scholarly journals In situ Polymerization of Polyaniline/Samarium Oxide - Anatase Titanium Dioxide (PANI/Sm2O3-TiO2) Nanocomposite: Structure, Thermal and Dielectric Constant Supercapacitor Application Study

2022 ◽  
Author(s):  
Zaid H. Mahmoud ◽  
Reem Adham AL-Bayati ◽  
Anees A. Khadom
Keyword(s):  
Dielectric Constant ◽  
Titanium Dioxide ◽  
Samarium Oxide ◽  
Application Study ◽  
Nanocomposite Structure ◽  
Supercapacitor Application

Plasticizer effect on dielectric properties of poly(methyl methacrylate)/titanium dioxide composites

2021 ◽  
pp. 096739112110147
Author(s):  
Ufuk Abaci ◽  
H Yuksel Guney ◽  
Mesut Yilmazoglu
Keyword(s):  
Dielectric Constant ◽  
Titanium Dioxide ◽  
Dielectric Properties ◽  
Methyl Methacrylate ◽  
Pure Pmma ◽  
Segmental Mobility ◽  
Scanning Calorimetry ◽  
Poly Methyl Methacrylate ◽  
Casting Technique ◽  
Lcr Meter

The effect of plasticizer on dielectric properties of poly(methyl methacrylate) (PMMA)/titanium dioxide (TiO2) composites was investigated. Propylene carbonate (PC) was used as plasticizer in the samples which were prepared with the conventional solvent casting technique. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX) and Differential scanning calorimetry (DSC) analyses and LCR Meter measurements (performed between 300 K and 400 K), were conducted to examine the properties of the composites. With the addition of plasticizer, the thermal properties have changed and the dielectric constant of the composite has increased significantly. The glass transition temperature of pure PMMA measured 121.7°C and this value did not change significantly with the addition of TiO2, however, 112°C was measured in the sample with the addition 4 ml of PC. While the dielectric constant of pure PMMA was 3.64, the ε′ value increased to 5.66 with the addition of TiO2 and reached 12.6 with the addition of 4 ml PC. These changes have been attributed to increase in amorphous ratio that facilitates polymer dipolar and segmental mobility.

Electrophoretic Deposition of CdSe Nanocrystals for Photovoltaic Applications

2007 ◽  
Vol 1031 ◽  
Author(s):  
Nathanael Smith ◽  
Kevin J Emmett ◽  
Sandra J Rosenthal
Keyword(s):  
Titanium Dioxide ◽  
Electrophoretic Deposition ◽  
Room Temperature ◽  
Tio2 Thin Film ◽  
Cdse Nanocrystals ◽  
Photovoltaic Devices ◽  
Photovoltaic Applications ◽  
Nanocrystalline Titanium ◽  
Alternative Techniques

AbstractCdSe nanocrystals chemically linked to nanocrystalline titanium dioxide substrates form a promising material for nanostructured photovoltaic devices. The usual method for attaching the nanocrystals to the titanium dioxide substrate is by means of a linking molecule (such as mercaptopropionic acid) or in-situ growth. In this paper, we report the use of an alternative technique, electrophoretic deposition (EPD), to directly deposit already formed CdSe nanocrystals onto the substrate. In EPD, a voltage is established between two electrodes that are immersed in a solution of nanocrystals. At room temperature, a fraction of the nanocrystals are thermally charged, and these charged nanocrystals migrate to the electrodes and adhere to the surface. A significant advantage of EPD over the use of linking molecules is the speed with which the nanocrystals are deposited: EPD takes only a few minutes, compared to the several hours required for the alternative techniques. Additionally, we have fabricated initial photovoltaic devices based on electrophoretically deposited CdSe nanocrystals on a planar TiO2 thin film.

