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In previous work, despite the positive effect of the titanium carbide + titanium diboride (TiC+TiB2) on the wear, hardness and erosion properties of the epoxy/glass fiber composites, the particles reduced tensile and flexural strength. This research targets to improve the tensile and flexural properties of the epoxy/glass fiber/TiC+TiB2 composites by adding clay nanoparticles in content of 1, 3, and 5 wt%. The effect of nano-clay content on mechanical (tensile, flexural, and hardness) properties and wear behavior of the hybrid composites was investigated. The field Emission Scanning Electron Microscopy (FE-SEM) images revealed the morphology, the fracture surface and failure mechanisms of the composites. The X-ray diffraction confirmed the formation of TiC+TiB2 particles and the nanocomposites. Tensile and flexural results showed that introducing clay nanoparticles increases tensile strength and flexural strength by 92% (from 116 to 223 MPa) and 67% (from 194 to 324 MPa), respectively. The nano-clay did not have a significant effect on the tensile and flexural modulus. The hardness increased from 35.1 to 79.4 HRP. Wear properties results revealed that clay nanoparticles improve the wear resistance of the composite samples significantly. The addition of 5 wt% of clay nanoparticles decreased wear rate from 3.7 to 0.4 mg/Nm. [ABSTRACT FROM AUTHOR]

This paper contributes to the expanding knowledge base on nanomaterial-enhanced cementitious composites, offering valuable insights for developing high-performance, sustainable concrete solutions. The study assessed the effects of three different types of nanomaterials—nano clay (NC), nano silica (NS), and nano cellulose (NCel)—on the compressive strength of high-early-strength concrete (HESC) through both experimental studies and a 23 factorial design. Incorporating nanomaterials into the HESC matrix led to a decrease in workability, with NCel demonstrating the least impact on this property across all studied replacement percentages. All HESC mixes containing nanomaterials exhibited higher compressive strength than the control mix (M mix) across all ages. The optimal percentages for compressive strength enhancement were 4.5% NC (33.43% increase at 3 days, 22.29% at 7 days, and 12.15% at 28 days), 4.5% NS (20.12%, 11.14%, and 4.89% respectively), and 0.0375% NCel (34.91%, 25.76%, and 13.46% respectively). The highest compressive strength was observed in the hybrid mix containing 4.5% NC and 0.0375% NCel, yielding strength enhancements of 35.7%, 26%, and 12.75% compared to the M mix. Statistical analysis indicated that nano cellulose had the most significant contribution to enhancing compressive strength, followed by nano clay. The mathematical models derived from the statistical analyses provide a reliable means of predicting the compressive strength of HESC at 3, 7, and 28 days based on nanomaterial content. Contour plots illustrated the optimization of compressive strength across different nanomaterial contents at each age. In summary, the findings underscore the potential of waste-derived nanomaterials to enhance the performance of HESC, paving the way for innovative waste utilization strategies in construction. The study emphasizes the importance of reducing curing times, improving structural durability, and minimizing the environmental impact associated with concrete production. [ABSTRACT FROM AUTHOR]

More than 50% of the flame retardants used in the polymer and plastic industries are metal hydroxides. Among them, aluminum trihydroxide (ATH) is the most widely used due to its low toxicity and corrosiveness and its cost-effectiveness. The use of high-volume ATH in polymers reduces the mechanical properties. In this work, clay nanoparticles were added into epoxy/glass fiber/ATH hybrid composites to improve the mechanical and thermal properties of the composites. The effect of nano-clay content (1, 3, and 5 phr) on mechanical properties such as tensile and flexural strength and modulus, and thermal properties was investigated. Thermal properties were evaluated by Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). The result of mechanical tests showed that adding 3 phr of clay nanoparticles increases tensile and flexural strength by 10% and 9.2%, respectively. The flammability of the composites was measured in horizontal mode. The flammability results revealed that introducing 3 phr of nano-clay improves the flammability of the composites by 41%. [ABSTRACT FROM AUTHOR]

