scholarly journals Assessment of the Functional Properties of 316L Steel Alloy Subjected to Ion Implantation Used in Biotribological Systems

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5525
Author(s):  
Katarzyna Piotrowska ◽  
Monika Madej ◽  
Dariusz Ozimina

Clinical trials conducted in many centres worldwide indicate that, despite advances made in the use of biomaterials for medical applications, tribocorrosive wear remains a significant issue. The release of wear residue into body fluids can cause inflammation and, as a result, implant failure. Surface modification is one of the methods used to improve the mechanical, tribological, and fatigue properties of biomaterials. In this article, the authors investigated the impact of ion implantation on improving the functional properties of implant surfaces. This paper presents morphology, geometric surface structure, hardness, and tribological test results for layers obtained by ion implantation with nitrogen and oxygen ions on alloy 316L. The surface morphology and thickness of the implanted layer were examined using scanning microscopy. Atomic force microscopy was used to evaluate the geometric structure of the surface. Instrumented indentation was used to measure nanohardness. Model tribo tests were carried out for reciprocating motion under conditions of dry friction and lubricated friction with Ringer’s solution. The tribological tests showed that the implanted samples had a lower wear than the reference samples. Nitrogen ion implantation increased the hardness of 316L steel by about 45% and increased it by about 15% when oxygen ions were used.

2011 ◽  
Vol 264-265 ◽  
pp. 1312-1317
Author(s):  
A.H. Ramezani ◽  
M.R. Hantezadeh ◽  
M. Ghoranneviss ◽  
A.H. Sari

This paper is the results of oxygen ion implantation on morphological and electrical properties of indium phosphate (InP) semiconductor wafers. The oxygen ions were implanted at 30 keV and various doses in the range between 5×10 15 to 5×10 17 ions/cm2 and at nearly room temperature. The changes in surface roughness and resistivity before and after the implantation is studied using atomic force microscopy (AFM) and four-point probes technique, respectively. The results show that the resistivity is depend on the ion implantation dose. In addition, the RMS roughness of implanted samples dramatically increases by accumulation of oxygen ion dose.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 544
Author(s):  
Roberto Frigerio ◽  
Angelo Musicò ◽  
Marco Brucale ◽  
Andrea Ridolfi ◽  
Silvia Galbiati ◽  
...  

Since the outbreak of the COVID-19 crisis, the handling of biological samples from confirmed or suspected SARS-CoV-2-positive individuals demanded the use of inactivation protocols to ensure laboratory operators’ safety. While not standardized, these practices can be roughly divided into two categories, namely heat inactivation and solvent-detergent treatments. These routine procedures should also apply to samples intended for Extracellular Vesicles (EVs) analysis. Assessing the impact of virus-inactivating pre-treatments is therefore of pivotal importance, given the well-known variability introduced by different pre-analytical steps on downstream EVs isolation and analysis. Arguably, shared guidelines on inactivation protocols tailored to best address EVs-specific requirements will be needed among the analytical community, yet deep investigations in this direction have not yet been reported. We here provide insights into SARS-CoV-2 inactivation practices to be adopted prior to serum EVs analysis by comparing solvent/detergent treatment vs. heat inactivation. Our analysis entails the evaluation of EVs recovery and purity along with biochemical, biophysical and biomolecular profiling by means of a set of complementary analytical techniques: Nanoparticle Tracking Analysis, Western Blotting, Atomic Force Microscopy, miRNA content (digital droplet PCR) and tetraspanin assessment by microarrays. Our data suggest an increase in ultracentrifugation (UC) recovery following heat treatment; however, it is accompanied by a marked enrichment in EVs-associated contaminants. On the other hand, solvent/detergent treatment is promising for small EVs (<150 nm range), yet a depletion of larger vesicular entities was detected. This work represents a first step towards the identification of optimal serum inactivation protocols targeted to EVs analysis.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 900
Author(s):  
Maria Vardaki ◽  
Aida Pantazi ◽  
Ioana Demetrescu ◽  
Marius Enachescu

In this work we present the results of a functional properties assessment via Atomic Force Microscopy (AFM)-based surface morphology, surface roughness, nano-scratch tests and adhesion force maps of TiZr-based nanotubular structures. The nanostructures have been electrochemically prepared in a glycerin + 15 vol.% H2O + 0.2 M NH4F electrolyte. The AFM topography images confirmed the successful preparation of the nanotubular coatings. The Root Mean Square (RMS) and average (Ra) roughness parameters increased after anodizing, while the mean adhesion force value decreased. The prepared nanocoatings exhibited a smaller mean scratch hardness value compared to the un-coated TiZr. However, the mean hardness (H) values of the coatings highlight their potential in having reliable mechanical resistances, which along with the significant increase of the surface roughness parameters, which could help in improving the osseointegration, and also with the important decrease of the mean adhesion force, which could lead to a reduction in bacterial adhesion, are providing the nanostructures with a great potential to be used as a better alternative for Ti implants in dentistry.


