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1

The Effects of Travel Speed of Tungsten Inert Gas Cladding of Tungsten Carbide and Nickel Composites on the Microstructure of Stainless Steel

Oleiwi Aws Ali, Jilabi Abdul Sameea Jasim

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 4

177--190

EN

he scientific and industrial communities now consider surface modification of steel-based alloys to be essential. One effective method of altering these alloys' surfaces is tungsten inert gas (TIG) cladding.The purpose of this study is to investigate how the surface characteristics of austenitic stainless steel substrates are affected by TIG-deposited composite coatings made of tungsten carbide and nickel (WC-Ni). The study also intends to investigate the influence of the WC-Ni composite coatings' travel speed, and as a result, the heat input usually has significant effects on the microstructure. The coating layers were deposited at different travel speeds (67, 107, and 122 mm/min) using pre-placed composite pastes that were 1 mm thick and contained the same weight percentage of WC (65). The clad layers showed a variety of microstructures in optical and scanning electron microscopy, primarily nickel solid solution dendrites with WC particles scattered throughout the matrix. The dendrites at various locations across the clad layers were few or dense, finer or coarser, equiaxial or columnar, densely or less densely branched, depending on the cooling rates and the density of WC in the composite. Energy dispersive spectroscopy demonstrated that the Fe element that was transferred from the substrate material to the molten pool was primarily concentrated in the matrix, not the dendrites, while the dendrite locations and orientations were amply demonstrated by the distribution of the W element.

2

Surface Modification of the Ti-35Nb-7Zr-5Ta Bio Alloy by the PM-EDM Route

Hayyawi Ahmed Rabeea, Al-Ethari Haydar, Haleem Ali Hubi

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 3

140--150

EN

One of the most attractive β-Ti alloys is Ti–35Nb–7Zr–5Ta wt% (TNZT) alloy, which has one of the minimal Young’s moduli among the β-Ti family (about 55 GPa) and contains no cytotoxic elements. On the other hand, β-type Ti alloys are susceptible to bacterial infection because they lack an antibacterial function and can get contaminated quickly after implantation, making surface modification a keyway to improve these alloys' antibacterial properties. A recently created technique called powder mixed-EDM can improve machining, mechanical, and biological properties at the same time. In this research, silver was added to the dielectric fluid during PM-EDM of Ti-35Nb-7Zr-5Ta wt% alloy prepared by powder metallurgy route. The surface composition, Brinell hardness, corrosion resistance, ion release, and antibacterial properties were evaluated for TNZT alloy before and after surface modification. The results show better hardness and corrosion resistance as well as lower ion release for the PM-EDMed specimen due to the presence of Ag, oxides, and carbides such as NbC, TiC, TiO2, ZrO2, and Nb2O5 that’s deposited and embedded as a hard phase in the recast layer of the machined surface. Also, the antibacterial property of the PM-EDMed specimen is effectively improved as silver is an antibiotic with a wide range, so it has favorable antibacterial properties for Gram-negative and Gram-positive bacteria.

3

Coaxial Laser Wire Deposition of AISI 316L steel - research on influence of processing parameters

Koruba Piotr, Radkiewicz Przemysław, Kędzia Jakub, Dziedzic Robert, Smuga Piotr, Reiner Jacek

Welding Technology Review

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2023

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R. 95

67--77

EN

Laser cladding technology is a well-established process, commonly used for deposition of improved-property coatings, repair of machine parts and additive manufacturing. Currently, in terms of application of laser cladding, the method based on powder deposition is much more common, as the use of an adapted nozzle allows the coaxial and direction-independent feeding of additional material into the weld pool. However, laser cladding with powder also has some significant drawbacks, e.g., limited powder feeding and melting efficiency, lower productivity and the resulting dust that poses a health risk to operators. The solution to these limitations is the use of additional material in the form of wire. To maintain the ability to coaxially feed the wire to the laser beam interaction point, a specialized cladding head is necessary. In mentioned system the laser beam, while being passed through the optical system, is divided into three separate beams that are focused on the substrate on the working point of the head. In this study, the COAX wire cladding head was integrated into the robot station and laser cladding process was carried out to determine the influence of the processing parameters on the deposition results. The parameters of the cladding system were identified, including the measurement of laser beam caustic. The experimental trials were carried out using AISI 316L wire deposited on S420MC substrate. The effect of the processing parameters on the geometry of the clad was determined with particular emphasis on the wire feeding.

