Contact Angles of Submillimeter Particles:  Connecting Wettability to Nanoscale Surface Topography

Langmuir ◽  
2007 ◽  
Vol 23 (10) ◽  
pp. 5255-5258 ◽  
Author(s):  
Keith M. Forward ◽  
Amanda L. Moster ◽  
Daniel K. Schwartz ◽  
Daniel J. Lacks
Keyword(s):  
Surface Topography ◽  
Contact Angles

Design Parameters for Superhydrophobicity and Superoleophobicity

MRS Bulletin ◽  
2008 ◽  
Vol 33 (8) ◽  
pp. 752-758 ◽  
Author(s):  
Anish Tuteja ◽  
Wonjae Choi ◽  
Gareth H. McKinley ◽  
Robert E. Cohen ◽  
Michael F. Rubner
Keyword(s):  
Surface Tension ◽  
Surface Topography ◽  
Leaf Surface ◽  
Contact Angles ◽  
Design Parameters ◽  
Lotus Leaf ◽  
General Design ◽  
Composite Interface

AbstractRecent experiments have revealed that the wax on the lotus leaf surface, by itself, is weakly hydrophilic, even though the lotus leaf is known to be superhydrophobic. Conventional understanding suggests that a surface of such waxy composition should not be able to support superhydrophobicity and high contact angles between a liquid and the surface. Here, we show that the unexpected superhydrophobicity is related to the presence of “reentrant texture” (that is, a multivalued surface topography) on the surface of the lotus leaf. We exploit this understanding to enable the development of superoleophobic surfaces (i.e., surfaces that repel extremely low-surface-tension liquids, such as various alkanes), where essentially no naturally oleophobic materials exist. We also develop general design parameters that enable the evaluation of the robustness of the composite interface on a particular surface. Based on these design parameters, we also rank various superhydrophobic and superoleophobic substrates discussed in the literature, with particular emphasis on surfaces developed from inherently hydrophilic or oleophilic materials.

Construction of a bioactive surface with micro/nano-topography on titanium alloy by micro-milling and alkali-hydrothermal treatment

2016 ◽  
Vol 230 (12) ◽  
pp. 1086-1095 ◽  
Author(s):  
Teng Wang ◽  
Yi Wan ◽  
Zhaojun Kou ◽  
Yukui Cai ◽  
Bing Wang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Titanium Alloy ◽  
Surface Topography ◽  
Laser Scanning ◽  
Hydrothermal Reaction ◽  
Contact Angles ◽  
Micro Milling ◽  
In Vitro Tests ◽  
Structured Surface

The surface topography and wettability are important factors that determine the biocompatibility of biomaterials. In this article, the hierarchical micro/nano-topography of titanium alloy surface was fabricated by micro-milling and alkali-hydrothermal reaction. The surface topography and chemical composition of treated surfaces were characterized using laser scanning microscope and scanning electron microscope. The contact angles of surfaces with different micro/nano-topographies were measured by contact angle tester. MC3T3s morphology and osteocalcin productions were characterized to investigate the influence of surface modification on implants’ biocompatibility. The results show that hydrophilicity of micro-structured surface decreased compared to the untextured surface and contact angle values decreased with the increase in micro-groove spacing in small increments. In addition, the surfaces treated with alkali-hydrothermal reaction displayed strong hydrophilicity and the surface energy increased by 40 nJ/cm2 approximately. In vitro tests indicated that micro/nano-structured surface improved the adhesion, spreading, and differentiation of MC3T3s.

scholarly journals Effect of Hydrothermal (Sr)-Hydroxyapatite Coatings on the Corrosion Resistance and Mg2+ Ion Release to Enhance Osteoblastic Cell Responses of AZ91D Alloy

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 591 ◽  
Author(s):  
Chung-Wei Yang ◽  
Guan-Kai Wang
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Surface Topography ◽  
Contact Angles ◽  
The Body ◽  
Mg Alloy ◽  
Hydroxyapatite Coating ◽  
Control Group ◽  
Osteoblastic Cell ◽  
Static Contact

