Micro/Nano Indentation and Micro-FTIR Spectroscopy Study of Weathering of Coated Engineering Thermoplastics

2005 ◽  
Vol 875 ◽  
Author(s):  
Samik Gupta ◽  
Jan Lohmeijer ◽  
Savio Sebastian ◽  
Nisha Preschilla ◽  
Amit Biswas
Keyword(s):  
Ftir Spectroscopy ◽  
Performance Prediction ◽  
Mechanical Performance ◽  
Coating Layer ◽  
Chemical Properties ◽  
Depth Sensing ◽  
Nano Indentation ◽  
Physico Chemical ◽  
Spectroscopy Studies ◽  
Micro Indentation

AbstractA novel combination of depth-sensing nano-indentation, micro-indentation and micro-FTIR techniques is employed towards understanding the durability of coating layers used on engineering thermoplastics upon exposure to harsh weathering environments. This combination of techniques enables study of changes in surface-to-bulk properties in the clearcoat-substrate system upon weathering; typically observed as a degradation starting from the surface and then proceeding inwards to the bulk of the material. Nano-indentation measurements carried out to understand the mechanical properties of the coating layer provide insights into the changes in hardness and modulus upon prolonged weathering exposure. Depth-sensing micro-indentation and micro-FTIR spectroscopy studies performed to evaluate mechanical performance and chemical changes, respectively, explain the influence of the substrate on the coating layer, especially at the interface upon weathering. This unique combination of depth-sensing indentation and micro-FTIR spectroscopy has led to an understanding of the properties of the coating layer and the substrate individually as well as an integral system as a function of weathering exposure time. Finally, the physico-chemical properties of the coating and substrate are linked to performance prediction, enabling optimization of coating-substrate combinations.

INFLUENCE OF ALUMINUM ON PHYSICO-CHEMICAL PROPERTIES OF LITHIUM IRON PHOSPHATE

2011 ◽  
Vol 04 (02) ◽  
pp. 123-127 ◽  
Author(s):  
MUNEHIRO KIMURA ◽  
KONRAD ŚWIERCZEK ◽  
JACEK MARZEC ◽  
JANINA MOLENDA
Keyword(s):  
Electrical Conductivity ◽  
Chemical Composition ◽  
Lithium Batteries ◽  
Lithium Iron Phosphate ◽  
Chemical Properties ◽  
Iron Phosphate ◽  
Electrochemical Tests ◽  
Physico Chemical ◽  
Spectroscopy Studies ◽  
Initial Results

In this work we present results of measurements of structural (XRD), microstructural (SEM, EDX, TEM) and transport (electrical conductivity, Seebeck coefficient) properties as well as results of Mössbauer and FTIR spectroscopy studies of phospho-olivine materials with assumed chemical composition Li 1-3x Al x FePO 4 (x = 0, 0.001, 0.005, 0.01, 0.02, 0.05 and 0.1). Based on the performed research, possibility of lithium sublattice doping by Al is discussed. Additionally, initial results of electrochemical tests of lithium batteries with obtained, phospho-olivine based cathode materials are provided.

scholarly journals Influence of Dispersing Method on the Quality of Nano-Admixtures Homogenization in Cement Matrix

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4865
Author(s):  
Elżbieta Horszczaruk ◽  
Paweł Łukowski ◽  
Cyprian Seul
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Cement Composite ◽  
Cement Matrix ◽  
Cement Composites ◽  
Nano Sio2 ◽  
Mechanical Stirring ◽  
Physico Chemical ◽  
Nano Fe3o4

In recent years, a nano-modification of the cement composites allowed to develop a number of new materials. The use of even small amount of nano-admixture makes possible not only to improve the physico-mechanical properties of the cement materials, but also to obtain the composite with high usability, optimised for the given application. The basic problem of nano-modification of the cement composites remains the effectiveness of dispersing the nanomaterials inside the cement matrix. This paper deals with the effect of the type and size of the nanoparticles on the tendency to their agglomeration in the cement matrix. The main techniques and methods of dispersing the nanomaterials are presented. It has been demonstrated, on the basis of the results of testing of three nanomodifiers of 0D type (nano-SiO2, nano-Fe3O4 and nano-Pb3O4), how the structure and properties of the nanomaterial affect the behaviour of the particles when dissolving in the mixing water and applying a superplasticiser. The nanoparticles had similar size of about 100 nm but different physico-chemical properties. The methods of dispersing covered the use of high-speed mechanical stirring and ultrasonication. The influence of the method of nano-modifier dispersing on the mechanical performance of the cement composite has been presented on the basis of the results of testing the cement mortars modified with 3% admixture of nano-SiO2.

