scholarly journals Influence of Textile Structure and Silica Based Finishing on Thermal Insulation Properties of Cotton Fabrics

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
G. Rosace ◽  
E. Guido ◽  
C. Colleoni ◽  
G. Barigozzi
Keyword(s):  
Thermal Properties ◽  
Thermal Insulation ◽  
Sol Gel ◽  
Silica Coatings ◽  
Plain Weave ◽  
Weave Fabric ◽  
Sol Gel Process ◽  
Yarn Count ◽  
Ft Ir ◽  
Finishing Agent

The aim of this work is to investigate the influence of weave structures and silica coatings obtained via sol-gel process on the thermal insulation properties of cotton samples. For this reason three main weave structures (plain, satin, and piqué) of cotton fabric were selected with different yarn count, threads per cm, and mass per square meter values. Thereafter, only for the plain weave, the samples were padded using silica sol formed by hydrolysis and subsequent condensation of 3-glycidoxypropyltrimethoxysilane under acidic conditions. The silanized plain weave samples were characterized by TGA and FT-IR techniques. The thermal properties were measured with a home-made apparatus in order to calculate thermal conductivity, resistance, and absorption of all the treated fabric samples. The relationship between the thermal insulation properties of the plain weave fabrics and the concentration of sol solutions has been investigated. Fabrics weave and density were found to strongly influence the thermal properties: piqué always shows the lowest values and satin shows the highest values while plain weave lies in between. The thermal properties of treated high-density cotton plain weave fabric were proved to be strongly influenced by finishing agent concentration.

scholarly journals Thermal Diffusion in Fibrous Aerogel Blankets

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 823 ◽  
Author(s):  
Ákos Lakatos ◽  
Anton Trník
Keyword(s):  
Thermal Properties ◽  
Thermal Annealing ◽  
Thermal Insulation ◽  
Sol Gel ◽  
Theoretical Background ◽  
Design Stage ◽  
Scanning Calorimetry ◽  
Insulation Materials ◽  
Sol Gel Process ◽  
Transient Thermal

Nowadays, the usage of thermal insulation materials is widespread not only in the building sector but also in the vehicle industry. The application of fibrous or loose-fill insulation materials like glass wool or mineral wool as well as aerogel is well known. Aerogel-based materials are among the best solid materials for thermal insulation available today; they are prepared through a sol–gel process. For building walls, the glass-fiber-enhanced types are the frequently used ones. They are prepared by adding the liquid–solid solution to the fibrous batting, which is called a sol–gel process. In the present paper, the changes in the most important building physical properties of aerogel blankets after thermal annealing are presented. The samples were subjected to isochronal heat treatments from 70 to 210 °C for 24 h. The changes in the thermal conductivity were followed by Holometrix Lambda heat flow meter, and differential scanning calorimetry results were also recorded. From the measured values, together with the densities, the most important thermal properties were calculated, such as thermal resistance, diffusivity, effusivity (heat absorption), and thermal inertia. In this paper, we attempt to clarify the role played by thermal annealing in the transient thermal properties of aerogel materials. Besides presenting the measurement results, a theoretical background is given. The investigations of not only the steady-state but also the transient thermal parameters of the materials are momentous at the design stage.

Preparation and Properties of UV Curable Silica Coatings from MPTMS and TEOS

2011 ◽  
Vol 181-182 ◽  
pp. 611-616 ◽  
Author(s):  
Feng Liao ◽  
Xing Rong Zeng
Keyword(s):  
Sol Gel ◽  
Hybrid Coating ◽  
Curing Time ◽  
Uv Curable ◽  
Silica Coatings ◽  
Organic Hybrid ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Mixture System ◽  
Molecular Compounds

UV curable 3-(trimethoxysilyl) propyl methacrylate MPTMS modified silica hybrid coating was prepared through sol-gel process from TEOS and MPTMS in acid medium for different ratios between TEOS and MPTMS. The structure of the hybrid coating and the formation of inorganic-organic hybrid networks were studied by FT-IR. It was found that the organic networks were formed by the polymerization of C=C bonds at 1638 cm-1. The influences of the photoinitiator content and the curing time on the curing degree of the mixture system were investigated. The results showed that the optimal photoinitiator content was 3%, and curing time was 180 s. The thermal stability of the UV cured coating was investigated by TG-DTA. The results showed that the contents of low-molecular compounds such as H2O, CH3OH, etc. were decreased in cured coatings with the increasing of the MPTMS concentration, thus significantly decreasing of the thermal weight-loss at temperature lower than 400°C.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

scholarly journals Synthesis of ZnO and CuO nanoparticles via Sol gel method and Its Characterization by using XRD and FT-IR Analysis

