scholarly journals Influence of Surface Properties on the Adhesion ofStaphylococcus epidermidisto Acrylic and Silicone

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Cláudia Sousa ◽  
Pilar Teixeira ◽  
Rosário Oliveira
Keyword(s):  
Surface Properties ◽  
Staphylococcus Epidermidis ◽  
Bacterial Adhesion ◽  
Surface Characteristics ◽  
Surface Hydrophobicity ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Biomaterial Surface

The aim of the present study was to compare the ability of eightStaphylococcus epidermidisstrains to adhere to acrylic and silicone, two polymers normally used in medical devices manufacture. Furthermore, it was tried to correlate that with the surface properties of substrata and cells. Therefore, hydrophobicity and surface tension components were calculated through contact angle measurements. Surface roughness of substrata was also assessed by atomic force microscopy (AFM). No relationship was found between microbial surface hydrophobicity and adhesion capability. Nevertheless,Staphylococcus epidermidisIE214 showed very unique adhesion behaviour, with cells highly aggregated between them, which is a consequence of their specific surface features. All strains, determined as being hydrophilic, adhered at a higher extent to silicone than to acrylic, most likely due to its more hydrophobic character and higher roughness. This demonstrates the importance of biomaterial surface characteristics for bacterial adhesion.

scholarly journals Dynamic Cell Surface Hydrophobicity of Lactobacillus Strains with and without Surface Layer Proteins

2004 ◽  
Vol 186 (19) ◽  
pp. 6647-6650 ◽  
Author(s):  
Virginia Vadillo-Rodríguez ◽  
Henk J. Busscher ◽  
Willem Norde ◽  
Joop de Vries ◽  
Henny C. van der Mei
Keyword(s):  
Ionic Strength ◽  
Cell Surface ◽  
Cell Surface Hydrophobicity ◽  
Interaction Force ◽  
Surface Hydrophobicity ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Dynamic Cell

ABSTRACT Variations in surface hydrophobicity of six Lactobacillus strains with and without an S-layer upon changes in ionic strength are derived from contact angle measurements with low- and high-ionic-strength aqueous solutions. Cell surface hydrophobicity changed in response to changes in ionic strength in three out of the six strains, offering these strains a versatile mechanism to adhere to different surfaces. The dynamic behavior of the cell surface hydrophobicity could be confirmed for two selected strains by measuring the interaction force between hydrophobic and hydrophilic tips with use of atomic force microscopy.

scholarly journals Physical and Morphological Changes of Poly(tetrafluoroethylene) after Using Non-Thermal Plasma-Treatments

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2013 ◽  
Author(s):  
Jorge López-García ◽  
Florence Cupessala ◽  
Petr Humpolíček ◽  
Marian Lehocký
Keyword(s):  
Surface Properties ◽  
Morphological Changes ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Afm Imaging ◽  
Contact Angle Measurements ◽  
Isoelectric Points ◽  
Non Thermal Plasma ◽  
Surface Modified

A commercial formulation of poly(tetrafluoroethylene) (PTFE) sheets were surface modified by using non-thermal air at 40 kHz frequency (DC) and 13.56 MHz radiofrequency (RF) at different durations and powers. In order to assess possible changes of PTFE surface properties, zeta potential (ζ), isoelectric points (IEPs) determinations, contact angle measurements as well as Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) imaging were carried out throughout the experimentation. The overall outcome indicated that ζ-potential and surface energy progressively changed after each treatment, the IEP shifting to lower pH values and the implicit differences, which are produced after each distinct treatment, giving new surface topographies and chemistry. The present approach might serve as a feasible and promising method to alter the surface properties of poly(tetrafluoroethylene).

Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong
Keyword(s):  
Irradiation Time ◽  
Polymer Surface ◽  
Laser Source ◽  
Free Standing ◽  
Force Microscopy ◽  
Nanostructure Formation ◽  
Physicochemical Changes ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

Micro/Nano-Tribological Behavior of Octadecyltrichlorosilane on Silicon as a Coating for MEMS

2005 ◽  
Author(s):  
J. Barriga ◽  
B. Ferna´ndez ◽  
E. Abad ◽  
B. Coto
Keyword(s):  
Liquid Phase ◽  
Vapour Phase ◽  
Stick Slip ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Assembled Monolayers ◽  
The Coefficient Of Friction ◽  
Semicontact Mode

Despite progresses achieved in the technology of MEMS, the tribological problem continues being an unresolved matter. Wear and stick-slip phenomena are many times the origin of failure of these devices. The application of self-assembled monolayers (SAMs) in liquid phase seems to be a solution to this problems. SAMs of octadecyltrichlorosilane (CH3(CH2)17SiCl3, OTS) were attached to Si(100) oxidized in liquid phase. Contact angle measurements were used for characterizing the grade of hydrophobicity. The topography of the coating was obtained with an Atomic Force Microscopy (AFM) in semicontact mode. The images showed the presence of particles related to the polymerization of the precursor molecule during the formation process of the SAMs. Creating the film of lubricant in vapour phase would avoid this undesirable effect. Tribological tests were carried out with a microtribometer in linear reciprocating movement with a ball of 2 mm of diameter (100Cr6 and Si3N4) and load of some milinewtons. Results were compared with those obtained for silicon oxidized without any coating. The coefficient of friction (COF) and wear (substrate and ball) were studied under different test conditions.

scholarly journals Separation of Water/Oil Emulsions by an Electrospun Copolyamide Mat Covered with a 2D Ti3C2Tx MXene

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3171
Author(s):  
AbdolAli Moghaddasi ◽  
Patrik Sobolčiak ◽  
Anton Popelka ◽  
Igor Krupa
Keyword(s):  
Contact Angle ◽  
Vegetable Oil ◽  
Separation Efficiency ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Oil Emulsions ◽  
Uv Transmittance ◽  
Stock Solutions

Purpose: Copolyamide 6,10 (coPA) electrospun mats were covered with multilayered (ML) and single-layered (SL) MXene (Ti3C2Tx) as a membrane for the separation of water/vegetable oil emulsions. Methods: Prepared membranes were characterized by atomic force microscopy (AFM), profilometry, the contact angle measurements of various liquids in air, and the underwater contact angle of vegetable oil. The separation efficiency was evaluated by measuring the UV transmittance of stock solutions compared to the UV transmittance of the filtrate. Results: The MXene coating onto coPA mats led to changes in the permeability, hydrophilicity, and roughness of the membranes and enhanced the separation efficiency of the water/vegetable oil emulsions containing 10, 100, and 1000 ppm of sunflower vegetable oil. It was found that membranes were highly oleophobic (>124°) under water, unlike in air, where the membranes showed high oleophobicity (<5°). The separation efficiency of water/oil emulsions for both types of covered membranes reached over 99%, with a surface coverage of 3.2 mg/cm2 Ti3C2Tx (for ML-Ti3C2Tx) and 2.9 mg/cm2 (for SL-Ti3C2Tx). Conclusions: The separation efficiency was greater than 98% for membranes covered with 2.65 mg/cm2 of ML-Ti3C2Tx, whereas the separation efficiency for membranes containing 1.89 and 0.77 mg/cm2 was less than 90% for all studied emulsion concentrations.

scholarly journals Surface properties and color stability of an acrylic resin combined with an antimicrobial polymer

2013 ◽  
Vol 42 (4) ◽  
pp. 237-242 ◽  
Author(s):  
Ana Carolina Pero ◽  
Jaqueline Ignárcio ◽  
Gabriela Giro ◽  
Danny Omar Mendoza-Marin ◽  
André Gustavo Paleari ◽  
...  
Keyword(s):  
Surface Properties ◽  
Color Stability ◽  
Acrylic Resin ◽  
Surface Characteristics ◽  
National Bureau ◽  
Color Changes ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Color Data ◽  
Student’S T

