scholarly journals Study of Magnesium Hydroxide Protective Coating against Corrosion, Applied on Poly(methyl methacrylate) Plates, By Using the Sulfuric Acid Attack Acceleration Test

2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Domna Merachtsaki ◽  
Eirini-Chrysanthi Tsardaka ◽  
Eleftherios Anastasiou ◽  
Anastasios Zouboulis
Keyword(s):  
Sulfuric Acid ◽  
Methyl Methacrylate ◽  
Magnesium Hydroxide ◽  
Concrete Surface ◽  
X Ray Diffraction ◽  
Acid Attack ◽  
Poly Methyl Methacrylate ◽  
Concrete Pipes ◽  
Custom Made ◽  
Microbiologically Induced Corrosion

Microbiologically induced corrosion (MIC) leads to the degradation/deterioration of concrete pipes, due to the formation of gypsum. Magnesium hydroxide powders may protect the concrete surface by maintaining alkaline pH values at the surface, or by neutralizing the biogenic produced sulfuric acid. An accelerated sulfuric acid spraying test in a custom-made spraying chamber used to examine the consumption of magnesium hydroxide coating, which was applied on poly (methyl methacrylate) plates, instead of applying it on concrete substrates. In that way, only the magnesium hydroxide coating can interact with the acid and can be examined separately. Surface pH measurements and the mass changes were daily conducted, during the four-day accelerated spraying test. The mineralogical phases of the surface were determined by using X-ray Diffraction (XRD) measurements.

scholarly journals Comparison of Different Magnesium Hydroxide Coatings Applied on Concrete Substrates (Sewer Pipes) for Protection against Bio-Corrosion

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1227
Author(s):  
Domna Merachtsaki ◽  
Eirini-Chrysanthi Tsardaka ◽  
Eleftherios K. Anastasiou ◽  
Haris Yiannoulakis ◽  
Anastasios Zouboulis
Keyword(s):  
Sulfuric Acid ◽  
Magnesium Hydroxide ◽  
Concrete Surface ◽  
Sem Analysis ◽  
Acid Attack ◽  
Sewer Pipes ◽  
Surface Ph ◽  
Adhesion Ability ◽  
Coating Mass ◽  
Surface Morphologies

Several coatings and linings have been examined and used for the protection of sewer concrete pipes, against mainly biogenic-provoked corrosion due to the production of bio-sulfuric acid, leading to the degradation of the pipes’ structure and eventually, to their collapse and need for costly replacement. This study aimed to examine the potential differences between five different magnesium hydroxide coatings, prepared from powders presenting different purity, surface area and pore size distribution, when applied as corrosion protection agents. These coatings were tested by using accelerated sulfuric acid spraying tests, both in dry and wet coating conditions. The coating adhesion ability and their microstructure were examined by the application of pull-off measurements and of SEM analysis, respectively and were found to present certain differences, regarding the adhesion ability and the surface morphologies. During the acid spraying procedure, the surface pH and the mass change of coated concrete specimens were recorded daily. The surface pH was reduced towards acidic values and the mass reduction approached almost −20% in comparison with the initial coating mass for certain cases. Additionally, the hardness and roughness of concrete surface under the coating layer (i.e., the interface between the coating and the surface) after four days of acid spraying, exhibited much smaller changes (due to protection) in contrast to the uncoated concrete specimens (used as blank/comparison experiments), which were found to be highly affected/corroded. The formation of concrete corrosion and coating by-products, as noticed after the respective chemical reactions, was recorded by X-ray diffraction (XRD) measurements and the respective quantification of obtained results. In all the coated specimens only very small amounts of the major by-product (gypsum) was observed, indicating that the concrete surface was sufficiently protected from sulfuric acid attack.

scholarly journals Properties and Performance of Novel Mg(OH)2-Based Coatings for Corrosion Mitigation in Concrete Sewer Pipes

