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1.
Water Res ; 255: 121457, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38555783

RESUMO

This study focuses on enhancing the photocatalytic properties of carbon-doped Ta2O5CuO (C-Ta2O5CuO) nanocomposites for drinking water purification. The nanocomposites were fabricated by depositing C-Ta2O5CuO onto Nematic Liquid Crystal Polaroid (NLCP) obtained from a discarded laptop monitor, employing the sputter deposition method. The X-ray diffraction (XRD) and High-resolution transmission electron microscopy (HRTEM) determined the nanocomposite thin films' crystallinity and structural properties. The EDX and XPS analyses confirmed the elemental composition and reality of the Cu-incorporated Ta2O5 nanocomposites, respectively. The combination of electron tunneling enhancement provided by the NLCP and graphitic carbon led to exceptional photocatalytic performance. This was particularly evident in the efficient degradation of P-Rosaniline Hydrochloride (PRH) dye in an aqueous medium. C-Ta2O5CuO catalytic activities were estimated at various dye concentrations, repeatability, reusability with time, and kinetics. Coating's stability and long-term activity in photocatalysis reactions were also tested. Additionally, Cu present in the C-Ta2O5CuO and ˙OH radicals exhibited remarkable bactericidal activity. They displayed significant antibacterial efficacy against both gram-positive Escherichia coli (E. coli) and gram-negative Staphylococcus aureus (S. aureus) bacteria. These findings have significant implications for the development of advanced materials with potent photocatalytic and antibacterial properties, holding promise for improving drinking water quality and addressing environmental and health challenges.

2.
J Hazard Mater ; 452: 131283, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37023577

RESUMO

This study demonstrated the formation of N-enriched mixed metal oxides (Ta2O5-Nb2O5-N and Ta2O5-Nb2O5) thin film composites used as photocatalysts to degrade P-Rosaniline Hydrochloride (PRH-Dye) dye under solar radiation. By controlling the N gas flow rate during the sputtering process, the N concentration in the Ta2O5-Nb2O5-N composite is significantly included, and demonstrated by XPS and HRTEM analysis. With the help of XPS and HRTEM investigations, it was determined that the addition of N to Ta2O5-Nb2O5-N significantly enhances the active sites. The Ta-O-N bond (N 1 s and Ta 4p3/2 spectra) was verified by the XPS spectra. Ta2O5-Nb2O5 was found to have a lattice interplanar distance (d-spacing) of 2.52, whereas Ta2O5-Nb2O5-N showed the 2.5 (620 planes). A sputter-coated Ta2O5-Nb2O5and Ta2O5-Nb2O5-N photocatalysts were prepared, and their photocatalytic activity was evaluated using PRH-Dye as a model pollutant under solar radiation by adding H2O2 (0.01 mol). The photocatalytic activity of the Ta2O5-Nb2O5-N composite was compared with TiO2 (P-25) and Ta2O5-Nb2O5. Ta2O5-Nb2O5-N showed very high photocatalytic activity compared to Degussa P-25 TiO2 and Ta2O5-Nb2O5 under solar radiation and confirmed the presence of N in Ta2O5-Nb2O5-N significantly increased the generation of ˙OH radicals (in pH 3, 7 and 9). With the use of LC/MS, the stable intermediates or metabolite created during the photooxidation of PRH-Dye were assessed. The results of this study will provide useful insights on how Ta2O5-Nb2O5-N influences the efficiency of water pollution remediation.

3.
Biomed Mater ; 18(1)2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36541465

RESUMO

Magnesium (Mg) and its alloys have attracted attention as biodegradable materials for biomedical applications owing to their mechanical properties being comparable to that of bone. Mg is a vital trace element in many enzymes and thus forms one of the essential factors for human metabolism. However, before being used in biomedical applications, the early stage or fast degradation of Mg and its alloys in the physiological environment should be controlled. The degradation of Mg alloys is a critical criterion that can be controlled by a surface modification which is an effective process for conserving their desired properties. Different coating methods have been employed to modify Mg surfaces to provide good corrosion resistance and biocompatibility. This review aims to provide information on different coatings and discuss their physical and biological properties. Finally, the current withstanding challenges have been highlighted and discussed, followed by shedding some light on future perspectives.


Assuntos
Magnésio , Oligoelementos , Humanos , Ligas , Corrosão , Materiais Revestidos Biocompatíveis
4.
Colloids Surf B Biointerfaces ; 212: 112342, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35085937

RESUMO

Biodegradable magnesium (Mg) based implants have considerable interest in the biomedical field as their use nullifies the necessity for implant removal surgery and avoids the long-standing adverse reaction of permanent bioimplants. The degradation resistance and biocompatibility of the Mg alloys can be improved by coating them with a suitable thin film. Here, thin films of niobium and niobium oxide were developed on the AZ31B Mg alloy by sputtering technique and their biocompatibility and corrosion resistance was examined. X-ray diffraction (XRD) and Transmission electron microscope (TEM) techniques confirmed the crystallinity of the thin films. Subsequently, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques were employed to evaluate the morphology and chemical composition of the thin film surfaces, respectively. Thin-film coated Mg alloys revealed good corrosion resistance compared to their uncoated bare counterparts in simulated body fluid (SBF). The contact angle study was performed on the coated specimens to investigate their wettability which revealed their hydrophobic character. The cell viability studies on thin-film coated specimens exhibited significant cell proliferation, and cell morphological studies showed good cell attachment and growth. The in vitro MTT assay on mouse osteoblast precursor cells (MC3T3-E1) indicated that the Nb-based coatings are cytocompatible and promote cell proliferation.