4

Abrasion Resistance Test of the Modified Ti13Nb13Zr Alloy Surface

Lisoń-Kubica Julia, Taratuta Anna, Antonowicz Magdalena, Basiaga Marcin

Tribologia

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2023

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nr 2

55--64

EN

The research describes an atomic layer deposition (ALD) coating method and its application on a new generation of titanium alloy (Ti13Nb13Zr) for biomedical applications. The study aimed to assess the physicochemical properties and mechanics of a titanium alloy coated with titanium oxide (TiO2) or aluminium oxide (Al2O3) using the ALD method. The physicochemical properties of the surface coatings were evaluated through microscopic observations, potentiodynamic tests, surface wettability tests, optical profilometry scratch tests, and abrasion tests. Based on the data obtained, different physicochemical properties of the alloy with titanium nitride and titanium oxide coatings were found. Such differences were dependent on the number of cycles used and the temperature of the manufacturing process. The coatings have reduced the abrasion coefficient, thus improving the abrasion resistance of the Ti13Nb13Zr alloy, which enables their use within the skeletal system. These findings are of practical importance for applying this type of surface modification to various types of miniaturised implants used in the skeletal system.

PL

Badania polegają na opisaniu metody osadzania powłok atomowych i możliwości jej zastosowania na stopie tytanu nowej generacji do zastosowań biomedycznych. Celem pracy jest ocena wpływu właściwości fizyko chemicznych i mechanicznych zmodyfikowanego stopu Ti13Nb13Zr powłoką tlenku tytanu (TiO2) oraz tlenku glinu (Al2O3) przy użyciu metody ALD. W ramach oceny własności fizykochemicznych tak powstałych powłok powierzchniowych przeprowadzono obserwacje mikroskopowe (SEM), badania potencjodynamiczne, badania zwilżalności powierzchni, profilometrię optyczną, scratch test oraz badania ścieralności powłok. Na podstawie uzyskanych danych stwierdzono zróżnicowane własności fizykochemiczne stopu z powłokami tlenku glinu oraz tlenku tytanu w zależności od zastosowanej ilości cykli oraz temperatury procesu wytwarzania. Powłoki mają obniżony współczynnik ścieralności, poprawiając tym samym odporność na ścieranie stopu Ti13Nb13Zr, co umożliwia ich zastosowanie w układzie kostnym. Uzyskana na tej podstawie wiedza ma znaczenie praktyczne dla zastosowania tego typu modyfikacji powierzchni dla różnych rodzajów zminiaturyzowanych implantów znajdujących swoje zastosowanie w układzie kostnym.

5

Enhanced sulfidation of chrysocolla with ammonium carbamate and its effect on flotation

