological material on underwater surfaces, which has plagued both commercial and naval fleets. Biomimetic approaches may well provide new insights into designing and developing alternative, non-toxic, surface-active antifouling (AF) technologies. In the marine environment, all submerged surfaces are affected by the attachment of fouling organisms, such as bacteria, diatoms, algae and invertebrates, causing increased hydrodynamic drag, resulting in increased fuel consumption, and decreased speed and operational range. There are also additional expenses of dry-docking, together with increased fuel costs and corrosion, which are all important economic factors that demand the prevention of biofouling. Past solutions to AF have generally used toxic paints or coatings that have had a detrimental effect on marine life worldwide. The prohibited use of these antifoulants has led to the search for biologically inspired AF strategies. This review will explore the natural and biomimetic AF surface strategies for marine systems.

Surface Properties of Molten Bismuth-Bismuth Chloride in Contact with Uranium Dioxide

1961 ◽  
Vol 14 (3) ◽  
pp. 409 ◽  
Author(s):  
DH Bradhurst ◽  
AS Buchanan
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Properties ◽  
Uranium Dioxide ◽  
Surface Active Agent ◽  
Active Agent ◽  
Effective Surface ◽  
Liquid Bismuth ◽  
Surface Active ◽  
Bismuth Chloride

The wetting of uranium dioxide by liquid bismuth has been investigated by means of measurements of surface tension of the liquid and contact angle of the liquid on the solid. Bismuth chloride in low concentration was found to be a very effective surface active agent in improving the wetting of the solid by the metal.

Gastric mucosal barrier: hydrophobic lining to the lumen of the stomach

1983 ◽  
Vol 244 (5) ◽  
pp. G561-G568 ◽  
Author(s):  
B. A. Hills ◽  
B. D. Butler ◽  
L. M. Lichtenberger
Keyword(s):  
Contact Angle ◽  
Gastric Mucosa ◽  
Aqueous Fluid ◽  
Mucosal Surface ◽  
Mucosal Barrier ◽  
Acid Attack ◽  
A Value ◽  
Gastric Mucosal Barrier ◽  
Surface Active ◽  
The Mean

The contact angle subtended between a droplet of aqueous fluid and nonwettable surfaces provides a direct estimation of their degree of hydrophobicity. The mean contact angle recorded in dogs at the oxyntic mucosal surface was 85.2 degrees, a value characteristic of acid-resistant substances such as polyethylene. This indicates that the mucosal surface of the stomach has a hydrophobic lining that may be attributed to the surface-active phospholipids known to be present in both the gastric mucosa and juice. Barrier breakers such as bile and aspirin were found virtually to eliminate the hydrophobicity. Hydrophobicity was found to be different in the esophagus, antrum, proximal and distal duodenum, and the colon but consistent with their resistance to acid attack. Endogenous surfactants are discussed for their capability to provide a cohesive and strongly adsorbed protective monolayer--a physical model for the gastric mucosal barrier compatible with the major properties of the gastric lining and many features of ulcerogenesis, including the protection afforded by prostaglandins.

Surface Properties of Liquid Sodium and Sodium-Potassium Alloys in Contact with Metal Oxide Surfaces

1961 ◽  
Vol 14 (3) ◽  
pp. 397 ◽  
Author(s):  
DH Bradhurst ◽  
AS Buchanan
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Contact Angles ◽  
Liquid Sodium ◽  
Oxide Surfaces ◽  
Sodium Potassium ◽  
Solid Oxides ◽  
Metal Oxide Surfaces ◽  
Surface Active ◽  
Sufficient Oxygen

Dissolved oxygen was shown to be surface active in liquid sodium from measurements of surface tension and of contact angle of the liquid on various oxide surfaces. When sufficient oxygen was present wetting of UO2 by liquid sodium could be brought about at temperatures above approximately 300 �C. Observations on the wetting of several solid oxides by sodium gave some support to the hypothesis that wetting was more effective on those oxides with larger cations. Sodium-potassium alloys showed non-wetting contact angles when relatively free of oxygen but wetting occurred when the oxygen content of the liquid was increased.

