Nano Silicate Research Articles

Facile synthesis of sustainable magnetic core-shell silicate nano copolymers for toxic metals extraction in fixed bed column

Heavy metals enter our environment through diverse resources, causing harmful effects owing to their inherent toxicity and facile migration into aqueous medium, becoming an environmental challenge. Among technologies able to remove these contaminants, the adsorption process emerges as a promising application for water treatment. Herein, functionalized silica magnetic nanoparticles using inorganic and organic have been employed as adsorbents to remove environmental hazards from wastewater effectively. Magnetic silicate core-shell amino-functionalized (Fe3O4 @SiO2-AP) nanocomposites were synthesised using acrylic acid (AA) and para-aminobenzoic acid (PABA) as dual copolymer for Cd (II) removal. The characterization analysis confirmed the formed crystal nanostructure and the copolymers were chemically introduced in the magnetic silicate core-shell nanoparticle. The Cd (II) adsorption results on (Fe3O4 @SiO2-AP) nanocomposites achieved an impressive qmax of 32.50 mg/g at pH 8, adsorbent dosage of 3 g/L, and Cd (II) concentration of 100 ppm. The laboratory-scale fixed-bed column showed the breakthrough curves are flow rate independent, achieving metal removal of 99% for 405 min, at pH 8, influent ion concentration of 100 ppm, flow rate of 5 mL/min, and 1 cm bed height. The Freundlich model was the most suitable for fitting equilibrium data (R2adj = 0.981) indicating a multi-layer adsorption phenomenon in the heterogeneous surface sites of the (Fe3O4 @SiO2-AP) nanocomposites. The pseudo-second-order model (R2adj =0.999) confirms that the adsorption rate depends on nanocomposites active sites and occurs by chemical sorption mechanism. The reusability adsorption-desorption experiments slightly decreased from 97.5 to 86.7% in the sixth cycle stability, demonstrating the material stability.

Effects of incorporation of nano particles on the mechanical properties of maxillofacial silicone elastomer subjected to outdoor weathering

Statement of problemNatural weathering has varied effects on the service life of maxillofacial silicones due to its direct implications on the tear strength and hardness of the material. PurposeThe purpose of this study was to evaluate the effect of incorporation of nano oxides on the mechanical properties of maxillofacial silicone elastomer subjected to outdoor weathering. Material and methodsThis in-vitro study was conducted in the Department of Prosthodontics, on maxillofacial silicone elastomer samples incorporated with nano particles subjected to outdoor weathering for a time period of 6 months. Sample size of eighty-four was determined using the results of the article studying the effects of incorporation of nano oxides on the colour stability of maxillofacial silicone elastomer subjected to outdoor weathering by R.N Akash et al. in the year 2015 [(Akash and Guttal, 2015). The samples were divided into three groups. Control group comprised of 14, maxillofacial silicone elastomer without nano particles, the second group, ZnO2 consisted of 14, maxillofacial silicone elastomer containing 2 % zinc oxide nano particles and the third group ZrSiO2 included 14, maxillofacial silicone elastomer containing 1.5 % zirconium silicate nano particles. 14 samples were prepared as the same sample was used to test both hardness and tear strength. ResultsThe hardness values for maxillofacial silicone in group 3 (with zirconium silicate) was found to be 38.74 which was the lowest in comparison to control and zinc oxide groups. The tear strength of silicone specimens with 1.5 % zirconium silicate it was found to be 5.37 kN/m, which was the highest in comparison to the zinc oxide and the control groups. ConclusionsThe difference in mean hardness and mean tear strength of silicone elastomer with 1.5 % zirconium silicate was found to be, statistically significant. This study suggests that, even after being exposed to the effects of natural weathering, zirconium silicate nano particles may keep the tear strength and hardness of medical grade maxillofacial silicone elastomer up to acceptable ISO criteria.

