scholarly journals The Influence of Battery Acid on the Destruction of Acrylic Coatings of Car Bodies

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 967
Author(s):  
Danuta Kotnarowska
Keyword(s):  
Surface Roughness ◽  
Chemical Structure ◽  
Considerable Increase ◽  
Polar Component ◽  
Surface Layers ◽  
Interferometric Method ◽  
Sharp Difference ◽  
Acrylic Coatings ◽  
Ageing Period ◽  
Dsc Method

Renovation coatings of car bodies undergo destruction under the influence of operational factors. Like ultraviolet radiation, erosion, and aggressive media (among others, battery acid). This article concerns the evaluation of the influence of battery acid on the destruction of acrylic coatings previously non-aged, as well as aged climatically for 2 years. Ageing of the coatings with battery acid contributed to a degradation increase of their chemical structure. It was supported by a considerable increase in the polar component of surface free energy (SFE) of the coatings. In the case of prior climate ageing, the increase in the polar component was even higher. Moreover, the coating’s ability to absorb battery acid increased, which induced blistering. The DSC method revealed that the action of battery acid caused more intense oxidation of coating material, and as a result, the brittleness increased, leading to chipping of the coating surface layers. This led to the increase in surface roughness, measured using an interferometric method. The coatings previously climatically aged for 2 years presented higher values of surface roughness parameters than the non-aged ones. The increase in the surface roughness contributed to a substantial decrease in the gloss of coatings. A sharp difference in colour escalating with the lengthening of the ageing period was also observed using the spectrophotometric method.

A look into the interaction of metal oxide thin films with biological media: Albumin and Fibrinogen adsorption

2012 ◽  
Vol 1376 ◽  
Author(s):  
P. Silva-Bermudez ◽  
S. Muhl ◽  
M. Rivera ◽  
S. E. Rodil
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Protein Adsorption ◽  
Photoelectron Spectroscopy ◽  
Ex Situ ◽  
Polar Component ◽  
Metal Oxide Thin Films ◽  
Adsorbed Protein ◽  
Major Chemical ◽  
Fibrinogen Adsorption

ABSTRACTIn the present work, the adsorption of albumin and fibrinogen on Ta, Nb, Ti and Zr oxidesthin films deposited on Si (100) wafers by magnetron sputtering was studied in order to get a better understanding of the correlation among the surface properties of these oxides and the protein adsorption phenomena on their surfaces. The surface energy, hydrophobicity, chemical composition, roughness and atomic order of the films were characterized. The films were immersedfor 45 minutes in single protein solutions; either albumin or fibrinogenand the adsorbed protein layer on the films was studied ex-situ in a dry ambient using bothX-ray photoelectron spectroscopy and atomic force microscopy.The adsorption of albumin and fibrinogen on the films modified the surface morphology and decreased the surface roughness for all the four different metal oxides. The XPS results confirmed the presence of the protein on the surface of the films and showed that the two proteins studied were adsorbed without undergoing a major chemical decomposition. A correlation between the surface roughness,the polar component of the surface energy of the films and the atomic percentage of nitrogen on the films after protein adsorption, an indirect signal of the amount of protein adsorbed, was found for albumin and fibrinogen adsorption on Ta, Nb and Ti oxides; the largest the roughness or the polar component the largest amount of adsorbed protein.

scholarly journals Properties of the Surface Layer After Trochoidal Milling and Brushing: Experimental Study and Artificial Neural Network Simulation

2019 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Monika Kulisz ◽  
Ireneusz Zagórski ◽  
Jakub Matuszak ◽  
Mariusz Kłonica
Keyword(s):  
Neural Networks ◽  
Surface Roughness ◽  
Artificial Neural Networks ◽  
Cutting Speed ◽  
Mg Alloy ◽  
Polar Component ◽  
Maximum Height ◽  
Roughness Parameters ◽  
Surface Geometry ◽  
Artificial Neural

The aim of this study was to investigate the effect of milling and brushing cutting data settings on the surface geometry and energy parameters of two Mg alloy substrates: AZ91D and AZ31. In milling, the cutting speed and the trochoidal step were modified (vc = 400–1200 m/min and str = 5–30%) to investigate how they affect selected 2D (Rz, Rku, Rsk, RSm, Ra) and 3D (Sa, Sz, Sku, Ssk) roughness parameters. The brushing treatment was carried out at constant parameters: n = 5000 rev/min, vf = 300 mm/min, ap = 0.5 mm. The surface roughness of specimens was assessed with the Ra, Rz, and RSm parameters. The effects of the two treatments on the workpiece surface were analyzed comparatively. It was found that the roughness properties of the machined surface may be improved by the application of a carbide milling cutter and ceramic brush. The use of different machining data was also shown to impact the surface free energy and its polar component of Mg alloy specimens. Complementary to the results from the experimental part of the study, the investigated machining processes were modelled by means of statistical artificial neural networks (the radial basis function and multi-layered perceptron). The artificial neural networks (ANNs) were shown to perform well as a tool for the prediction of Mg alloy surface roughness parameters and the maximum height of the profile (Rz) after milling and brushing.