Wang Ziang, Wu Dandan, Cao Jing, Chen Huiqin

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 3

atr. no. 168573

EN

In this study, flotation experiments, zeta potential, XPS, AFM, SEM-EDS, and contact angle measurements were performed to study the influence of ammonium carbamate (CH6N2O2) on the sulfidation flotation of chrysocolla. The results of the sulfidation flotation experiments showed that the recovery of chrysocolla increased more than 40% on the optimal condition after adding ammonium carbamate. In addition, the zeta potential of samples with ammonium carbamate was clearly higher than ores for pH > 6, which was due to the complexation reaction between ammonium carbamate and copper ion on the surface of chrysocolla samples. The activity of copper adsorption has also been improved. Furthermore, the XPS data indicated that the content of Cu-S compounds on the mineral surface has been significantly enhanced after ammonium carbamate complex sulfidation. The chemical analysis of the solution led to the same conclusion. The AFM results showed that ammonium carbamate had a positive impact on the adsorption of minerals surface, and increased the flotation recovery. It can be deduced from the SEM-EDS analysis that the surface of chrysocolla better combined with S-, and more Cu-S components were generated on the surface, which led to 1.04% increase of S atomic concentration. Finally, the contact angle measurements showed that the water contact angle of chrysocolla after adding ammonium carbamate could reach 90.4°, which proved that the sulfidation improved the floatability of the chrysocolla sample.

6

Influence of surface-modified nanoclay on the flexural strength of unsaturated polyester resin

Stępka Dominik

Inżynieria Materiałowa

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2023

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Vol. 44, nr 5

5--10

EN

This study delves into the influence of surface-modified nanoclay on the flexural strength of Unsaturated Polyester Resins (UPRs). UPRs, known for their robust mechanical properties, find extensive applications across various industries. With the aim of further enhancing these properties, nanofillers, specifically surface-modified nanoclay, were incorporated into the resin matrix. Our research revealed a significant improvement in flexural strength with an optimal nanoclay addition of 0.1% by weight. However, the morphological analysis identified the presence of nanoclay agglomerates, indicating potential areas for optimization in the dispersion process. The findings present a promising direction for developing advanced UPR-based materials, emphasizing the pivotal role of nanofillers in achieving superior mechanical performance.

PL

Analizowano wpływ nanoglinki o modyfikowanej powierzchni na wytrzymałość na zginanie nienasyconych żywic poliestrowych (UPR). UPR, znane ze swoich solidnych właściwości mechanicznych, znajdują szerokie zastosowanie w różnych gałęziach przemysłu. W celu dalszej poprawy tych właściwości do matrycy żywicznej wprowadzono nanonapełniacz, a dokładnie nanoglinkę z modyfikowaną powierzchnią. Badania wykazały znaczną poprawę wytrzymałości na zginanie przy optymalnym dodatku nanoglinki w ilości 0,1% mas. Analiza morfologiczna wykazała obecność aglomeratów nanoglinki, wskazując potencjalne obszary optymalizacji w procesie dyspersji. Odkrycia wyznaczają obiecujący kierunek rozwoju zaawansowanych materiałów na bazie UPR, podkreślając kluczową rolę nanonapełniaczy w osiąganiu doskonałych parametrów mechanicznych.

7

Influence of sisal fibre modification on the microbial stability of poly(hydroxybutyrate-co-valerate): thermal analysis

Kittikorn Thorsak, Strömberg Emma, Ek Monica, Karlsson Sigbritt

Polimery

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2022

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Vol. 67, nr 3

93--101

EN

The effect of modification of sisal fibre with propionic anhydride and vinyltrimethoxy silane on the microbiological stability of poly(hydroxybutyrate-co-valerate) (PHBV) was investigated. The effect of the coupling agent – PHBV grafted with maleic anhydride (PHBV-g-MA) was also investigated. The best adhesion at the interface was observed for propionylation of sisal fibre, which improved the thermal properties of the composites. Composites with modified sisal fibre were characterized by higher activation energy (155 kJ/mol), which is related to stronger interactions at the matrix-fibre interface. In the microbial growth test, all biocomposites showed a decrease in molecular weight due to enzymatic degradation by Aspergillus niger. The most resistant to microorganisms was the composite containing propionylated sisal fibre. DMTA and TGA also confirmed the highest microbiological stability of the composite with the addition of propionylated sisal fibre, as evidenced by the smallest change in the properties after the microbiological growth test. In contrast, PHBV- g-MA caused significant enzymatic degradation due to the presence of large amorphous regions.

