Electrophoretic deposition of TiO2 nanopillars from stable colloidal solution.

2013 ◽  
Vol 1578 ◽  
Author(s):  
Vincent Jouenne ◽  
Jean-Luc Duvail ◽  
Luc Brohan ◽  
Mireille Richard-Plouet
Keyword(s):  
Titanium Dioxide ◽  
Oleic Acid ◽  
Electrophoretic Deposition ◽  
Applied Voltage ◽  
Acid Treatment ◽  
Colloidal Solution ◽  
Titanium Dioxide Nanoparticles ◽  
Water Solution ◽  
Aao Template ◽  
Hydrolysis And Condensation

ABSTRACTTitanium dioxide nanoparticles were synthesized by solvothermal treatment in the presence of oleic acid and oleylamine. As Ti(IV) reactant, crystals of [Ti8O12 (H2O)24]Cl8, HCl, 7H2O were preferred because their hydrolysis and condensation can be controlled in ethanol/water solution. The organic surfactants allowed the control of the shape and they can be removed by an acid treatment of the particles. The TiO2 nanoparticles can then be re-dispersed in an ethanol-based charging solution. A fixed applied voltage promotes the electrophoretic deposition of the nanoparticles (<15 nm in size) into pores of anodized aluminium oxide (AAO) template.

Study of the Electrophoretic Deposition of Chitosan/Halloysite Nanotubes/Titanium Dioxide Composite Coatings Using Taguchi Experimental Design Approach

2015 ◽  
Vol 654 ◽  
pp. 230-239 ◽  
Author(s):  
Namir S. Jackoub Raddaha ◽  
Sigrid Seuss ◽  
Aldo R. Boccaccini
Keyword(s):  
Titanium Dioxide ◽  
Electrophoretic Deposition ◽  
Applied Voltage ◽  
Deposition Time ◽  
Composite Coatings ◽  
Halloysite Nanotubes ◽  
Partial Least Square ◽  
Halloysite Nanotube ◽  
Taguchi Design Of Experiments ◽  
Deposition Yield

This study presents experimental results on the electrophoretic deposition (EPD) of chitosan/halloysite nanotube/titanium dioxide composite coatings based on the Taguchi design of experiments (DOE) approach. Taguchi array of L18type with mixed levels of the control factor was used to study the influence of EPD parameters, including halloysite nanotubes concentration, electric voltage and deposition time, on deposition yield. For identifying the significant factors that affected the deposition yield, multivariate analysis of variance (MANOVA) and regression analysis based on partial least-square method were used. The coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analyses, respectively. It was found that the deposition time has significantly influenced the deposition rate but the halloysite nanotube concentration and the applied voltage have the smallest effect on the deposition. The optimum condition for high yield of deposition with low standard deviation is achieved when the concentration of halloysite nanotubes is 0.3 g/L and the applied voltage is 40 volt with 300 sec. as a deposition time. The predicted EPD conditions were verified by experiments and qualitative agreement was obtained.

Bionanomaterials: Thermal Stability of the Oleic Acid / alpha- and beta-cyclodextrin Complexes

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Daniel I. Hadaruga ◽  
Nicoleta G. Hadaruga ◽  
Anca Hermenean ◽  
Adrian Rivis ◽  
Vasile Paslaru ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Oleic Acid ◽  
Solution Method ◽  
Degradation Products ◽  
Water Solution ◽  
Fatty Acid Esters ◽  
Cyclodextrin Complexes ◽  
Free Oleic Acid ◽  
Thermal Stability Of ◽  
Acid Esters

This paper presents the thermal stability of the oleic acid encapsulated in a- and b - cyclodextrin. The complexation of the oleic acid was achieved by the ethanol-water solution method and the nanoparticles were analyzed by DSC. The free oleic acid and the encapsulated one were subjected to the thermal degradation in the range of 50-150�C and the degradation products were identified and quantified by GC-MS analysis of the fatty acid esters obtained by deriving with methanol/boron trifluoride, both for free compounds and for the encapsulated ones. The oleic acid complexes were very stable in this range of temperature.

scholarly journals Salt Stress Mitigation via the Foliar Application of Chitosan-Functionalized Selenium and Anatase Titanium Dioxide Nanoparticles in Stevia (Stevia rebaudiana Bertoni)

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4090
Author(s):  
Morteza Sheikhalipour ◽  
Behrooz Esmaielpour ◽  
Gholamreza Gohari ◽  
Maryam Haghighi ◽  
Hessam Jafari ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Salt Stress ◽  
Titanium Dioxide Nanoparticles ◽  
Chitosan Nanoparticles ◽  
Stevia Rebaudiana ◽  
High Salt ◽  
Steviol Glycosides ◽  
Rebaudioside A ◽  
Tio2 Nps ◽  
Stevia Rebaudiana Bertoni

High salt levels are one of the significant and major limiting factors on crop yield and productivity. Out of the available attempts made against high salt levels, engineered nanoparticles (NPs) have been widely employed and considered as effective strategies in this regard. Of these NPs, titanium dioxide nanoparticles (TiO2 NPs) and selenium functionalized using chitosan nanoparticles (Cs–Se NPs) were applied for a quite number of plants, but their potential roles for alleviating the adverse effects of salinity on stevia remains unclear. Stevia (Stevia rebaudiana Bertoni) is one of the reputed medicinal plants due to their diterpenoid steviol glycosides (stevioside and rebaudioside A). For this reason, the current study was designed to investigate the potential of TiO2 NPs (0, 100 and 200 mg L−1) and Cs–Se NPs (0, 10 and 20 mg L−1) to alleviate salt stress (0, 50 and 100 mM NaCl) in stevia. The findings of the study revealed that salinity decreased the growth and photosynthetic traits but resulted in substantial cell damage through increasing H2O2 and MDA content, as well as electrolyte leakage (EL). However, the application of TiO2 NPs (100 mg L−1) and Cs–Se NPs (20 mg L−1) increased the growth, photosynthetic performance and activity of antioxidant enzymes, and decreased the contents of H2O2, MDA and EL under the saline conditions. In addition to the enhanced growth and physiological performance of the plant, the essential oil content was also increased with the treatments of TiO2 (100 mg L−1) and Cs–Se NPs (20 mg L−1). In addition, the tested NPs treatments increased the concentration of stevioside (in the non-saline condition and under salinity stress) and rebaudioside A (under the salinity conditions) in stevia plants. Overall, the current findings suggest that especially 100 mg L−1 TiO2 NPs and 20 mg L−1 Cs–Se could be considered as promising agents in combating high levels of salinity in the case of stevia.

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.

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