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.
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The main goal of carried out tests were the impact of physicochemical properties of surface layers on the course of processes taking place on the surface of implants made of metallic biomaterials used in the bone system. As a precursor of ZnO, diethylzinc (DEZ) has been used, which reacted with water enabling the deposition of thin films. The chamber temperature was as follows—T = 200°–300 °C. The number of cycles was 500, 1000, and 1500. In the first stage, pitting corrosion test was carried out. Corrosion resistance has been tested under conditions simulating tissue environment. Moreover, the created layers were tested using electrochemical impedance spectroscopy (EIS). The conducted electrochemical tests showed the beneficial effect of the ZnO layer on the substrate made of 316 LVM steel, as evidenced by the obtained parameters describing the corrosion resistance. Furthermore, tests were performed on mechanical properties (scratch test), surface morphology (SEM and AFM method), and physical properties (wettability and thickness layers) for samples with different surface treatments. The investigations of the surface morphology of the applied ZnO layer using the ALD method showed a tendency to inherit the substrate independently of the used application parameters. On the other hand, the tests of adhesion to the substrate showed that the number of cycles of the application process has a fundamental impact on the adhesion of the applied layer to the substrate. Summarizing tests have clearly shown that the number of cycles and temperature in the case of the ZnO coating is significant and positively influences the increase of electrochemical, mechanical, and physical properties of layers.
The aim of the study was assessment of the influence of stainless steel 316 LVM surface modification on its functional properties. The analyzed steel undergone a surface treatment consisting of the following processes: mechanical polishing, chemical passivation and deposition of Al2O3 layers by Atomic Layer Deposition method. The proposed variant of surface treatment will undoubtedly contribute to improving the functional properties of stainless steel intended for implants. In order to assess functional properties of the steel, electrochemical studies, adhesion (scratch test), wetting angle tests and topography of surface (AFM method) were performed. The obtained results of the study showed clearly that the proposed by the authors way of surface treatment including: mechanical polishing, chemical passivation and deposition of Al2O3 layer by means of the ALD method effectively improves the corrosion resistance of stainless steel.
PL
Celem pracy była ocena wpływu modyfikacji powierzchni stali nierdzewnej 316 LVM na jej właściwości funkcjonalne. Obróbka powierzchni składała się z następujących procesów: polerowanie mechaniczne, chemiczna pasywacja i naniesienie warstw Al2O3 metodą ALD (Atomic Layer Deposition). Zaroponowany wariant obróbki powierzchni niewątpliwie przyczyni się do poprawy właściwości funkcjonalnych stali przeznaczonej na implanty. W celu oceny właściwości funkcjonalnych stali przeprowadzono badania elektrochemiczne, badania adhezji warstw (scratch test), oraz badania zwilżalności (kąt zwilżania i badania topografii powierzchni metodą AFM). Uzyskane wyniki badań wykazały wyraźnie, że zaproponowany przez autorów sposób obróbki powierzchni, w tym: polerowanie mechaniczne, pasywacja chemiczna i naniesienie warstw Al2O3 metodą ALD skutecznie poprawia odporność na korozję stali nierdzewnej.
As a consequence of the weathering the pirite is combined together with the oxygen and water, Acid Mine Drainage is produced, with rather low pH and dissolved metals. In order to treat the polluted water it could be good to increase its alkalinity. There are several ways to increase the water alkalinity. One of them is the ALD, limestone beds buried trough which the polluted water flows, in which carbonates are dissolved, (mostly calcium carbonate), in media lacking of oxygen.
PL
Wietrzenie pirytu przy dostępie tlenu i wody wywołuje zjawisko określane jako Acid Mine Drainage, oznaczające silne zakwaszenie wód kopalnianych przy równoczesnym wzbogaceniu ich w jony metali. Oczyszczanie takich wód wymaga podwyższenia ich alkaliczności. Jedna z używanych w tym celu metod opera się na zastosowaniu usytuowanych pod ziemią beztlenowch filtrów węglanowych (ALD). Przepływająca przez nie woda wzbogacana jest w węglany, przy równoczesnym niedostatku tlenu.
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