Amorphous TiO2 nanoparticles: Synthesis and antibacterial capacity

Vargas, Mónica Andrea; Páez, Jorge Enrique Rodríguez

doi:10.1016/j.jnoncrysol.2017.01.018

Cited by 81 publications

(48 citation statements)

References 106 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DSC thermograms show two thermal transitions: i) the T m of PEO blocks in T1107 at 50–52 °C and ii) the phase transition from amorphous TiO 2 to crystalline anatase at T > 300 °C ( Figure A) . These results indicate the amorphous nature of the ceramic component in the hybrid nanoparticles.…”

Section: Resultsmentioning

confidence: 96%

Hybrid Titanium Oxide/Polymer Amphiphilic Nanomaterials with Controlled Size for Drug Encapsulation and Delivery

Melnitzer

Sosnik

2018

Adv Funct Materials

View full text Add to dashboard Cite

This work describes for the first time the synthesis of hybrid drug-loaded TiO 2 /polymer amphiphilic nanoparticles of finely controlled size utilizing a simple and reproducible sol-gel process that comprises the formation of a titanium(IV)/acetone oxo-organo complex followed by its blending with an amphiphilic poly(ethylene oxide)-b-poly(propylene oxide) block copolymer in acetone and its aqueous-phase nanoprecipitation. The size of the hybrid nanoparticles is governed by the complex aging, e.g., hybrid nanoparticles display diameter between 228 and 53 nm for aging of 1 and 36 days, respectively (dynamic light scattering). In addition, they show excellent physical stability in water owing to the coating of the surface with poly(ethylene oxide) blocks of the copolymer. Conversely, polymer-free TiO 2 particles are large and precipitate fast. Incorporation of a model hydrophobic drug, nitazoxanide, to the precursor solution results in hybrid nanoparticles containing 12.9% w/w cargo that is released following a bimodal profile. High-resolution transmission electron microscopy (Titan Cubed Themis G2 300) analysis reveals the porous amorphous nanostructure of these novel hybrids and colocalization of drug and copolymer in the nanoparticle bulk. Finally, upon ultrasonication, our hybrid nanoparticles produce reactive oxygen species in vitro which paves the way for their use in sonodynamic and drug release therapies.

show abstract

Section: Resultsmentioning

confidence: 96%

Hybrid Titanium Oxide/Polymer Amphiphilic Nanomaterials with Controlled Size for Drug Encapsulation and Delivery

Melnitzer

Sosnik

2018

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…Furthermore, highly crystalline materials are of great importance for the effective photocatalysis. In general, nanosized anatase TiO 2 demonstrates the photocatalytic performance inferior to that exhibited by other phases (amorphous, rutile, brookite) or bulk material . However, it is worth mentioning that the photoactivity of low crystalline titanium‐based materials is still debatable in the literature.…”

Section: Introductionmentioning

confidence: 74%

“…Figure shows the FT‐IR spectra of the TiO 2 ‐NPs. The typical bands at ∼3400 cm ‐1 (stretching modes) and ∼1630 cm ‐1 (bending modes) can be resulted from the presence of water/hydroxyl groups which remain on the material surface even after the thermal treatment …”

Section: Resultsmentioning

confidence: 99%

Electrochemical Synthesis of TiO₂ under Pulse Alternating Current: Effect of Thermal Treatment on the Photocatalytic Activity

et al. 2019

View full text Add to dashboard Cite

The current work aimed to study the effect of thermal treatment on the structural, optical, and photocatalytic properties of TiO2 nanoparticles synthesized by a novel large‐scale electrochemical method using pulse alternating current (PAC). The obtained titania was characterized via XRD, TEM, XPS, UV‐Vis DRS, PL, Raman and FTIR spectroscopy. The as‐prepared TiO2 was found to be poorly crystallized and partly amorphous. Following thermal annealing, the anatase structure is developed at temperatures of 400–600 °C. The photoreactivity of the TiO2 nanoparticles was evaluated for the degradation of methylene blue (MB) and rhodamin B (RhB) dyes under UVA irradiation. As shown, the adsorption properties and photocatalytic activity of the as‐prepared TiO2 strongly depend on the chemical nature of the dye. The enhanced photocatalytic performance for the MB and RhB degradation was observed for the sample annealed at 400 °C, which coincides with a balance between the degree of crystallinity, specific surface area, optical properties and efficiency of electron‐hole pair separation.