An understanding of the mechanical behavior of polymeric materials is crucial for making advancements in the applications and efficiency of nanocomposites, and encompasses their service life, load resistance, and overall reliability. The present study focused on the prediction of the mechanical behavior of biopolymeric nanocomposites with nano-clays as the nanoadditives, using a new modeling and simulation method based on Comsol Multiphysics software 6.1. This modeling considered the complex case of flake-shaped nano-clay additives that could form aggregates along the polymeric matrix, varying the nanoadditive thickness, and consequently affecting the resulting mechanical properties of the polymeric nanocomposite. The polymeric matrix investigated was biopolyamide 11 (BIOPA11). Several BIOPA11 samples reinforced with three different contents of nano-clays (0, 3, and 10 wt%), and with three different nano-clay dispersion grades (employing three different extrusion screw configurations) were obtained by the compounding extrusion process. The mechanical behavior of these samples was studied by the experimental tensile test. The experimental results indicate an enhancement of Young's modulus as the nano-clay content was increased from 0 to 10 wt% for the same dispersion grades. In addition, the Young's modulus value increased when the dispersion rate of the nano-clays was improved, showing the highest increase of around 93% for the nanocomposite with 10 wt% nano-clay. A comparison of the modeled mechanical properties and the experimental measurements values was performed to validate the modeling results. The simulated results fit well with the experimental values of Young's modulus. [ABSTRACT FROM AUTHOR]

The sandwich panels are widely used in many industrial applications due to their high mechanical properties. Their core design is most important parameter in enhancing their mechanical strength. Flexibility in the design of the core structure leads to the achievement of high strength and light structures. In this paper, the results of the optimized geometry in the previous work are used to investigate the capability of the core geometry design with different materials. Therefore, using the different materials, the peak enhancement of strength-to-weight ratio in sandwich panels besides core behavior during pressure testing are investigated. To this end, a new lattice core is brought forth as the first level; then, three types of materials including AL3105, glass, and innegra fiber/epoxy composites are used to fabricate the cores, in order to compare the compressive strength and the peak. The Nano-clay cloisite 20A is also utilized in construction of sandwich panels. The result indicates that the AL3105 lattice core has the highest strength-to-weight ratio, while the innegra fiber composite core has the highest toughness. Applying curve studies and the SEM Fig. 13, it is concluded that the addition of Nano-clay to composites leads to an increase in both of the strain and the core strength. Comparing the results of experimental and finite element modeling (FEM) data (in ABAQUS software) represented that there is a suitable compliance between them. Our results with the positional variation in core design can pave way in designing advanced engineered sandwich structures in aerospace, shipping, automotive industries. Therefore, these structures will have wide applications in the field of light structure, heat and fluid transfer, sound and vibration control. [ABSTRACT FROM AUTHOR]

Nano-clay has the potential to improve the properties of cement-based materials. However, the effectiveness of this improvement is influenced by the dispersion of the nano-clay. The effects of different nano-clay dispersion techniques on cement-based material properties and pore structure complexity were studied. The samples were prepared using manual and mechanical dispersion methods. The mechanical properties of the specimens were evaluated, and the pore characteristics of the cement-based materials were analysed using mercury intrusion porosimetry. The study investigated the effect of the dispersion method on the nano-clay dispersion. The complexity of the pore structure was evaluated using a fractal model, and the relationship between the fractal dimension, mechanical properties, and pore structure was analysed. The findings indicate that mechanical dispersion results in better dispersion than manual dispersion, and the mechanical properties of mechanical dispersion are superior to those of manual dispersion. Nano-clay particles can improve the internal pore structure of cement materials. Through mathematical calculation, the surface fractal dimension is between 2.90 and 2.95, with good fractal characteristics. There is a good correlation between the surface fractal dimension and the mechanical properties. The addition of nano-clay can reduce the complexity of the pore structure, and the fractal dimension has an excellent linear relationship with the pore structure. [ABSTRACT FROM AUTHOR]