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5291
Author(s):  
Domna Merachtsaki ◽  
Georgios Fytianos ◽  
Efthimios Papastergiadis ◽  
Petros Samaras ◽  
Haris Yiannoulakis ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Magnesium Hydroxide ◽  
Low Cost ◽  
Concrete Surface ◽  
Initial Surface ◽  
Acid Attack ◽  
Sewer Pipes ◽  
Surface Samples ◽  
Protected Surface ◽  
And Performance

The biological activity occurring in urban sewerage systems usually leads to the (biogenic) corrosion of pipe infrastructure. Anti-corrosion coating technology was developed in an effort to protect sewer pipes from degradation. This study evaluates a new class of relatively low-cost magnesium hydroxide-based coatings, regarding their ability to adhere efficiently onto the concrete surface, and offer efficient corrosion protection. Six magnesium hydroxide-based coatings were prepared with the addition of two different types of cellulose, used as adhesion additives, and these were applied on concrete specimens. Pull-off measurements showed that the addition of higher amounts of cellulose could improve the coating adhesion onto the concrete surface. An accelerated sulfuric acid spraying test was used to evaluate the consumption time of the applied coatings and their efficiency in maintaining over time slightly alkaline pH values (above 8) on the coated/protected surfaces. At the end of spraying test, a mineralogical analysis of surface samples was performed, indicating that the formation of corrosion by-products (mainly gypsum) was increased when the added amount of cellulose was lower. Hardness and roughness measurements were also conducted on the concrete surfaces, revealing that the coatings helped the concrete surface to preserve its initial surface properties, in comparison to the uncoated specimens. A SEM/microstructure analysis showed that aggregates were formed (possibly consisting of Mg(OH)2), affecting the reactivity of the protected surface against sulfuric acid attack.

Properties of Carbon Nanofibers Prepared from Polyacrylonitrile/Poly(methyl Methacrylate) Blend

2009 ◽  
Vol 79-82 ◽  
pp. 353-356
Author(s):  
Wei Pan ◽  
Yan Chen ◽  
Xiao Wei He
Keyword(s):  
Methyl Methacrylate ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
Nitrogen Atmosphere ◽  
Wet Spinning ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Methyl Methacrylate ◽  
Graphite Crystallite ◽  
Raman Microspectrometry

The polyacrylonitrile(PAN)/poly (methyl methacrylate)(PMMA) blend fibers were prepared by wet-spinning technique and carbonized over the temperature range of 400-1000°C in nitrogen atmosphere. After carbonization of the blend fibers, the PMMA component removed and the PAN component left in the form of carbon nanofibers. Morphology of the carbon nanofibers were investigated via scanning electron microscopy (SEM), and the carbonization behavior of the fibers were examined via x-ray diffraction (XRD), Raman microspectrometry. The optimal condition made carbon fibers with great L/D ratio and diameter less than 200 nm. XRD and Raman spectra shows that the PAN/PMMA blend fibers treated at 600°C produced some graphite crystallite.

scholarly journals Corrosion Inhibitory Effects of Mullite in Concrete Exposed to Sulfuric Acid Attack

2020 ◽  
Vol 1 (2) ◽  
pp. 282-295
Author(s):  
Shima Taheri ◽  
Gerardo Pareja Delgado ◽  
Oluwatoosin B. A. Agbaje ◽  
Paritosh Giri ◽  
Simon Martin Clark
Keyword(s):  
Sulfuric Acid ◽  
Prolonged Exposure ◽  
Acid Corrosion ◽  
Hardness Test ◽  
Aluminum Silicate ◽  
Acid Attack ◽  
Concrete Pipes ◽  
Physicochemical Changes ◽  
Sulfuric Acid Solutions

Prolonged exposure to low pH conditions affects the durability of concrete. In this work, the effect of mullite, aluminum silicate, on the strength and the acid corrosion of mortar and concrete under induced accelerated conditions in sulfuric acid solutions at pH of 0.25 and 1 was studied. The characterization of physicochemical changes was performed using techniques including compressive strength, scanning electron microscopy, micro-X-ray fluorescence spectrometry, and the Vickers hardness test. The results indicate that the addition of mullite does not have any significant effect on the overall strength of mortar and concrete samples, while it significantly increases their resistance to corrosion caused by sulfate attack by 90%, therefore, it is expected to increase the life span and decrease the maintenance costs of concrete pipes subjected to acid corrosion in sewer environments. The inhibition efficiency is observed to be sensitive to acid concentration and was improved with increase in the amount of mullite in samples.

