Alkali resistance enhancement of basalt fibers by hydrated zirconia films formed by the sol-gel process

1994 ◽  
Vol 9 (4) ◽  
pp. 1006-1013 ◽  
Author(s):  
T. H. Jung ◽  
R. V. Subramanian
Keyword(s):  
Ethyl Acetoacetate ◽  
Chemical Constituents ◽  
Sol Gel ◽  
Fiber Surface ◽  
Alkali Resistance ◽  
Chemical Compositions ◽  
Basalt Fibers ◽  
Zirconia Coating ◽  
Zirconium Alkoxide ◽  
Hydrated Zirconia

Basalt fibers were dip-coated in zirconium-n-propoxide, unstabilized or stabilized by chelation with ethyl acetoacetate. The thermal transformations of the hydrated zirconia coatings formed were investigated by dynamic x-ray diffraction and differential thermal analysis. The changes in the surface chemical compositions of coated and uncoated fibers, following alkali immersion extending to 90 days, were characterized by EDXA and IR spectral analysis. Fiber strengths were also measured after immersion in 0.1 M NaOH for different durations. It was found that the transition of the amorphous zirconia coating to the tetragonal crystalline phase is shifted to higher temperatures by chelation of the zirconium alkoxide. Alkali corrosion of the uncoated basalt fibers results in dissolution of the oxides of Si, Al, and Ca, and the formation of unsoluble hydroxides of Fe, Mg, and Ti from the chemical constituents of basalt. These reactions are suppressed by the protective zirconia coating on basalt fibers formed by the unstabilized zirconium alkoxide. However, the coating formed from zirconium propoxide stabilized by ethyl acetoacetate does not form an effective barrier against alkali attack since it is easily detached from the fiber surface during alkali immersion. The tensile strength of uncoated basalt fibers is drastically reduced by alkali attack. But the strength of zirconia-coated basalt fibers is maintained even after 90 days of alkali immersion. The vastly improved alkaline durability of the coated fibers shows the potential of zirconia-coated basalt fibers for cement reinforcement.

Effect of ZrO2 on the alkali resistance and mechanical properties of basalt fibers

2012 ◽  
Vol 48 (7) ◽  
pp. 751-756 ◽  
Author(s):  
Ya. V. Lipatov ◽  
S. I. Gutnikov ◽  
M. S. Manylov ◽  
B. I. Lazoryak
Keyword(s):  
Mechanical Properties ◽  
Alkali Resistance ◽  
Basalt Fibers

Applications and Advantages of Basalt Assembly in Construction Industry

2011 ◽  
Vol 332-334 ◽  
pp. 1937-1940 ◽  
Author(s):  
Wei Wei Hu ◽  
Hua Wu Liu ◽  
Dang Feng Zhao ◽  
Zong Bin Yang
Keyword(s):  
Construction Industry ◽  
High Performance ◽  
Inorganic Material ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Chemical Compositions ◽  
Basalt Fibers ◽  
Reinforced Polymer ◽  
Reinforcing Fibers ◽  
Reinforcement Material

Basalt fiber is a novel high-performance inorganic material, recently has been well received as a reinforcement in China. However, the applications in civil engineering have been rather limited. The chemical compositions, the characteristics of basalt fibers, and the typical products of basalt, including chopped yarn of basalt fiber, basalt fiber geo-textiles and basalt fiber reinforced polymer, were introduced．The advantages of basalt fibers as a reinforcement of concrete were explored in comparison with the commonly used reinforcing fibers, which indicates that basalt fiber is the most promising reinforcement material for concrete and will significantly benefit civil construction industries in the future.

scholarly journals Biocomposite of Cassava Starch Reinforced with Cellulose Pulp Fibers Modified with Deposition of Silica (SiO2) Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Joabel Raabe ◽  
Alessandra de Souza Fonseca ◽  
Lina Bufalino ◽  
Caue Ribeiro ◽  
Maria Alice Martins ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Sol Gel ◽  
Fiber Surface ◽  
Sio2 Nanoparticles ◽  
Thermoplastic Starch ◽  
Cassava Starch ◽  
Sem Analysis ◽  
Pulp Fibers ◽  
Moisture Adsorption ◽  
Cellulose Pulp

Eucalyptuspulp cellulose fibers were modified by the sol-gel process for SiO2superficial deposition and used as reinforcement of thermoplastic starch (TPS). Cassava starch, glycerol, and water were added at the proportion of 60/26/14, respectively. For composites, 5% and 10% (by weight) of modified and unmodified pulp fibers were added before extrusion. The matrix and composites were submitted to thermal stability, tensile strength, moisture adsorption, and SEM analysis. Micrographs of the modified fibers revealed the presence of SiO2nanoparticles on fiber surface. The addition of modified fibers improved tensile strength in 183% in relation to matrix, while moisture adsorption decreased 8.3%. Such improvements were even more effective with unmodified fibers addition. This result was mainly attributed to poor interaction between modified fibers and TPS matrix detected by SEM analysis.

