Structure of Silane Films and their Adhesion Properties

1995 ◽  
Vol 407 ◽  
Author(s):  
Y. Carolina Araujo ◽  
Pedro G. Toledo
Keyword(s):  
Contact Angle ◽  
Surface Coverage ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Flow In Porous Media ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Glass Surfaces

ABSTRACTSilane films, their structure and stability, are of great interest in processes such as flow in porous media, mineral flotation, chromatography and corrosion. Here, the structure of octadecyl thriclorosilane (OTS) films on glass surfaces is studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), their adhesion properties by contact angle measurements and adhesion tests. Complete glass surface coverage by the silane is attained after an immersion time tc characteristic of the OTS compound. The time evolution of the OTS films regarding surface coverage is monitored by SEM with a BSE detector, by measuring the OTS film thicknesses from XPS data, by AFM and by contact angle measurement. At tc the structure of the films changes from micromolecular to macromolecular. Below tc the glass coverage has a fractal geometry and various degrees of hydrophobicity are possible. At t > tc the surface coverage is complete and the contact angle achieved a well defined constant value.

scholarly journals Surface Properties of Alginate/Chitosan Biofilm for Wound Healing Application

2020 ◽  
Vol 1010 ◽  
pp. 602-607
Author(s):  
Maizlinda Izwana Idris ◽  
Mohammed Firdaus Adzhari ◽  
Siti Natrah Abdul Bakil ◽  
Tee Chuan Lee ◽  
Mohamad Ali Selimin ◽  
...  
Keyword(s):  
Contact Angle ◽  
Wound Healing ◽  
Surface Properties ◽  
Healing Process ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Force Microscopy ◽  
Good Surface ◽  
Atomic Force ◽  
Biopolymer Film

This work focuses on the fabrication of film based on natural biopolymers for wound healing application. Alginate and chitosan were choosen because of their oustanding properties such as biocompatible, hydrophilic and non-toxic. Earlier, the biopolymer film was fabricated by using alginate 1% wt and chitosan 1% wt. solutions at volume ratios of 99:1 and 97:3. Next, the biopolymer film solution was cross-linked with 1M CaCl2.2H2O for two hours and later dried for 24 hours at room temperature. Then, the surface properties of the prepared biopolymer films were characterised via Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM) and contact angle measurement. It was observed that the surface of the biopolymer film became rougher as the volume of the chitosan increases. This condition was confirmed with average surface roughness, RA for biopolymer film with ratio of 97:3 resulted in higher values. Also it was found that the surface of biopolymer films were hydrophilic after the contact angle was less than 90°. This can be concluded that the biopolymer based on alginate/chitosan is a promising candidate for wound healing materials particularly with good surface properties for faster healing process at the wound areas.

Surface hydrophilizing modification of polytetrafluoroethylene/glass fiber fabric through oxidant-induced polydopamine deposition

2019 ◽  
Vol 50 (3) ◽  
pp. 364-379
Author(s):  
Yanfen Zhou ◽  
Liang Jiang ◽  
Zhiqing Jiang ◽  
Shaojuan Chen ◽  
Jianwei Ma
Keyword(s):  
Contact Angle ◽  
Glass Fiber ◽  
Water Contact Angle ◽  
Mechanical Stability ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fiber Fabric

This paper reports surface hydrophilizing modification of polytetrafluoroethylene/glass fiber fabric by employing bio-inspired polydopamine functionalization. The modification process was accelerated by introducing sodium periodate (NaIO4) as oxidant. Surface morphology and chemical composition of the modified polytetrafluoroethylene/glass fiber fabric were characterized by using scanning electron microscopy, atomic force microscopy (AFM), and Fourier transform infrared spectroscopy, respectively. Hydrophilicity of the polytetrafluoroethylene/glass fiber fabric was investigated through water contact angle measurement. It was found that polydopamine successfully deposited on the surface of polytetrafluoroethylene/glass fiber fabric and the uniformity of the polydopamine coating increased with increasing modification time. Water contact angle of polytetrafluoroethylene/glass fiber fabric decreased after polydopamine modification and reached 29° when the sample was treated for 120 min, indicating an improved hydrophilic performance. The formed polydopamine coating was also demonstrated to have reliable chemical and mechanical stability.

Surface Treatments of 4H-SiC Evaluated by Contact Angle Measurement

2011 ◽  
Vol 679-680 ◽  
pp. 374-377 ◽  
Author(s):  
Tomoaki Hatayama ◽  
Hiroyuki Suzuki ◽  
Hidenori Koketsu ◽  
Hiroshi Yano ◽  
Takashi Fuyuki
Keyword(s):  
Contact Angle ◽  
Oxide Layer ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Substrate Surfaces

Surface properties of the 4H-SiC (0001) Si faces could be evaluated by the contact angle measurements with water droplet method, X-ray photoelectron spectroscopy and an atomic force microscope. The contact angles do not depend on the surface roughness under 3nm. The substrate surfaces with the contact angles over 30o will be terminated by hydrogen related species. The contact angles around 20o on 4H-SiC is caused by the removal of oxide layer with fluoride acid and terminated subsequently by the -CF species on the surface. The hydrophile surface of 4H-SiC is caused by the formation of chemical oxide layer as well as the case of the silicon wafers.

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.

Super-Hydrophobic Surfaces Improve Corrosion Resistance of Fe3Al-Type Intermetallic in Seawater

2008 ◽  
Vol 47-50 ◽  
pp. 173-176 ◽  
Author(s):  
Tao Liu ◽  
Kin Tak Lau ◽  
Shou Gang Chen ◽  
Sha Cheng ◽  
Yan Sheng Yin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Contact Angle ◽  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Hydrophobic Surface ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Atomic Force ◽  
Scanning Electron

A novel super-hydrophobic film was prepared by myristic acid (CH3(CH2)12COOH) chemically adsorbed onto the polyethyleneimine (PEI) coated Fe3Al-type intermetallic wafer. The film character and structure were probed with contact angle measurement, scanning electron microscopy (SEM) and atomic force microscope (AFM). The results suggest that the structure of the film is similar to lotus and the seawater contact angle is larger than 150◦. Moreover, the corrosion resistances of untreated and modified samples in seawater were investigated by electrochemical impedance spectroscopy (EIS). Experimental results show that the corrosion rate of Fe3Al-type intermetallic with super-hydrophobic surface decreases dramatically because of its special microstructure.

scholarly journals Characterization of Lipid Membrane Properties for Tunable Electroporation

2012 ◽  
Author(s):  
H. Jeremy Cho ◽  
Shalabh C. Maroo ◽  
Evelyn N. Wang
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membrane ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Membrane Properties ◽  
Force Microscopy ◽  
Packing Structure ◽  
Atomic Force ◽  
Dynamics Simulations

Lipid bilayers form nanopores on the application of an electric field. This process of electroporation can be utilized in different applications ranging from targeted drug delivery in cells to nano-gating membrane for engineering applications. However, the ease of electroporation is dependent on the surface energy of the lipid layers and thus directly related to the packing structure of the lipid molecules. 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid monolayers were deposited on a mica substrate using the Langmuir-Blodgett (LB) technique at different packing densities and analyzed using atomic force microscopy (AFM). The wetting behavior of these monolayers was investigated by contact angle measurement and molecular dynamics simulations. It was found that an equilibrium packing density of liquid-condensed (LC) phase DPPC likely exists and that water molecules can penetrate the monolayer displacing the lipid molecules. The surface tension of the monolayer in air and water was obtained along with its breakthrough force.

Sign in / Sign up

Export Citation Format

Share Document