A Study on Luminescence Enhancement in Ion Irradiated TiO2/Poly(methyl methacrylate) Nanocomposites

2012 ◽  
Vol 585 ◽  
pp. 139-143 ◽  
Author(s):  
Sarla Sharma ◽  
Rishi Vyas ◽  
Y.K. Vijay
Keyword(s):  
Methyl Methacrylate ◽  
Ion Beam ◽  
Visible Region ◽  
Heavy Ion ◽  
X Ray Diffraction ◽  
Casting Method ◽  
Poly Methyl Methacrylate ◽  
Swift Heavy Ion ◽  
Vis Spectroscopy ◽  
Solution Casting Method

Swift heavy ion induced modification in the optical properties of TiO2/Poly (Methyl methacrylate) nanocomposites is reported in this paper. The as prepared anatase TiO2 nanoparticles were uniformly dispersed in PMMA matrix using solution casting method. These nanocomposites were then irradiated with Ag+12 (120 MeV) ion beam and characterized by X-ray diffraction, scanning electron microscopy, UV-Vis spectroscopy, PL and Raman spectroscopy. The PL spectra exhibited an enhanced broad emission peak in visible region (400 nm - 750 nm) while UV-Vis spectroscopy revealed an increased absorption in visible region in irradiated specimen in comparison to unirradiated sample.

scholarly journals Preparation and Characterization of Zinc Oxide (Zno)/Polymethyl Methacrylate (PMMA) Nanocomposites

2021 ◽  
Vol 04 (04) ◽  
Author(s):  
Jayashree Bagawade ◽  
Keyword(s):  
Zinc Oxide ◽  
Methyl Methacrylate ◽  
Zinc Oxide Nanoparticles ◽  
Nanocomposite Films ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Methyl Methacrylate ◽  
Absorption Measurements

A series of novel zinc oxide / Poly (methyl methacrylate) nanocomposite films with different ZnO contents were prepared through inclusion of pre-synthesized zinc oxide nanoparticles. The physical composition and morphology of the as-prepared nanocomposites were studied by XRD and TEM. The TEM analyses revealed that the zinc oxide nanoparticles have a particle size of ~3–5 nm. X-ray diffraction proved the presence of the amorphous PMMA in the nanocomposites. The intermolecular interactions within the polymer nanocomposites were explored by FTIR and XRD. FTIR spectra confirmed the dispersion of the zinc oxide nanoparticles in the Poly (methyl methacrylate) i.e. PMMA matrices. The UV-Vis absorption measurements of the ZnO/PMMA nanocomposites proved their potential optical properties.

scholarly journals Preparation and Photoluminescence of Transparent Poly(methyl methacrylate)-Based Nanocomposite Films with Ultra-High-Loading Pendant ZnS Quantum Dots

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1217 ◽  
Author(s):  
Jinku Xu ◽  
Dongmei Li
Keyword(s):  
Quantum Dots ◽  
Thermogravimetric Analysis ◽  
Methyl Methacrylate ◽  
Nanocomposite Films ◽  
High Loading ◽  
Pmma Film ◽  
X Ray Diffraction ◽  
Poly Methyl Methacrylate ◽  
Transmission Electron ◽  
Original Crystal

