Spatially-Regulated Deposition of Quantum Dots on the Patterned Polymer Brush

2020 ◽  
Vol 20 (8) ◽  
pp. 5201-5210
Author(s):  
Tomoya Sato ◽  
Gary J. Dunderdale ◽  
Chihiro Urata ◽  
Atsushi Hozumi
Keyword(s):  
Quantum Dots ◽  
Chemical Reactivity ◽  
Sol Gel ◽  
Polymer Brush ◽  
Silicon Substrates ◽  
Mild Conditions ◽  
Air Atmosphere ◽  
Direct Patterning ◽  
Functionalized Nanomaterials ◽  
Epoxy Groups

We have demonstrated direct patterning of surface initiator layer (SIL) for Atom Transfer Radical Polymerization (ATRP) using a sol–gel based “ink” containing (p-chloromethyl)phenyltrimethoxysilane and tetraethoxysilane for an inkjet printer. Mechanically/chemically robust and smooth micropatterns of SIL several tens of micrometer in width and 15 nm thickness were directly printed on silicon substrates under mild conditions (open to the atmosphere, at ~28 °C under >60% relative humidity). Subsequent surface-initiated ATRP of glycidyl methacrylate (GMA) under the air atmosphere gave area-selective/stepwise growth of homogeneous polyGMA brushes (pGMA) from the micropatterns of SIL. This area-selective growth of pGMA was also confirmed by a fluorescence microscopy. Because of chemical reactivity of epoxy groups on the grafted pGMA surfaces toward amino-functionalized nanomaterials, CdS/ZnS-alloyed quantum dots were spatially deposited only on the pGMA-covered regions with a complete area-selectivity.

scholarly journals Carbon Nitride Quantum Dots Modified TiO2 Inverse Opal Photonic Crystal for Solving Indoor VOCs Pollution

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 464
Author(s):  
Jie Yu ◽  
Angel Caravaca ◽  
Chantal Guillard ◽  
Philippe Vernoux ◽  
Liang Zhou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Nitride ◽  
Sol Gel ◽  
Green Energy ◽  
Inverse Opal ◽  
Oxidation Reactions ◽  
Composite Photocatalyst ◽  
Colloidal Photonic Crystals ◽  
Inverse Opal Structure

Indoor toxic volatile organic compounds (VOCs) pollution is a serious threat to people’s health and toluene is a typical representative. In this study, we developed a composite photocatalyst of carbon nitride quantum dots (CNQDs) in situ-doped TiO2 inverse opal TiO2 IO for efficient degradation of toluene. The catalyst was fabricated using a sol-gel method with colloidal photonic crystals as the template. The as-prepared catalyst exhibited excellent photocatalytic performance for degradation of toluene. After 6 h of simulated sunlight irradiation, 93% of toluene can be converted into non-toxic products CO2 and H2O, while only 37% of toluene is degraded over commercial P25 in the same condition. This greatly enhanced photocatalytic activity results from two aspects: (i) the inverse opal structure enhances the light harvesting while providing adequate surface area for effective oxidation reactions; (ii) the incorporation of CNQDs in the framework of TiO2 increases visible light absorption and promotes the separation of photo-generated charges. Collectively, highly efficient photocatalytic degradation of toluene has been achieved. In addition, it can be expanded to efficient degradation of organic pollutants in liquid phase such as phenol and Rhodamine B. This study provides a green, energy saving solution for indoor toxic VOCs removal as well as for the treatment of organic wastewater.