Assuntos
Implantes Absorvíveis , Nióbio , Ligas/química , Ligas/farmacologia , Animais , Materiais Revestidos Biocompatíveis/química , Corrosão , Teste de Materiais , Camundongos , Nióbio/química , Óxidos
5.
Colloids Surf B Biointerfaces ; 202: 111684, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33721806

RESUMO

The aim of our study is to investigate the effect of boron with different ratios in Ti-Cu-Pd-Zr metallic glass (MG) matrix (Ti-Cu-Pd-Zr:B) fabricated by Pulsed Laser Deposition (PLD) for biomedical implants. The Ti based Thin Film Metallic Glasses (TFMGs) in combination with boron (in different atomic %) was assessed in attaining the combined properties, like outstanding corrosion resistant properties and good biocompatibility in this work. The disordered structure and amorphous nature of the Ti-Cu-Pd-Zr:B thin films systems were achieved by the PLD process and affirmed by XRD and transmission electron microscopy. The boron incorporation in the TFMG has been elucidated by XPS analysis. The boron containing films displays distribution of boron protuberances interleaved in the amorphous matrix was stated from SEM analysis. It is found that increase in atomic percentage of boron contents in TFMG results in the improvement in glass transition temperatures. The electrochemical parameters suggest better corrosion resistance and capabilities of passivity when boron percentage was increased in the film thereby preventing adverse biological reactions. TFMGs exhibited excellent hemocompatibility by preventing the platelet activation. MTT assay manifests increase in cell concentration with culture period on the TFMGs for the MC3T3-E1 preosteoblasts cells. Cell morphology was also studied which confirmed the viable state of the cells on the TFMG surfaces. The combination of such distinctive properties marks these TFMG systems as prospective aspirants for biomedical implants.


Assuntos
Vidro , Lasers , Boro , Corrosão , Estudos Prospectivos
6.
Biomed Mater ; 15(6): 065019, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32615545

RESUMO

Surface-modified commercially pure titanium (Cp-Ti) with zirconium (Zr)-based thin film metallic glasses (Zr-TFMGs) and ZrO2 thin films were surgically implanted into the tibiae of rats; the bone formation was analyzed to examine the performance of the coatings as a biomaterial. Zr-TFMGs and ZrO2 thin films were coated on Cp-Ti substrates to monitor the control of assimilation in vitro and in vivo. The microstructural and elemental analyses were carried out for the as deposited thin films by x-ray diffraction (XRD), transmission electron microscopy and x-ray photoelectron spectroscopy. TFMG- and ZrO2-coated Ti specimens were immersed in simulated body fluid (SBF) for a period of 21 days to evaluate the calcium phosphate precipitation in vitro. XRD, x-ray photoelectron spectroscopy and scanning electron microscopy/energy dispersive x-ray spectroscopy were used to quantify the mineralization on the coated Zr-TFMG and ZrO2. In vitro corrosion studies showed that the Zr-based TFMG and ZrO2 coatings sustained in the SBF, exhibited superior corrosion resistance to the bare crystalline Ti substrate. Wettability studies showed TFMG and ZrO2 coatings with a hydrophobic nature, and the TFMG-coated SBF-submerged specimens showed a hydrophilic nature. The in vitro cell viability of MC3T3-E1 cells showed good cell proliferation and low cytotoxicity. The calcification deposits were evaluated by staining with alizarin red S, which showed a lower calcium formation on Zr-TFMG compared to ZrO2. The present work also aims to assess the assimilation behavior of Cp-Ti, Zr-TFMG and ZrO2 in vivo by inserting the coated specimen in the femur of rats. After post-implantation of 8 weeks, specimens were examined by micro-CT evaluation. The bone contact ratios as calculated were 72.75%, 15.32% and 38.79%. Consequently, the bone affinity was Cp-Ti wire >ZrO2-coated Ti wire >Zr48Cu36Ag8Al8-coated Ti wire.


Assuntos
Osso e Ossos/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/química , Vidro , Metais/química , Titânio/química , Zircônio/química , Células 3T3 , Animais , Cálcio/química , Corrosão , Eletroquímica , Humanos , Teste de Materiais , Camundongos , Microscopia Eletrônica de Transmissão , Espectroscopia Fotoeletrônica , Ratos , Estresse Mecânico , Molhabilidade , Difração de Raios X , Microtomografia por Raio-X
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