Effect Of Nanoclay Research Articles

Effect of Nanoclays on Moisture Susceptibility of SBS‐Modified Asphalt Binder

Moisture susceptibility plays an important role in the damage of asphalt pavement. Failure occurs when asphalt is removed from the aggregate particles due to the decreased adhesion between the asphalt and aggregate in comparison with that between water and the aggregate. In recent years, efforts utilizing nanomaterials to improve the diverse properties of asphalt have proven to be effective. In this study, three types of nanoclays were used to modify styrene‐butadiene‐styrene‐ (SBS‐) modified asphalt. The resistances to water damage of the modified binders were evaluated using the surface free energy (SFE) and atomic force microscopy (AFM). The results revealed that the total SFE decreased and the energy ratio (ER) increased when the asphalt binder was modified with the nanoclays, indicating that the addition of nanoclays can improve the moisture resistance of these aggregate‐binder systems. After immersion, a decreased amount of bee structures was observed in both the SBS and nanoclay‐modified asphalts due to the interactions between water and bitumen. However, the residual amount of bee structures was higher in the nanoclay‐modified asphalts than in the SBS‐modified asphalt, indicating that the addition of nanoclay makes the surface morphology of asphalt more resistant to water damage. Finally, freeze‐thaw splitting tests were used to verify the results obtained through the SFE and AFM tests.

Improvement of consistency limits, specific gravities, and permeability characteristics of soft soil with nanomaterial: Nanoclay

Soil consists of several particles of different sizes varied from 4.75 cm to 1 nm; more voids spaces developed between soil particles depend on their specific sizes. If void spaces elevated in the soil structure, soil acted like high permeable, more settlement, less stability, enhanced the plasticity index, impact on shear strength, compaction, and consolidation characteristics. The regaining of the structure against all the properties introduced a new technology for stabilization: nanotechnology. Nanotechnology is an innovative method that describes nanomaterials additional to weak natural soil for filling the voids in Nano level i. e 1 nm to 100 nm and will improve all geotechnical properties. The main advantage of this innovative method is using nanomaterials; the size nanomaterials are lying between 15 and 80 nm filled with any size of void space. In the present study, aimed to be improved the plasticity index, specific gravity, compaction, shear strength (Unconfined Compressive Strength-UCS), and permeability characteristics by adding nanomaterial: Nanoclay. Stabilization of soil with Nanoclay proven excellent results and improved all geotechnical properties such as index and engineering properties. Determine the optimum dosage of the Nanoclay effect on the soil and responses on specific gravity, index, and engineering properties of soil. At the optimum dosage of Nanoclay proved maximum escaped all voids and filled with Nanoclay particles. The stabilization is useful for all embankments related to civil, geotechnical, transported, and slope stability also.

Environmentally benign invert emulsion mud with optimized performance for shale drilling

Drilling muds having less environmental footprint are highly desired, especially for drilling into sensitive formation. In this research, an environmentally benign invert emulsion mud having Indian mango methyl ester (IMME) continuous phase was developed for shale drilling. The properties of the mud were tuned using nanoclay and gum acacia in order to minimize shale instability associated with rock-fluid interactions. The effect of nanoclay and gum acacia content on the rheological behavior and fluid loss of the developed mud was assessed. Furthermore, the thermal and mechanical stability of the mud were estimated. Results obtained with nanoclay and gum acacia were compared with the conventional bentonite and carboxymethyl cellulose additives. Muds containing nanoclay and gum acacia outperformed conventional additive-containing muds in all measures. The rheological properties, such as apparent and plastic viscosities, yield point and gel strength, of the mud formulated with gum acacia and nanoclay were remarkably enhanced. Moreover, the mud containing nanoclay and gum acacia was mechanically and thermally stable up to 100 °C. Particle size analysis of this mud confirmed the suitability of the additives toward shale plugging. The invert emulsion with the nanoclay and gum acacia achieved 95% weight recovery comparing with the conventionally used bentonite and CMC, which only achieved 64% weight recovery. Overall, the 40:60 (W/O) invert emulsion with IMME continuous phase and nanoclay and gum acacia additives portrayed ideal viscosity, rheology, fluid loss, particle size distribution and stability suited for shale drilling.