scholarly journals Production, Characterization, and Evaluation of Pellets from Rice Harvest Residues

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 479 ◽  
Author(s):  
Cristina Moliner ◽  
Alberto Lagazzo ◽  
Barbara Bosio ◽  
Rodolfo Botter ◽  
Elisabetta Arato
Keyword(s):  
Moisture Content ◽  
Rice Straw ◽  
Rice Husk ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Quality Standards ◽  
Operational Conditions ◽  
Diametral Compression ◽  
Physical Chemical ◽  
Physico Chemical

Pellets from residues from rice harvest (i.e., straw and husk) were produced and their main properties were evaluated. Firstly, rice straw pellets were produced at lab scale at varying operational conditions (i.e., load compression and wt % of feeding moisture content) to evaluate their suitability for palletization. Successively, rice straw and husk pellets were commercially produced. All the samples were characterized in terms of their main physical, chemical, and physico-chemical properties. In addition, axial/diametral compression and durability tests were performed to assess their mechanical performance. All the analyzed properties were compared with the established quality standards for non-woody pellets. In general, rice straw pellets presented suitable properties for their use as pelletized fuels. Rice husk pellets fell out of the standards in recommended size or durability and thus preliminary treatments might be required prior their use as fuels.

scholarly journals Fiber-Templated 3D Calcium-Phosphate Scaffolds for Biomedical Applications: The Role of the Thermal Treatment Ambient on Physico-Chemical Properties

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2198
Author(s):  
Aura-Cătălina Mocanu ◽  
Florin Miculescu ◽  
George E. Stan ◽  
Andreea-Mădălina Pandele ◽  
Mihai Alin Pop ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Performance Assessments ◽  
Mechanical Reinforcement ◽  
Architectural Features ◽  
Fast Bone ◽  
Physico Chemical ◽  
Mechanical Performances

A successful bone-graft-controlled healing entails the development of novel products with tunable compositional and architectural features and mechanical performances and is, thereby, able to accommodate fast bone in-growth and remodeling. To this effect, graphene nanoplatelets and Luffa-fibers were chosen as mechanical reinforcement phase and sacrificial template, respectively, and incorporated into a hydroxyapatite and brushite matrix derived by marble conversion with the help of a reproducible technology. The bio-products, framed by a one-stage-addition polymer-free fabrication route, were thoroughly physico-chemically investigated (by XRD, FTIR spectroscopy, SEM, and nano-computed tomography analysis, as well as surface energy measurements and mechanical performance assessments) after sintering in air or nitrogen ambient. The experiments exposed that the coupling of a nitrogen ambient with the graphene admixing triggers, in both compact and porous samples, important structural (i.e., decomposition of β-Ca3(PO4)2 into α-Ca3(PO4)2 and α-Ca2P2O7) and morphological modifications. Certain restrictions and benefits were outlined with respect to the spatial porosity and global mechanical features of the derived bone scaffolds. Specifically, in nitrogen ambient, the graphene amount should be set to a maximum 0.25 wt.% in the case of compact products, while for the porous ones, significantly augmented compressive strengths were revealed at all graphene amounts. The sintering ambient or the graphene addition did not interfere with the Luffa ability to generate 3D-channels-arrays at high temperatures. It can be concluded that both Luffa and graphene agents act as adjuvants under nitrogen ambient, and that their incorporation-ratio can be modulated to favorably fit certain foreseeable biomedical applications.

scholarly journals Evaluation of new biodegradable fluid on the basis  of accelerated durability test, FTIR and ICP spectroscopy