PL

Zbadano wpływ modyfikacji włókna sizalowego bezwodnikiem propionowym i winylotrimetoksy silanem na stabilność mikrobiologiczną poli(hydroksymaślanu-co-walerianianu) (PHBV). Zbadano również wpływ środka sprzęgającego − PHBV szczepionego bezwodnikiem maleinowym (PHBV-g-MA). Najlepszą adhezję na granicy faz stwierdzono w przypadku zastosowania propionylowania włókna sizalowego, co poprawiło właściwości termiczne kompozytów. Kompozyty z modyfikowanym włóknem sizalowym charakteryzowały się wyższą energią aktywacji (155 kJ/mol), co wiąże się z silniejszymi oddziaływaniami na granicy faz osnowa-włókno. W teście wzrostu drobnoustrojów wszystkie biokompozyty wykazywały zmniejszenie masy cząsteczkowej na skutek enzymatycznej degradacji przez Aspergillus niger. Najbardziej odporny na działanie mikroorganizmów były kompozyt zawierający propionylowane włókno sizalowe. DMTA i TGA potwierdziły również najwyższą stabilność mikrobiologiczną kompozytu z dodatkiem propionylowanego włókna sizalowego, o czym świadczy najmniejsza zmiana badanych właściwości po teście wzrostu mikrobiologicznego. Natomiast, PHBV-g-MA powodował znaczną degradację enzymatyczną ze względu na obecność dużych obszarów amorficznych.

8

Surface modifications of biomaterial with different cold plasma reactors to improve cell adhesion

Terebun Piotr, Wójcik Michał, Trzaskowska Marta, Kwiatkowski Michał, Zarzeczny Dawid, Kazimierczak Paulina, Pawłat Joanna, Przekora Agata

Engineering of Biomaterials

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2022

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vol. 25, no. 165

2--6

EN

There is a growing trend in the engineering of biomaterials, focusing on surface modifications of biomaterials to improve their mechanical strength, corrosion resistance, and biological properties. Cold plasma treatment may improve biological properties of biomaterials for biomedical applications by enhancing their integration with host tissue. This study investigated the influence of different cold plasma treatments on the surface properties of a polysaccharides- -based biomaterial to improve cell adhesion to its surface. The samples were subjected to plasma treatment using three different reactors operating at atmospheric pressure: gliding arc discharge (GAD) reactor, dielectric barrier discharge (DBD) plasma jet, and DBD surface reactor. Next, surface chemistry of the biomaterial after plasma treatment was determined by ATR-FTIR analysis. Furthermore, a cell adhesion assay on the samples was carried out using normal human skin fibroblasts (BJ cell line). The attenuated total reflection Fourier transform infrared analysis (ATR- -FTIR) showed that new potential functional groups could be formed on the material surface after plasma treatment. However, plasma treatment of the samples did not enhance cell adhesion to the surface of the polysaccharides-based biomaterial. Thus, the obtained results indicate that plasma treatment using GAD reactor, DBD plasma jet, and DBD surface reactor was not effective for surface modification and cell responses.

9

Microstructure and antibacterial properties of a ZnO coating on a biomaterial surface

Basiaga Marcin, Paszenda Zbigniew, Lisoń Julia, Taratuta Anna, Kazek-Kęsik Alicja, Krok-Borkowicz Małgorzata, Nuckowski Paweł, Szindler Magdalena, Staszuk Marcin, Major Łukasz, Major Roman, Barabaszová Karla Čech, Dyner Marcin