2022 ◽  
Author(s):  
Monika Patel ◽  
Sunita Mishra ◽  
Ruchi Verma ◽  
Deep Shikha
Keyword(s):  
Particle Size ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Broad Band ◽  
Zinc Nitrate ◽  
Zno Nanoparticle ◽  
Absorption Bands ◽  
Characteristic Absorption ◽  
Sol Gel Process ◽  
Ft Ir

Abstract Nanotechnology is a completely unique branch of technology that offers with substances in a very small size between (1-100 nm) with various crystal shapes which include spherical nanoparticles, flower shaped, Nano rods, Nano ribbons, and Nano platelets. Metals have ability to produce large number of oxides. These metal oxides play an major role in many areas of chemistry, physics, material science and food science. In this research, Zinc Oxide (ZnO) and Copper (II) oxide nanoparticles were synthesized via sol-gel process using zinc nitrate and copper (II) nitrate as precursor respectively. The characterization of CuO and ZnO nanoparticles was done by using various techniques. X-ray Diffraction (XRD) indicates the crystallinity and crystal size of CuO and ZnO nanoparticle. Fourier transform infrared spectroscopy (FT-IR) was used to get the infrared spectrum of the sample indicating composition of the sample which contains various functional groups. XRD result shows the particle size of CuO at highest peak 29.40140 was 61.25 nm and the particle size of ZnO at highest peak 36.24760 was 21.82 nm. FT-IR spectra peak at 594.56 cm-1 indicated characteristic absorption bands of ZnO nanoparticles and the broad band peak at 3506.9 cm-1 can be attributed to the characteristic absorption of O-H group. The analysis of FT-IR spectrum of CuO shows peaks at 602.09, 678.39, and 730.19cm−1 which refer to the formation of CuO. A broad absorption peak noticed at 3308.2 cm−1 attributed to O–H stretching of the moisture content.

Hybrid Nanocomposites Based on Metal Oxides and Polysiloxanes with Controlled Morphology

2007 ◽  
Vol 1007 ◽  
Author(s):  
Sorin Ivanovici ◽  
Christoph Rill ◽  
Claudia Feldgitscher ◽  
Guido Kickelbick
Keyword(s):  
Metal Oxides ◽  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
Hybrid Nanoparticles ◽  
Spectroscopic Methods ◽  
Metal Alkoxides ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Controlled Morphology

ABSTRACTHybrid materials based on polysiloxanes and metal oxides (SiO2, TiO2, ZrO2) were prepared by hydrosilation of allyl acetoacetate (AAA) modified metal alkoxides (M(OR)4; M = Ti, Zr; R = ethyl, isopropyl) or vinyl triethoxysilane with poly(dimethylsiloxane-co-hydrosiloxane) (PDMS-co-PMHS). The obtained compounds acted as single-source precursors in the sol-gel process. Various spectroscopic methods showed the complete functionalization of the polysiloxane chains with the complexes. When alcohols were used as solvents in the sol-gel process, hybrid nanoparticles were obtained, as observed by dynamic light scattering (DLS) measurements, transmission electron microscopy (TEM), and spectroscopic methods such as NMR and FT-IR.

One-pot synthesis of organo-silica hybrids with high thermal properties via a simple sol–gel process

2019 ◽  
Vol 140 (5) ◽  
pp. 2267-2274
Author(s):  
Fatemeh Javanbakht ◽  
Bahareh Razavi ◽  
Mehdi Salami-Kalajahi ◽  
Hossein Roghani-Mamaqani ◽  
Masoud Ommati
Keyword(s):  
Thermal Properties ◽  
Sol Gel ◽  
One Pot ◽  
One Pot Synthesis ◽  
Sol Gel Process ◽  
Silica Hybrids

Influence of Li2+ Doping on the Structural and Optical Properties of CaO Synthesized by Sol–Gel Process

2019 ◽  
Vol 07 (01n02) ◽  
pp. 1950002
Author(s):  
Nadir Lalou ◽  
Ahmed Kadari
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Lithium Nitrate ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Sol Gel Process ◽  
Ft Ir ◽  
First Time