Study on the Use of Rhodamine Doped Nanocomposite for Latent Fingerprint Detection

2011 ◽  
Vol 295-297 ◽  
pp. 813-816 ◽  
Author(s):  
Li Liu
Keyword(s):  
High Surface ◽  
Sol Gel ◽  
Volume Ratio ◽  
Molecular Complexes ◽  
Optical Devices ◽  
Chemical Compositions ◽  
Loading Capacity ◽  
Optical And Mechanical Properties ◽  
Fluorescent Compounds ◽  
Fingerprint Detection

Silicon dioxide-based nanocomposites offer large loading capacity for various doping chemicals or molecular complexes, high surface to volume ratio and customizable surface chemistry for the creation and development of novel sensors and devices [1-2]. When compared with other sol-gel materials, xerogels represent a class of nanocomposites that are relatively easy to fabricate but with unique thermal, acoustic, optical and mechanical properties for rapid sensor or device prototyping development [3-4]. Xerogels in solids are formed by controlled evaporation of the liquid in the hydro-gel. Their porosity and morphology depend largely on the temperature, gel chemical compositions and pH in the fabrication process. When impregnated with fluorescent compounds in their nanosize cavities, the doped xerogels exhibit strong and stable fluorescence properties that are useful for the developing of ion-exchange sensors and optical devices. However, the use of these fluorescently doped xerogels in forensic applications was still largely unexplored.

Preparation and Property of Epoxy Based Nano-SiO2/TiO2/Polyimide Hybrid Enhanced Sizing

2011 ◽  
Vol 335-336 ◽  
pp. 96-100
Author(s):  
Cun Zhou ◽  
Jian Li Cheng ◽  
Yu Sun
Keyword(s):  
Carbon Fiber ◽  
Sol Gel ◽  
Fiber Surface ◽  
Nano Particles ◽  
Interface Properties ◽  
Particle Size Analyzer ◽  
Complex Technology ◽  
Carbon Fiber Surface ◽  
Interlaminar Shear ◽  
Micro Morphology

Abstract: An epoxy based nano-SiO2/TiO2/polyimide hybrid enhanced sizing for carbon fiber was prepared by modified SiO2/TiO2precursor in PAA collosol with silane couple agent(WD-50) and eligibility surfactant via sol-gel reaction, and both ultrasonic cavitation and multi-complex technology were used during the process. The properties of PAA-SiO2-TiO2hybrid sizing and micro-morphology of carbon fiber surface were analyzed by FTIR, DSC, Particle Size Analyzer and STM. The results indicated that nanoscale SiO2•TiO2particles dispersed in the hybrid sizing film homogeneously, and a layer with nano particles was formed on carbon fiber surface after treated by the hybrid enhanceing sizing. The roughness was increased and interface properties of carbon fiber would be improved. At the same time both tensile strength and the interlaminar shear strength were increased obviously.

scholarly journals Effect of Conditions of Sol-Gel Synthesis and Post-Synthetic Treatment on Photoelectrochemical and Electro-Catalytic Properties of Titanium Oxide Nanostructures and Tio2-Au Nanocomposites

2021 ◽  
Vol 57 (4) ◽  
pp. 1-14
Author(s):  
N.I. Romanovska ◽  
◽  
P.A. Manorik ◽  
V.S. Vorobets ◽  
G.Ya. Kolbasov ◽  
...  
Keyword(s):  
Visible Light ◽  
Au Nanoparticles ◽  
Sol Gel ◽  
Au Nanoparticle ◽  
Chemical Compositions ◽  
High Catalytic Activity ◽  
Electron Microscopies ◽  
Treatment Conditions ◽  
Carboxylate Groups ◽  
Tio2 Nanostructures

Carbon-doped mesoporous TiO2 nanostructures and TiO2-Au nanocomposites with stabilized Au nanoparticles have been synthesized by the sol-gel template method and characterized by X-ray diffraction, scanning and transmission electron microscopies, Fourier-transform infrared spectroscopy, N2 adsorption/desorption, ultraviolet-visible spectroscopy, and photoelectrochemical current spectroscopy. The synthesis hydrothermal treatment conditions affected the particle size, electronic structure, morphology, phase, and chemical compositions, as well as the texture of the synthesized materials. The TiO2 and TiO2-Au based electrodes were light-sensitive in a wavelength range of 250–412 nm and were distinguished by a high catalytic activity during oxygen electroreduction. The presence of -ol and carboxylate groups in the amorphous phase is the main factor affecting the photosensitivity of TiO2 nanostructures to visible light and an increase in their photoactivity during the decomposition of methylene blue upon irradiation with ultraviolet and visible light relative to pure anatase. The higher photosensitivity and photoactivity of TiO2-Au nanocomposites compared with those of the corresponding starting TiO2 is due to the synergistic effect of Au nanoparticles and interstitial Ti-O-C groups, which depends on the Au nanoparticle content of the composite and on the mesopore size.