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 2

art. no. e93, 1--18

EN

A promising strategy for fighting the bacterial biofilm on the surface of biomaterials involves modification of their surface with the use of bactericidal and bacteriostatic coatings. Ongoing studies concentrate on the development of material that can limit bacterial colonisation and is safe for the human organism. Therefore, the current research focuses on the conditions related to implant coating to limit biofilm formation. However, previous outcomes in this area have not been satisfactory. Accordingly, the main goal of the carried out tests was to study the impact of the physicochemical properties of the surface layers on the course of processes taking place on the surface of implants made of metallic biomaterials used in the bone system. The surface of the analysed biomaterial -316LVM steel - was modified using such processes as grinding, electrochemical polishing, sandblasting, application of a ZnO layer using low-temperature Atomic Layer Deposition (ALD), and medical sterilisation. Initial assessments involved the chemical composition, phase composition, and the microstructure of the surface layer. The last stage involved microbiological studies, including an assessment of the adhesion of Gram-positive and Gram-negative bacteria to the modified surface, proliferation of MG-63 osteoblast-like cells and cytotoxicity tests. The analysis of adhesion of S. aureus and E. coli colonies confirmed that the ZnO coating is effective in reducing bacterial adhesion to the 316LVM steel substrate, regardless of the number of cycles, process temperature and surface treatment method.

10

Wettability of the surface of bacterial cellulose film modified with the ion implantation

Betlej Izabela, Barlak Marek, Wilkowski Jacek, Werner Zbigniew, Zagórski Jerzy, Lipska Karolina, Boruszewski Piotr

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2022

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No. 118

15--21

EN

Wettability of the surface of bacterial cellulose film modified with low energy ion implantation The paper presents the preliminary results of the modification on the water wettability of cellulose, using ion implantation method. Two kinds ions of the noble gases, i.e. helium and argon were implanted with fluences of 1e15 nand 1e16 cm-2, and with the ion energy of 60 keV. The measurements of the contact angle values show the different influence of both types ions on the hydrophobicity of the modified cellulose, but the hydrophobicity of implanted cellulose increases in all cases. The real investigations were supplemented with the modelling results of the depth profiles of the implanted ions and the main parameters of the modelled peaks.

PL

Zwilżalność powierzchni celulozy bakteryjnej modyfikowanej metodą implantacji jonów. Artykuł przedstawia wstępne wyniki modyfikacji na zwilżalność wodą implantowanej jonami celulozy. W badaniach wykorzystano dwa rodzaje gazów szlachetnych, tj. hel i argon. Implantowane dawki wynosiły 1e15 i 1e16 cm-2, a energia jonów 60 keV. Pomiary kąta zwilżania pokazują różny wpływ obydwu typów jonów na hydrofobowość modyfikowanej celulozy, jednakże hydrofobowość wzrasta we wszystkich przypadkach. Badania zostały uzupełnione wynikami modelowania głębokosciowych profili implantowanych jonów i głównych parametrów modelowanych pików.

11

Modern methods of surface modification for new-generation titanium alloys

Lisoń-Kubica Julia, Taratuta Anna, Goldsztajn Karolina, Antonowicz Magdalena, Walke Witold, Dyner Aneta, Basiaga Marcin

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 4

147--158

EN

The constantly growing need for the use of implants in osteotomy is mainly due to the aging population and the need for long-term use of this type of biomaterials. Improving implant materials requires the selection of appropriate functional properties. Currently used titanium (Ti) alloys, such as Ti6Al4V and Ti6Al7Nb, are being replaced by materials with better biocompatibility, such as vanadium(V) or niobium (Nb), allowing for creation of the so-called new generation alloys. These new alloys, with the incorporation of zirconium (Zr), iron, and tantalum, possess Young’s modulus close to that of a bone, which further improves the improves the biomaterial’s. biocompatibility. This article describes the atomic layer deposition (ALD) method and its possible applications in the new generation of titanium alloys for biomedical applications. Also, the exemplary results of tin oxide (SnO2) thin coatings deposited by ALD and physical vapor deposition (PVD) methods are presented. This study aimed to evaluate the physicochemical properties of a Ti13Nb13Zr alloy used for elements in the skeletal system. As the temperature and the number of cycles vary, the results demonstrate that the surface area of the samples changes. The uncoated Ti13Nb13Zr alloy exhibits hydrophilic properties. However, all coated specimens improve in this respect and provide improved clinical results. after the applied modification, the samples have a smaller contact angle, but still remain in the range of 0–90°, which makes it possible to conclude that their nature remains hydrophilic. Coating the specimens decreased the mineralization risk of postoperative complications. As a result, the biomaterials demonstrated improved effectiveness, decreased complication indicators, and improved patient well-being.

