scholarly journals Performance of rubber mortars containing silica coated rubber

2021 ◽  
Vol 71 (342) ◽  
pp. e244
Author(s):  
J. Li ◽  
P. Chen ◽  
H. Cai ◽  
Y. Xu ◽  
X. Tian ◽  
...  
Keyword(s):  
Absorption Rate ◽  
Sol Gel ◽  
Silica Coating ◽  
Capillary Water ◽  
Hydrophobic Properties ◽  
Capillary Water Absorption ◽  
Fine Aggregates ◽  
Rubber Particles ◽  
Surface Modified ◽  
Mechanical Strengths

This paper investigates the influence of silica coated rubber on the performance of rubber mortars. A classical Stöber sol-gel method is applied to produce a layer of silica coating on rubber particles, which is used to partially replace the fine aggregates in concrete. The effects of the surface-modified rubber particles on the flowability, mechanical strength, capillary water absorption rate, and microstructure of mortars are examined. The results show that the silica coating on the rubber particles reduces the contact angle between the rubber particles from 120° to 103° (i.e., by 17°) and changes the hydrophobic properties from strong hydrophobicity to weak hydrophobicity. The mechanical strengths of mortars are significantly improved by the incorporation of surface-modified rubber particles, i.e., from 41.60% to 44.86% (compressive strength) and from 7.80% to 26.28% (flexural strength). In addition, the incorporation of surface modified rubber particles increases the density of the mortar’s microstructure and enhances the interfaces with its surrounding pastes.

scholarly journals Effects of Imposed Damage on the Capillary Water Absorption of Recycled Aggregate Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Gao ◽  
Zhiming Ma ◽  
Jianzhuang Xiao ◽  
Fuan Li
Keyword(s):  
Absorption Coefficient ◽  
Water Absorption ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Capillary Absorption ◽  
Capillary Water ◽  
Aggregate Concrete ◽  
Capillary Water Absorption ◽  
Freeze Thaw ◽  
Loading Level

Capillary water absorption of concrete is closely related to its pore structure, permeability, and durability. This paper intensively investigates the effects of imposed damage, including freeze-thaw damage and loading damage, on the capillary water absorption of recycled aggregate concrete (RAC). Freeze-thaw cycle test, loading test, and the experiment of capillary water absorption were carried out, respectively. The results demonstrate that the addition of recycled coarse aggregate (RCA) results in the increase in the capillary absorption behavior of RAC without imposed damage, and there exists a linear correlation between the behaviors of capillary water absorption and chloride penetration of RAC. The imposed freeze-thaw damage or load damage of RAC boosts with the increase of RCA replacement percentages after suffering the same freeze-thaw cycles or loading level. The imposed freeze-thaw damage and load damage further lead to the increase in the capillary water absorption of RAC, and the capillary absorption coefficient of RAC increases linearly with the increased RCA replacement percentages, after suffering the same freeze-thaw cycles or loading level. Furthermore, capillary absorption coefficient increases linearly with the growth of imposed freeze-thaw damage or load damage degree, which can be used to estimate the capillary absorption behavior of RAC exposed to the extreme environment.

Antibacterial Activity of Surface-Modified Fabric with Ag/AgCl-Doped Quaternary Ammonium-Modified Silicate Hybrid

2019 ◽  
Vol 19 (11) ◽  
pp. 7285-7293 ◽  
Author(s):  
Kuo-Hui Wu ◽  
Yin-Chiung Chang ◽  
Ken-Fa Cheng ◽  
Je-Chuang Wang
Keyword(s):  
Colloidal Suspension ◽  
Sol Gel ◽  
Antimicrobial Properties ◽  
Woven Fabrics ◽  
Dipolar Interactions ◽  
Zone Of Inhibition ◽  
E Coli ◽  
Antibacterial Material ◽  
Surface Modified

An organic–inorganic hybrid antibacterial material based on Ag/AgCl and quaternary ammoniummodified silicate (Ormosil (NR+4 Cl-)) was prepared by sol–gel processes and an in situ reduction method, in which silver nitrate, tetraethoxysilane (TEOS), N-trimethoxysilylpropyl-N,N,Ntrimethylammonium chloride (TMAPS) and N-[3-(trimethoxysilyl)propyl]diethylenetriamine (ATS) acted as precursor, linker and colloidal suspension stabilizer, respectively. The physical properties of the Ormosil (NR+4 Cl-) and Ormosil (NR+4 Cl-)/Ag hybrids were examined using XPS and TGA spectroscopy, the results of which indicated that Ag/AgCl was immobilized in channels by dipolar interactions with the Ormosil (NR+4 Cl-) matrix. Ormosil (NR+4 Cl-) and Ormosil (NR+4 Cl-)/Ag sol solutions were used to functionalize non-woven fabrics by simply immersing the textiles into the dispersions in order to obtain antimicrobial fabrics. The antibacterial effects of the Ormosil/Ag- and Ormosil (NR+4 Cl-)/Ag-modified fabrics against Gram-negative P. aeruginosa and E. coli, and Grampositive S. aureus and B. subtilis, were assessed using the zone of inhibition and the plate-counting method. The antibacterial efficacy was maintained even after 20 laundry cycles. The results indicated that the Ormosil/Ag and Ormosil (NR+4 Cl-)/Ag hybrids are useful as non-leaching agents imparting durable antimicrobial properties to fabrics.