The biomedical applications of Mg-based alloys are limited by their rapid corrosion rate in the body fluid. In this study, the hydrothermal synthesis is employed to produce protective bioactive hydroxyapatite coating (HAC) and strontium-substituted hydroxyapatite coating (Sr-HAC) to further enhance the corrosion resistance and in vitro biocompatibility of biodegradable AZ91D Mg alloy in physiological environments. For comparison, the brucite Mg(OH)2 prepared by the alkaline pre-treatment is designated as a control group. Experimental evidences of XRD and XPS analysis confirm that Sr2+ ions can be incorporated into HA crystal structure. It is noted that the hydrothermally synthesized Sr-HAC conversion coating composed of a specific surface topography with the nanoscaled flake-like fine crystallites is constructed on the AZ91D Mg alloy. The hydrophilicity of Mg substrate is effectively enhanced with the decrease in static contact angles after performing alkaline and hydrothermal treatments. Potentiodynamic polarization measurements reveal that the nanostructured Sr-HAC-coated specimens exhibit superior corrosion resistance than HAC and alkaline pre-treated Mg(OH)2. Moreover, immersion tests demonstrate that Sr-HAC provides favorable long-term stability for the Mg alloy with decreasing concentration of released Mg2+ ions in the SBF and the reduced corrosion rate during the immersion length of 30 days. The cells cultured on Sr-HAC specimens exhibit higher viability than those on the alkaline-pre-treated Mg(OH)2 and HAC specimens. The Sr-substituted HA coating with a nanostructured surface topography can help to stimulate the cell viability of osteoblastic cells.

scholarly journals Injection-type Denture Base Materials Surface Modification after Vapor Plasma Deposition

2021 ◽  
Vol 58 (2) ◽  
pp. 1-7
Author(s):  
Titus Alexandru Farcasiu ◽  
Daniela Ioana Tarlungeanu ◽  
Gabriela Ciavoi ◽  
Liana Todor ◽  
Magdalena Natalia Dina ◽  
...  
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Surface Topography ◽  
Plasma Deposition ◽  
Artificial Saliva ◽  
Contact Angles ◽  
Initial Contact ◽  
Denture Base ◽  
Base Materials ◽  
Injection Type

The purpose of this study was to investigate changes of superficial topography and wettability of two injection-type denture base materials following low pressure plasma treatment. Samples of denture base materials (Polyan and Biodentaplast) were fabricate using dedicated technology and were exposed to plasma treatment. Resin surface topography and rugosity were evaluated using SEM and AFM, while wettability was determined through contact angle measurements. Artificial saliva was the testing liquid. Initial contact angles for the two materials are close (Biodentaplast-37.60�, Polyan-36.75�). Plasma treatment halves the values of the contact angle. 30-days measurement reveals a reduced bounce-back effect (Biodentaplast-20.68�, Polyan-20.11�). Surface topography modified differently for the two materials. Rugosity increased significantly for both materials (p[0.05). Surface rugosity values pre- and post-plasma treatment respect the biological threshold of fungal adhesion. Plasma exposure increased injection-type denture base materials wettability with artificial saliva and surface roughness. Injection-type denture base materials and artificial saliva can enhance prosthetic experience of xerostomic patients.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Effects of Ion Beam Milling on Surface Topography

1973 ◽  
Vol 31 ◽  
pp. 84-85
Author(s):  
P.G. Pawar ◽  
P. Duhamel ◽  
G.W. Monk
Keyword(s):  
Surface Topography ◽  
Ion Beam ◽  
Solid Material ◽  
Beam Current ◽  
Atomic Mass ◽  
Micro Milling ◽  
Ion Milling ◽  
Controlled Atmospheres ◽  
Milling Operations ◽  
Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

Low-Loss Images in a Stem/Tem Microscope

1976 ◽  
Vol 34 ◽  
pp. 496-497 ◽  
Author(s):  
David C. Joy ◽  
Dennis M. Maher
Keyword(s):  
High Resolution ◽  
Surface Topography ◽  
Beam Direction ◽  
Low Loss ◽  
Specimen Holder ◽  
Glancing Angle ◽  
High Resolution Images ◽  
Set Up ◽  
Conventional Manner ◽  
Objective Type

