Tungsten Oxide Thin Films Grown by Thermal Evaporation with High Resistance to Leaching

Corrêa, Diogo da Silva; Pazinato, Julia Cristina Oliveira; Freitas, Maurício Azevedo de; Dorneles, L. S.; Radtke, C.; Garcia, Irene Teresinha Santos

doi:10.5935/0103-5053.20140041

Cited by 4 publications

(2 citation statements)

References 3 publications

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“…3 ) show signatures of the W(VI) oxidation state and O 2− , OH − and H 2 O in the hydrated TO (ref. 46 ), further confirming that the electrodeposited films consist of WO 3 ·H 2 O (tungstite). Similar observations were made when molybdenum oxide, which has strong chemical similarity to TO (refs 43 , 47 ), was electrodeposited from alkali solutions 48 .…”

Section: Resultssupporting

confidence: 53%

Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel

Kim²,

et al. 2015

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Formation of unwanted deposits on steels during their interaction with liquids is an inherent problem that often leads to corrosion, biofouling and results in reduction in durability and function. Here we report a new route to form anti-fouling steel surfaces by electrodeposition of nanoporous tungsten oxide (TO) films. TO-modified steels are as mechanically durable as bare steel and highly tolerant to compressive and tensile stresses due to chemical bonding to the substrate and island-like morphology. When inherently superhydrophilic TO coatings are converted to superhydrophobic, they remain non-wetting even after impingement with yttria-stabilized-zirconia particles, or exposure to ultraviolet light and extreme temperatures. Upon lubrication, these surfaces display omniphobicity against highly contaminating media retaining hitherto unseen mechanical durability. To illustrate the applicability of such a durable coating in biofouling conditions, we modified naval construction steels and surgical instruments and demonstrated significantly reduced marine algal film adhesion, Escherichia coli attachment and blood staining.

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Section: Resultssupporting

confidence: 53%

Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel

Kim²,

et al. 2015

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“…XPS peaks at 36.1 and 38.2 eV correspond to W 6+ , while the peaks at 34.7 and 36.8 eV correspond to W 5+ . The spin–orbital doublet splitting of 2.1 eV and an area ratio of 4:3 are characteristic for both ions. − Thus, the cumulative chemical formula for the NPs is WO 3– x ·H 2 O with x = 0.03 calculated from the ratio of the XPS peaks.…”

Section: Results and Discussionmentioning

confidence: 99%

Chiral Ceramic Nanoparticles and Peptide Catalysis

et al. 2017

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The chirality of nanoparticles (NPs) and their assemblies has been investigated predominantly for noble metals and II-VI semiconductors. However, ceramic NPs represent the majority of nanoscale materials in nature. The robustness and other innate properties of ceramics offer technological opportunities in catalysis, biomedical sciences, and optics. Here we report the preparation of chiral ceramic NPs, as represented by tungsten oxide hydrate, WO·HO, dispersed in ethanol. The chirality of the metal oxide core, with an average size of ca. 1.6 nm, is imparted by proline (Pro) and aspartic acid (Asp) ligands via bio-to-nano chirality transfer. The amino acids are attached to the NP surface through C-O-W linkages formed from dissociated carboxyl groups and through amino groups weakly coordinated to the NP surface. Surprisingly, the dominant circular dichroism bands for NPs coated by Pro and Asp are different despite the similarity in the geometry of the NPs; they are positioned at 400-700 nm and 500-1100 nm for Pro- and Asp-modified NPs, respectively. The differences in the spectral positions of the main chiroptical band for the two types of NPs are associated with the molecular binding of the two amino acids to the NP surface; Asp has one additional C-O-W linkage compared to Pro, resulting in stronger distortion of the inorganic crystal lattice and greater intensity of CD bands associated with the chirality of the inorganic core. The chirality of WO·HO atomic structure is confirmed by atomistic molecular dynamics simulations. The proximity of the amino acids to the mineral surface is associated with the catalytic abilities of WO·HO NPs. We found that NPs facilitate formation of peptide bonds, leading to Asp-Asp and Asp-Pro dipeptides. The chiroptical activity, chemical reactivity, and biocompatibility of tungsten oxide create a unique combination of properties relevant to chiral optics, chemical technologies, and biomedicine.

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Photochromic Nanomaterials with Photocatalytic Application

Soares

Alves

2021

Environmental Applications of Nanomaterials

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Tungsten Oxide Thin Films Grown by Thermal Evaporation with High Resistance to Leaching

Cited by 4 publications

References 3 publications

Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel

Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel

Chiral Ceramic Nanoparticles and Peptide Catalysis

Photochromic Nanomaterials with Photocatalytic Application

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