Moisture Susceptibility of Asphalt Concrete Pavement Modified by Nanoclay Additive

Durability of hot mix asphalt (HMA) against moisture damage is mostly related to asphalt-aggregate adhesion. The objective of this work is to find the effect of nanoclay with montmorillonite (MMT) on Marshall properties and moisture susceptibility of asphalt mixture. Two types of asphalt cement, AC(40-50) and AC(60-70) were modified with 2%, 4% and 6% of Iraqi nanoclay with montmorillonite. The Marshall properties, Tensile strength ratio(TSR) and Index of retained strength(ISR) were determined in this work. The total number of specimens was 216 and the optimum asphalt content was 4.91% and 5% for asphalt cement (40-50) and (60-70) respectively. The results showed that the modification of asphalt cement with MMT led to increase Marshall stability and the addition of 6% of MMT recorded the highest increase, where it increased by 26.35% and 22.26% foe asphalt cement(40-5) and(60-70) respectively. Also, the addition of MMT led to increase moisture resistance of asphalt mixture according to the increase in TSR and IRS. The addition of 4% and 6% of MMT recorded the highest increase in TSR and IRS for asphalt cement (40-50) and (60-70) respectively, where they increased by 11.8% and 17.5% respectively for asphalt cement (40-50) and by 10% and 18% respectively for asphalt cement (60-70).

Effect of nanoclay and nanosilica on carbon black reinforced EPDM/CIIR blends for nuclear applications

Elastomeric components used in nuclear reprocessing plants have to withstand the combined effect of radiation exposure and hydrocarbon ageing. For such applications, EPDM/CIIR blends were reinforced with varying amounts of nanoclay and nanosilica along with carbon black. The effect of nanofiller type and content on mechanical properties, compression set and solvent sorption coefficient for hybrid nanocomposites were evaluated and compared with carbon black filled compound. Both nanofillers enhanced the mechanical properties while reducing the solvent permeation. Nanocomposites with 10 phr nanoclay had the highest strength. Studies on Payne effect in hybrid nanocomposites confirmed the interaction between nanofillers and rubber matrix that enhanced mechanical properties. The dispersion of nano and micro filler was analysed with transmission electron microscopy (TEM). The test specimens were exposed to cumulative doses of 500, 1000 and 2000 kGy γ-radiation. Both chain scission and crosslinking of polymer chains occurred upon irradiation. The percentage change in mechanical properties upon ageing was least for ternary composites with 5 phr nanoclay and 10phr nanosilica. The creation of tortuous path on incorporation of nanoparticles in the blend decreased solvent permeation and free radical migration resulting in reducing the ageing effects in the hybrid nanocomposites. FTIR and ESR spectra provided insight on chemical changes and presence of free radicals after irradiation.

Effect of Nanoclay/Nanosilica on the Mechanical Properties, Abrasion and Swelling Resistance of EPDM/SBR Composites

In this research work, ethylene-propylene-diene monomer (EPDM)/styrene butadiene rubber (SBR) hybrid composites reinforced with nanoclay (NC) and nanosilica (NS) were prepared and investigated. The synergistic effect of NC and NS on the mechanical properties of the EPDM/SBR hybrid composites was examined. Three different crosslinking systems were used, namely: sulphur, dicumyl peroxide and the mixed system consisting of sulphur and peroxide in this research work. The tensile strength, elongation at break, 100% modulus, tear strength, hardness, rebound resilience, abrasion resistance, compression set, swelling resistance and microstructure of the EPDM/SBR hybrid composites were evaluated. The concentration nanosilica along with nanoclay plays a most vital role in the micro-structural, mechanical and other properties of the nanocomposites. From the study, it was clear that the nanocomposites containing 7.5 parts per hundred rubber (phr) of nanoclay and 4 phr of nanosilica shows a maximum mechanical properties along with its abrasion and swelling resistance characteristics. In particular, the sulphur cured EPDM/SBR hybrid composites containing nanoclay and nanosilica results in best mechanical properties and abrasion resistance.