Morphology and thermomechanical properties of epoxy composites highly filled with waste bulk molding compounds (BMC)

2015 ◽  
Vol 35 (8) ◽  
pp. 805-811 ◽  
Author(s):  
Danuta Matykiewicz ◽  
Mateusz Barczewski ◽  
Tomasz Sterzyński
Keyword(s):  
Chemical Structure ◽  
Low Cost ◽  
Thermomechanical Properties ◽  
Epoxy Composites ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Coating Materials ◽  
Molding Compounds ◽  
Dsc Method ◽  
Resin Curing

Abstract The aim of this study was to produce epoxy composites highly filled with waste bulk molding compounds (BMC). The used amount of filler ranged from 30 wt% to 60 wt%. The influence of BMC on the epoxy resin curing process was monitored with the differential scanning calorimetry (DSC) method. Fourier transform infrared (FTIR) spectroscopy was used to evaluate the chemical structure of composites. The mechanical and thermal properties were examined by means of dynamic mechanical thermal analysis (DMTA), the Charpy method and the Shore D test. The fracture surface morphology of composites was observed with scanning electron microscopy (SEM). The storage modulus G′ of the epoxy composites with BMC was higher than the reference epoxy sample and significantly dependent on filler content. All investigated materials showed similar values of hardness, but at the same time low values of impact strength. Therefore, obtained composites can be used as low cost coating materials.

Destruction of Epoxy Coatings under the Influence of Climatic Factors

2013 ◽  
Vol 199 ◽  
pp. 581-586 ◽  
Author(s):  
Danuta Kotnarowska
Keyword(s):  
Surface Roughness ◽  
Environmental Factors ◽  
Climatic Factors ◽  
Incidence Angle ◽  
Surface Layers ◽  
Coating Structure ◽  
Epoxy Coatings ◽  
Coating Surface ◽  
Light Incidence Angle ◽  
Structure Destruction

The paper presents investigation results of climatic as well as environmental factors influence on surface state of three-layer epoxy coatings. A three-year investigation documented substantial destruction of coating surface layers. In particular, a significant increase of aged coating surface roughness, evaluated on the basis of Ra and Rz parameters, was observed. Studies made with SEM corroborated a delamination as well as pigment and filler crumbling from surface layers of coatings. In the final period of ageing craters and superficial cracks appeared in the coating structure. Destruction of aged coating surfaces contributed to their gloss loss by over 98% (for light incidence angle α = 60o) decreasing in this way coating decorative properties.

scholarly journals Evaluation of UV radiation influence on abrasivity of protective-decorative coatings for car bodies

2019 ◽  
Vol 24 (6) ◽  
pp. 192-197
Author(s):  
Danuta Kotnarowska ◽  
Dariusz Stanisławek
Keyword(s):  
Surface Roughness ◽  
Mass Loss ◽  
Uv Radiation ◽  
Ageing Time ◽  
Chemical Properties ◽  
Roughness Parameters ◽  
Surface Layers ◽  
Progressive Decline ◽  
Time Flow ◽  
Physico Chemical

The paper presents investigations concerning physico-chemical properties as well as a resistance to abrasion (abrasivity) of three-layer acrylic-polyester (renovation) coating systems after ageing with ultraviolet (UV) radiation. Generated by UV radiation photodestruction and photodegradation of examined coatings surface layers caused their chipping. This had an impact on progressive decline of the coatings thickness and hardness with the ageing time flow. UV ageing caused also almost twofold increase in surface roughness parameters Ra and Rz values. Surface roughness of the aged coatings increasing with the ageing time flow as well as their decreasing hardness contributed to their resistance to abrasion decrease, measured with the mass loss of abraded (using T-07 apparatus) coating material.

