Titanium Dioxide Nanoparticles:  Effect of Sol−Gel pH on Phase Composition, Particle Size, and Particle Growth Mechanism

2008 ◽  
Vol 112 (12) ◽  
pp. 4469-4474 ◽  
Author(s):  
Sara L. Isley ◽  
R. Lee Penn
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Phase Composition ◽  
Growth Mechanism ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Particle Growth ◽  
Gel Ph

scholarly journals Sol-Gel Titanium Dioxide Nanoparticles: Preparation and Structural Characterization

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Oon Lee Kang ◽  
Azizan Ahmad ◽  
Usman Ali Rana ◽  
Nur Hasyareeda Hassan
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Structural Characterization ◽  
Analytical Approach ◽  
Acidic Solution ◽  
Size Range ◽  
Lattice Defect ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Particle Size Range

Titanium dioxide (TiO2) nanoparticle was achieved in an alternative sol-gel route, as involved in 1 M acidic solution: HCl-tetrahydrofuran (HCl-THF), HNO3-tetrahydrofuran (HNO3-THF), and ClHNO2-tetrahydrofuran (ClHNO2-THF) solution. Resultant TiO2 nanoparticle was further investigated in a systematic analytical approach. Nanoscale TiO2 structure was observed at a moderate hydrolysis ratio (8≤RH≤16). Particle size range was much narrower in an aprotic HNO3-THF medium, as compared to a differential HCl-THF medium. Biphasic TiO2 structure was detected at a certain hydrolysis ratio (RH≥16). Even so, relative anatase content was rather insignificant in an aprotic HCl-THF medium, as compared to a differential HNO3-THF medium. Tetragonal TiO2 structure was observed in the entire hydrolysis ratio (4≤RH≤32). Interstitial lattice defect was evident in an aprotic HNO3-THF medium but absent in a differential ClHNO2-THF medium.

scholarly journals Effect of Titanium Dioxide Nanoparticles on the Expression of Efflux Pump and Quorum-Sensing Genes in MDR Pseudomonas aeruginosa Isolates

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Fatma Y. Ahmed ◽  
Usama Farghaly Aly ◽  
Rehab Mahmoud Abd El-Baky ◽  
Nancy G. F. M. Waly
Keyword(s):  
Titanium Dioxide ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Efflux Pumps ◽  
Antibiofilm Activity ◽  
The Impact

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.

Composition and Properties of TiO2 Sol to Produce a Photocatalytic Composite Material

2020 ◽  
Vol 854 ◽  
pp. 45-50
Author(s):  
Ekaterina N. Gubareva ◽  
Valeria V. Strokova ◽  
Yulia N. Ogurtsova ◽  
Pavel S. Baskakov ◽  
Lok Pratap Singh
Keyword(s):  
Composite Material ◽  
Titanium Dioxide ◽  
Ethyl Alcohol ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Component Composition ◽  
Optimal Composition ◽  
Optimal Ratio ◽  
Nanosized Titanium Dioxide ◽  
Sol Gel Synthesis

The paper presents the process of sol-gel synthesis of titanium dioxide nanoparticles, the peculiarities of the influence of component composition (titanium precursor content, solvent and stabilizer − surfactant) on the properties of sol and powder obtained on its basis. As a result of the study, the nature of the influence of the type and content of the surfactant in the solution of tetrabutoxytitanium in ethanol on the size of the synthesized particles of titanium dioxide was revealed. The optimal composition of the reaction mixture of TiO–R sol was obtained and the optimal ratio of tetrabutoxytitanium and ethyl alcohol was revealed using which a material with a high content of nanosized titanium dioxide was obtained.

scholarly journals Effect of the suspension of Ag-incorporated TiO2 nanoparticles (Ag-TiO2 NPs) on certain growth, physiology and phytotoxicity parameters in spinach seedlings

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244511
Author(s):  
Fernando Gordillo-Delgado ◽  
Jakeline Zuluaga-Acosta ◽  
Gonzalo Restrepo-Guerrero
Keyword(s):  
Particle Size ◽  
Titanium Dioxide Nanoparticles ◽  
Germination Rate ◽  
Sol Gel ◽  
Control Group ◽  
Human Consumption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Growth Physiology ◽  
Powder Samples

In this work, the effect of the inoculation of silver-incorporated titanium dioxide nanoparticles (Ag-TiO2 NPs) in spinach seeds was evaluated on certain growth, physiology and phytotoxicity parameters of the plants. This is an important crop for human consumption with high nutritional value due to their low calorie and fat content, providing various vitamins and minerals, especially iron. These NPs were obtained by means of the sol-gel method and heat treatment; the resulting powder material was characterized using X-ray diffraction and scanning electron microscopy and the influence of these NPs on plants was measured by estimating the germination rate, monitoring morphological parameters and evaluating phytotoxicity. The photosynthetic activity of the spinach plants was estimated through the quantification of the Ratio of Oxygen Evolution (ROE) by the photoacoustic technique. Samples of TiO2 powder with particle size between 9 and 43 nm were used to quantify the germination rate, which served to determine a narrower size range between 7 and 26 nm in the experiments with Ag-TiO2 NPs; the presence of Ag in TiO2 powder samples was confirmed by energy-dispersive X-ray spectroscopy. The analysis of variance showed that the dependent variable (plant growth) could be affected by the evaluated factors (concentration and size) with significant differences. The statistical trend indicated that the application of the Ag-TiO2 NPs suspension of lowest concentration and smallest particle size could be a promoting agent of the growth and development of these plants. The inoculation with NPs of 8.3 nm size and lowest concentration was related to the highest average ROE value, 24.6 ± 0.2%, while the control group was 20.2 ± 0.2%. The positive effect of the Ag-TiO2 NPs treatment could be associated to the generation of reactive oxygen species, antimicrobial activity, increased biochemical attributes, enzymatic activity or improvements in water absorption.

Photoconversion of CO2 using copper-modified titanium dioxide nanoparticles

2011 ◽  
Vol 76 (11) ◽  
pp. 1335-1346 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao
Keyword(s):  
Titanium Dioxide ◽  
Photoelectron Spectroscopy ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Chemical Properties ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Illumination ◽  
One Step

A series of copper-modified titanium dioxide (Cu/TiO2) nanoparticles were synthesized via one-step sol-gel method. The crystal structure and chemical properties were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Cu/TiO2nanoparticles were applied to CO2photoconversion and the yield of formaldehyde was used to evaluate the photocatalytic performance. The optimum amount of copper modifying was 0.6 wt.% and the yield of formaldehyde was 946 μmol/gcatunder UV illumination for 6 h. 20 wt.% Cu/TiO2also performed a high photocatalytic activity, which yielded 433 μmol/gcatformaldehyde under UV illumination for 6 h.

Sol–gel preparation of titanium dioxide nanoparticles in presence of a linear polysaccharide

2009 ◽  
Vol 4 (4) ◽  
pp. 187-191 ◽  
Author(s):  
H.A. Monreal ◽  
A. Martínez-Villafañe ◽  
P.G. Casillas ◽  
C.A. Martínez ◽  
U. Arce-Colunga ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Gel Preparation
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