Nano-clay has the potential to improve the properties of cement-based materials. However, the effectiveness of this improvement is influenced by the dispersion of the nano-clay. The effects of different nano-clay dispersion techniques on cement-based material properties and pore structure complexity were studied. The samples were prepared using manual and mechanical dispersion methods. The mechanical properties of the specimens were evaluated, and the pore characteristics of the cement-based materials were analysed using mercury intrusion porosimetry. The study investigated the effect of the dispersion method on the nano-clay dispersion. The complexity of the pore structure was evaluated using a fractal model, and the relationship between the fractal dimension, mechanical properties, and pore structure was analysed. The findings indicate that mechanical dispersion results in better dispersion than manual dispersion, and the mechanical properties of mechanical dispersion are superior to those of manual dispersion. Nano-clay particles can improve the internal pore structure of cement materials. Through mathematical calculation, the surface fractal dimension is between 2.90 and 2.95, with good fractal characteristics. There is a good correlation between the surface fractal dimension and the mechanical properties. The addition of nano-clay can reduce the complexity of the pore structure, and the fractal dimension has an excellent linear relationship with the pore structure.

Polymer-based composite structures have a unique advantage over other materials, given that the reinforcement has the necessary properties. Natural fibre-based composites are new materials domains that have emerged in engineering applications in the recent past due to the extensive availability of natural fibres that are less expensive, low density, and biodegradable. Several researchers explored natural fibres' use as reinforcements in various polymer matrices to improve mechanical and tribological properties. In this context, the adoption of bi-directional silk fibres appears to be very beneficial, and minimal research for structural applications is recorded in this regard. In the present analysis, bi-directional silk fibre is used as a reinforcement medium in a plain-woven fabric with High-Density Polyethylene (HDPE) matrix, with a varying Nano-Clay (NC) percentage from 0.1 to 1 % wt. The compression moulding process is used to process test specimens, and these specimens are further studied for the characterisation of Mechanical Properties. The tensile samples are analysed for fracture analysis by using the Scanning Electron Microscopy (SEM). [ABSTRACT FROM AUTHOR]

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This study deals with the investigation of the mechanical and water absorption properties of jute fibre reinforced epoxy composites prepared by using hand layup method. The effects of fibre length (10, 20, 30 and 40 mm), fibre weight fraction (0%, 5%, 10%, 15%, 20% and 25%), concentration of NaOH treatment (5% and 10%) and nano-clay addition (1, 3, 5 and 7 wt%) on the aforementioned properties were determined. Morphological characterisation was performed for the tensile and flexural fractured surface of the specimens to study their microstructural failures. The results revealed that the composites reinforced with 5% of NaOH-treated fibre and 5 wt% of nano-clay exhibited higher tensile, flexural and impact strengths of 103.05 MPa, 162.8 MPa and 0.358 kJ/mm2 respectively, and lower water absorption rate. Moreover, the optimum fibre length and fibre weight fraction were found to be 30 mm and 20% respectively for better overall properties. These composites can be used for light and medium load applications. [ABSTRACT FROM AUTHOR]

Highlights • Investigate the effect of nano-clay de-agglomeration on concrete properties. • The optimum percentage of dispersed nano-clay particle was recommended. • Studying the effect of dispersed nano-clay on the concrete microstructure. Abstract This paper investigates the effect of nano-clay dispersion on concrete properties. This was extensively studied by using various percentages of nano-clay (5, 7.5, and 10%) as cement partial replacements by two ways; added as-received, added after being dispersed in water by using bath sonicator. The evaluation was based on the compressive strength, split tensile strength, flexural strength, slipping bond strength, and split bond strength of nano-clay concrete and the microstructure analysis was verified by SEM, XRD, and AFM examinations. The test results revealed that the sonication of nano-clay particles significantly enhanced concrete properties when compared to those of as-received nano-clay concrete. The optimum percentage for cement substitution by Nano-clay was found to be 7.5% for both; the as-received, and the sonicated nano-clay. The presence of NC particles resulted in dense and well-compacted matrix than that of the control mix as has shown in the SEM micrographs, the XRD and AFM results indicated the higher reactivity of the sonicated NC than the as-received NC. [ABSTRACT FROM AUTHOR]