PROCESS FOR RECOVERING SILICA FROM LITHOMARG CLAY: VALUE ADDITION OF UNEXPLOITEDMINING REJECT

Physico-chemical treatment was adopted for processing alumino-siliceous lithomarg clay known as saprolite. The study explained the potential of utilizing saprolite clay as fast resource for recovering silica mineral phases for value added utilization of unused mining reject. The conversion of saprolite to silica enriched low iron precursor was achieved by chemical activation with 1:1 v/v aqueous hydrochloric acid. Recovery of nano-silicate was achieved from the low iron precursor by dissolution in aqueous sodium hydroxide followed by precipitation in acid medium and centrifugation. Physical characterization of silicate nano particle was accomplished by scanning electron microscopy (SEM) and the range of impurities was determined by inductively coupled plasma (ICP) analysis.

Synthesis of biologically active spiro oxindole through multicomponent reaction and it’s physico-chemical studies

Indole-2,3-dione has been utilized in many multicomponent reactions that produce complex spiro compounds with readily available starting materials and considered as an importantbuilding block in organic synthesis. Spiro compounds in which two cyclic rings are fused at a common carbon atom are promising interesting skeletal systems in drug discovery due to their unique conformational features, structural complexity and rigidity. Here we have synthesized a spiro-oxindole which has been synthesized from indole-2,3-dione, dimedone and 2-aminobenzimidazole using nickel-zinc ferrite silicate nano composite as catalyst, and characterization of synthesized spiro-oxindole compound were carried. Computationalstudies of the synthesized compound were performed using DFT method at the CAM-B3LYP/6–311++G (d, p) level. Geometry optimization, FMO studies, vibrational and NBO analysis reveals the molecular structure, electronic transitions and intramolecular charge delocalization of the Spiro oxindole.Molecular docking studies of the synthesized compound was evaluated for their antimicrobial activities against three bacteria viz., Staphylococcus aureus, E-Coli, Klebsiella species andfungus viz., Aspergillus Niger. The spiro-oxindole compound showed very good invitro DPPH scavenging antioxidantproperty.

Nanosilicate-hydrogel microspheres formed by aqueous two-phase separation for sustained release of small molecules

Introduction: Hydrogel microspheres are an attractive option for drug delivery applications due to their ease of injection and potential for tunable controlled delivery. However, their utility is limited due to high initial burst release and rapid overall release, which is especially pronounced for small molecules or small size microspheres. We and others have shown that the addition of two-dimensional nanosilicate (NS) particles to hydrogels can significantly prolong release kinetics from hydrogels while minimizing burst release.Materials and Methods: Here we explored whether NS could modulate release kinetics of small molecules from small size injectable microspheres. Polyethylene glycol (PEG)-based hydrogel microspheres were fabricated via polymer/salt aqueous two-phase separation (ATPS), which is facile, high yield, and scalable, without the need for organic solvents or oils.Results and Discussion: Importantly, NS and acridine orange (AO), a model cationic small molecule, were shown to phase separate into the PEG-rich phase, allowing for successful encapsulation within hydrogel microspheres. The fabricated microspheres were stable, similar in size to red blood cells, and easily injectable. The effect of various fabrication parameters, including the addition of NS and AO, on microsphere size and polydispersity were explored. Release of AO was significantly slowed from PEG-NS microspheres compared to PEG-only microspheres and correlated with NS concentration. Two additional small molecules, the chemotherapeutic doxorubicin (positive charge), and the model small molecule Brilliant Blue FCF (negative charge), were shown to exhibit prolonged release, underscoring the broad utility of the system. The dependence of release kinetics on encapsulated NS concentration allows for tunable and prolonged release of small molecules from an injectable hydrogel delivery device.

Synthesis of ZnO-Containing Calcium Silicate Nano Powders: A study on Sinterability, Mechanical and Electrical Properties

Synthesis of ZnO-Containing Calcium Silicate Nano Powders: A study on Sinterability, Mechanical and Electrical Properties

Effects of Phosphate and Silicate Combined Application on Cadmium Form Changes in Heavy Metal Contaminated Soil