Transparent nanocomposite films containing quantum dots are popular because of their extensive applications. However, nanoparticles tend to aggregate, resulting in phase separation of the nanoparticles in the polymer matrix. Herein, we present a bulk thermo-curing copolymerization method to fabricate poly(methyl methacrylate)-based nanocomposite films with ultra-high-loading ZnS quantum dots (ZnS/PMMA), utilizing polymerizable group-capped ZnS and monomer of methyl methacrylate (MMA). We found that the nanocomposite film is highly transparent, although the transmittance decreases with the ZnS content, especially at the wavelength between 300 nm and 400 nm. The results from X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic mechanical thermal analysis (DMTA) show that the ZnS quantum dots maintain their original crystal structure, and are uniformly dispersed in the nanocomposite films, even with a very high ZnS content (41 wt %, determined by thermogravimetric analysis). The thermogravimetric analysis shows that the nanocomposite films possess a better thermal stability than that of pure PMMA film. The photoluminescence measurements show that ZnS/PMMA nanocomposite films have good optical properties. The fluorescence intensity increases with the increment of free ZnS content to 30 wt %, and then decreases due to self-reabsorption at a higher ZnS content. The transparent ZnS/PMMA nanocomposite films have a potential application as photoluminescence material.

scholarly journals Study of Corrosion Protection of Concrete in Sewage Systems with Magnesium Hydroxide Coatings

2020 ◽  
Vol 2 (1) ◽  
pp. 27 ◽  
Author(s):  
Domna Merachtsaki ◽  
Eirini-Chrysanthi Tsardaka ◽  
Evangelia Tsampali ◽  
Konstantinos Simeonidis ◽  
Eleftherios Anastasiou ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Protection ◽  
Magnesium Hydroxide ◽  
Low Cost ◽  
Methyl Cellulose ◽  
X Ray Diffraction ◽  
Sewer Pipes ◽  
Surface Ph ◽  
Time Period ◽  
Concrete Blocks

The purpose of the present work was to study the corrosion protection that relatively low-cost magnesium hydroxide coatings offer to concrete by stabilizing the surface pH. To facilitate the material’s adhesive ability, methyl-cellulose and carboxymethyl-cellulose were used as environmentally friendly additives in three different concentrations, 1, 0.4 and 0.1 wt.% of solids, respectively. The coatings were applied on the surface of concrete blocks, in two different coating thicknesses. A sulfuric acid solution was used to simulate the biologically produced acid in sewer pipes. Sulfuric acid was sprayed on the specimens, while the total amount of acid sprayed was calculated, in order to correspond to a specific reaction’s stoichiometry daily. The surface pH of coated specimens was monitored daily with a surface pH meter. The gypsum production was studied with X-ray diffraction, to evaluate the coatings’ protection. The experimental time period that coatings were consumed was compared with the theoretically consumption time.

Thermal and Mechanical Properties of Poly(methyl methacrylate) Nanocomposites Containing Polyhedral Oligomeric Silsesquioxane

2012 ◽  
Vol 557-559 ◽  
pp. 304-308 ◽  
Author(s):  
Chun Bao Zhao ◽  
Xin Wang ◽  
Xu Jie Yang ◽  
Wei Zhao
Keyword(s):  
Mechanical Properties ◽  
Methyl Methacrylate ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Bulk Polymerization ◽  
Thermal And Mechanical Properties ◽  
X Ray Diffraction ◽  
Poly Methyl Methacrylate ◽  
Pmma Matrix ◽  
Transmission Electron ◽  
Oligomeric Silsesquioxane

A series of poly(methyl methacrylate) (PMMA) composites containing polyhedral oligomeric silsesquioxane (POSS) were produced by bulk polymerization. The morphology, thermal and mechanical properties of the composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analyses (TGA) and dynamic mechanical analyses (DMA). Results show that the octa(3-chloropropyl)-POSS (ocp-POSS) and trisilanolphenyl-POSS (triol-POSS) have high compatibility with PMMA and can be uniformly dispersed into PMMA matrix. The separate incorporation of these two types of POSS contributes to the improvement of thermal stability of PMMA composites. When the content of POSS was 7.5 wt%, the thermal decomposition temperatures (5% mass loss) of PMMA composites with ocp-POSS and triol-POSS were increased by about 104 °C and 130 °C, respectively. The increase of triol-POSS content in the PMMA matrix gave slight enhanced storage modulus before glass transition.

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