scholarly journals Superhydrophobic/superoleophilic cotton-oil absorbent: preparation and its application in oil/water separation

RSC Advances ◽  
2018 ◽  
Vol 8 (53) ◽  
pp. 30257-30264 ◽  
Author(s):  
Na Lv ◽  
Xiaoli Wang ◽  
Shitao Peng ◽  
Lei Luo ◽  
Ran Zhou
Keyword(s):  
Cotton Fiber ◽  
Sol Gel ◽  
Fiber Surface ◽  
Water Separation ◽  
Gel Method ◽  
Oil Sorbent ◽  
Oil Water Separation ◽  
Oil Absorbent ◽  
Oil Water ◽  
Cotton Oil

A superhydrophobic and superoleophilic oil sorbent was prepared by attaching SiO2 particles onto a cotton fiber surface by a sol–gel method and subsequent octadecyltrichlorosilane modification.

scholarly journals Surface Functionalization of Cotton and PC Fabrics Using SiO2 and ZnO Nanoparticles for Durable Flame Retardant Properties

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 124 ◽  
Author(s):  
Sidra Saleemi ◽  
Tayab Naveed ◽  
Tabinda Riaz ◽  
Hafeezullah Memon ◽  
Javeed Ashraf Awan ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Flexural Rigidity ◽  
Sol Gel ◽  
Health And Safety ◽  
Fiber Surface ◽  
Safety Issues ◽  
Functional Textiles ◽  
Coated Fabric ◽  
Flame Retardant Properties ◽  
Silica Dioxide

In recent years, the use of functional textiles has attained attention due to their advantageous health and safety issues. Therefore, this study investigated the flame retardancy on cotton (COT) and polyester-cotton (PC) fabrics treated with different concentrations of silica and zinc nanoparticles through a sol-gel finishing technique. FTIR, SEM, and TGA were conducted for the characterization of coated fabric samples. The FTIR and SEM of Pristine and Treated Cotton and PC fabrics illustrated that the SiO2 (silica dioxide) and ZnO (Zinc oxide) nanoparticles were homogeneously attached to the fiber surface, which contributed to the enhancement of the thermal stability. The starting thermal degradation improved from 320 to 350 °C and maximum degradation was observed from 400 to 428 °C for the COT-2 cotton substrate. However, the initial thermal degradation improved from 310 to 319 °C and the highest degradation from 500 to 524 °C for the PC substrate PC-2. The outcomes revealed that the silica has a greater influence on the thermal properties of COT and PC fabric samples. Additionally, the tensile strength and flexural rigidity of the treated samples were improved with an insignificant decrease in air permeability.

scholarly journals Chemical Composition of Essential Oils Obtained from Heteromorpha arborescens (Spreng.) Cham. and Schltdl Leaves Using Two Extraction Methods

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Taiwo Oluwafunmilola Abifarin ◽  
Gloria Aderonke Otunola ◽  
Anthony Jide Afolayan
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Co2 Emission ◽  
Chemical Constituents ◽  
Solvent Free ◽  
Oil Yield ◽  
Chemical Components ◽  
Chemical Compositions ◽  
Microwave Extraction ◽  
Oxygenated Compounds

This study was aimed at comparing the essential oils obtained from Heteromorpha arborescens leaves by Solvent-Free Microwave Extraction (SFME) and Hydrodistillation (HD) methods in terms of their chemical compositions, yield, CO2 emission, and energy consumption. The solvent-free microwave extraction method indicated a higher oil yield of 0.7 mL/200 g (0.35%) as compared to 0.59 mL/200 g (0.295%) obtained through hydrodistillation. GC-MS analysis of the oils revealed a total of 52 chemical components from both methods with the presence of 35 (96.52%) and 30 (71.15%) chemical constituents for HD and SFME, respectively. The major constituents observed in the essential oil extracted by SFME methods include α-pinene (6%), D-limonene (11.27%), β-ocimene (9.09%), β-phellandrene (6.33%), β-mycene (8.49%), caryophyllene (5.96%), and camphene (4.28%). However, in the hydrodistillation method, the oil was majorly composed of a-pinene (4.41%), β-pinene (10.68%), β-ocimene (6.30%), germacrene-D (5.09%), humulene (5.55%), and α-elemene (6.18%). The SFME method was better in terms of saving energy (0.25 kWh against 4.2 kWh of energy consumed), reduced CO2 emission (200 g against 3360 g of CO2), a higher yield, and better quality of essential oil due to the presence of higher valuable oxygenated compounds (8.52%) against that of the hydrodistillation method (2.96%). The SFME method is, therefore, a good alternative for extracting the oils of H. arborescens leaves since the essential oil yield is higher with more oxygenated compounds, considerable energy savings, lower cost, and reduced environmental burden at substantially reduced extraction time (30 min as opposed to 180 min).

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