The effect of nano-clay platelets (Cloisite 30B) on the mechanical and thermal properties of fly ash geopolymer has been investigated in this paper. The nano-clay platelets are added to reinforce the geopolymer at loadings of 1.0%, 2.0%, and 3.0% by weight. The phase composition and microstructure of geopolymer nano-composites are also investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) techniques. Results show that the mechanical properties of geopolymer nano-composites are improved due to addition of nano-clay. It is found that the addition of 2.0 wt% nano-clay decreases the porosity and increases the nano-composite's resistance to water absorption significantly. The optimum 2.0 wt% nano-clay addition exhibited the highest flexural and compressive strengths, flexural modulus and hardness. The microstructural analysis results indicate that the nano-clay behaves not only as a filler to improve the microstructure, but also as an activator to facilitate the geopolymeric reaction. The geopolymer nano-composite also exhibited better thermal stability than its counterpart pure geopolymer.

Highlights • The addition of nano-clay to self-consolidating concrete mix increased the viscosity and therefore prevented the segregation and bleeding. • Mechanical and more specifically, durability properties of self-consolidating concrete were enhanced with the addition of nano-clay. • Use of by-product mineral admixtures generally enhanced the properties of self-consolidating concrete. • Significant improvements in durability properties were observed with the addition of nano-clay to self-consolidating concretes, containing by-product mineral admixtures. Abstract The effects of nano-clay (NC) addition on fresh state, mechanical, and durability properties of plain and blended cement self-consolidating concrete (SCC) incorporating mineral admixtures as supplementary cementitious materials were investigated. Mineral admixtures such as silica fume (SF), class F fly ash (FA), rice husk ash (RHA), and ground granulated blast furnace slag (GGBFS) were used as partial replacement of cement. Initially, SCC mixes with 1%, 2%, and 3% NC as cement replacement, by weight, were prepared and the workability properties (i.e. slump flow, T50 and V-funnel flow time, and passing ability ratio via L-box test), the mechanical properties (i.e. compressive strength, splitting tensile strength, the modulus of elasticity and the ultrasonic pulse velocity), and the durability properties (i.e. water absorption, water penetration depth via water permeability test, electrical resistivity, chloride migration coefficient and the time-dependent corrosion current variation via impressed voltage test) were determined for evaluating the effectiveness of NC inclusion on characteristics of SCC. According to the results, the addition of NC to plain SCC satisfied all the required specifications for SCC as per EFNARC (European Federation for Specialist Construction Chemicals and Concrete Systems). While the addition of 3% NC by weight of cement improved the durability performance significantly, its effects on mechanical properties were observed to be limited. However, NC replacement dosage of 3%, by weight of cement, can be considered as the optimal content for SCC in comparison with the NC replacement of 1% and 2%. In the second step of this experiment, the effects of 3% NC inclusion on properties of blended cement SCC containing optimum levels of SF, FA, RHA and GGBFS (15%, 30%, 15%, and 45%, respectively, based on literature) were assessed. The results indicated that by incorporating 3% NC in blended cement SCC, satisfactory workability and mechanical properties can be achieved. Remarkable enhancements were also observed in durability properties of blended cement SCC with the presence of NC compared to that of the reference concretes confirming that a small dosage of NC can effectively be used to make big improvements in the properties of environmentally friendly SCC mixes. [ABSTRACT FROM AUTHOR]

In this study, a combination of polylactic acid polymer and thermoplastic polyurethane with the addition of nano-clay particles was used. The reason for using clay nanoparticles and their strength is the low price and availability of this material. Adding nano-clay particles to the polymer composition improves the mechanical properties of the composite as they will interact with functional groups of the polymer. The results of the FTIR spectroscopy confirmed the presence of three components in the compound indicating that no chemical reactions occurred among the three components during the compounding process. The FE-SEM images taken from the compounds showed that TPU and nano-clay particles were evenly distributed in the PLA matrix. The DMTA results were utilized to determine the transfer temperature of the compounds as well as the storage and loss modulus and the shape memory properties. The XRD spectroscopy was used to determine the crystallinity and exfoliation of the nanoparticles. The mechanical properties of the fabricated polymer compounds were determined. It was found that the sample with 3% by weight of clay nanoparticles had the highest strength, and the sample with 5 wt% of clay nanoparticles had the highest toughness among nanocomposites. According to the hardness measurement, the sample with 5% by weight of clay nanoparticles has the highest hardness amongst all prepared composites. The memory properties of the prepared nanocomposites showed a significant improvement with increasing the amount of nanoparticles. This study showed the suitability and efficiency of PLA, TPU, and clay nanoparticle melt mixing methods in achieving a relatively tough shape memory composite. At the same time, this method is also inexpensive and scalable. [ABSTRACT FROM AUTHOR]