Microwave Absorbing Ferrite Thin Films for Microwave Heating of Microstructured Reactors

2009 ◽  
Vol 1222 ◽  
Author(s):  
Pengzhao Gao ◽  
Evgeny V. Rebrov ◽  
Jaap C. Schouten ◽  
Richard Kleismit ◽  
John Cetnar ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Microwave Heating ◽  
Near Field ◽  
Coplanar Waveguide ◽  
Sol Gel ◽  
Microwave Cavity ◽  
Silicon Substrates ◽  
Microwave Microscopy ◽  
Zn Ferrite

AbstractNanocrystalline Ni0.5Zn0.5Fe2O4 thin films have been synthesized with various grain sizes by sol–gel method on polycrystalline silicon substrates. The morphology and microwave absorption properties of the films calcined in the 673–1073 K range were studied by using XRD, AFM, near–field evanescent microwave microscopy, coplanar waveguide and direct microwave heating measurements. All films were uniform without microcracks. The increase of the calcination temperature from 873 to 1073 K and time from 1 to 3h resulted in an increase of the grain size from 12 to 27 nm. The complex permittivity of the Ni-Zn ferrite films was measured in the frequency range of 2–15 GHz. The heating behavior was studied in a multimode microwave cavity at 2.4 GHz. The highest microwave heating rate in the temperature range of 315–355 K was observed in the film close to the critical grain size of 21 nm in diameter marked by the transition from single– to multi–domain structure of nanocrystals in Ni0.5Zn0.5Fe2O4 film and by a maximum in its coercivity.

scholarly journals Nanostructure Analysis of Sol-gel PZT Thin Films Derived from Different Chemical Routes

2009 ◽  
Vol 15 (S3) ◽  
pp. 53-54
Author(s):  
Aiying Wu ◽  
P. M. Vilarinho
Keyword(s):  
Thin Films ◽  
Data Storage ◽  
Chemical Reactivity ◽  
Sol Gel ◽  
Random Access ◽  
Lead Zirconate ◽  
Piezoelectric Response ◽  
Metal Alkoxides ◽  
Pzt Thin Films ◽  
Wide Range

AbstractLead zirconate - lead titanate (PZT) materials are commercially important piezoelectric and ferroelectrics in a wide range of applications, such as data storage (dynamic access and ferroelectric random access memories) and sensing and actuating devices. PZT with the morphotropic phase boundary composition offers the highest piezoelectric response and at the present there are no fullydeveloped alternative materials to PZT. The importance of PZT associated with the continuous requirements of device miniaturization, imposes the development of high quality PZT thin films with optimized properties. Concomitantly due to the dependence of the final properties of thin films on the details of the microstructure a thoroughly analysis at the local scale of their microstructure is necessary. Sol-gel method, is one of the Chemical Solution Deposition techniques used to prepare oxide thin films, such as PZT. Starting from a solution, a solid network is progressively formed via inorganic polymerisation reactions. Most metal alkoxides used for sol-gel synthesis are highly reactive towards hydrolysis and condensation. Therefore their chemical reactivity has to be tailored via the chemical modification (or complexation) of metal alkoxides to avoid uncontrolled reactions and precipitation. For PZT sol gel thin film preparation, two chemical routes are frequently used depending on the nature of the molecular precursor, namely methotoxyethanol (MOE) route and diol-route.

Preparation and non-linear optical properties of CdS quantum dots in Na2O-B2O3-SiO2 glasses by the sol-gel technique

1996 ◽  
Vol 31 (2) ◽  
pp. 423-430 ◽  
Author(s):  
T. Takada ◽  
J. D. Mackenzie ◽  
M. Yamane ◽  
K. Kang ◽  
N. Peyghambarian ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Sol Gel ◽  
Cds Quantum Dots ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Gel Technique ◽  
Linear Optical

Effect of Precursor Sol Ageing on Sol-Gel Derived Ruthenium Oxide Thin Films

1999 ◽  
Vol 606 ◽  
Author(s):  
S. Bhaskar ◽  
S. B. Majumder ◽  
P. S. Dobal ◽  
R. S. Katiyar ◽  
A. L. M. Cruz ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Ruthenium Oxide ◽  
Precursor Solution ◽  
Silicon Substrates ◽  
Solution Deposition ◽  
Precursor Material ◽  
Afm Analysis