12

A study on the physicochemical properties of surface modified Ti13Nb13Zr alloy for skeletal implants

Lisoń Julia, Taratuta Anna, Paszenda Zbigniew, Dyner Marcin, Basiaga Marcin

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 1

39--47

EN

As it is widely stated in the literature, biofilms are responsible for most chronic infections, which have grown exponentially over the past three decades. The use of so-called alloys, as a new generation of materials, enables us to find the golden mean in the arena widely known as implantology. The use of the surface layer, using the chosen Atomic Layer Deposition method, is to be the basis for minimizing the risk of an organism reactions. Therefore, the primary objective of this study was to observe the impact of physicochemical properties of the surface layers (bactericidal) on the processes that occur on the implants surface made of titanium biomaterials used in bone structures. The study also attempted to evaluate the physicochemical properties of the ZnO coatings, deposited on the substrate of one of the new generation Ti13Nb13Zr alloys, using the ALD method. Included in the assessment of the physicochemical properties of the surface layers formed in this manner, we perform pitting corrosion resistance tests, scratch tests, tribological tests and surface wettability tests. Based on the obtained data, the differing physicochemical properties of the alloy with ZnO coatings are found to be dependent on the applied surface modification. For the conducted tests, differences are determined for the tests on the corrosion resistance, surface wettability and the abrasion resistance for samples with and without the ZnO coating. In addition, tests show that the coating applied to the alloy, which is previously subjected to the sand-blasted process, is characterized by improved adhesion.

13

Perspektywy rozwoju technik hydrofobizacji papieru

Ganicz Tomasz

Przegląd Papierniczy

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2021

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R. 77, nr 1

53--61

PL

Materiały celulozowe o powierzchniowej hydrofobowości i właściwościach barierowych dla wody stanowią coraz większy odsetek rynku papierniczego, co wynika w dużym stopniu ze zmian struktury handlu detalicznego oraz środowiskowych regulacji prawnych. Niniejsza praca omawia stan legislacji europejskiej w tym zakresie oraz dokonuje przeglądu współczesnej literatury naukowej, opisującej nowe zastosowania tradycyjnych metod, nowych obiecujących technologii do zastosowań masowych, a także propozycji nadawania właściwości superhydrofobowych i kombinacji hydrofobowych z innymi właściwościami. Potencjalnie może to znaleźć zastosowania niszowe, takie jak: specjalne metody zabezpieczania banknotów, medyczne testy diagnostyczne i elektronika mikroprzepływowa.

EN

Cellulose materials with surface hydrophobicity and water barrier properties constitute an increasing percentage of the paper market. It is largely due to changes in the structure of retail trade and environmental legal regulations. This paper discusses the state of European legislation in this area and contemporary literature describing new applications of traditional methods, new promising technologies for mass applications as well as attempts of imparting superhydrophobic properties and combinations of hydrophobicity with other properties. These could potentially find niche applications such as special security methods for banknotes, medical diagnostic tests or microfluidic electronics.

14

Study on surface modification of cerussite by thermochemical processing with pyrite

Zheng Yong-Xing, Ning Ji-Lai, Xie Haiyun, Lv Jin-Fang, Hu Pan-Jin, Pang Jie

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 1

156--167

EN

In this paper, surface modification of cerussite by thermochemical processing with pyrite was studied based on microflotation tests, X-ray powder diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA). Microflotation test results showed that the surface modification facilitated flotation of the treated cerussite and improved the flotation recovery to approximately 90%. The results of XRD analyses confirmed that cerussite was transformed into massicot, which then interacted with pyrite to form PbS, PbSO4, PbO•PbSO4 and 4PbO•PbSO4. XPS analyses results revealed that both PbS and PbS2 were formed on the mineral surface, and the percentage of PbS increased with increasing FeS2/PbCO3 (F/P) mole ratio, which was advantageous for the flotation of the modified cerussite. EPMA analyses showed that particles with layered configurations were obviously formed after thermochemical processing. The thickness of the products at the outer layer of the particles increased when the F/P mole ratio increased. Moreover, the S and O contents in the products increased and decreased, respectively.

