Production of CNT forests by a simple layer building method on a conductive substrate

The carbon nanotubes (CNTs) play an important role in nanotechnology research today because the CNT have outstanding properties. Many substrates can be used to fabricate carbon nanotube forests (CNT forests); however, it is important that the desired structure is achieved on a conductive substrate, and for these reasons, carbon nanotube forests have been synthetized on a titanium substrate in this research. Environmental protection is highly discussed nowadays, therefore it is necessary to be able to produce CNT forests with less energy investment and costeffectively. For these reasons, we used dip-coating method, which is a simple process and without heat-treatments step to save energy in achieving the forest structure. Therefore, this research uses a dip-coating method to form a catalyst layer on the surface of the substrate, and to investigate the effect of heat-treatment of the substrate to produce CNT forests directly on the titanium substrate

A simple method to build catalyst layers for the synthesis of vertically aligned carbon nanotubes

Nowadays, environmental protection and sustainability are getting more and more attention. Thus, our aim was to develop a cost and energy efficient catalyst layer building method for the synthesis of carbon nanotube forests. A simple spray coating method was used to develop a catalyst layer on the surface of the titanium substrates. Then vertically aligned carbon nanotubes (VACNTs) were synthesized directly on the substrate via catalytic chemical vapor deposition (CCVD) method. During our research, the effect of catalyst layer deposition parameters on the structure of CNTs was investigated and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy

Solvothermal synthesis of ZnO spheres: Tuning the structure and morphology from nano- to micro-meter range and its impact on their photocatalytic activity

Nano- and micro-sized ZnO spheres were fabricated via a simple solvothermal synthesis using two different precursors, while diethanolamine was used to control the morphology. The applied solvent composition, pre- cursor ratio and solvothermal treatment temperature were mathematically correlated with the diameter of spheres. The crystallite size could be easily controlled by adjusting the temperature, providing flexibility during synthesis. The photocatalytic activity and its dependence on the unique morphology were investigated via the decomposition of phenol model pollutant. It was revealed that the surface proprieties were more defining than the secondary particle size in this regard. A surprising synergic effect was observed between the ratio of exposed crystallographic planes of (100) and (002) and crystallite size upon the activity, while the size of the spheres shows little influence. The presented method enables the flexible design of ZnO photocatalysts with spherical morphology in a tunable size range

Arany nanorészecskéket tartalmazó bioaktív üveg – biopolimér kompozítok előállítása, jellemzése és alkalmazhatósága: Synthesis, characterization and applicability of bioactive glass – biopolymer composites with gold nanoparticles

Considering that the median age of our population is increasing, bone disorders or skin regeneration problems are of significant concern. The bioactive glass-biopolymer composites are materials with real potential to be used in tissue engineering. It is well-known, that the bioactive glasses (BG) can lead the promotion of growth of granulation tissue. The gold nanoparticles (AuNPs; ~20 nm) can induced the acceleration of wound healing including tissue regeneration, connective tissue regeneration and angiogenesis. It was demonstrated that the AuNPs in the sol-gel derived glass structure retain their properties. Alginate-pullulan (Alg-Pll) composites have good bioactivity and in vivo qualities in terms of bone regeneration. The goal of this study was to obtain the functional composites for future tissue engineering applications using BG with AuNPs introduced in Alg-Pll composites. After structural and morphological characterization of the composites, in vitro and in vivo bioactivity and biocompatibility were evaluated. The obtained results suggest that the obtained composites are materials for future soft tissue and bone engineering applications.  Kivonat A várható élettartam növekedésével egyre növekszik azon betegek száma, amelyek ortopédiai vagy bőr rekonstrukcióra szorulnak. A bioaktív üveg-biopolimer kompozitok potenciálisan alkalmazható anyagok a szövettani sebészetben. Ismert dolog, hogy a bioaktív üvegek (BG) elősegítik a granulációs szövetek növekedését. Az arany nanorészecskék (AuNPs; ~20 nm) gyorsítják a sebgyógyulást beleértve angiogenézist, a szövetek és kötőszövet regenerálódását. Tudjuk, hogy a szól-gél módszerrel előállított üveg szerkezetben bevitt AuNPs képes megőrizni ezen tulajdonságait. Az alginát-pullulán (kompozitok) remek bioaktivitásuknak köszönhetően aktívan részt vesznek az in vivo csont regenerálódásban. A tanulmány célja, hogy olyan funkcionális kompozitokat hozzunk létre, amelyek alkalmazhatók a szövettani sebészetben. Ehhez az Alg-Pll kompozitokban AuNPs tartalmazó BG vittünk be, majd szerkezeti és morfológiai jellemzéseket végeztünk. Ezt követtően az in vitro és in vivo bioaktivitás, valamint biokompatibilitást vizsgáltuk. A kapott eredmények azt sugallják, hogy az előállított kompozitok megfelelnek a lágyrész- és csonttechnikai alkalmazás elvárásainak

Decoration of Vertically Aligned Carbon Nanotubes with Semiconductor Nanoparticles Using Atomic Layer Deposition

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Solvothermal Crystallization of Ag/AgxO-AgCl Composites: Effect of Different Chloride Sources/Shape-Tailoring Agents

In the present work, AgCl microcrystals were obtained by solvothermal crystallization to investigate the effect of H+, Na+, K+, and different shape-tailoring agents (non-ionic: polyvinylpyrrolidone vs. anionic: sodium dodecyl sulfate) on the textural and photocatalytic properties of the samples. The crystallization process resulted in secondary products, such as AgxO or Ag, AgClO3, AgClO4, which were further transformed during the photocatalytic tests. The most efficient photocatalyst (assessed for methyl orange degradation) was synthesized using HCl, as a chloride source and polyvinylpyrrolidone, as a shape-tailoring agent. Therefore, the ability of polyvinylpyrrolidone to enhance the photocatalytic activity was also investigated, and it was found that the addition of 0.6 g polyvinylpyrrolidone resulted in the most efficient photocatalyst. Moreover, AgxO, being a charge separator, could play a critical role in the photocatalytic process, while reversibly transforming to Ag back and forth