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The purpose of the study is regarding the development of eco-oriented technologies for obtaining the building gypsum materials with the involvement of industrial by-products or waste.

The scanning electron microscopy, X-ray microanalysis and IR spectral analysis were used to study the structure of gypsum matrix. The method of comparison of modified and unmodified gypsum matrix was used. Physical modeling of gypsum matrix crystallization is used to study changes in the morphology of hydration products.

The experimental results show that the addition of technical soot into a gypsum binder leads to a change in the morphology of crystalline hydrates of calcium sulfate dihydrate. Results of the scanning electron microscopy, X-ray microanalysis and IR spectral analysis confirm the change of physical and mechanical characteristics of the gypsum binder due to the structural modification of the gypsum matrix with ultrafine carbon soot. The achieved degree of the structural modification of the gypsum matrix is compatible with the results obtained when the gypsum binder was modified with dispersions of carbon nanotubes.

The morphology of the crystalline hydrates of the gypsum matrix with the addition of 0.04%, 0.06% and 1% of the carbon soot is characterized by the transition of the classical needle-like structure of gypsum dihydrate to the lamellar structure of increased density. One can observe the formation of intergrowths around ultrafine carbon soot particles. The studied carbon additive can improve strength characteristics of the gypsum matrix.

The aim of this research is to study the role and formation of hydration products particularly crystalline portlandite Ca(OH)2 in MWCNT-reinforced concrete at 28 days. Concrete is the largest manufactured building material in world in which cement, sand aggregates and water cement ratio plays governing role. Water–Cement ratio decides it strength, usage, serviceability and durability. As strength of concrete depends on formation of crystalline hydrates; therefore, water–cement ratio can alter formation of hydrates also. Unfortunately, concrete is the most brittle material and to overcome brittleness of conventional concrete is tailored with some fibers. Till now, multiwalled carbon nano tubes are the most tensile and strongest materials discovered. Addition of multiwalled carbon nano tubes changes basic properties of conventional concrete. Therefore, it is important to evaluate formation of crystalline hydrates in multiwalled carbon nano tube–reinforced concrete by micro structure analysis.

Till now, multiwalled carbon nano tube–reinforced concrete has not been analyzed at micro structure level. To accomplish the objective, four concrete mixes with 0.45, 0.48, 0.50 and 0.55 water–cement ratio having 0.5 and 1% multiwalled carbon nano tubes incorporated by weight of cement, respectively. For hardening property analysis, compressive strength was obtained by crushing cubes; flexural strength was obtained by three-point loading; and split tensile strength was obtained by splitting cylindrical specimens. For analyzing role and formation of crystalline portlandite Ca(OH)2 hydrates, X-ray diffraction test was conducted on 75-µ dust of each mix. Scanning electron microscopy analysis was performed on fractured samples of crushed cubes of multiwalled carbon nano tube–reinforced concrete samples to check aggloremation.

It was observed multiwalled carbon nano tubes successfully enhanced compressive strength, flexural strength and split tensile strength by 8.89, 5.33 and 28.90%, respectively, in comparison to reference concrete at 0.45 water–cement ratio and 0.5% multiwalled carbon nano tubes by weight of cement. When its content was increased from 0.5 to 1% by weight of cement compressive strength, flexural strength and split tensile strength diminished by 2.04, 0.32 and 1.18%, respectively, at 0.45 water–cement ratio. With the increment of water–cement ratio, overall strength decreased in all mixes, but in multiwalled carbon nano tube–reinforced concrete mixes, strength was more than reference mixes. In reference, concrete at 0.45 water–cement ratio crystalline portlandite Ca(OH)2 crystals are of nano metre size, but in carbon nano tube–reinforced concrete mix having 0.45 water–cement ratio and 0.5% multiwalled carbon nano tubes by weight of cement, its size is much smaller than reference mix, thereby enhancing mechanical strength. In reference, concrete at 0.55 water–cement ratio size of crystalline portladite Ca(OH)2 crystals is large, but with incorporation of multiwalled carbon nano tubes, their size reduced, thereby enhancing mechanical strength of carbon nano tube–reinforced concrete having 0.55 water–cement ratio and 0.5 and 1% multiwalled carbon nano tubes by weight of cement, respectively. Also at 1% multiwalled carbon nano tubes by weight of cement, agglomeration and reduction in formation of crystalline portlandite Ca(OH)2 crystals were observed. Multiwalled carbon nano tubes effectively refine pores and restrict propagation of micro cracks and act as nucleation sites for Calcium-Silicate-Hydrate phase. Geometry of crystalline axis of fracture for portlandite Ca(OH)2 crystals is altered with incorporation of multiwalled carbon nano tubes. Crystalline portlandite Ca(OH)2 crystals and bridging effect of multiwalled carbon nano tubes is governing factor for enhancing strength of multiwalled carbon nano tube reinforced concrete.

