Study of the Durability of a Mineral Bilayer Material: Case of Granito Coated Tiles
Bachir Kolade Adelakoun Ambelohoun,
Koffi Judicael Agbelele,
Yelome Judicael Fernando Kpomahou,
Aristide Comlan Houngan
Issue:
Volume 11, Issue 4, December 2022
Pages:
77-84
Received:
4 August 2022
Accepted:
30 August 2022
Published:
11 October 2022
DOI:
10.11648/j.am.20221104.11
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Abstract: Granite coated tiles offer excellent mechanical properties for cladding applications. But, as with any application in the housing field, the question of their durability arises. The durability study and the alkaline degradation process of the cementitious medium were undertaken in this work to evaluate the effect of granite and marble coating on the substrate. The mixture of the constituents with different characteristics results in a material whose properties will vary depending on the density of each constituent. For this purpose, the bilayer materials were subjected to different chemical attacks such as concentrated solutions of strong and weak acids and strong bases and the resistance to chemical attack of the samples immersed in each of these solutions is evaluated according to ASTM C 267-96. The results obtained show that before 7 days of immersion, the bilayer materials and the mortar increase their capacity to resist the attack solutions. As for 35 days of immersion, the mass losses are 9.49%, 40.63%, 3.48% for the mortar; 3.81%, 18.51%, 1.07% for the granite bilayer materials and 10.44%, 22.62% 2.94% for the marble bilayer materials in HCl solutions. This study also highlights the alkaline degradation affecting the interface of bilayer materials and it is found that hydrated cement releases basic substances, which react with acidic solutions to give salts easily soluble in water.
Abstract: Granite coated tiles offer excellent mechanical properties for cladding applications. But, as with any application in the housing field, the question of their durability arises. The durability study and the alkaline degradation process of the cementitious medium were undertaken in this work to evaluate the effect of granite and marble coating on th...
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Organic-Inorganic Hybrid Materials: Crystal Growth and XRD Analysis of [(C38H30N8)2•CoCl4] and [(CH3NH3)2•CoCl4]
Mouhamadou Birame Diop,
Modou Sarr,
Mouhamadou Sembene Boye,
Sérigne Cissé,
Libasse Diop,
Allen G. Oliver,
David Renald
Issue:
Volume 11, Issue 4, December 2022
Pages:
85-93
Received:
7 October 2022
Accepted:
24 October 2022
Published:
30 October 2022
DOI:
10.11648/j.am.20221104.12
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Abstract: Two tetrachloridocobaltate (II) hybrid compounds were isolated and structurally characterized by single crystal X-ray crystallography. The compound [(C38H30N8)2•CoCl4] (1), crystallizes in the monoclinic space group P21/c with Z = 4, a = 12.0894(7) Å, b = 15.1839(8) Å, c = 19.8015(11) Å, β = 90.786(2)° and V = 3634.5(3) Å3. Compound [(CH3NH3)2•CoCl4] (2), crystallizes in the monoclinic space group P21/c with Z = 4, a = 7.6385(5) Å, b = 12.6684(8) Å, c = 10.8730(6) Å, β = 96.540(2)° and V = 1045.31(11) Å3. The compound 1 consists of 2,3,5-triphenyltetrazolium cations and tetrachloridocobaltate (II) ions connected through weak C-H•••Cl hydrogen bonds affording a 3D structure. Additional π•••π interactions consolidate the stability and the compactness of the 3D framework. The tetrazolium (C1N1N2N3N4) ring forms dihedral angles of 85.04(11), 49.37(11) and 27.85(11)° with the planes of the benzene rings of the substituent groups while the tetrazolium (C20N5N6N7N8) ring forms dihedral angles of 52.92(11), 47.37(11) and 9.97(11)° with the planes of the benzene rings of the substituent groups. The compound 2 is composed of methylammonium cations and tetrachloridocobaltate (II) dianions connected by extended N-H•••Cl hydrogen bonding patterns giving rise to a 3D structure. The methylammonium cations adopt a general position and are not exceptional. In both structures, the Co centre within the dianion is bonded to four chloride ligands and adopts a distorted tetrahedral geometry. The extensive hydrogen bonding patterns within compound 2 describe R22(4), R34(10), R44(12), R55(14), R46(14), R56(16) and R66(18) rings whereas 1, through the weak C-H•••Cl hydrogen bond patterns, generates mainly R21(4) rings and other hydrogen bonds of D type.