Fracture Resistance of HMA Mixtures Modified with Nanoclay and Nano-Al2O3

Abstract In recent years, the use of nanoparticles as a binder modifier has increased because of their unique properties. This article investigates the effect of nanoclay and nano–aluminum oxide (Al2O3) particles on mixed mode I/II fracture behavior of hot mix asphalt (HMA) mixtures. In this study, two types of modified HMA mixtures were prepared for conducting the fracture experiments using cracked semicircular bend specimens. These modified HMA mixtures contained five different percentages (i.e., 2, 2.5, 3, 3.5, and 4 %) of nanoclay and four different percentages (i.e., 0.1, 0.4, 0.8, and 1.2 %) of nano-Al2O3. The fracture experiments demonstrated that both the nanoclay and nano-Al2O3 particles improve the fracture resistance of HMA mixtures significantly, such that nanoclay particles with percentages of 2, 2.5, 3, 3.5, and 4 % increase the fracture resistance by 2, 8, 14, 19, and 31 %, respectively. As such, improvement in the fracture resistance that was achieved by the use of 0.1, 0.4, 0.8, and 1.2 % nano-Al2O3 was on average 6, 15, 21, and 27 %, respectively. Furthermore, the improvement effect of nanoclay and nano-Al2O3 was more pronounced when the HMA mixtures were loaded under high shear deformation modes.

Effects of Nanoclay on Tensile and Flexural Properties of Pineapple Leaf Fibre Reinforced Phenolic Composite

Phenolic based PALF/nanoclay hybrid composites was prepared by adding Montmorillonite (MMT) as filler at different loading (1%, 2% and 3%) by using hot press technique. Obtained results indicated that adding MMT in PALF/phenolic composites considerably improves the tensile and flexural strength and modulus. Tensile properties showed that the tensile strength increased after adding MMT though tensile modulus decreased. Flexural strength and modulus were enhanced after adding MMT up to 2%, further addition of MMT declined the properties. 2% MMT showed better tensile and flexural properties. 3% MMT/PALF hybrid composite showed no further improvement in tensile properties after 2% MMT, however the flexural properties were reduced. 3% MMT did not improved much maybe agglomeration accrued. PALF/nanoclay/phenolic hybrid composites revealed good mechanical properties that encourage to use for structural purposes.

The effects of nanoclay and deformation conditions on the inelastic behavior of thermoplastic polyurethane foams

Abstract Under cyclical loading–unloading compression conditions, flexible thermoplastic polyurethane (TPU)/nanoclay composite foams exhibit inelastic behaviors consisting of stress softening, hysteresis loss, and residual strain. In this research, the inelastic behavior of TPU and TPU/nanoclay composite foams was investigated by incorporating different amounts of nanoclay and maximizing strain deformation conditions. As the maximum compression strain was increased from 20% to 40%–60%, the inelastic behavior of TPU neat resin foams (TPUNR) with the same microcellular structures became more profound. Transmission electron microscopy (TEM) and compression testing results indicated that the nanoclay fillers were dispersed in the cell walls (struts). Fully exfoliated nanoclay increased the material's compression strength from 0.13 MPa for TPUNR foam to 0.16 MPa for TPU/5 wt% nanoclay foam (TPUNC5) and 0.36 MPa for TPU/10 wt% nanoclay foam (TPUNC10). With increasing nanoclay content, the relative hysteresis loss, relative residual strain, and relative stress softening of the TPU/nanoclay composite foams decreased markedly. Cell deformation mechanism analyses revealed that the dispersed nanoclay in the cell walls effectively reinforced the foams and retarded the permanent deformation of the cell walls, thereby reducing the inelastic behavior of the TPU/nanoclay foams. That is, the addition of organically modified nanoclay provided an effective way to tune the inelastic behavior of TPU and TPU/nanoclay composite foams.

