Sol–gel chemistry for graphene–silica nanocomposite films

2014 ◽  
Vol 38 (8) ◽  
pp. 3777-3782 ◽  
Author(s):  
Plinio Innocenzi ◽  
Luca Malfatti ◽  
Barbara Lasio ◽  
Alessandra Pinna ◽  
Danilo Loche ◽  
...  
Keyword(s):  
Sol Gel ◽  
Silica Sol ◽  
Optical Transparency ◽  
Nanocomposite Films ◽  
Silica Films ◽  
Exfoliated Graphene ◽  
Silica Nanocomposite

Graphene–silica films with high optical transparency have been obtained by adding a dispersion of exfoliated graphene into a silica sol.

scholarly journals Determination of growth kinetics and size dependent structural, morphological, optical characteristics of sol-gel derived silica nanoparticles in silica matrix

2019 ◽  
Vol 37 (1) ◽  
pp. 16-24
Author(s):  
Bengü Özuğur Uysal ◽  
Fatma Z. Tepehan
Keyword(s):  
Thin Films ◽  
Silica Nanoparticles ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Silica Film ◽  
Silica Sol ◽  
Nano Silica ◽  
Silica Films ◽  
Annealing Temperatures ◽  
Silica Thin Films

AbstractNanocomposite silica thin films made using the sol-gel method were studied. The nano-silica films were prepared using a mixture of tetraethyl orthosilicate (TEOS), deionized water, ethanol, and ammonia solution. To control the growth of the particles inside the film, the nanocomposite silica film was prepared using a mixture of the nano-silica sol and the silica sol. The change in the particle size with the heat treatment temperature ranging from 450 °C to 1100 °C was investigated. X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), NKD (refractive index-N, extinction coefficient-K, and thickness-D) and ultraviolet-visible (UV-Vis) spectrophotometry were used for characterization purposes. The XRD studies showed that the nano-silica thin films were amorphous at all annealing temperatures except for 1100 °C. The_-cristobalite crystal structure formed at the annealing temperature of 1100 °C. Optical parameters, such as refractive indices and extinction coefficients, were obtained using the NKD analyzer with respect to the annealing temperature of the films. The activation energy and enthalpy of the nanocomposite silica film were evaluated as 22.3 kJ/mol and 14.7 kJ/mol, respectively. The cut-off wavelength values were calculated by means of extrapolation of the absorbance spectra estimated using the UV-Vis spectroscopy measurements. A red shift in the absorption threshold of the nanocomposite silica films indicated that the size of the silica nanoparticles increased with an increase of the annealing temperatures from 450 °C to 900 °C, and this confirms the quantum confinement effect in the nanoparticles.

Synthesis and Characterization of Ordered Mesoporous Carbon/Silica Hybrid Thin Films

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiaoxian Wang ◽  
Tiehu Li ◽  
Qilang Lin ◽  
Dawei Wang ◽  
Tingkai Zhao
Keyword(s):  
Electron Microscopy ◽  
Pore Size ◽  
Self Assembly ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Matrix ◽  
Nanocomposite Films ◽  
Evaporation Induced Self Assembly ◽  
Hybrid Thin Films ◽  
Silica Nanocomposite

Carbon/silica nanocomposite films with a hexagonal P6mm structure were fabricated directly by the oxidation and carbonization of surfactant/silica nanocomposite films, which were obtained by a dip-coating technique through a combination of sol-gel and evaporation-induced self-assembly. The as-synthesized nanocomposite films were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy and N2 adsorption-desorption. These analyses reveal that the carbon/silica nanocomposite films, with a narrow pore size distribution of mesopores, have an ordered symmetric structure. The pore sizes of this hybrid film can be controlled within a certain range by changing the carbonization temperature. In addition, the films are composed of a continuous silica matrix and a continuous carbon coating in about 1 nm adhered well to the silica matrix. The formation of carbon coatings from surfactant acts as a framework support to prevent the pore size of the silica matrix from shrinking.

Effects of water on the preparation, morphology, and properties of polyimide/silica nanocomposite films prepared by sol–gel process

2007 ◽  
Vol 104 (3) ◽  
pp. 1579-1586 ◽  
Author(s):  
Lizhong Jiang ◽  
Wencai Wang ◽  
Xiaowei Wei ◽  
Dezhen Wu ◽  
Riguang Jin
Keyword(s):  
Sol Gel ◽  
Nanocomposite Films ◽  
Sol Gel Process ◽  
Silica Nanocomposite

A modified sol-gel process for multiferroic nanocomposite films

2007 ◽  
Vol 102 (8) ◽  
pp. 083911 ◽  
Author(s):  
Ming Liu ◽  
Xin Li ◽  
Jing Lou ◽  
Shijian Zheng ◽  
Kui Du ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nanocomposite Films ◽  
Sol Gel Process

scholarly journals A simple approach to prepare fluorescent molecularly imprinted nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7732-7737
Author(s):  
Fenying Wang ◽  
Dan Wang ◽  
Tingting Wang ◽  
Yu Jin ◽  
Baoping Ling ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Sol Gel ◽  
Silica Sol ◽  
Simple Approach ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Low Toxicity ◽  
Good Biocompatibility ◽  
Molecularly Imprinted Nanoparticles

Fluorescent molecularly imprinted polymer (FMIP) gains great attention in many fields due to their low cost, good biocompatibility and low toxicity. Here, a high-performance FMIP was prepared based on the autocatalytic silica sol–gel reaction.

Silica Sol-Gel Supported Nickel Nano-Catalyst for Hydrogen Production Using Microreactors

2005 ◽  
Vol 885 ◽  
Author(s):  
Krithi Shetty ◽  
Shihuai Zhao ◽  
Wei Cao ◽  
Naidu V. Seetala ◽  
Debasish Kuila
Keyword(s):  
Steam Reforming ◽  
Average Pore Size ◽  
Sol Gel ◽  
Supported Catalyst ◽  
Silica Sol ◽  
Average Pore ◽  
Steam Reforming Of Methanol ◽  
Nano Catalyst ◽  
Before And After ◽  
Reforming Reactions

ABSTRACTThe goal of this research is to investigate the activities of a non-noble nano-catalyst (Ni/SiO2) using Si-microreactors for steam reforming of methanol to produce hydrogen for fuel cells. The supported catalyst was synthesized by sol-gel method using Ni (II) salts and Si(C2H5O)4 as starting materials. EDX results indicate that the actual loading of Ni (5-6%) is lower than the intended loading of 12 %. The specific surface area of the silica sol-gel encapsulated Ni nano-catalyst is 452 m2/g with an average pore size of ∼ 3 nm. Steam reforming reactions have been carried out in a microreactor with 50 µm channels in the temperature range of 180-240 °C and atmospheric pressure. Results show 53% conversion of methanol with a selectivity of 74 % to hydrogen at 5 l/min and 200 °C. The magnetic properties of the catalysts were performed using a Vibrating Sample Magnetometer (VSM) to study the activity of the catalysts before and after the steam reforming reactions. The VSM results indicate much higher activity in the microreactor compared to macro-reactor and Ni forms non-ferromagnetic species faster in the microreactor.

Sign in / Sign up

Export Citation Format

Share Document