Thickness Measurements and Optical Characterization of Thin Polymer Films

1993 ◽  
Vol 304 ◽  
Author(s):  
J. F. Wall ◽  
J. C. Brumfield ◽  
R. W. Murray ◽  
E. A. Irene
Keyword(s):  
Protective Coatings ◽  
Pyrolytic Graphite ◽  
Force Microscopy ◽  
Near Ultraviolet ◽  
Atomic Force ◽  
Thin Polymer ◽  
Ultraviolet Spectral Region ◽  
The Subject ◽  
Thickness Measurements

AbstractPolyphenylene oxide (PPO) films have been investigated as protective coatings and as selective inhibitors to permeants.1,2,3 These films have been shown to be passivating materials and therefore are potentially interesting for a variety of applications. It is important for further applications to be able to measure the thickness of thin films by nondestructive techniques, which is the subject of this report. In this study PPO films of various thicknesses were electrodeposited on highly oriented pyrolytic graphite (HOPG) electrodes and examined by spectroscopic ellipsometry (SE) and atomic force microscopy (AFM). These techniques are combined to yield the thickness of the polymer film and the optical properties of the HOPG substrate and the PPO overlayer in the visible and near ultraviolet spectral region.

MOBILITY OF ADSORBED POLYMER CHAINS

2010 ◽  
Vol 83 (4) ◽  
pp. 323-330 ◽  
Author(s):  
D. Goeritz ◽  
R. W. P. Hofmann ◽  
H. H. Bissem
Keyword(s):  
Pyrolytic Graphite ◽  
Polymer Chains ◽  
Glass Layer ◽  
Layer System ◽  
Force Microscopy ◽  
Glass State ◽  
Atomic Force ◽  
Highly Ordered Pyrolytic Graphite ◽  
Adsorbed Polymer ◽  
Thin Polymer

Abstract The behavior of thin polymer films adsorbed on a graphite surface was investigated by means of atomic force microscopy. Via force–distance curves, which were recorded for layers of polyisoprene adsorbed on graphite [highly ordered pyrolytic graphite (HOPG)], a two-layer system was found. The upper layer proved to be soft and not in the glass state. No indications supporting the supposition of an additional glasslike polyisoprene layer underneath this soft layer could be found. Thus, if such a glass layer exists on the HOPG surface, the upper limit of its thickness is set to 3 nm. On the other hand, polystyrene adsorbed on graphite is in the glass state independent of thickness.

scholarly journals Characterization of the microscopic tribological properties of sandfish (Scincus scincus) scales by atomic force microscopy

2018 ◽  
Vol 9 ◽  
pp. 2618-2627 ◽  
Author(s):  
Weibin Wu ◽  
Christian Lutz ◽  
Simon Mersch ◽  
Richard Thelen ◽  
Christian Greiner ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Pyrolytic Graphite ◽  
Force Microscopy ◽  
Frictional Properties ◽  
Atomic Force ◽  
The Common ◽  
Adhesion Friction

Lizards of the genus Scincus are widely known under the common name sandfish due to their ability to swim in loose, aeolian sand. Some studies report that this fascinating property of sandfish is accompanied by unique tribological properties of their skin such as ultra-low adhesion, friction and wear. The majority of these reports, however, is based on experiments conducted with a non-standard granular tribometer. Here, we characterise microscopic adhesion, friction and wear of single sandfish scales by atomic force microscopy. The analysis of frictional properties with different types of probes (sharp silicon tips, spherical glass tips and sand debris) demonstrates that the tribological properties of sandfish scales on the microscale are not exceptional if compared to snake scales or technical surfaces such as aluminium, Teflon, or highly oriented pyrolytic graphite.

scholarly journals TEM & AFM - Complementary Techniques For Structural Characterization Of Nanobainitic Steel

2015 ◽  
Vol 60 (3) ◽  
pp. 1591-1594
Author(s):  
J. Dworecka ◽  
E. Jezierska ◽  
J. Rębiś ◽  
K. Rożniatowski ◽  
W. Świątnicki
Keyword(s):  
Plate Thickness ◽  
Nanocrystalline Structure ◽  
Bearing Steel ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Complementary Techniques ◽  
Thickness Measurements ◽  
Microscopic Techniques

Abstract The aim of this study was to analyse and to identify the phases which formed in 100CrMnSi6-4 bearing steel after the nanostructuring heat treatment. Especially designed thermal treatment parameters were applied in order to obtain a nanobainitic structure. Two different microscopic techniques were used for the precise examination of the microstructures obtained: transmission electron microscopy (TEM) and atomic force microscopy (AFM). Both analyses confirm that the examined steel has a nanocrystalline structure. However, it was discovered that the selected analysis methods affected the results of the plate thickness measurements.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

Stereometric characterization of Dinizia excelsa Ducke wood from Amazon rainforest using atomic force microscopy

2021 ◽  
Author(s):  
Willian Silva Conceição ◽  
Ştefan Ţălu ◽  
Robert Saraiva Matos ◽  
Glenda Quaresma Ramos ◽  
Fidel Guereiro Zayas ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Amazon Rainforest ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dinizia Excelsa

scholarly journals A Universal Model for the Log-Normal Distribution of Elasticity in Polymeric Gels and Its Relevance to Mechanical Signature of Biological Tissues

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Arnaud Millet
Keyword(s):  
Elastic Modulus ◽  
Normal Distribution ◽  
Biological Tissues ◽  
Force Microscopy ◽  
Polymeric Gels ◽  
Atomic Force ◽  
Clear Explanation ◽  
Log Normal ◽  
Log Normal Distribution

The mechanosensitivity of cells has recently been identified as a process that could greatly influence a cell’s fate. To understand the interaction between cells and their surrounding extracellular matrix, the characterization of the mechanical properties of natural polymeric gels is needed. Atomic force microscopy (AFM) is one of the leading tools used to characterize mechanically biological tissues. It appears that the elasticity (elastic modulus) values obtained by AFM presents a log-normal distribution. Despite its ubiquity, the log-normal distribution concerning the elastic modulus of biological tissues does not have a clear explanation. In this paper, we propose a physical mechanism based on the weak universality of critical exponents in the percolation process leading to gelation. Following this, we discuss the relevance of this model for mechanical signatures of biological tissues.

In Situ Characterization of the Mechanical Behavior of Gecko's Spatulae by Atomic Force Microscopy

2013 ◽  
Vol 22 ◽  
pp. 85-93
Author(s):  
Shuang Yi Liu ◽  
Min Min Tang ◽  
Ai Kah Soh ◽  
Liang Hong
Keyword(s):  
Mechanical Behavior ◽  
Hierarchical Level ◽  
Intrinsic Properties ◽  
In Situ Characterization ◽  
Force Microscopy ◽  
Atomic Force ◽  
Theoretical Predictions ◽  
Multi Mode

In-situ characterization of the mechanical behavior of geckos spatula has been carried out in detail using multi-mode AFM system. Combining successful application of a novel AFM mode, i.e. Harmonix microscopy, the more detail elastic properties of spatula is brought to light. The results obtained show the variation of the mechanical properties on the hierarchical level of a seta, even for the different locations, pad and stalk of the spatula. A model, which has been validated using the existing experimental data and phenomena as well as theoretical predictions for geckos adhesion, crawling and self-cleaning of spatulae, is proposed in this paper. Through contrast of adhesive and craw ability of the gecko on the surfaces with different surface roughness, and measurement of the surface adhesive behaviors of Teflon, the most effective adhesion of the gecko is more dependent on the intrinsic properties of the surface which is adhered.

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