Nano-clay and styrene-butadiene-styrene modified bitumen for improvement of rutting performance in asphalt mixtures containing steel slag aggregates

Nanoparticles have exhibited a promising potential in enhancing the bituminous materials’ performance. As a cost-effective material, hot mix asphalt (HMA) has been employed in pavement structure for a long time. Their viscoelasticity however results in various modes of failure under different temperature profiles and loading stress. Rutting of asphalt pavements is considered as the most prominent distress factor under almost all climate conditions. Moreover, steel slag has been employed for improvement of asphalt mixture properties as it exhibits excellent physical features. In this content the aim of the present research is to analyze improving effects of nano clay and styrene-butadiene-styrene (SBS) on the rutting resistance of modified steel slag asphalt mixture (SSAM). Various tests were employed to investigate the asphalt binder properties and the rheological characteristics of modified bitumen among which penetration grade, softening point, ductility and dynamic shear rheometer (DSR) can be mentioned. Marshal Test was applied to examine the optimum bitumen content in conventional and modified asphalt mixture. The rutting resistance against was then evaluated through two tests: repeated load axial (RLA) test and wheel track test. The results indicated respective improvement of toughness and viscosity by an average of 25% and 101% upon addition of nano-polymer which enhanced the bitumen rheological characteristics while reducing the penetration grade. The asphalt rutting resistance and rutting depth exhibited some improvements as well.

Effects of Nanoclay and Glass Fiber on the Microstructural, Mechanical, Thermal, and Water Absorption Properties of Recycled WPCs

When wood plastic composites (WPCs) have been used for a certain period of time, they become waste materials and should be recycled to reduce their environmental impact. Waste WPCs can be transformed into reinforced composites, in which fillers are used to improve their performance. In this study, recycled WPCs were prepared using different proportions of waste WPCs, nanoclay, and glass fiber. The effects of nanoclay and glass fiber on the microstructural, mechanical, thermal, and water absorption properties of the recycled WPCs were investigated. X-ray diffraction showed that the nanoclay intercalates in the WPCs. Additionally, scanning electron micrographs revealed that the glass fiber is adequately dispersed. According to the analysis of mechanical properties, the simultaneous incorporation of nanoclay and glass fiber improved both tensile and flexural strengths. However, as the amount of fillers increases, their dispersion becomes limited and the tensile and flexural modulus were not further improved. The synergistic effect of nanoclay and glass fiber in recycled WPCs enhanced the thermal stability and crystallinity (Xc). Also, the presence of nanoclay improved the water absorption properties. The results suggested that recycled WPCs reinforced with nanoclay and glass fiber improved the deteriorated performance, showing the potential of recycled waste WPCs.

Preparation and characterization of polypropylene/polylactide blends and nanocomposites and their biodegradation study

Melt blending technique was used for the preparation of blends of two different polymers (polypropylene (PP) and polylactide (PLA)) with/without compatibilizer and nanoclay. The effect of nanoclay on the properties of blends and PP was investigated. Compression molding was used for the preparation of films. PP/PLA (85/15) and PP/PLA/maleic anhydride (85/15/4) were chosen as optimum blends from tensile strength test for further characterization. Tensile strength of PP/PLA (85/15) blend improved with the addition of 4 phr resin compatibilizer. The content of nanoclay was varied from 0 wt% to 5 wt% in PP. The optimized blends were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry, rheological studies, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, biodegradability test, and ecotoxicology. FTIR studies indicated the presence of PLA and nanoclay in the PP matrix. The addition of compatibilizer increased the compatibility between PP and PLA. Biodegradability studies confirmed the biodegradable nature of the blends and composites. Nontoxic nature of biodegraded intermediates has been confirmed by the ecotoxicological tests.