Abstract: Two tetrachloridocobaltate (II) hybrid compounds were isolated and structurally characterized by single crystal X-ray crystallography. The compound [(C38H30N8)2•CoCl4] (1), crystallizes in the monoclinic space group P21/c with Z = 4, a = 12.0894(7) Å, b = 15.1839(8) Å, c = 19.8015(11) Å, β = 90.786(2)° and V = 3634.5(3) Å3. Compound [(CH3NH3)2•CoCl...
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Comparative Study on the Alternating Current Conduction and Dielectric Properties of Plasma Polymerized Monolayer and Bilayer Thin Films
Mohammad Mostofa Kamal,
Abu Hashan Bhuiyan
Issue:
Volume 11, Issue 4, December 2022
Pages:
94-101
Received:
17 November 2022
Accepted:
2 December 2022
Published:
15 December 2022
DOI:
10.11648/j.am.20221104.13
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Abstract: The alternating current (ac) electrical conduction and dielectric properties of plasma polymerized pyrrole-N,N,3,5 tetramethylaniline (PPPy-PPTMA) bilayer composite thin films and a comparative study of those properties of PPPy monolayer, PPTMA monolayer and PPPy-PPTMA bilayer thin films have been discussed in this article. The monolayer and bilayer composite thin films were deposited by using a parallel plate capacitively coupled glow discharge reactor. To prepare the PPPy-PPTMA bilayer films, pyrrole monomer was used as the mother-material and TMA monomer was deposited in different deposition time ratio after the pyrrole films were formed. To study the ac electrical properties of PPPy-PPTMA bilayer composite thin film of different thicknesses the dielectric constant (ε'), the dielectric loss factor (ε"), and the ac conductivity (σac) were investigated as the function of frequency at room temperature. It was observed that the ε' of bilayer thin films was decreased considerably with the increase of PPTMA content in the bilayer structure because PPTMA thin films has lower dielectric constant than that of the PPPy thin films, which was confirmed in the comparative study. This fact was explained by Maxwell-Wagner two-layered model and it was predicted that the grain size and the grain boundary capacitance were reduced with increasing PPTMA content in the bilayer structure which gives rise to a decrease in dielectric constant. The observed frequency dependence of the ε' was attributed to the dielectric relaxation process and to interfacial or space charge polarization. The peak appearing at a characteristic frequency in the dielectric loss spectra suggested that the charge motion and polymer segmental motion were strongly coupled which indicated the presence of relaxing dipoles in the PPPy-PPTMA bilayer thin films. However, the PPPy-PPTMA bilayer thin films were found to have higher values of ε' but lower values of ε" at any particular frequency for a particular thickness which suggested that they have higher ability to polarize and hold charge and also can store more energy but rate of energy dissipation is lower than that of its components PPPy and PPTMA thin films. The ac conductivity of the bilayer thin film was found to have lower values than those of its component films over whole frequency range. It was predicted that during the formation of bilayer thin films, inhomogeneous and irregular complex polymer-polymer interface might be formed whose disorderness may cause a decrease in the conductivity of those films.
Abstract: The alternating current (ac) electrical conduction and dielectric properties of plasma polymerized pyrrole-N,N,3,5 tetramethylaniline (PPPy-PPTMA) bilayer composite thin films and a comparative study of those properties of PPPy monolayer, PPTMA monolayer and PPPy-PPTMA bilayer thin films have been discussed in this article. The monolayer and bilaye...
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