High-resolution images of the surface topography of solid specimens can be obtained using the low-loss technique of Wells. If the specimen is placed inside a lens of the condenser/objective type, then it has been shown that the lens itself can be used to collect and filter the low-loss electrons. Since the probeforming lenses in TEM instruments fitted with scanning attachments are of this type, low-loss imaging should be possible.High-resolution, low-loss images have been obtained in a JEOL JEM 100B fitted with a scanning attachment and a thermal, fieldemission gun. No modifications were made to the instrument, but a wedge-shaped, specimen holder was made to fit the side-entry, goniometer stage. Thus the specimen is oriented initially at a glancing angle of about 30° to the beam direction. The instrument is set up in the conventional manner for STEM operation with all the lenses, including the projector, excited.

A procedure for cross-sectioning materials for TEM analysis without ion milling

1990 ◽  
Vol 48 (4) ◽  
pp. 742-743
Author(s):  
J.P. Benedict ◽  
Ron Anderson ◽  
S. J. Klepeis
Keyword(s):  
Surface Topography ◽  
Milling Time ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Cleaning Operation ◽  
Tem Analysis ◽  
Platinum Silicide ◽  
Surface Alteration ◽  
Polishing Damage ◽  
Tools And Methods

Traditional specimen preparation procedures for non-biological samples, especially cross section preparation procedures, involves subjecting the specimen to ion milling for times ranging from minutes to tens of hours. Long ion milling time produces surface alteration, atomic number and rough-surface topography artifacts, and high temperatures. The introduction of new tools and methods in this laboratory improved our ability to mechanically thin specimens to a point where ion milling time was reduced to one to ten minutes. Very short ion milling times meant that ion milling was more of a cleaning operation than a thinning operation. The preferential thinning and the surface topography that still existed in briefly ion milled samples made the study of interfaces between materials such as platinum silicide and silicon difficult. These two problems can be eliminated by completely eliminating the ion milling step and mechanically polishing the sample to TEM transparency with the procedure outlined in this communication. Previous successful efforts leading to mechanically thinned specimens have shown that problems center on tool tilt control, removal of polishing damage, and specimen cleanliness.

High Resolution Low Loss Microscopy of Crystalline Surfaces

1980 ◽  
Vol 38 ◽  
pp. 162-163
Author(s):  
William Krakow ◽  
Alec N. Broers
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Surface Topography ◽  
Secondary Electron ◽  
Objective Lens ◽  
Surface Imaging ◽  
Low Loss ◽  
Fine Grained ◽  
Scanning Electron ◽  
Crystalline Surfaces

Low-loss scanning electron microscopy can be used to investigate the surface topography of solid specimens and provides enhanced image contrast over secondary electron images. A high resolution-condenser objective lens has allowed the low-loss technique to resolve separations of Au nucleii of 50Å and smaller dimensions of 25Å in samples coated with a fine grained carbon-Au-palladium layer. An estimate of the surface topography of fine grained vapor deposited materials (20 - 100Å) and the surface topography of underlying single crystal Si in the 1000 - 2000Å range has also been investigated. Surface imaging has also been performed on single crystals using diffracted electrons scattered through 10−2 rad in a conventional TEM. However, severe tilting of the specimen is required which degrades the resolution 15 to 100 fold due to image forshortening.

How nanoscale surface steps promote ice growth on feldspar: microscopy observation of morphology-enhanced condensation and freezing

Nanoscale ◽  
2019 ◽  
Vol 11 (44) ◽  
pp. 21147-21154 ◽  
Author(s):  
Raymond W. Friddle ◽  
Konrad Thürmer
Keyword(s):  
Surface Topography ◽  
Video Microscopy ◽  
Microscopy Observation ◽  
Atmospheric Dust ◽  
Ice Growth ◽  
Surface Steps

Video microscopy and AFM are used to relate surface topography to a mineral's ability to promote ice growth. On feldspar, abundant as atmospheric dust, basic surface steps can facilitate condensation and freezing when air becomes saturated.

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