Hygrothermal effects on mechanical joints prepared from fiber reinforced plastic nanocomposites

The present work deals with the hygrothermal aging of the bolt joints prepared from glass fiber reinforced plastics. To investigate the effect of nanoclay on joint performance, nanoclay content was varied from 0 to 5 wt%, with laminates prepared from 3 wt% of nanoclay content demonstrating the best mechanical properties. Nanoclay acts as a mechanical interlock between the fiber and the epoxy and thus improves the interfacial bonding. A good dispersion of nanoclay also improves moisture barrier properties which in turn reduces the degradation of the composite material hygrothermal conditions. Bolt joints were prepared from woven glass fiber reinforced laminates incorporating 3 wt% of nanoclay content. To design the bolt joint, ASTM D5961 was used and the geometric parameters, i.e. edge distance to hole diameter (E/D) ratio and width to hole diameter (W/D) ratio were fixed to 5 and 6, respectively. Three different temperatures, i.e. 25℃, 50℃ and 75℃ were considered for the aging to three different duration of exposure, i.e. 1, 2 and 3 weeks. The effect of different levels of bolt torque, i.e. 0, 2 and 4 Nm were considered for the failure analysis of the joint. A full factorial design of experiment was conducted on important control factors, i.e. water temperature, exposure time, bolt torque and material variation. It was found that the hygrothermal conditions degraded the material with temperature as the most contributing factor.

Compressive characteristics of unmodified and nanoclay treated banana fiber reinforced epoxy composite cylinders

The objective of this work was to prepare a natural fiber reinforced composite product by using nanoparticle technique method. Nanoclay particles were infused into the banana fiber and these modified banana fibers were then reinforced in epoxy polymer composites. A short banana fiber reinforced epoxy polymer composite cylinder was prepared by resin impregnation method, and the compressive, tensile, interfacial and energy absorption characteristics were studied. The properties of nanoclay infused banana fiber reinforced composites were compared with alkaline (NaOH) treated and untreated banana fiber reinforced epoxy composites. It was observed that the nanoclay infused banana fiber composites has resulted in 17%, ∼2 times and 43% improved compressive yield stress, modulus and strength when compared with untreated banana fiber reinforced epoxy composite cylinder. However, nanoclay infusion induces brittleness into the fiber affecting the elongational properties. Tensile, flexural and short beam properties show that the reinforcement effect of nanoclay was higher in flexural and short-beam modes when compared with tensile mode, due to higher level of surface interaction of nanoclay particles in flexural and short-beam modes. About 2 times improved energy absorption properties were obtained in nanoclay infused banana fiber reinforced epoxy composites when compared with untreated banana fiber reinforced epoxy composites. Microscopy examination revealed that the nanoclay infusion in fiber improved fiber-matrix interfacial and load transfer characteristics leading to the higher level of property improvement in nanoclay infused banana fiber reinforced epoxy composites. The outcome of the result suggest that the nano-technique is very much useful and can be simply applied onto the natural fibers to realize the potential application of these materials.

The effect of nanoclay as bitumen modifier on rutting performance of asphalt mixtures containing high content of rejuvenated reclaimed asphalt pavement

Using some kinds of rejuvenators to restore the characteristics of aged binder in reclaimed asphalt pavement might lead to reduction in rutting resistance. In this research, nanocaly was used as virgin bitumen modifier to compensate for the negative effect of rejuvenator in asphalt mixtures containing high percentages of reclaimed asphalt pavement. For this purpose, dynamic creep test was conducted on the mixtures containing 2%, 4% and 6% modified NC and 25%, 50%, 75% RAP. Laboratory test results indicated that the reduction of flow number due to adding rejuvenator in the mixture can be compensated by using nanoclay modified virgin bitumen.

Synthesis and characterization of spin-coated clay/PVDF thin films

This paper reports the fabrication of Cloisite-15A (C-15A)-dispersed polyvinylidene fluoride (PVDF) nanocomposite thin films by spin coating and their characterization for sensor applications. The effects of nanoclay, duration of ultrasonication and spinning speed on the morphology and properties of thin films were studied. The influence of these parameters on the amount of \(\upbeta \)-phase was analysed using Fourier transform infrared (FTIR) and X-ray diffraction (XRD) techniques. The influence of C-15A on the morphology and surface quality of thin films was analysed by scanning electron microscopy (SEM). Piezoelectric coefficient was measured at 110 Hz and 0.25 N. Contact angle was measured to assess the hydrophobicity of thin films. The \(\upbeta \)-phase of 82.97% was obtained in the specimens with 5 wt% C-15A, processed at 500 rpm and spun for 35 min. The piezoelectricity of the specimens increased from \(-18\) to \(-25\hbox { pC N}^{-1}\). Experiments were conducted as per \(\hbox {L}_{16}\) orthogonal array.