show abstract

“…Recent applications include anodes for sodium ion rechargeable batteries [22], low temperature oxygen sensors [23], visible light photocatalysts [13,24], or biomedical applications [25,26]. …”

Section: Introductionmentioning

confidence: 99%

“…While the NPs crystalline core is essentially constant, the structure of the shell depends strongly on its size. A great number of structural defects, including under-coordinated sites (like TiO 3 , TiO 4 , or TiO 5 ) and dangling bonds, are present in the shell and play a determinant role in the properties of a-TiO 2 NPs [25]. Atomistic modelling simulations also predict a distorted octahedral structure for the core (with Z Ti-O ~6.0 and Z O-Ti ~3.0), with a more porous structure for the shell, with a large number of structural defects (with Z Ti-O ≠ 6.0 and Z O-Ti ≠ 3.0) [39,40] and a density value (3.74 g/cm 3 ) lower than for bulk anatase (3.90 g/cm 3 ).…”

Section: Introductionmentioning

confidence: 99%

Photonic Band Gap and Bactericide Performance of Amorphous Sol-Gel Titania: An Alternative to Crystalline TiO2

et al. 2018

View full text Add to dashboard Cite

In addition to its traditional application in white pigments, nanocrystalline titania (TiO2) has optoelectronic and photocatalytic properties (strongly dependent on crystallinity, particle size, and surface structure) that grant this naturally occurring oxide new technological applications. Sol-gel is one of the most widely used methods to synthesize TiO2 films and NPs, but the products obtained (mostly oxy-hydrated amorphous phases) require severe heat-treatments to promote crystallization, in which control over size and shape is difficult to achieve. In this work, we obtained new photocatalytic materials based on amorphous titania and measured their electronic band gap. Two case studies are reported that show the enormous potential of amorphous titania as bactericide or photocatalyst. In the first, amorphous sol-gel TiO2 thin films doped with N (TiO2−xNx, x = 0.75) were designed to exhibit a photonic band gap in the visible region. The identification of Ti-O-N and N-Ti-O bindings was achieved by XPS. The photonic band gaps were found to be 3.18 eV for a-TiO2 and 2.99 eV for N-doped a-TiO2. In the second study, amorphous titania and amine-functionalized amorphous titania nanoparticles were synthetized using a novel base-catalysed sol-gel methodology. All the synthesized amorphous TiO2 nanoparticles exhibit bactericide performance (E. coli, ASTME 2149-13).

show abstract

Amorphous TiO2 nanoparticles: Synthesis and antibacterial capacity

Cited by 81 publications

References 106 publications

Hybrid Titanium Oxide/Polymer Amphiphilic Nanomaterials with Controlled Size for Drug Encapsulation and Delivery

Hybrid Titanium Oxide/Polymer Amphiphilic Nanomaterials with Controlled Size for Drug Encapsulation and Delivery

Electrochemical Synthesis of TiO₂ under Pulse Alternating Current: Effect of Thermal Treatment on the Photocatalytic Activity

Photonic Band Gap and Bactericide Performance of Amorphous Sol-Gel Titania: An Alternative to Crystalline TiO2

Contact Info

Product

Resources

About

Amorphous TiO2 nanoparticles: Synthesis and antibacterial capacity

Cited by 81 publications

References 106 publications

Hybrid Titanium Oxide/Polymer Amphiphilic Nanomaterials with Controlled Size for Drug Encapsulation and Delivery

Hybrid Titanium Oxide/Polymer Amphiphilic Nanomaterials with Controlled Size for Drug Encapsulation and Delivery

Electrochemical Synthesis of TiO2 under Pulse Alternating Current: Effect of Thermal Treatment on the Photocatalytic Activity

Photonic Band Gap and Bactericide Performance of Amorphous Sol-Gel Titania: An Alternative to Crystalline TiO2

Contact Info

Product

Resources

About

Electrochemical Synthesis of TiO₂ under Pulse Alternating Current: Effect of Thermal Treatment on the Photocatalytic Activity