AbstractIn the present work we have optimized the process parameters to yield homogeneous, smooth ruthenium oxide (RuO2) thin films on silicon substrates by a solution deposition technique using RuCl3.×.H2O as the precursor material. Films were annealed in a temperature range of 300°C to 700°C, and it was found that RuO2 crystallizes at a temperature as low as 400°C. The crystallinity of the films improves with increased annealing temperature and the resistivity decreases from 4.86µΩ-m (films annealed at 400°C) to 2.94pµΩ (films annealed at 700°C). Ageing of the precursor solution has a pronounced effect on the measured resistivities of RuO2 thin films. It was found that the measured room temperature resistivities increases from 2.94µΩ-m to 45.7µΩ-m when the precursor sol is aged for aged 60 days. AFM analysis on the aged films shows that the grain size and the surface roughness of the annealed films increase with the ageing of the precursor solution. From XPS analysis we have detected the presence of non-transformed RuCl3 in case of films prepared from aged solution. We propose, that solution ageing inhibits the transformation of RuCl3 to RuO2 during the annealing of the films. The deterioration of the conductivity with solution ageing is thought to be related with the chloride contamination in the annealed films.

Photocatalytic and Self-cleaning Properties of Titania Coatings Prepared by Inkjet Direct Patterning of a Reverse Micelles Sol-gel Composition

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Petr Dzik ◽  
Magdalena Morozová ◽  
Petr Klusoň ◽  
Michal Veselý
Keyword(s):  
Material Properties ◽  
Reverse Micelles ◽  
Degradation Rate ◽  
Sol Gel ◽  
Basic Material ◽  
Fatty Acid Degradation ◽  
Direct Patterning ◽  
Atomic Force ◽  
Titania Coatings ◽  
Gel Composition

AbstractAn optimized reverse micelles sol-gel composition was deposited by inkjet direct patterning onto glass supports. Experimental “material printer” Fujifilm Dimatix 2831 was used for sol patterning. Printing was repeated up to 4 times in wet-to-dry manner and photocatalytic coatings of various thickness were obtained after final thermal calcination. Basic material properties of prepared coating were studied by optical microscopy, electron and atomic force imaging, Raman, XRD and UV-VIS spectrometry. Photocatalytic activity was evaluated by dye and fatty acid degradation rate as well as photoinduced hydrophilic conversion rate. Reverse micelles proved to be viable synthetic route for the preparation of titania coatings with even structure and their compatibility with inkjet direct patterning deposition was demonstrated.

Preparation of highly luminescent hybrid gel incorporating NAC-capped CdTe quantum dots through sol–gel processing

2015 ◽  
Vol 2 (3) ◽  
pp. 036202 ◽  
Author(s):  
Hang-Beom Bu ◽  
Taichi Watanabe ◽  
Masayuki Hizume ◽  
Tomomi Takagi ◽  
Susumu Sobue ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Sol Gel ◽  
Cdte Quantum Dots ◽  
Hybrid Gel ◽  
Gel Processing

Infrared Characterization of PMMA-SiO2 Hybrid Glasses Obtained by Sol-Gel Process

2010 ◽  
Vol 1278 ◽  
Author(s):  
L.L. Díaz-Flores ◽  
A. S. López Rodríguez ◽  
P. SifuentesGallardo ◽  
M.A. Hernàndez Rivera ◽  
M.a Garnica Romo ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Hybrid Coatings ◽  
Force Microscopy ◽  
Air Atmosphere ◽  
Atomic Force ◽  
Sol Gel Process ◽  
Traditional Process ◽  
And Chemical Properties

AbstractThis work is about the production of hybrid coatings of the system SiO2-PMMA (PMMA, polymethylmethacrylate). These materials have interesting mechanical and chemical properties useful for anticorrosive and wear resistance applications. SiO2-PMMA hybrids were obtained by the sol-gel traditional process, using tetraethylorthosilicate (TEOS) and methylmethacrylate (MMA) by Aldrich Co, as starting reagents. The SiO2:PMMA ratio was varied from 0:1 to about 1:1 at air atmosphere deposition. The coatings were obtained on acrylic sheets and silicon wafers. A diversity of coatings with chemical composition ranging from SiO2 and PMMA to obtain the SiO2-PMMA hybrids were obtained. Infrared (IR) and atomic force microscopy (AFM), were performed to determinate structural and morphological behavior.

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