Multiwalled carbon nano tube–reinforced concrete can be used to make strain sensing concrete.

Change in geometry and size of axis of fracture of crystalline portladite Ca(OH)2 crystals with incorporation of multiwalled carbon nano tubes.

The purpose of this paper is to study the effect of nano alumina (Al₂O₃) on the properties of fresh concrete, hardened concrete and microstructure of concrete incorporated with high range water reducer (HRWR). This initiative was taken to improve characteristic properties of concrete using nano alumina because nano alumina can be easily be manufactured from a scrap of industrial aluminum products, so its incorporation in concrete will not only reduce industrial aluminum waste but will also change the morphology of concrete at the microstructural level.

To accomplish the objectives of the research, four different concrete mixes with the constant water–cement ratio (W/C) and superplasticizer (SP) content 0.4 and 0.6% by weight of cement, respectively, were prepared, whereas nano alumina content was altered by 0.3% and 0.4% by weight of cement. Fresh property of concrete was analyzed by using slump cone test, whereas hardened properties of concrete were analyzed through compression test and flexural strength test. The interaction of nano alumina with concrete composite was evaluated using an X-ray diffraction test.

It was observed that 0.6% superplasticizer by weight of cement increased workability by 22% but with the addition of 0.3%, nano alumina by weight of cement workability decreased by 31%. Compressive strength increased by 4.88% with the addition of 0.6% superplasticizer but with the addition of 0.3% nano alumina by weight of cement compressive strength increased by 18.60%. Also, flexural strength increased by 1.21% with the addition of 0.6% superplasticizer by weight of cement but with the addition of 0.3% nano alumina by weight of cement flexural strength increased by 8.76%. With the addition of superplasticizer, alite and belite phases remained un-hydrated but with the addition of nano alumina alite phase was hydrated while belite phase was un-hydrated. The size of belite crystals in mixes having nano alumina was less than that of mix having 0.6% superplasticizer. Also with the addition of nano alumina, a calcium aluminum silicate phase was formed which was responsible for the increment of strength in mixes having nano alumina.

Incorporation nano alumina (Al₂O₃) in concrete will not only reduce industrial aluminum waste but will also reduce CO₂ emission. Nano alumina (Al₂O₃) also changes morphology of concrete at micro structural level.

The study reported here concerned production of green pigments, hydrated nickel(II) silicates and oxides, obtained by precipitation from solutions of sodium metasilicate and sodium hydroxide using nickel(II) sulphate.

The pigments were analysed using a number of techniques including scanning electron microscopy for particle surface morphology and dynamic light scattering for particle structure and the tendency of the particles to agglomerate.

The most desirable physicochemical parameters were shown by highly dispersed nickel(II) silicates precipitated in presence of the modifying agents. Silicate pigments precipitated in the presence of Rokanol K‐7 had low bulk densities, a high capacity to absorb water, dibutyl phthalate and paraffin oil within the primary particles, which is particularly noteworthy.

Due to their good dispersibility, well developed surface and appropriate coating power, coloured silicates of, e.g. chromium(III) and nickel(II) may be used as pigments and fillers for surface coatings.

The method of obtaining nickel(II) pigments developed was novel and provided a solution for problem of post‐galvanic nickel solutions.

This study aims to motivate the application of some low-cost minerals in synthesizing nanoparticles as effective additives on the performance of liquid crystal (LC) hydroxypropyl cellulose (HPC) nanocomposite film, in comparison with carbon nanoallotrope.

Metallic nanoparticles of vanadium oxide, montmorillonite (MMT) and bentonite were synthesized and characterized by different techniques (Transmission electron microscopy [TEM], X-ray diffraction [XRD] and Fourier transform infrared [FTIR]). While the XRD, FTIR, non-isothermal analysis thermogravimetric analysis, mechanical analysis, scanning electron microscope and polarizing microscope were techniques used to evaluate the key role of metallic nanoparticles on the performance of HPC-nanocomposite film.

The formation of nanoparticles was evidenced from TEM. The XRD and FTIR measurements of nanocomposite films revealed that incorporating the mineral nanoparticles led to enhance the HPCs crystallinity from 14% to 45%, without chemical change of HPC structure. It is interesting to note that these minerals provide higher improvement in crystallinity than carbon nanomaterials (28%). Moreover, the MMT provided film with superior thermal stability and mechanical properties than pure HPC and HPC containing carbon nanoparticles, where it increased the E_a from 583.6 kJ/mol to 669.3 kJ/mol, tensile strength from 2.25 MPa to 2.8 MPa, Young’s modulus from 119 MPa to 124 MPa. As well as it had a synergistic effect on the LC formation and the birefringence texture of the nanocomposites (chiral nematic).

