Sol-Gel Chemistry for Carbon Dots

A new fluorescence composite material for the sensitive and selective determination of 4-nitrophenol (4-NP) was developed based on molecularly imprinted polymers (MIPs) incorporated with carbon dots (CDs). First, fluorescent CDs with a high quantum yield (QY) of 51.8% were prepared by hydrothermal synthesis method by using anhydrous citric acid as carbon source and AEAPMS as surface modifier. Then, CDs were fabricated with MIPs (CDs@MIPs) by sol–gel method using 4-NP as template, (3-aminopropyl) triethoxysilane (APTES) as functional monomer, tetraethoxysilane (TEOS) as cross-linker and CDs as signal sources, respectively. The CDs@MIPs exhibited strong fluorescence property and high selectivity to 4-NP as it incorporated merits of CDs and MIPs. Under optimized conditions, the relative fluorescence intensity of CDs@MIPs decreased linearly with the concentration of 4-NP from 0.025[Formula: see text][Formula: see text]g[Formula: see text]mL[Formula: see text] to 5[Formula: see text][Formula: see text]g[Formula: see text]mL[Formula: see text]. The limit of detection (LOD) of 4-NP was 5[Formula: see text]ng[Formula: see text]mL[Formula: see text] (35[Formula: see text]nM). Specificity and selectivity experiments showed that CDs@MIPs can selectively detect 4-NP with rare interference of other competitive analogs and metal ions. Finally, CDs@MIPs was successfully used to detect 4-NP in river water samples with the recoveries ranging from 94.0% to 103.4%. The results demonstrated that the prepared CDs@MIPs can be applied to the selective and sensitive detection of trace 4-NP in real samples.

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One‐Step Microwave Approach to Generate Carbon Dots/Gelatin Composite with Both Thermoresponsive Sol–Gel Transition and Fluorescence Properties

Macromolecular Materials and Engineering ◽

10.1002/mame.202000035 ◽

2020 ◽

Vol 305 (5) ◽

pp. 2000035

Author(s):

Xia Wang ◽

Hui Liu ◽

Wencheng Wu ◽

Yanfei Xiong ◽

Wei Chen ◽

...

Keyword(s):

Carbon Dots ◽

Sol Gel ◽

Fluorescence Properties ◽

One Step ◽

Sol Gel Transition ◽

Gel Transition

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Solar light driven photocatalytic degradation of levofloxacin using TiO2/carbon-dot nanocomposites

New Journal of Chemistry ◽

10.1039/c7nj05118b ◽

2018 ◽

Vol 42 (9) ◽

pp. 7445-7456 ◽

Cited By ~ 22

Author(s):

Shelja Sharma ◽

Ahmad Umar ◽

Surinder Kumar Mehta ◽

Alex O. Ibhadon ◽

Sushil Kumar Kansal

Keyword(s):

Quantum Dots ◽

Photocatalytic Degradation ◽

Carbon Dots ◽

Sol Gel ◽

Solar Light ◽

Carbon Dot ◽

Hydrothermal Methods

This paper reports the synthesis of TiO2 quantum dots, carbon dots (C-dots), and TiO2/C-dots using facile sol–gel and hydrothermal methods.

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Flash-cooling assisted sol-gel self-ignited synthesis of magnetic carbon dots-based heterostructure with antitumor properties

Materials Science and Engineering C ◽

10.1016/j.msec.2020.111288 ◽

2020 ◽

Vol 117 ◽

pp. 111288

Author(s):

Adrian Borhan ◽

Dumitru-Daniel Herea ◽

Daniel Gherca ◽

Cristina Stavila ◽

Anca-Emanuela Minuti ◽

...

Keyword(s):

Carbon Dots ◽

Sol Gel ◽

Flash Cooling ◽

Antitumor Properties ◽

Magnetic Carbon

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Synthesis of Photoluminescent Core–Shell-Structured Carbon dots@silica Nanocomposite Fingermark Powders for Latent Fingermarks Visualization

NANO ◽

10.1142/s1793292019500681 ◽

2019 ◽

Vol 14 (06) ◽

pp. 1950068

Author(s):

Hong Yu Chen ◽

Li Liu

Keyword(s):

Carbon Dots ◽

Uv Light ◽

Sol Gel ◽

Fluorescent Label ◽

Core Shell ◽

X Ray Diffraction ◽

Visible Absorption ◽

Transmission Electron ◽

Reduced Iron Powder ◽

Latent Fingermark

To obtain solid-state photoluminescent core–shell-structured carbon dots@silica (C-dots@SiO2) nanocomposites, the C-dots were synthesized by microwave irradiation and were dispersed in SiO2through sol–gel technique. Then, the excellent fluorescent property with excitation-independent feature and the core–shell structure of C-dots@SiO2nanocomposites were successfully characterized through the fluorescence spectroscopy, ultraviolet–visible absorption spectroscopy (UV-Vis), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The as-prepared C-dots@SiO2powder was mixed with reduced iron powder and then applied to latent fingermark detection. The latent fingermarks on several surfaces labeled with C-dots@SiO2fingermark powders emitted blue fluorescence under 365[Formula: see text]nm UV light and exhibited high contrast between the background and the ridges. Additionally, the C-dots@SiO2fingermark powder as a fluorescent label for enhancing latent fingermarks demonstrated greater advantages as compared to the conventional fluorescent fingermark powder especially for latent fingermark deposited on porous surfaces.

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TEM visualization of surface replicated acid and base catalyzed sol-gel glasses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014381x ◽

1986 ◽

Vol 44 ◽

pp. 448-449

Author(s):

George C. Ruben ◽

Merrill W. Shafer

Keyword(s):

Elevated Temperatures ◽

Sol Gel ◽

Basic Medium ◽

Glass Transition Point ◽

Structural Space ◽

Acid And Base ◽

Organometallic Precursors ◽

New Processing ◽

Gel Glasses ◽

Physical Phenomena

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.

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Electron microscopy studies of PZT ferroelectric film capacitor structures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131450 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1364-1365

Author(s):

V. Kaushik ◽

P. Maniar ◽

J. Olowolafe ◽

R. Jones ◽

A. Campbell ◽

...

Keyword(s):

Electric Fields ◽

Sol Gel ◽

Ferroelectric Material ◽

Dielectric Constants ◽

Dielectric Films ◽

Lead Zirconium Titanate ◽

Si Substrate ◽

Film Capacitor ◽

Pzt Films ◽

High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

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The crystallization of thin-film ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122095 ◽

1992 ◽

Vol 50 (1) ◽

pp. 338-339

Author(s):

J.M. Schwartz ◽

L.F. Francis ◽

L.D. Schmidt ◽

P.S. Schabes-Retchkiman

Keyword(s):

Thin Films ◽

Grain Size ◽

Sol Gel ◽

Processing Route ◽

Small Areas ◽

Ceramic Thin Films ◽

Complex Shapes ◽

Sol Gel Process ◽

Ceramic Precursors ◽

Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

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