15

Effect of polyacrylic acid molar mass as a surface modifier on rheological properties of calcium carbonate suspensions

Selim Khaled Abdelaal, Farghaly Mohamed Galal, Abdallah Samah Saleh, Abdel-Khalek Mohamed Abdel-Dayem

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 4

18--26

EN

Suspensions of calcium carbonate are of a major concern in various fields, such as coating, painting and ceramics and their rheological properties are very important. The effect of polyacrylic acid (PAA) of different molecular mass as a surface modifier on the surface and rheological properties of the aqueous suspension of calcium carbonate was investigated. The effect of the volume fraction of particles and polymer concentration on the viscosity at lower shear rate was discussed. The flow behavior of the concentrated suspension in the presence of PAA can be explained by the difference of the repulsive force among particles, induced by the adsorbed polymer. The results showed that the dispersibility is more pronounced by the steric hindrance behavior rather than the electrostatic behavior.

16

The polymeric EPD - the influence of process parameters and solution characteristics on the electrophoretic modification of fibrous carriers

Pabjańczyk-Wlazło Ewelina, Tarzyńska Nina, Bednarowicz Anna, Szparaga Grzegorz, Puszkarz Adam

Engineering of Biomaterials

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2021

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Vol. 24, no. 163

13

17

Chemical and physical modifications of electrospun fibers as a method to stimulate tissue regeneration – minireview

Kurpanik Roksana, Stodolak-Zych Ewa

Engineering of Biomaterials

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2021

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Vol. 24, no. 159

31--41

EN

Fibrous scaffolds based on (bio)polymers are observed as mimicking the microstructure of the extracellular matrix. Thus, they are considered as an example of a utilitarian scaffold, useful for the regeneration of various types of tissues. The techniques described in the literature are well known to obtain submicrometric and nanometric fibers that, when randomly arranged, mimic the ECM. The biomimetic scaffold criterion might be even better reflected if the cell adhesion sites are present on the surface of such fibers. They promote the formation of the focal adhesion contact or facilitate the formation of a protein film on the fiber surface. Such a process is enhanced by an appropriate physical or chemical modification that activates the protein adsorption and the subsequent cell adhesion. The aim of this paper is to present different methods of physical and/or chemical modifications of fibrous materials: which can serve as scaffolds to support the regeneration processes of various tissues. In terms of physical methods, only weak interactions between the surface and the modifier were observed. This technique is simple but not durable. Chemisorption used as a second method of fiber modification is possible if a covalent or ionic bond is formed between the fiber and the modifier. Therefore, the chemical adsorption may not be fully reversible and requires a sequence of chemical actions to form a chemical bond. The most commonly used methods are the combined methods where the first step is the physical activation of the fiber surface, which facilitates the chemical modification step.

18

Corrosion resistance characteristics of a Ti-6Al-4V ELI alloy fabricated by electron beam melting after the applied post-process treatment methods

Szymczyk-Ziółkowska Patrycja, Hoppe Viktoria, Gąsiorek Jolanta, Rusińska Małgorzata, Kęszycki Dawid, Szczepański Łukasz, Dudek-Wicher Ruth, Detyna Jerzy