scholarly journals Silica coating of indium phosphide nanoparticles by a sol–gel method and their photobleaching properties

2019 ◽  
Vol 1 (12) ◽  
Author(s):  
Masaya Kambayashi ◽  
Noriko Yamauchi ◽  
Kouichi Nakashima ◽  
Masaki Hasegawa ◽  
Yuki Hirayama ◽  
...  
Keyword(s):  
Indium Phosphide ◽  
Sol Gel ◽  
Silica Coating ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals The Influence of 30 Years Outdoor Weathering on the Durability of Hydrophobic Agents Applied on Obernkirchener Sandstones

Buildings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 18 ◽  
Author(s):  
Jeanette Orlowsky ◽  
Franziska Braun ◽  
Melanie Groh
Keyword(s):  
Water Absorption ◽  
Water Uptake ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Absorption Determination ◽  
Colour Changes ◽  
Uptake Velocity ◽  
Outdoor Weathering

The durability of eleven different water repellents applied on one sandstone type was studied after a long-term weathering at seven different locations in Germany. By measuring colour changes, it could be shown that the formation of black crusts, the deposition of particles and biogenic growth caused a gradual darkening as well as significant changes in total colour over time. Additionally, the water absorption behaviour was investigated with two different methods: applying a low pressure using the pipe method and capillary water absorption measurements from a wet underlay. Afterwards, the test results were analysed with four different evaluation methods: calculation of the protection degree from pipe method and capillary water absorption, determination of the velocity of water uptake during capillary water absorption and calculation of the damaged depth of the stone surface using single-sided NMR technique. The growing damaged depth leads to an increase of the water uptake velocity and to a decrease of the protection degree of the applied hydrophobing agents. Three protective agents based on isobutyltrimethoxysilane showed already after two years of outdoor weathering a clear loss of performance, which significantly increased after 30 years of exposure.

scholarly journals The effect of silica-coating by sol-gel process on resin-zirconia bonding

2013 ◽  
Vol 32 (1) ◽  
pp. 165-172 ◽  
Author(s):  
Christie Ying Kei LUNG ◽  
Edwin KUKK ◽  
Jukka Pekka MATINLINNA
Keyword(s):  
Sol Gel ◽  
Silica Coating ◽  
Sol Gel Process

Study on TiO2/Tourmaline Composite Photocatalyst Materials

2013 ◽  
Vol 423-426 ◽  
pp. 67-71
Author(s):  
Yan Wen Feng
Keyword(s):  
Heat Treatment ◽  
Electron Probe ◽  
Absorption Rate ◽  
Sol Gel ◽  
Visible Region ◽  
Reaction System ◽  
Water Molecules ◽  
Photocatalytic Reaction ◽  
Composite Photocatalyst ◽  
Gel Technique

TiO2/tourmaline composite photocatalyst materials were fabricated mainly by the sol-gel technique. Study found that, TiO2/tourmaline composite photocatalyst materials, under the bombardment by electron beam in SEM, would turn to be brighter and attract each other, and the electrostatic gravitation among the TiO2/tourmaline composite photocatalyst materials granules grow up evidently on their surfaces with the accumulations of electron from the electron probe, so as to be strong enough to force the TiO2/tourmaline composite photocatalyst materials granules to be shifted rapidly and accumulated into clusters ultimately, and the granules which were heat treatment on 600°C for 3h shifted most strongly. And the average absorption rate of TiO2/tourmaline composite photocatalyst material was stronger than nano-TiO2, in the visible region of wavelength 400-500nm. In addition, TiO2/tourmaline composite photocatalyst materials were capable of activating water molecules to reduce agglomeration of water molecules, and to increase the amount of dissolved oxygen in the Photocatalytic reaction system.

An Effective Approach to Improve the Oxidation Resistance of Ti-6Al-4V Alloy by Combination of Phosphorization and Silica Coating

2011 ◽  
Vol 148-149 ◽  
pp. 534-537
Author(s):  
Chun Xiang Gao
Keyword(s):  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Behavior ◽  
Sol Gel ◽  
Synergetic Effect ◽  
Silica Coating ◽  
Dip Coating ◽  
Sio2 Coating ◽  
Amorphous Sio2 ◽  
Dip Coating Technique

A very effective approach to improve the oxidation resistance of Ti-6Al-4V alloy was proposed. The Ti-6Al-4V alloy was firstly phosphated and then coated by silica using sol-gel dip-coating technique. A duplex layer of TiP2O7 and amorphous silica was synthesized at the alloy surface. The isothermal and cyclic oxidation behavior of the treated alloy with silica coating and the corresponding bare alloy was investigated at 600 oC in static air to investigate the synergetic effect of phosphorization and amorphous SiO2 coating on the oxidation resistance of the alloy. The isothermal and cyclic oxidation resistances of the alloy were greatly improved.

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