The Performance of Silicone Coatings Filled with Modification Carbon Nanotubes

2011 ◽  
Vol 687 ◽  
pp. 557-561
Author(s):  
Wu Gao Qiu ◽  
Zhan Ping Zhang ◽  
Yu Hong Qi ◽  
Peng Chao Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Contact Angle ◽  
Surface Energy ◽  
Low Frequency ◽  
Lower Surface ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Low Surface Energy ◽  
Silicone Coatings ◽  
Lower Surface Energy

Silicones coatings were widely used owing to their excellent low surface energy and good flexibility. The structure of the modified multiple wall nanotubes (MWNTs) was tested by IR. Influence of content and sort of MWNTs on microstructures, hydrophobicity of coatings and EIS was investigated using SEM, contact angle measurement (CAM) and electrochemical workstation. The results show that various groups had embedded carbon nanotubes, the coating modified by MWNTs has much lower surface energy than that of the coating wothout modification, the coating modified by different MWNTs have diverse surface energy, and the low-frequency impedance of the coatings was not decreased as the weight of MWNTs increased.

Morphological behavior of compatibilized ternary blends prepared by mechanical mixing

1993 ◽  
Vol 51 ◽  
pp. 1200-1201
Author(s):  
S.D. Smith ◽  
R.J. Spontak ◽  
D.H. Melik ◽  
S.M. Buehler ◽  
K.M. Kerr ◽  
...  
Keyword(s):  
Interfacial Adhesion ◽  
Diblock Copolymers ◽  
Ternary Blends ◽  
Mechanical Mixing ◽  
Design Considerations ◽  
Covalently Bonded ◽  
Homopolymer Blends ◽  
Emulsifying Agent ◽  
Surface Active ◽  
Low Entropy

When blended together, homopolymers A and B will normally macrophase-separate into relatively large (≫1 μm) A-rich and B-rich phases, between which exists poor interfacial adhesion, due to a low entropy of mixing. The size scale of phase separation in such a blend can be reduced, and the extent of interfacial A-B contact and entanglement enhanced, via addition of an emulsifying agent such as an AB diblock copolymer. Diblock copolymers consist of a long sequence of A monomers covalently bonded to a long sequence of B monomers. These materials are surface-active and decrease interfacial tension between immiscible phases much in the same way as do small-molecule surfactants. Previous studies have clearly demonstrated the utility of block copolymers in compatibilizing homopolymer blends and enhancing blend properties such as fracture toughness. It is now recognized that optimization of emulsified ternary blends relies upon design considerations such as sufficient block penetration into a macrophase (to avoid block slip) and prevention of a copolymer multilayer at the A-B interface (to avoid intralayer failure).

Investigation of behavior of the dynamic contact angle in a problem of convective flows

2017 ◽  
Vol 5 (4) ◽  
pp. 27-42
Author(s):  
O.N Goncharova ◽  
◽  
I.V. Marchuk ◽  
A.V. Zakurdaeva ◽  
◽  
...  
Keyword(s):  
Contact Angle ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Convective Flows

Controlling porosity and density of nanocellulose aerogels for superhydrophobic light materials

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 145-153 ◽  
Author(s):  
Chengua Yu ◽  
Feng Wang ◽  
Shiyu Fu ◽  
Lucian Lucia
Keyword(s):  
Contact Angle ◽  
Freeze Drying ◽  
Engine Oil ◽  
High Porosity ◽  
Water Mixture ◽  
Waste Engine Oil ◽  
Hydrophobically Modified ◽  
Static Contact ◽  
Oil Water ◽  
Hydrophobic Material

A very low-density oil-absorbing hydrophobic material was fabricated from cellulose nanofiber aerogels–coated silane substances. Nanocellulose aerogels (NCA) superabsorbents were prepared by freeze drying cellulose nanofibril dispersions at 0.2%, 0.5%, 0.8%, 1.0%, and 1.5% w/w. The NCA were hydrophobically modified with methyltrimethoxysilane. The surface morphology and wettability were characterized by scanning electron microscopy and static contact angle. The aerogels displayed an ultralow density (2.0–16.7 mg·cm-3), high porosity (99.9%–98.9%), and superhydrophobicity as evidenced by the contact angle of ~150° that enabled the aerogels to effectively absorb oil from an oil/water mixture. The absorption capacities of hydrophobic nanocellulose aerogels for waste engine oil and olive oil could be up to 140 g·g-1 and 179.1 g·g-1, respectively.

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