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Wyszukujesz frazę "nanotechnology," wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Nanomaszyny molekularne
Molecular nanomachines
Autorzy:
Barzyk, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/172494.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
nanotechnologia
maszyny molekularne
nanosamochody
nanotechnology
molecular nanomachines
nanocars
Opis:
The work discusses the beginning of nanotechnology, mentions its creators and tells about breakthrough discoveries that contributed to its developments as a science. Next, the focus was on several of the most important nanomaterials, including the C60-fullerene, which is very important for nanomachines and several of their applications. This is followed by two approaches to the synthesis of these nanomaterials and nanomachines - bottom-up and top-down, with a very important aspect that is the self-assembly of nanoparticles The next chapter presents the types, construction, and methods of synthesis of selected nanomachines, including: nanowheelbarrows, which are the kind of prototype to nanomachines; nano-trucks, the first generation of nanomachines; second generation nanomachines - nanosamines and trimers; motorized nanocar. A bit was also mentioned about nanobooks with carborane and organometalo wheels. The penultimate chapter discusses the movement of nanovehicles - what influences it and how it looks, depending on the construction and properties of the machine. Finally very briefly various applications of nanomachines were described, especially in medicine, but also in agriculture, environmental protection or cosmetology.
Źródło:
Wiadomości Chemiczne; 2019, 73, 1-2; 115-
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania nanokompozytów hydroksyapatytowych wobec bakterii beztlenowych
Investigations of hydroxyapatite nanocomposites against anaerobic bacteria
Autorzy:
Kędziora, A.
Bernat, A.
Wiglusz, R. J.
Powiązania:
https://bibliotekanauki.pl/articles/172369.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
nanotechnologia
hydroksyapatyt
endodoncja
bakterie beztlenowe
nanotechnology
hydroxyapatite
endodontics
anaerobic bacteria
Opis:
Nanocrystalline apatites Ca10(PO4)6(OH)2 (HAp) non-doped and doped with Ag+ and Eu3+ ions were synthesized by different wet chemistry methods. The obtained hydroxyapatite was loaded with Ag0, as well as nitroimidazole antimicrobials: metronidazole and tinidazole. The antimicrobial activity of the obtained materials against Prevotella bivia and Parabacteroides distasonis was studied. The method used for the antibacterial susceptibility testing was broth microdilution, according to the CLSI – Clinical and Laboratory Standard Institute – standard M11-A8; agar Schaedler, enriched with 50% LHB - Lysed Horse Blood, was used as a medium for culturing strains. The antibacterial activity increased for the immobilized antibiotics – HAp doped with metronidazole and tinidazole was six times more bactericidal than non-immobilised metronidazole for both clinical isolates. In comparison with non-immobilised tinidazole, HAp immobilised with tinidazole was six thousand times more effective against P. distasonis and two hundred times more effective against P. bivia. HAp doped with tetracycline was over two times more bactericidal than tetracycline non-immobilised (according to the literature data). The exact MIC for bionanocomposites of HAp and silver was not obtained. The research shows that bionanocomposites of hydroxyapatite are good drug carriers for both antibiotics and silver particles and ions. The use of bionanocomposites of apatite immobilised with antibiotics in dentistry could result in a prolonged antibacterial activity of these compounds.
Źródło:
Wiadomości Chemiczne; 2018, 72, 7-8; 417-447
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fotoaktywne układy polimerowe o rozmiarach nanometrycznych
Nanometric scale photoactive polymer systems
Autorzy:
Wróbel, M. J.
Powiązania:
https://bibliotekanauki.pl/articles/172487.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
układy fotoaktywne
polimery
transfer energii
nanotechnologia
photoactive systems
polymers
energy transfer
nanotechnology
Opis:
Sun is the most powerful source of clean, cheap and environmentally friendly source of energy, but still, the usage of this resource cover less than 1% of current world energy requirements [1]. However, nature realizes efficient conversion of solar energy to chemical energy on mass scale in different photoactivated processes like photosynthesis, which are essential for our life on this planet. The process takes place in green parts of plants with exceptional efficiency and precision. Natural photosystems like that attract attention to many researchers to develop artificial energy conversion devices. Many photoactive materials (polymers, nanostructures and small molecules) exhibiting high solar energy conversion and catalytic activity have been synthesized and rapidly applied in fields like pollutant removal [2] or solar cells [3]. Although significant development of artificial devices that can mimic natural processes have been achieved, their commercialization still remains a problem. Construction of molecular structure that can mimic natural photosystems is very challenging with regard to synthetic chemistry and impossibility of use the “top – down” methods which cannot reach the molecular level. Generally, photoactive materials have low stability and short lifetime due to their oxidative and aqueous degradation and decomposition under high intensity of light [4]. One of the most challenging problems during designing of artificial photosystems is directionality of excitation energy transfer along properly ordered chromophores. What is more, the mechanism of energy migration often cannot be described using well-known Förster or Dexter theories [5]. This work will focus on the selected artificial photosystems based on polymers. First, short theory of energy transport is presented, followed by description of devices based on multilayered films, repairable polymeric systems, nanohybrids of carbon nanotubes and photoactive polymers, light harvesting conjugated microporous polymers and polymer brushes.
Źródło:
Wiadomości Chemiczne; 2018, 72, 5-6; 279-297
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Szczotki polimerowe : otrzymywanie, charakteryzacja, zastosowanie
Polymer brushes : synthesis, characterization and applications
Autorzy:
Wójcik, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/171855.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
nanotechnologia
szczotki polimerowe
SI-ATRP
proces szczepienia
nanotechnology
polymer brushes
Surface Initiated Atom Transfer Radical Polymerization
grafting from process
Opis:
In 1959 Feynman said the future of engineering and science belongs to the nanotechnology [1, 2]. After fifty-seven years it has been proved that he was completely right. A perfect example of systems obtained in a nanometers scale, with huge development potential is a polymer brush. Polymer brushes consist of polymer chains tethered by one end to a commonly solid substrate. For a sufficiently high grafting density the macromolecules are arranged sticking out perpendicularly to the surface. Such systems could be prepared following two main strategies: “grafting to” and “grafting from” processes by means of various polymerization methods. The most popular ones are controlled radical polymerizations, especially surface-initiated atom transfer radical polymerization (SI-ATRP) [3], but brushes may also be fabricated using surface-initiated anionic or cationic polymerization processes. The architecture of the polymer systems could be very precisely controlled by selection of monomers used for the polymerization, substrates, types of solvents, temperature and duration of the whole synthesis. A postmodification of the produced brushes is also possible [4, 5]. Both structure and composition of polymer brushes may be characterized by means of numerous methods applied for a surface characterization including grazin- angle infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) or even gel permeation chromatography (GPC) [6]. Thanks to the above mentioned distinguishing properties polymer brushes have found a lot of applications. They have been used e.g. in the construction of modified graphene surfaces (they improved solubility, mechanical properties, thermal stability and electrical conductivity of the material), by manipulation of cell adhesion processes, in the column chromatography (to change quality of the stationary phase what enabled more efficient proteins separation) etc. [4]. In this review the synthesis, characterization and applications of varied polymer brushes are discussed.
Źródło:
Wiadomości Chemiczne; 2016, 70, 5-6; 391-410
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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