Hydroxylpropyl cellulose-nanocomposite films were prepared by dissolving the HPC powder in water to prepare 50% concentration, (free or with incorporating 5% synthesized nanoparticles). To obtain films with uniform thickness, the prepared solutions were evenly spread on a glass plate via an applicator, by adjusting the thickness to 0.2 mm, then air dried.

These minerals provide higher improvement in crystallinity than carbon nanomaterials (28%), moreover, the MMT and bentonite provided films with superior thermal stability than pure HPC and HPC containing carbon nanoparticles. The mineral nanoparticles (especially MMT nanoclays) had a synergistic effect on LC formation and the birefringence texture of the nanocomposites (chiral nematic).

This study presents the route to enhance the utilization of claystone available in El-Fayoum Province as the precursor for nanoparticles and production high performance LC nanocomposites.

This study presents the route for the valorization of low-cost mineral-based nanoparticles in enhancing the properties of HPC-film (crystallinity, thermal stability, mechanical strength), in comparison with carbon-based nanoparticles. Moreover, these nanoparticles provided more ordered mesophases and, consequently, good synergetic effect on LCs formation and the birefringence texture of the HPC-films.

Kaolin (hydrated aluminum silicate) is one of few minerals that are found in nature in a relatively pure state which is abundant in many places of the world. In this research, a simple chemical treatment using traces of ammonium molybdate was carried out to enhance the anticorrosive properties of kaolin.

The steps of treatment of kaolin at 1,000°C were estimated. Characterization of three different combinations of aluminum oxide with iron oxide were studied using spectroscopic methods of analysis via X‐ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM). Also, evaluation of the prepared pigments using (oil absorption, specific gravity, water‐soluble matter, and pH) international standard testing methods were estimated. Then these prepared pigments were incorporated in anticorrosive paint formulations based on medium oil alkyd resin as a binder, the physico‐mechanical and anticorrosive properties of paint films were detected by testing them in 3.5 percent NaCl solution for 28 days.

Introduction of small amounts of ammonium molybdate in kaolin promoted its physico‐mechanical and anticorrosive properties. Although, this process of treatment is economically feasible, treated kaolin can replace expensive commercial pigments found in markets with an almost near quality to their performance.

Treated kaolin can be applied in many industries beside pigment manufacture, and paint formulations, it can be applied as reinforcing filler in rubber, plastics, and ceramic composites. Also it is applied in paper filling, paper coatings, and electrical insulation.

The purpose of this paper is to explore the synthesis, preparation and investigation of micro structural, optical and mechanical studies of polyvinyl alcohol (PVA) doped with tungsten oxide (WO₃) nanocomposites films. These films were prepared by simple solvent casting method is further characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-visible spectroscopy, universal testing machine (UTM), scanning electron microscope (SEM), energy-dispersive analysis of X-rays (EDAX) and atomic force microscope (AFM) techniques to determine the enhancement in structural, optical and mechanical properties with increase in dopant concentration.

The present paper deals with the synthesis of WO₃ nanoparticles using precipitation method and doping into PVA matrix to prepare a polymer nanocomposite film using coagulation and solvent casting method. The FTIR explores the interaction of dopants with PVA matrix. The XRD spectra investigate the variation of crystallinity. The UV/Vis-spectra reveals the information of optical energy band gap and the Urbach Energy for different doping concentrations. The mechanical properties of the nanocomposites were exposed using UTM. The phase homogeneity, film topography, chemical composition of nanocomposites is analyzed using SEM, EDAX and AFM techniques supporting the above results.

The films characterized by FTIR spectroscopy explores the irregular shift in the bands of pure and doped PVA can be understood on the basis of intra/inter molecular hydrogen bonding with the adjacent OH group of PVA backbone. The XRD result reconnoiters that the particle size and crystallinity increases whereas microstructural strain and dislocation density decreases with increase in dopant concentration. Further the drastic decrease in optical energy band gap E _g =0.94 eV for doping concentration x=15 wt% and the increase in values of Urbach Energy (E _u ) with doping concentrations were investigated by UV/Vis spectra. Also the extinction coefficient was high in the wavelength range of 250-400 nm and low in the wavelength range of 400-1,200 nm. The mechanical studies indicates that the addition of the WO₃ with weight percentage concentration x=15 percent increases the tensile strength and Young’s modulus. The phase homogeneity, the particle size of the dopants and chemical composition of nanocomposites is analyzed using SEM and EDAX. The film topography of the nanocomposites is analyzed using AFM techniques supporting the above results.

The investigation of synthesis, preparation and investigation of micro structural, optical and mechanical studies of PVA doped with WO₃ nanocomposites films as been done. The results prove that these nanocomposites having good mechanical strength with crystalline nature and also very low optical energy gap value that could find possible applications in industries.

