Pokročilé nízkodimenzionální nanomateriály
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- ItemUltrathin TiO2 Coatings via Atomic Layer Deposition Strongly Improve Cellular Interactions on Planar and Nanotubular Biomedical Ti Substrates(AMER CHEMICAL SOC, 2024-01-26) Čapek, Jan; Sepúlveda Sepúlveda, Lina Marcela; Báčová, Jana; Rodriguez Pereira, Jhonatan; Zazpe Mendioroz, Raúl; Čičmancová, Veronika; Nývltová, Pavlína; Handl, Jiří; Knotek, Petr; Baishya, Kaushik; Sopha, Hanna Ingrid; Šmíd, Lenka; Roušar, Tomáš; Macák, JanThis work aims to investigate the chemical and/or structural modification of Ti and Ti-6Al-4V (TiAlV) alloy surfaces to possess even more favorable properties toward cell growth. These modifications were achieved by (i) growing TiO2 nanotube layers on these substrates by anodization, (ii) surface coating by ultrathin TiO2 atomic layer deposition (ALD), or (iii) by the combination of both. In particular, an ultrathin TiO2 coating, achieved by 1 cycle of TiO2 ALD, was intended to shade the impurities of F- and V-based species in tested materials while preserving the original structure and morphology. The cell growth on TiO2-coated and uncoated TiO2 nanotube layers, Ti foils, and TiAlV alloy foils were compared after incubation for up to 72 h. For evaluation of the biocompatibility of tested materials, cell lines of different tissue origin, including predominantly MG-63 osteoblastic cells, were used. For all tested nanomaterials, adding an ultrathin TiO2 coating improved the growth of MG-63 cells and other cell lines compared with the non-TiO2-coated counterparts. Here, the presented approach of ultrathin TiO2 coating could be used potentially for improving implants, especially in terms of shading problematic F- and V-based species in TiO2 nanotube layers.
- ItemBio-AFM exploits enhanced response of human gingival fibroblasts on TiO2 nanotubular substrates with thin TiO2 coatings(ELSEVIER, 2023-12-01) Baishya, Kaushik; Vrchovecká, Katarina; Alijani, Mahnaz; Rodriguez Pereira, Jhonatan; Thalluri, Sitaramanjaneya Mouli; Pávková Goldbergová, Monika; Přibyl, Jan; Macák, JanThe present work studies anodic TiO2 nanotube (TNT) layers and their surface modifications for enhancing the cell behavior of human gingival fibroblast cells (hGFs) with the contribution of bio-AFM (Atomic Force Micro-scopy) method. TNT layers, prepared via electrochemical anodization of Ti, with an average tube diameter of 15, 30, and 100 nm, were used as primary substrates for the study. Flat Ti foils were used as reference substrates. Part of the substrates was coated by ultrathin TiO2 coatings (approximate to 0.3 nm thin) using Atomic Layer Deposition (ALD). The cell growth and adhesion of hGFs on the TNT layers and Ti foils were compared between ALD coated and uncoated ones. The supplemental coatings altered the surface chemistry of the TNT layers, particularly shading the fluorine and carbon impurities within anodic TiO2, while preserving the original structure and morphology. The presented approach of very mild surface modification remarkably effects the material's biocompatibility and possess great prospect as implant materials. For the first time, the TNT/cell interface was investigated using bio-AFM in terms of Young's modulus, stiffness, cell adhesive force and roughness. Improved biocompatibility was studied in terms of increased cell viability, density, cell cytoskeleton orientation and overall stiffness of the hGFs.
- ItemGas Phase Photocatalysis on Large-Scale TiO2 Nanotube Layers for Pollutant Degradation: Influence of the Nanotube Crystallinity(American Chemical Society, 2023-09-12) Sopha, Hanna Ingrid; Baudys, Michal; Sepúlveda Sepúlveda, Lina Marcela; Rusek, Jakub; Hromádko, Luděk; Rodriguez Pereira, Jhonatan; Krýsa, Josef; Macák, JanIn this work, for the first time, the influence of the crystallinity of TiO2 nanotube (TNT) layers on their gas phase photocatalytic performance was investigated under ISO standards using two distinct model pollutants, namely, hexane and acetaldehyde. TNT layers (1 mu m thick) on 5 x 10 cm(2) large Ti substrates were employed in this work due to their excellent adhesion to Ti upon annealing at high temperatures. Annealing of the TNT layers was carried out in a temperature range between 300 and 700 degrees C, resulting in TNT layers with different crystallinities, i.e., from the pure anatase phase to an 85% rutile phase. The superior performance of the TNT layers annealed at 600 degrees C with mixed anatase and rutile phase compared to other specimens was observed for both model pollutants, stemming from the band alignment between the two crystalline phases. For higher annealing temperatures, however, the photocatalytic performance of the TNT layers was reduced due to a partial disintegration of the TNTs. No surface contamination of the TNT layers with residues of pollutant degradation products was observed after experiments.
- ItemFlow-through Gas Phase Photocatalysis Using TiO2 Nanotubes on Wirelessly Anodized 3D-Printed TiNb Meshes(American Chemical Society, 2023-07-12) Sopha, Hanna Ingrid; Kashimbetova, Adelia; Baudys, Michal; Chennam, Pavan Kumar; Sepúlveda Sepúlveda, Lina Marcela; Rusek, Jakub; Kolíbalová, Eva; Čelko, Ladislav; Montufar Jimenez, Edgar Benjamin; Krýsa, Josef; Macák, JanIn this work, for the first time 3D Ti-Nb meshes of differentcomposition,i.e., Ti, Ti-1Nb, Ti-5Nb, and Ti-10 Nb, were produced by direct inkwriting. This additive manufacturing method allows tuning of the meshcomposition by simple blending of pure Ti and Nb powders. The 3D meshesare extremely robust with a high compressive strength, giving potentialuse in photocatalytic flow-through systems. After successful wirelessanodization of the 3D meshes toward Nb-doped TiO2 nanotube(TNT) layers using bipolar electrochemistry, they were employed forthe first time for photocatalytic degradation of acetaldehyde in aflow-through reactor built based on ISO standards. Nb-doped TNT layerswith low concentrations of Nb show superior photocatalytic performancecompared with nondoped TNT layers due to the lower amount of recombinationsurface centers. High concentrations of Nb lead to an increased numberof recombination centers within the TNT layers and reduce the photocatalyticdegradation rates.
- ItemPolymeric ionic liquid-based formulations for the fabrication of highly stable perovskite nanocrystal composites for photocatalytic applications(Royal Society of Chemistry, 2023-03-09) Miralles-Comins, Sara; Zanatta, Marcileia; Gualdron-Reyes, Andres F.; Rodriguez Pereira, Jhonatan; Mora-Sero, Ivan; Sans, VíctorHalide perovskite nanocrystals (PNCs) have emerged as potential visible-light photocatalysts because of their outstanding intrinsic properties, including high absorption coefficient and tolerance to defects, which reduces non-radiative recombination, and high oxidizing/reducing power coming from their tuneable band structure. Nevertheless, their sensitivity to humidity, light, heat and water represents a great challenge that limits their applications in solar driven photocatalytic applications. Herein, we demonstrate the synergistic potential of embedding PNCs into polymeric ionic liquids (PILs@PS) to fabricate suitable composites for photodegradation of organic dyes. In this context, the stability of the PNCs after polymeric encapsulation was enhanced, showing better light, moisture, water and thermal stability compared to pristine PNCs for around 200 days.