Wyniki wyszukiwania - BazTech

1

Diamond nanocrystals with nitrogen-vacancy centers as new type temperature sensors

Rudnicki D., Mrózek M., Gawlik W., Wojciechowski K.

Mechanik

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2016

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R. 89, nr 5-6

526--527

EN

Nitrogen vacancy color centers in diamond (NVs) as a new type of temperature sensors were presented in the article. Recent progress in the field of NV thermometry and summarize the techniques of NVs manufacturing was briefly discussed. The use of NVs for characterization of thermoelectric materials was proposed.

PL

W artykule zaprezentowano centra barwne azot wakan-cja (NV) w diamentach w roli czujnika temperatury nowego typu. Krótko omówiono ostatnie doniesienia naukowe oraz podsumowano techniki wytwarzania diamentów z centrami NV. Zaproponowano nowatorskie wykorzystanie centrów NV do badania materiałów termoelektrycznych

2

Nanocomposite Ni/diamond layers produced by the electrocrystallization method

Trzaska M., Mazurek A.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 75, nr 1

34--40

EN

Purpose: The aim of this paper concerns the manufacturing of nanocomposite Ni/diamond surface layers deposited on S235JR carbon steel using electrocrystallization method and examinations of their structures and properties. Design/methodology/approach: The performed research covers Ni/diamond nanocomposite layers and for comparison purposes also nickel layers produced by the electrocrystallization method. The disperse phase structure and whole produced layers were characterized by: X-ray diffraction (XRD), scanning electron microscope (SEM), optical microscopy. The realized research was performed to select the features of the produced layers such as microhardness, tribological properties and corrosion resistance. Findings: The results of completed studies indicate on a compact structure and a good adhesion of produced layers with the steel substrate. The Ni/diamond nanocomposite layer shave a higher hardness and wear resistance, as well as greater corrosion resistance tested in a corrosive environment as compared to Ni nanocrystalline layers. Research limitations/implications: It is reasonable to continue further research on influences of different amount of nanodiament in nickel matrix and its impact on the tribological, corrosion, and thermal properties so produced nanocomposite layers.

3

Surface modification of nanodiamonds for biomedical application and analysis by infrared spectroscopy

Burleson T., Yusuf N., Stanishevsky A.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

258-263

EN

Purpose: Diamond nanoparticles are gaining much interest in biomedical applications due to the attractive chemical and biological properties. Studies have shown the potential of these “nanodiamonds” (NDs) for bioimaging, drug delivery, and biosensing. However, depending on the origin, the nanodiamond surface is often rich in various functional groups which can result in diverse behaviours in biological environments ranging from bioinertness to changes in cell function and cytotoxicity. We have observed the substantial difference in cellular response of several cell lines to NDs of various origins. Therefore, the aim of this study was to modify nanodiamond surface in a controlled manner to discriminate the effect of different functional groups on the cellular response. Design/methodology/approach: Commercial detonation nanodiamond powders with the mean grain size 5 nm but different size of agglomerates and synthetic diamond particles ranging from 50 nm to 1 ěm were modified under hydro- and solvo- thermal conditions to introduce specific functional groups to the surface. The processed nanoparticles were investigated with Fourier Transform Infrared (FTIR) spectroscopy and the results were compared between the samples. Modified NDs were tested for their toxicity in vitro with several cell lines (cell viability studies) and for the capability for small molecule anti-cancerous drug loading. Findings: We demonstrated that different chemical groups can be introduced and controlled onto the synthetic diamond surface depending on the solvent and process parameters used. In vitro assays showed that no cellular toxicity was found when CO, OH, or NH-groups dominated on the surface of the diamond particle. Practical implications: Many potent drugs that have proven to be useful in treating diseases such as cancer pose a challenge in delivery because they are not soluble in polar protic solvents such as water. These drugs are soluble in polar aprotic solvents that are harmful to the body. Nanodiamond surface modification in conjunction with drug-loading is a potential solution to this problem as nanodiamonds are nontoxic and have the ability to transport significant amounts of drugs. Originality/value: Nanodiamond particles are considered nontoxic and capable of absorption of a variety of organic molecules. This study should further advance the knowledge on the potential of surface-engineered NDs in therapeutic and drug delivery applications.