The purpose of this study is to investigate the using of rice husk (RH) which is a green material derived from agricultural waste with the ability to absorb heavy metal. It has been used in wastewater treatment. In this research, a kaolin-based green ceramic water filter (CWF) incorporated with two different additives (RH and zeolite-based RH ash [RHA]) was successfully fabricated.

The weight ratio of kaolin:additive was varied (90:10, 80:20 and 70:30) and fabricated via the slip-casting technique. The green CWFs were dried (60°C for 1 h), followed by sintering (1,200°C).

The green CWF of kaolin:RH with a weight ratio of 70:30 showed the best properties and satisfactory performance with a porous cross-section microstructure, highest porous area (4.58 µm²), good structure, lowest shrinkage (8.00%), highest porosity (45.10%), lowest density (1.79 g cm⁻³), highest water absorption (55.50%) and hardness (241.40 Hv). This green CWF has also achieved good permeability (42.00 L m⁻²h⁻¹) and removal of the textile dye (27.88%). The satisfactory characterization and good textile dye removal performance (75.47%) were also achieved from green CWF with kaolin:zeolite at a weight ratio of 80:20.

This research is focused on green CWF and zeolite at a certain amount with the specific characterization analysis methods.

The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye will enhance the using of green material.

Avoiding the waste sludge that can pollute the environment can create a health issue. The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye can avoid the waste sludge that can pollute the environment and create serious health issue.

All the kaolin-based green CWFs incorporated with two different additives (RH and zeolite-based RHA) fabricated using a simple slip-casting technique have shown the potential to be used as a filter in wastewater treatment applications.

The purpose of this paper is to investigate the electrical transport mechanism of the Al‐doped ZnO nanorods at different temperatures by employing impedance spectroscopy.

Al‐doped ZnO nanorods were grown on silicon substrate using step sol‐gel method. For the seed solution preparation Zinc acetate dihydrate, 2‐methoxyethanol, monoethanolamine and aluminum nitrite nano‐hydrate were used as a solute, solvent, stabilizer and dopant, respectively. Prior to the deposition, P‐type Si (100) wafer was cut into pieces of 1 cm×2 cm. The samples were then cleaned in an ultrasonic bath with acetone, ethanol, and de‐ionized (DI) water for 5 min. The prepared seed solution was coated on silicon substrate using spin coater at spinning speed of 3000 rpm for 30 s and then dried at 250°C for 10 min followed by annealing at 550°C for 1 h. The hydrothermal growth was carried out in a solution of zinc nitrate hexahydrate (0.025M), Hexamethyltetramine (0.025M) in DI water.

Al‐doped ZnO nanorods were characterized using scanning electron microscope (SEM), X‐ray diffraction (XRD) and impedance spectroscopy. The impedance measurements were carried out at various temperatures (100°C‐325°C). The impedance results showed that temperature has great influence on the impedance; the impedance value decreased as the temperature increased. This decrement is attributed to the increase of the mobility of the defects, especially the oxygen vacancies. The surface morphology of the samples was measured by SEM and X‐ray diffraction. The SEM images show that the high density of Al‐doped ZnO nanorods covers the silicon substrate, whereas the XRD pattern shows the (002) crystal orientation.

This paper demonstrates the electron transport mechanism of Al‐doped ZnO nanorods, at different temperatures, to understand the charge transport model.

This paper seeks to synthesize needle‐shaped anticorrosion pigments based on the ferrites of Zn, Ca and Mg for metal protecting paints.

Anticorrosion pigments were synthesized from oxides or carbonates at hot temperatures. The following pigments were synthesized: ZnFe₂O₄, MgFe₂O₄, CaFe₂O₄, Mg_0.2Zn_0.8Fe₂O₄, and Ca_0.2Zn_0.8Fe₂O₄. The prepared pigments were characterized by means of X‐ray diffraction analysis, by measuring the distribution of particle size and by means of scanning electron microscopy. The synthesized anticorrosion pigments were used to formulate epoxy coatings with PVC = 10 per cent for the synthesized pigment and with the PVC/CPVC ratio = 0.3. The coatings were tested for physical‐mechanical properties and in corrosion atmospheres. The corrosion test results were compared with aluminium zinc phosphomolybdate.

The needle‐shaped particles were identified in the formulated pigments. It was found that all of the synthesized pigments had high anticorrosion efficiency comparable with that of Zn‐Al phosphomolybdate. The needle‐shaped particles markedly contributed to the advancement of the physical‐mechanical properties of epoxy coatings.

The synthesized pigments can be conveniently used in coatings protecting metal bases against corrosion.

The application of the synthesized pigments with the needle‐shaped particles in anticorrosion paints protecting metals presents a new method. The benefit of the application and method of synthesizing anticorrosion pigments is that they do not contain heavy metals and are acceptable for the environment.