Biocybernetics and Biomedical Engineering

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2021

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Vol. 41, no. 4

1575--1588

EN

Post-process modifications in the form of Hot Isostatic Pressing or surface treatment methods such as sandblasting ormachining have been widely used in the case of improving the quality of elements manufactured with the use of EBM (Electron Beam Melting). The corrosion resistance of titanium alloys for medical applications is a key and critical aspect for the use of personalized components as implants, especially when investigating the issue of additive manufacturing. This paper presents the results of research on the influence of HIP processing on the functional properties of the material produced with the use of EBM, considering the aspect of reconstructive medicine. Both the influence of surface modification and the influence of post-process treatment on microstructural, mechanical, and corrosion properties were investigated. A wide range of research has been carried out using scanning and transmission electron microscopy methods, in combination with three-point static bending tests and performing corrosion tests using potentiodynamic polarization and electrochemical spectroscopic impedance (EIS) in Hank‘s solution. The results showed that HIP treatment has a positive effect on the corrosive properties of the material in terms of increased corrosion resistance compared to materials not subjected to this type of post-process treatment. This fact is also related to the change of the alloy microstructure and the change of mechanical properties towards increased plasticity. In the case of the production of personalized implants with the use of EBM, it is worth considering the benefits of the HIP.

19

An Attempt to Use Various Metallurgical Slags in the Modification Processes of Casting Alloys

Sitko Jacek

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1067--1074

EN

The paper presents preliminary results of research on the use of certain smelting slags in the process of modification of casting alloys, leading to a change in the structure of these alloys and improvement of their mechanical and operational properties. The positive effect of ground copper slag with a fraction below 0.1 mm on the effect of modifying the hypoeutectic silumin AlSi7Mg towards changing the morphology of coarse-grained eutectic to fine-dispersive was demonstrated. The modifying effect also applies to the pre-eutectic α phase and results in the formation of additional crystallization sites (nucleation process), which was demonstrated by the thermal ATD solidification analysis, showing an increase in the temperature Tliq and TE max. The positive and noticeable influence of the mixture of copper and steel slag on the surface modifying effect of fragmentation of the structure was demonstrated in casting nickel superalloy IN-713C. Based on the results of research conducted so far on the modifying effect of cobalt aluminate, a hypothetical model of the impact of reduced metallic components of the applied metallurgical slags on the nucleation process and shaping of the microstructure of nickel alloys was developed.

20

Nanocellulose as a new sustainable material for various applications: a review

Fahma F., Febiyanti I., Lisdayana N., Arnata I.W., Sartika D.

Archives of Materials Science and Engineering

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2021

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Vol. 109, nr 2

49--64

EN

Purpose: This paper presents a comprehensive review of nanocellulose and its application in several applications, including composites, biomedical, and food packaging fields. Design/methodology/approach: General explanations about cellulose and nanocellulose have been described. Different types of nanocellulose (cellulose nanofibers, cellulose nanocrystals, bacterial nanocellulose) as well as their isolation processes (mechanical process, chemical process) have been reviewed. Several surface modifications have been explained to improve the dispersion of nanocellulose in non-polar polymers. The possible utilization of nanocellulose in composites, biomedical, and food packaging fields have also been analysed. Findings: This review presents three application fields at once, namely composites, biomedical, and food packaging fields. In the composite field, nanocellulose can be used as a reinforcing agent which increases the mehcnical properties such as tensile strength and toughness, and thermal stability of the final composites. In the biomedical field, nanocellulose is reinforced into hydrogel or composites which will be produced as tissue scaffolding, wound dressing, etc. It is found that the addition of nanocellulose can extend and control the drug release. While in the packaging field, nanocellulose is added into a biopolymer to improve the barrier properties and decrease the water and oxygen vapor transmission rates. Research limitations/implications: Nanocellulose has a hydrophilic nature, thus making it agglomerated and difficult to disperse in most non-polar polymers. Therefore, certain surface modification of nanocellulose are required prior to the preparation of composites or hydrogels. Practical implications: Further research regarding the toxicity of nanocellulose needs to be investigated, especially when applying it in the biomedical and food packaging fields. Originality/value: This review presents three application fields at once, namely composites, biomedical, and food packaging fields.