Stress Development in Low Dielectric Constant Silica Films During Drying and Heating Process

1999 ◽  
Vol 594 ◽  
Author(s):  
Mengcheng Lu ◽  
C. Jeffrey Brinker
Keyword(s):  
Dielectric Constant ◽  
Tensile Stress ◽  
Sol Gel ◽  
Low Dielectric Constant ◽  
Heating Process ◽  
Residual Tensile Stress ◽  
Silica Films ◽  
Stress Development ◽  
Low Dielectric

AbstractLow dielectric constant silica films are made using a surfactant templated sol-gel process (K∼2.5) or an ambient temperature and pressure aerogel process (K∼1.5). This paper will present the in-situ measurement and analysis of stress development during the making of these films, from the onset of drying till the end of heating. The drying stress is measured by a cantilever beam technique; the thermal stress is measured by monitoring the wafer curvature using a laser deflection method. During the course of drying, the surfactant templated films experience a low drying stress due to the influence of the surfactant on surface tension and extent of siloxane condensation. The aerogel films first develop a biaxial tensile stress due to solidification and initial drying. At the final stage of drying where the drying stress vanishes, dilation of the film recreates the porosity of the wet gel state, reducing the residual stress to zero. For the surfactant templated films, very small residual tensile stress remains after the heat treatment is finished (∼30MPa). Aerogel film has almost no measurable stress developed in the calcination process. In situ spectroscopic ellipsometry analysis during drying and heating, and TGA/DTA are all used to help understand the stress development.

scholarly journals Enhanced Antibacterial Activity of Silver Doped Titanium Dioxide-Chitosan Composites under Visible Light

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1403 ◽  
Author(s):  
Jie Li ◽  
Bing Xie ◽  
Kai Xia ◽  
Yingchun Li ◽  
Jing Han ◽  
...  
Keyword(s):  
Particle Size ◽  
Antibacterial Activity ◽  
Titanium Dioxide ◽  
Visible Light ◽  
Silver Ions ◽  
Antibacterial Activities ◽  
Nano Tio2 ◽  
Inverse Emulsion ◽  
Potential Applications

Nano titanium dioxide (TiO2) with photocatalytic activity was firstly modified by diethanolamine, and it was then doped with broad spectrum antibacterial silver (Ag) by in situ method. Further, both Ag doped TiO2-chitosan (STC) and TiO2-chitosan (TC) composites were prepared by the inverse emulsion cross-linking reaction. The antibacterial activities of STC composites were studied and their antibacterial mechanisms under visible light were investigated. The results show that in situ doping and inverse emulsion method led to good dispersion of Ag and TiO2 nanoparticles on the cross-linked chitosan microsphere. The STC with regular particle size of 1–10 μm exhibited excellent antibacterial activity against E. coli, P. aeruginosa and S. aureus under visible light. It is believed that STC with particle size of 1–10 μm has large specific surface area to contact with bacterial cell wall. The increased antibacterial activity was attributed to the enhancement of both electron-hole separations at the surface of nano-TiO2 by the silver ions under the visible light, and the synergetic and sustained release of strong oxidizing hydroxyl radicals of nano-TiO2, together with silver ions against bacteria. Thus, STC composites have great potential applications as antibacterial agents in the water treatment field.

In situprecipitation of hydrous titanium dioxide for dispersive micro solid-phase extraction of nucleosides and their separation

2018 ◽  
Vol 42 (7) ◽  
pp. 4909-4914 ◽  
Author(s):  
Yuanyuan Xu ◽  
Yue Yang ◽  
Aifang Xue ◽  
Hao Chen ◽  
Shengqing Li
Keyword(s):  
Titanium Dioxide ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Phase Extraction

In situprecipitated TiO2·nH2O exhibits higher affinity forcis-diol ribonucleosides than both commercial P25 and lab-calcinated TiO2adsorbents.

In situ growth of manganese oxide nanosheets over titanium dioxide nanofibers and their performance as active material for supercapacitor

2019 ◽  
Vol 555 ◽  
pp. 373-382 ◽  
Author(s):  
Elisangela P. Da Silva ◽  
Adley F. Rubira ◽  
Odair P. Ferreira ◽  
Rafael Silva ◽  
Edvani C. Muniz
Keyword(s):  
Titanium Dioxide ◽  
Manganese Oxide ◽  
Active Material ◽  
In Situ Growth
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