The effect of nano-clay platelets (Cloisite 30B) on the mechanical and thermal properties of fly ash geopolymer has been investigated in this paper. The nano-clay platelets are added to reinforce the geopolymer at loadings of 1.0%, 2.0%, and 3.0% by weight. The phase composition and microstructure of geopolymer nano-composites are also investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) techniques. Results show that the mechanical properties of geopolymer nano-composites are improved due to addition of nano-clay. It is found that the addition of 2.0 wt% nano-clay decreases the porosity and increases the nano-composite's resistance to water absorption significantly. The optimum 2.0 wt% nano-clay addition exhibited the highest flexural and compressive strengths, flexural modulus and hardness. The microstructural analysis results indicate that the nano-clay behaves not only as a filler to improve the microstructure, but also as an activator to facilitate the geopolymeric reaction. The geopolymer nano-composite also exhibited better thermal stability than its counterpart pure geopolymer. [ABSTRACT FROM AUTHOR]

In this research, fully environment-friendly, sustainable and biodegradable 'green' composites were fabricated. A novel material comprised of microfibrillated cellulose and laponite clay with different inorganic/organic ratios (m/m) was prepared. The composites were characterized by tensile, bending and water absorption tests as well as dynamic mechanical analysis. The morphologies of these nanocomposites were evaluated through scanning electron microscopy. Results showed considerable improvement of mechanical properties; specifically in elastic modulus, tensile strength and flexural modulus with the addition of nanoclay up to 7.5 wt% nano-clay. The modulus of elasticity increased significantly by about 26 % at 5 wt% nanocaly. The flexural modulus increased by about 90 % at 7.5 wt% nanoclay. However, with an increased load of clay in the nanocomposite, the mechanical properties decreased due to the agglomeration of excessive nanoclay. The storage modulus was significantly increased at high temperature with increasing the load of nanoclay. [ABSTRACT FROM AUTHOR]

To observe the effect of recycled sand and nano-clay on the improvement of the early strength of soil-cement (7d), 0%, 10%, 15% and 20% recycled sand were added. While maintaining a fixed moisture content of 30%, the ratios of each material are specified in terms of soil mass percentage. The shear strength of CSR (recycled sand blended soil-cement) was investigated by direct shear test and four groups of specimens (CSR-1, CSR-2, CSR-3 and CSR-4) were obtained. In addition, 8% nano-clay was added to four CSR groups to obtain the four groups of CSRN-1, CSRN-2, CSRN-3 and CSRN-4 (soil-cement mixed with recycled sand and nano-clay), which were also subjected to direct shear tests. A detailed analysis of the modification mechanism of soil-cement by recycled sand and nano-clay was carried out in combination with scanning electron microscopy (SEM) and IPP (ImagePro-Plus) software. The test results showed that: (1) CSR-3 has the highest shear strength due to the "concrete-like" effect of the incorporation of recycled sand. With the addition of 8% nano-clay, the overall shear strength of the cement was improved, with CSRN-2 having the best shear strength, thanks to the filling effect of the nano-clay and its high volcanic ash content. (2) When recycled sand and nano-clay were added to soil-cement, the improvement in shear strength was manifested in a more reasonable macroscopic internal structure distribution of soil-cement. (3) SEM test results showed that the shear strength was negatively correlated with the void ratio of its microstructure. The smaller the void ratio, the greater the shear strength. This shows that the use of reclaimed sand can improve the sustainable development of the environment, and at the same time, the new material of nano-clay has potential application value. [ABSTRACT FROM AUTHOR]