Effect of nano clay on tensile and flexural properties of vakka fiber polyester composites

Abstract Natural fibers played a significant role in human civilization. The application of fiber reinforced composites reveals the scope to widen and to adopt the natural fibre composites for industrial requisitions. Composites consisting of polyester resin were prepared by reinforcing with vakka fiber. The effect of nano clay on mechanical properties is observed in the present research work. It is determined that the mean tensile strength and flexural strength of nano clay filled vakka fiber polyester composites is 21.2% and 55% higher than those of composites without the addition of nano clay at 45% volume fraction.

A study on the effect of nano clay and GGBS on the strength properties of fly ash based geopolymers

The role of reactive alumina and process variables such as sodium content and molarity on alkaline activation of different Nano clay and GGBS are explored. The reactive alumina content of fly ash is the key parameter which determines the maximum compressive strength achieved from the alkaline activation. In this paper, Effects of the incorporation of nano-clay in fly ash based geopolymer binders have been investigated. Low-calcium fly ash was used as the principal source of alumino silicate and it was blended with blast furnace slag in small percentages in order to accelerate the curing at room temperature. Nano-clay was added at different rates to the total binder on the 3, 7 and 28 day of curing.

The Effect of Nanoclays on Nanofiber Density Gradient in 3D Scaffolds Fabricated By Divergence Electrospinning

Abstract Tissue engineering generally requires the use of artificial scaffolds to recreating the in vivo milieu which coordinates complex spatiotemporal mechanisms to guide cell behavior. Studies showed that aligned nanofiber scaffolds provide biophysical stimuli to promote cell adhesion, proliferation, morphogenesis, and motility. This study presents a 3D assembly process of aligned polycaprolactone nanofibers directed by a symmetrically divergent electric field. Nanoclays (phyllosilicate) were added into the polymer solution to enhance the homogeneity of fiber distribution within the scaffold. The conductivity and viscosity of solutions were characterized. The nanofiber attributes including fiber diameter, fiber density, and fiber alignment were analyzed by scanning electron microscopy. The results showed that the homogeneity of nanofiber distribution with regard to density and alignment were positively correlated with the conductivity and viscosity of polymer solution. This study demonstrated the feasibility of fine-tuning the microstructure of 3D assembled nanofiber scaffolds by altering the material properties.

Experimental and Numerical Modeling of Nano-clay Effect on Seepage Rate in Earth Dams

Earth dams control and store river water. Type of the earth dam is selected on the basis of available borrow sources. Where it is not possible to have access to suitable fine-grained sources for constructing an earth dam, then using homogeneous materials and an impermeable blanket is recommended. In this research, a mixture of sandy soil with 0.25, 0.5, 0.75, and 1 wt% of montmorillonite nano-clay was used to make the impermeable blanket. After initial tests of gradation, permeability, and optimum moisture content on the soils, experimental models of homogeneous earth dam with an impermeable blanket were constructed. The time needed to reach the steady-state phreatic line and seepage discharge in the models was compared in transient and unsaturated cases. Results showed that increasing the amount of nano-clay from 0.25 to 1.0%, decreased seepage discharge by 19, 67, 89, and 97%, respectively, compared to the control model. Then, a numerical model of the earth dam was prepared using SEEP/W software and was validated with the experimental results. Results of measured and modeled phreatic lines indicated that the numerical model is accurate enough. Results of sensitivity analysis for blanket thickness showed that seepage rate in 0.5% nano-clay model was 9.46 × 10−6, 8.93 × 10−6, and 8.01 × 10−6 m3/s and in 1.0% nano-clay model was 2.1 × 10−6, 1.44 × 10−6, and 7.80 × 10−7 m3/s for 3, 5, and 10 cm blankets, respectively. In general, using a blanket with small amount of nano-clay on the reservoir side of the earth dam could alleviate seepage problems.