This work proposes the synthesis of nanocrystalline calcium oxide (CaO) pure and doped with different concentrations of lithium (Li[Formula: see text]) ions by sol–gel process. Calcium nitrate (Ca(NO[Formula: see text]4H2O; 99.99%) and lithium nitrate (LiNO3; 99.99%) were used as precursors. The synthesized powders were characterized by several techniques such as: UV-Vis transmission spectroscopy, Fourier Transform Infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD). The main objective of this paper is to study the influence of lithium (Li[Formula: see text] ratio) on the structural and optical properties of synthesized powders. The band gap values decreased with the increasing of Li[Formula: see text] ions in CaO lattice; the slight change in the band gap was directly related to the energy transfer between the CaO excited states and the 2s levels of Li[Formula: see text] ions. The influence of Li[Formula: see text] doping on the physical properties of CaO nanocrystalline will be studied for the first time in this work; no literature has previously published this kind of impurities.

Synthesis of V2O5 Powders by EDTA Assistance Ultrasound Sol-Gel Process

2012 ◽  
Vol 512-515 ◽  
pp. 207-210
Author(s):  
Quan Wen ◽  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu
Keyword(s):  
Activation Energy ◽  
Raw Materials ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Calcination Temperatures ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Precursor Powders ◽  
Influence Of Ph

V2O5 powders were successfully synthesized by the EDTA assistanced ultrasound sol-gel process using NH4VO3 and EDTA, NH3•H2O as raw materials. The synthesized activation energy and the influence of pH values and the calcination temperatures on the phases and microstructures of powders were particularly investigated. The precursor powders and the V2O5 powders were characterized by X-ray diffraction (XRD), fourier transform inelectron microscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry-thermal gravimetric (DSC-TG). Results show that the obtained products exhibit good crystallization under the conditions of pH=4, calcination temperature 400~500 °C and calcination time 0.5 h during the synthesizing process. The as-prepared V2O5 powders show preferred growth orientation along (001) plane at the pH=4. By DSC analysis, the ultrasonic cavitation result in the decrease in synthesized activation energy obviously than that was prepared without ultrasonic irradiation.

Effect of TiO2 Nanoparticles on the Hydrophilicity of Sulfonated-Polyethersulfone

2009 ◽  
Vol 79-82 ◽  
pp. 663-666 ◽  
Author(s):  
Ming Liang Luo ◽  
Qing Zhi Wen ◽  
Hong Jian Liu ◽  
Jia Lin Liu
Keyword(s):  
Sol Gel ◽  
Coordination Bond ◽  
Tio2 Nanoparticle ◽  
Interaction Theory ◽  
Tio2 Content ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Nanoparticle Composites ◽  
Sulfonated Polyethersulfone ◽  
Nanosized Tio2

Sulfonated-polyethersulfone/TiO2 (SPES/TiO2) nanoparticle composites with different TiO2 content were prepared by a sol-gel process. These composites have nanosized TiO2 rich domains well dispersed within SPES matrix observed by SEM photograph. The effect of TiO2 nanoparticles on the hydrophilicity of SPES was discussed by contact angle goniometer. The mechanism of the hydrophilicity improvement of these composites was analyzed by the molecular interaction theory and FT-IR. The hydrogen bond and coordination bond between SPES and TiO2 nanoparticle were observed. Comparing with the pure SPES, the SPES/TiO2 composites exhibited an outstanding increase in hydrophilicity.

Synthesis, Structure and Spectral Properties of Eu:YGO Phosphor Powders

2016 ◽  
Vol 852 ◽  
pp. 585-590
Author(s):  
Lin Sang ◽  
Ning Pan ◽  
Jing Su ◽  
Xiao Mei Tan ◽  
Hang Li ◽  
...  
Keyword(s):  
Spectral Properties ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectroscopy ◽  
Fluorescence Properties ◽  
Sol Gel Process ◽  
Different Temperatures ◽  
Ft Ir ◽  
Polycrystalline Phase ◽  
Precursor Powders

3at. % Eu3+ doped (Y, Gd)2O3 precursor powders with various compositions were synthesized via a sol-gel process, and the precursors were sintered at different temperatures. XRD, FT-IR, Raman and photoluminescence spectroscopy were used to study the phase, microstructure and luminescent properties of the precursors and the sintered powders. The results show that pure (Y, Gd)2O3 polycrystalline phase can be obtained from sintering the precursors at 700°C. The influences of the host compositions on the microstructures and fluorescence properties were analyzed, and the optimized composition was obtained for 3at. % Eu3+ doped (Y, Gd)2O3 powders.

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