4

Surface modification and functionalization of nanostructured carbons

Stanishevsky A., Catledge S. A., Vohra Y.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

348-353

EN

Purpose: Nanostructured carbon nanomaterials (e.g., nanocrystalline diamond films and particles, carbon nanotubes, carbon onions, fullerenes, etc.) are being extensively explored for numerous biomedical applications in surgical implants, therapy, drug delivery, and biosensoring due to their interesting physical, chemical, and biological properties. Such applications of carbon nanomaterials often require specific surface functionality to be introduced for better integration of these materials with physiological environment. In the last decade, substantial progress has been made in the development of controllable surface modification methods and in the introduction of different functional groups on the surface of carbon nanomaterials. Design/methodology/approach: This paper briefly overviews the surface modification and functionalization approaches for various carbon nanomaterials, and it focuses on the plasma modification and functionalization of nanocrystalline diamond films, diamond nanoparticles, and carbon nanospheres. The results on the surface characterization using FTIR and XPS techniques, and the preliminary studies of cellular response to these modified carbon nanomaterials are presented and discussed. Findings: The results of surface modification of NCD films, detonation nanodiamonds, and carbon nanospheres, demonstrate the flexibility of nanocarbons to attain various surface functionality that can be adjusted for specific applications. It has been shown that neither of tested nanocarbon materials was cytotoxic in this study, although the attachement and proliferation of various cells was strongly affected by the specific type of surface functionalization. Research limitations/implications: At the present, it is not clear to what degree the available surface sites on NCD films or carbon nanoparticles can be occupied with functional groups. Furthermore, while there is clear selectivity of cellular response to H, O, and F surface-terminated NCD films, the role of specific type of surface groups present on carbon nanoparticles has yet to be determined. Practical implications: The development of optimal strategies to functionalize various nanocarbons will have strong impact on the design of efficient nanostructured surfaces and particles for a variety of biological and medical applications. Originality/value: This work adds new insights to the expanding research in biomedical applications of nanoscale carbon materials.

5

Nanodiamonds in meteorites: properties and astrophysical context

Ott U.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

779-784

EN

Purpose: This contribution provides an overview on properties and origin of nanodiamonds in primitive meteorites. Nanodiamond are a type of stardust, i.e. “pre-solar” grains that formed in the outflows or ejecta of stars. Design/methodology/approach: We summarize previously obtained results and include our results dealing with recoil loss from nanoparticles during radioactive decay of trace elements within them. Findings: Nanodiamonds in primitive meteorites have a mean size of ~2.6 nm and an abundance reaching up to ~0.15 % by weight. They contain trace noble gases, notably xenon, with an unusual isotopic composition. The latter is reminiscent of the p- and r-processes of nucleosynthesis that are thought to occur during supernova explosions. Our new results show that recoil loss during â decay of implanted 22Na does not exceed what is expected from energy distribution and range-energy relations in matter. While a CVD origin for the diamonds appears likely (but is not assured), the noble gases were probably introduced by ion implantation. Research limitations/implications: The isotopic pattern of Xe contained in nanodiamonds indicates some unconventional types of element synthesis in stars or modification by secondary processes. Recoil loss from nanometer-sized grains during decay of unstable precursor nuclides has been suggested as an explanation, but our experiments do not support this idea. Originality/value: Other processes must be invoked for explanation of the isotopically unusual xenon trapped in meteoritic nanodiamonds. Ion implantation experiments suggest of “trapped” cosmic ray 3He for deriving an age for the diamonds.

6

The effect of particles, including nanoparticles, on macrophages in vitro and in vivo

Revell P.A., Altaf H., McFarlane T., Bociaga D., Mitura K.

Inżynieria Biomateriałów

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2006

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R. 9, nr 56-57

29-31

EN

Macrophages remove foreign material from the body and are recruited to sites were there are particles present. Multinucleate giant cells from by the fusion of macrophages. In the presence of particles, macrophages produce various chemical mediators, known as cytokines, as well as enzymes. Some of the cytokines are pro-inflammatory (for example, IL1Beta, IL6 and TNFalpha) while others promote giant cell formation (GM-CSF, M-CSF, TGF). The presence of these cellular products can be shown by examining tissue sections with immunohistochemistry and by western blotting. The message (mRNA) for the synthesis of these molecules can be demonstrated by in situ hybridization and the polymerase chain reaction. Macrophages process ingested material and present it as antigen to lymphocytes. Antigen-presenting macrophages play an important part in the initiation of metal sensitization. Surface receptors and their counterligands are expressed on macrophages and lymphocytes during antigen presentation. The particles present in tissues around joint prostheses have been isolated and characterized. Over 95% of these are less than 1 micron (ECD) in size. Transmission electron microscopy has revealed nanoparticles of metal in the range 15-20 nm. Such particles are too small to be phagocytosed. Hydroxyapatite, diamond-like carbon (nano-diamond) and metal particles are being studied and results compared with those of particles in the micrometer range. There is a different response to different nanoparticles.

7

The chlorinated synthetic diamond surface interaction with C-nucleophiles

Korolkov V.V., Tarasevich B.N., Kulakova I.I., Lisichkin G.V.

Inżynieria Biomateriałów

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2006

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R. 9, nr 56-57

16-19

EN

Several reactions of C-nucleophiles with the chlorinated surface of two types of diamond were implemented. Detonating nanodiamond "UDA-SF" and synthetic diamond "DALAN" have been employed in the above procedures. The incorporation of butyl and nitrile groups has been achieved. However the incorporating of phenyl groups via reaction with PhLi is still a problem. For the first time NMR-H1 spectroscopy of suspension was used for elucidating structure of grafting compounds was proposed.