2017 ◽  
Vol 63 (No. 1) ◽  
pp. 1-9 ◽  
Author(s):  
Tulík Juraj ◽  
Hujo Ľubomir ◽  
Kosiba Jan ◽  
Jablonický Juraj ◽  
Jánošová Michela
Keyword(s):  
Ftir Spectroscopy ◽  
Chemical Properties ◽  
Hydraulic Pump ◽  
Spectroscopy Analysis ◽  
Durability Test ◽  
Operational Conditions ◽  
Physico Chemical ◽  
Hydraulic Fluids ◽  
Accelerated Durability Test ◽  
Agricultural Machines

The paper deals with the properties of newly developed synthetic biodegradable fluid in terms of its operational and physico-chemical properties. The evaluated fluid is a new biodegradable fluid MOL Farm UTTO Synt, which belongs to the group of universal gear-hydraulic fluids. At the beginning, the fluid was subjected to accelerated durability test under laboratory conditions, with monitoring its impact on technical conditions of the used hydraulic pump UD 25. After that, the FTIR spectroscopy analysis was performed, with monitoring thermal oxidation, oxidation by acid products, water content and additives depletion. Depletion of additives was also monitored by the ICP spectroscopy. Based on these results, it can be stated that the newly developed fluid has good operational and physico-chemical properties after the durability test and is suitable for further testing under operational conditions without a risk of damaging agricultural machines.

scholarly journals Analysis of Mechanical Performance of Bitumen Modified with Waste Plastic and Rubber Additives by Rheology and Self Diffusion NMR Experiments

2019 ◽  
Vol 21 (3) ◽  
pp. 235 ◽  
Author(s):  
P. Caputo ◽  
M. Porto ◽  
V. Loise ◽  
B. Teltayev ◽  
C. Oliviero Rossi
Keyword(s):  
Mechanical Performance ◽  
Spin Echo ◽  
Chemical Properties ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Modified Bitumen ◽  
Waste Plastic ◽  
Self Diffusion ◽  
Physico Chemical ◽  
Styrene Butadiene

In this study, the mechanical and physico-chemical properties of a new kind of modified bitumen are presented. The bituminous binders have been modified in order to understand the effect on the structural properties of several compounds such as a Polymer elastomer as Styrene Butadiene Rubber (SBR), Polymer thermoplastic polypropylene (PP) and a waste plastic (Waste PP). Laboratory tests have been focused on the characterization of bitumen modified with single product and their binary combinations compared with pristine binder as a reference. Characterization has been conducted by using conventional as well as advanced methods on bitumens. Fundamental rheological tests, based on dynamic shear rheometer in the temperature range from -30 °C to +160 °C have been performed and the structure of a bitumens and modified bitumens has been analysed by the mobility of the oily maltene by self-diffusion Pulsed field gradient spin-echo (PGSE) FT-NMR experiments.

scholarly journals Monolayers of Cholesterol and Cholesteryl Stearate at the Water/Vapor Interface: A Physico-Chemical Study of Components of the Meibum Layer

2021 ◽  
Vol 5 (2) ◽  
pp. 30
Author(s):  
Ramón G. Rubio ◽  
Eduardo Guzmán ◽  
Francisco Ortega ◽  
Libero Liggieri
Keyword(s):  
Cell Membranes ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
Langmuir Monolayers ◽  
Tear Film ◽  
Chemical Study ◽  
Lipid Monolayer ◽  
Molar Ratio ◽  
Physico Chemical

Langmuir monolayers containing different amounts of cholesterol and cholesteryl stearate were studied at two different temperatures (24 °C and 35 °C). The main goal was to contribute towards the understanding of how the variations in the chemical composition may affect the physico-chemical properties of these specific lipid monolayers. The model mixture was chosen considering that cholesteryl esters are present in cell membranes and some other biological systems, including human tear lipids. Therefore, an investigation into the effect of the lipid monolayer composition on their interfacial properties may elucidate some of the fundamental reasons for the deficiencies in cell membranes and tear film functioning in vivo. The experimental results have shown that the molar ratio of the mixture plays a crucial role in the modulation of the Langmuir film properties. The condensing effects of the cholesterol and the interactions between the lipids in the monolayer were the main factors altering the monolayer response to dilatational deformation. The modification of the mixture compositions leads to significant changes in the Langmuir films and the mechanical performance, altering the ability of the monolayer to reduce the surface tension and the viscoelastic properties of the monolayers. This suggests that subtle modifications of the biomembrane composition may significantly alter its physiological function.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

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