2003 ◽  
Vol 788 ◽  
Author(s):  
R. Job ◽  
Y. Ma ◽  
A. G. Ulyashin

ABSTRACTHydrogen plasma treatments applied on standard Czochralski silicon (Cz Si) wafers cause a structuring of the surface regions on the sub-100 nm scale, i.e. a thin ‘nano-structured’ Si layer is created up to a depth of ∼ 150 nm. The formation of the ‘nano-structures’ and their evolution in dependence on the process conditions was studied. The impact of post-hydrogenation annealing on the morphology of the structural defects was studied up to 1200 °C. The H-plasma treated and annealed samples were analyzed at surface and sub-surface regions by scanning electron microscopy (SEM), atomic force microscopy (AFM), and μ-Raman spectroscopy.


2018 ◽  
Author(s):  
Molla Islam ◽  
Maddie Tumbarello ◽  
Andrew Lyon

<div>We demonstrated the deswelling induced morphological change in dual pH and Temperature responsive ultra-low crosslinked Poly (N-isopropyl acrylamide)-co-acrylic acid microgels. The responsivity with pH and temperature were studied by light scattering and atomic force microscopy. Light scattering data suggest that at pH 4.5 the microgels undergo multiple transitions associated with collapse of pNIPAm-rich segments and repulsion between the AAc-rich segments. The evolution of punctate structures around the periphery or throughout the whole microgels at pH 4.5 and 6.5 respectively was revealed by AFM, further illustrating the heterogeneous deswelling present in the ionized copolymer microgels.</div><div>The impact of this study and understanding how ionization state of copolymer dictates the overall structural properties of microgels will widen our understanding for their applications in biotechnology</div><div><b><br></b></div>


2012 ◽  
Vol 730-732 ◽  
pp. 257-262
Author(s):  
Bruno Nunes ◽  
Sergio Magalhães ◽  
Nuno Franco ◽  
Eduardo Alves ◽  
Ana Paula Serro ◽  
...  

Aiming to improve the nanotribological response of Si-based materials we implanted silicon wafers with different fluences of iron ions (up to 2x1017 cm-2). Implantation was followed by annealing treatments at temperatures from 550°C to 1000°C. The implanted surfaces were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and wettability tests. Then, samples were submitted to AFM-based nanowear tests. We observe an increase of both hidrophobicity and and wear resistance of the implanted silicon, indicating that ion implantation of Si can be a route to be deeper explored in what concerns tribomechanical improvement of Si.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anna Maria Goździejewska ◽  
Monika Gwoździk ◽  
Sławomir Kulesza ◽  
Mirosław Bramowicz ◽  
Jacek Koszałka

Abstract Water from mining drainage is turbid because of suspensions. We tested the hypothesis that the chemical composition as well as shape and size of particles in suspensions of natural origin affect the density and functional diversity of zooplankton. The suspensions were analyzed with atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and optical microscopy. Elements found in the beidellite clays were also identified in the mineral structure of the particles. As the size of the microparticles decreased, the weight proportions of phosphorus, sulfur, and chlorine increased in the suspensions. These conditions facilitated the biomass growth of large and small microphages and raptorials. As the size of the nanoparticles decreased, the shares of silicon, aluminum, iron, and magnesium increased. These conditions inhibited raptorials the most. Ecosystem functionality was the highest with intermediate suspension parameters, which were at the lower range of the microphase and the upper range of the nanophase. The functional traits of zooplankton demonstrate their potential for use as sensitive indicators of disruptions in aquatic ecosystems that are linked with the presence of suspensions, and they facilitate gaining an understanding of the causes and scales of the impact of suspensions.


2001 ◽  
Vol 16 (11) ◽  
pp. 3293-3303 ◽  
Author(s):  
S. J. Bull ◽  
Yu. P. Sharkeev ◽  
S. V. Fortuna ◽  
I. A. Shulepov ◽  
A. J. Perry

The life of TiN-coated tools can be improved by a post-coating ion implantation treatment, but the mechanism by which this occurs is still not clear. Nitrogen implantation of both physical-vapor-deposited TiN and CVD TiN leads to surface softening as the dose increases, which has been attributed to amorphization. In this study a combination of transmission electron microscopy and atomic force microscopy was used to characterize the microstructure of implanted TiN coatings on cemented carbide for comparison with mechanical property measurements (nanoindentation, residual stress, etc.), made on the same samples. Ion implantation leads to a slight reduction in the grain size of the TiN in the implanted zone, but there is no evidence for amorphization. Surface softening is observed for physical-vapor-deposited TiN, but this is probably due to a combination of changes in surface composition and the presence of a layer of bubbles generated by the very high implantation doses used.


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