Nanomechanical Properties of Aluminum 390-T6 Rough Surfaces Undergoing Tribological Testing

2004 ◽  
Vol 126 (3) ◽  
pp. 573-582 ◽  
Author(s):  
Shaun R. Pergande ◽  
Andreas A. Polycarpou ◽  
Thomas F. Conry
Keyword(s):  
Surface Roughness ◽  
Material Properties ◽  
Bulk Material ◽  
Normal Load ◽  
Effective Elastic Modulus ◽  
Surface Microstructure ◽  
Surface Material ◽  
Surface Layers ◽  
Near Surface ◽  
Nanomechanical Properties

The nanoindentation technique was used to quantify nano-scale changes in material properties (effective elastic modulus and hardness) of Al390-T6 samples that have undergone tribological testing under a protocol in a high-pressure tribometer where the applied normal load was step-wise increased until failure by scuffing occurred. The test was highly repeatable, so additional tests were run to three intermediate fractions of the total-time-to-scuffing-failure, which provided data on the progressive wear of the surfaces preparatory to reaching the scuffed condition. The samples were engineering surfaces with significant surface roughness, nonhomogeneous surface microstructure and unknown, nonuniform surface layers. This study demonstrated that nanomechanical techniques can be extended to characterize the material properties of rough engineering surfaces. For the samples subjected to tribological testing, the material at the surface, and to approximately 60 nm below the surface, exhibited significantly higher hardness than the bulk material. Also, progressive wear of the surfaces resulted in a corresponding weakening of the near-surface material below the surface to a depth of 60 nm, while the hardness of material below the 60 nm depth remained relatively unchanged. The hardness data for the scuffed samples showed a large amount of scatter in the data, indicating that the surface is not homogeneous and that the protective surface layer is removed, at least at some points on the surface.

RELATIONSHIP BETWEEN PROGESTATIONAL ACTIVITY AND CHEMICAL STRUCTURE OF SYNTHETIC STEROIDS

1964 ◽  
Vol 30 (2) ◽  
pp. 159-170 ◽  
Author(s):  
G. K. SUCHOWSKY ◽  
G. BALDRATTI
Keyword(s):  
Oral Administration ◽  
Chemical Structure ◽  
Considerable Increase ◽  
Parent Compound ◽  
Parent Molecule ◽  
Female Patients ◽  
Basic Activity ◽  
Synthetic Steroids

SUMMARY Forty-two synthetic steroids have been studied for which certain relationships between chemical structure and progestational activity could be established. Thus, unsaturation and esterification in pregnane derivatives enhances progestational potency. Of the 4-dehydro derivatives, the 6α-CH3 and the 6α-fluoro compounds were the most active. Progestational potency on oral administration was increased in the 4-hydroxy derivatives. In the group with the 1:4-dehydro configuration, the basic activity of the parent compound was increased only by the introduction of a 6α-chloro or fluoro group. The 4:6-dehydro derivative showed an increase in potency on oral administration of about the same extent on introduction of a 6-chloro, a 6-fluoro or a 6:16α-dimethyl group. Only in the group of pregnane derivatives did changes of the parent molecule lead to a considerable increase in potency to inhibit ovulation. Since the maintenance of pregnancy in spayed animals is a parameter of progestational activity, it is felt that the results in animals are difficult to compare with those in female patients.

Tribological Properties of Ground Surfaces

2005 ◽  
Author(s):  
Miroslav Babic
Keyword(s):  
Surface Roughness ◽  
Tribological Properties ◽  
Contact Surface ◽  
Surface States ◽  
The State ◽  
Design Phase ◽  
Surface Layers ◽  
Correct Definition ◽  
Definition Of

This paper presents the results of tribometric investigations of ground surfaces machined with different combinations of grinding regime. Though they belong to the same class of surface roughness, they show significant differences in tribological properties. This is a consequence of differences in the state of material in the surface layers, which arise from the machining regime parameters variation. These results emphasize the essential importance of correct definition of tribological criteria for contact surface states in the design phase.

scholarly journals Interaction of Surface Energy Components between Solid and Liquid on Wettability, and Its Application to Textile Anti-Wetting Finish

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 498 ◽  
Author(s):  
Kwanwoo Song ◽  
Jinwook Lee ◽  
Seong-O Choi ◽  
Jooyoun Kim
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Experimental Validation ◽  
Polar Component ◽  
Basic Information ◽  
Surface Energies ◽  
Energy Profiles ◽  
Silane Coating ◽  
Energy Components

With various options of anti-wetting finish methods, this study intends to provide basic information that can be applied in selecting a relevant anti-wetting chemical to grant protection from spreading of liquids with different surface energy profiles. With such an aim, the anti-wetting effectiveness of fluorinated coating and silane coating was investigated for liquids having different surface energy components, water (WA), methylene iodide (MI) and formamide (FA). The wetting thermodynamics was experimentally investigated by analyzing dispersive and polar component surface energies of solids and liquids. The role of surface roughness in wettability was examined for fibrous nonwoven substrates that have varied surface roughness. The presence of roughness enhanced the anti-wetting performance of the anti-wetting treated surfaces. While the effectiveness of different anti-wetting treatments was varied depending on the liquid polarities, the distinction of different treatments was less apparent for the roughened fibrous surfaces than the film surfaces. This study provides experimental validation of wetting thermodynamics and the practical interpretation of anti-wetting finishing.

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