INTRODUCTION: The occurrence of stomatitis is common since the surface characteristics of the dentures may act as reservoirs for microorganisms and have the potential to support biofilm formation. PURPOSE: To assess the surface properties (wettability/roughness) and color stability of an acrylic resin combined with the antimicrobial polymer poly (2-tert-butylaminoethyl) methacrylate (PTBAEMA). MATERIAL AND METHOD: Thirty disc-shaped specimens of an acrylic resin (Lucitone 550) were divided into three groups: 0% (control); 5% and 10% PTBAEMA. Surface roughness values (Ra) were measured using a profilometer and wettability was determined through contact angle measurements using a goniometer and deionized water as a test liquid. Color data were measured with a spectrophotometer. Kruskal-Wallis and Dunn's test were used to compare roughness values. Wettability data were analyzed using ANOVA and Tukey's test. Color data were compared using the Student's t-test and ∆E values were classified according to the National Bureau of Standards (NBS). All statistical analyses were performed considering α=.05. RESULT: Significant differences (p<.05) were detected among the groups for roughness, wettability and color stability. According to the NBS, the color changes obtained in the 5% and 10% PTBAEMA groups were "appreciable" and "much appreciable", respectively. CONCLUSION: It could be concluded that PTBAEMA incorporation in an acrylic resin increased the roughness and wettability of surfaces and produced color changes with clinical relevance.

Corrosion inhibition behavior of four benzimidazole derivatives and benzotriazole on copper surface

2020 ◽  
Vol 67 (6) ◽  
pp. 565-574
Author(s):  
Lin Liu ◽  
Shuang Lu ◽  
Ya Qi Wu ◽  
Jin Yin Xie ◽  
Jinjuan Xing
Keyword(s):  
Electrochemical Measurement ◽  
Copper Surface ◽  
Molar Ratio ◽  
Benzimidazole Derivatives ◽  
Content Type ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Mixture Concentration ◽  
Contact Angle Measurements

Purpose This paper aims to reduce environment pollution caused by benzotriazole. The authors chose one of the best inhibitors from 2-aminobenzimidazole, 2-methylbenzimidazol, 2-mercaptobenzimidazole and benzimidazole in combination with benzotriazole. Design/methodology/approach The electrochemical measurement indicated that 2-methylbenzimidazol had the best inhibition behavior. Then, it was mixed with benzotriazole. Techniques such as field emission scanning electron microscopy, atomic force microscopy, Raman spectroscopy and optical contact angle measurements were used. Findings The results showed that the inhibition efficiency was up to 99.98%, when the mixture concentration was 20 mmol/L and the molar ratio 1:1. Originality/value 1-benzotriazole was mixed with 2-methylbenzimidazol for the first time. During the exist of methyl, 2-methylbenzimidazol has the better inhibition; this point was ignored by researchers. Graphical abstract

Novel vapor phase method for making ultra thin conformal films of polytetrafluoroethylene (PTFE)

2007 ◽  
Vol 992 ◽  
Author(s):  
Sushant Gupta ◽  
Arul Arjunan Chakkaravarthi ◽  
Rajiv Singh ◽  
Jeff Opalko ◽  
Deepika Singh
Keyword(s):  
Chemical Nature ◽  
Phase Method ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Pulsed Electron Deposition ◽  
Afm Micrographs ◽  
High Degree ◽  
Deposition Conditions

AbstractUltra-thin conformal polytetrafluoroethylene (PTFE) films were prepared by a novel physical vapor technique i.e., pulsed electron deposition (PED) technique. Prepared PTFE or Teflon thin films show high degree of conformity on patterned substrates. Under optimized deposition conditions the films exhibit superhydrophobicity. The PED processed films were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM) micrographs and the surface morphology and the conformal nature of the films were studied. The chemical nature and hydrophobicity were studied by FTIR and contact angle measurements, respectively.

PLATING OF COPPER LAYERS ON POLYIMIDES USING ELECTROLESS PLATING BY SURFACE MODIFICATION

2007 ◽  
Vol 14 (04) ◽  
pp. 593-596 ◽  
Author(s):  
EUN SUN JI ◽  
YOUNG HWAN KIM ◽  
YONG CHEOL KANG ◽  
YOUNG SOO KANG ◽  
BYUNG HYUN AHN
Keyword(s):  
Electroless Plating ◽  
Electroless Deposition ◽  
Solution Treatment ◽  
Polyimide Films ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Plating Method ◽  
Contact Angle Measurements ◽  
Activated Surface

This work describes electroless deposition of copper layers onto a polyimide (PI) film. The film was modified by etching with 1.0 M KOH solution treatment, and an activated Ag thin film was developed on this surface using 0.1 M AgNO 3. The Cu layers were coated on the activated surface of polyimide films by electroless plating method. The thickness and surface morphology of Cu layers on the PI films were characterized with atomic force microscopy. The surface properties of PI film were identified with contact angle measurements.

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