Pollution by heavy metal cadmium (Cd) in soil is still serious and control measures are constantly updated. In this paper, one indoor culture method was applied to investigate the effect of phosphate and thermo-activated nano silicate combined application on soil cadmium (Cd) speciation transformation. A total of 7 treatments were designed, which were: simulated cadmium-contaminated soil without phosphate and silicate recorded as the reference (CK) treatment; mixtures of 0.5%, 1.0%, and 2.0% soil heavy dose of potassium dihydrogen phosphate and 700 °C thermo-activated nano serpentine (potassium dihydrogen phosphate: thermo-activated nano serpentine ratio = 1:2) added to simulated cadmium-contaminated soil, denoted as nPS700-0.5, nPS700-1.0, and nPS700-2.0, respectively; and 0.5%, 1.0%, and 2.0% soil heavy dose of potassium dihydrogen phosphate and 700 °C thermo-activated nano zeolite mixture (potassium dihydrogen phosphate: thermo-activated nano zeolite ratio = 1:2) added to simulated cadmium-contaminated soil, denoted as nPF700-0.5, nPF700-1.0, and nPF700-2.0, respectively. The results showed that the combined application of potassium dihydrogen phosphate with thermo-activated nano serpentine or potassium dihydrogen phosphate with thermo-activated nano zeolite reduced the soil exchangeable Cd content to varying degrees and increased levels of carbonate-bound, Fe-Mn oxide-bound, organic-bound, and residual Cd forms to different degrees. In combined application of phosphate and thermo-activated nano silicate, the higher the dosage level, the greater the reduction of exchangeable Cd content and the better the effect on Cd-contaminated soil remediation: nPS700-2.0 > nPS700-1.0 > nPS700-0.5, nPF700-2.0 > nPF700-1.0 > nPF700-0.5 (N, P, S, and F represent nano, KH2PO4, serpentine, and zeolite, respectively, and 700 represents the activation temperature). At the same dosage level, the combined application of potassium dihydrogen phosphate and thermo-activated nano serpentine was more effective than that of potassium dihydrogen phosphate and thermo-activated nano zeolite in repairing Cd-contaminated soil (nPS700-2.0 > nPF700-2.0, nPS700-1.0 > nPF700-1.0, nPS700-0.5 > nPF700-0.5), which indicated that the combination of phosphate and thermo-activated nano silicate can passivate heavy metal cadmium (Cd) to a certain extent and promote the transformation of bioavailable Cd into an unusable state. The reason why potassium dihydrogen phosphate, zeolite, and serpentine can absorb heavy metal cadmium after entering the soil is because the silicate mineral itself can directly absorb cadmium. Second, after nano treatment and thermal activation, the specific surface areas and pores of the minerals increase, which enhances the adsorption performance. Third, because the pH value of the mineral itself is high, the pH value of the soil environment will rise, thereby transforming H2PO4− into PO43−, which is conducive to the adsorption of Cd2+.

Gelatin methacryloyl/nanosilicate nanocomposite hydrogels encapsulating dexamethasone with a tunable crosslinking density for bone repair

Despite various strategies have been proposed to accelerate bone regeneration, the treatment of bone defects in critical size still remains a clinical challenge. In this study, we fabricated nanocomposite gelatin methacryloyl (GelMA)/nanosilicate (NS) hydrogels for the delivery of dexamethasone (DEX), and systematically investigated their performance in drug delivery for bone repair. Nanocomposite hydrogels were fabricated by mold casting, and exposed to ultraviolet (UV) light to induce covalent crosslinking. Afterwards, we conducted a systematic characterization study to determine the effects of varying NS concentration, GelMA methacrylation degree and UV exposure time on mechanical, structural, and drug release behaviors of nanocomposite hydrogels. In particular, the higher methacrylation degree of GelMA, longer UV exposure and the presence of NS exhibited gradually enhanced mechanical properties. For instance, the compressive strengths of nanocomposite hydrogels containing 0% (w/v) NS (G0NS120) and 3% (w/v) NS (G3NS120) at 120 s of UV exposure were 194.816 kPa–367.284 kPa (p < 0.001), respectively. Similarly, they exhibited higher swelling ratio (%) and slower degradation rate (%) with longer UV exposure and increased NS amount. Nanocomposite hydrogels revealed slower drug release rate due to longer UV exposure and increased NS amount. At day 14 of the release study, 99.53% and 60.687% of DEX were released from G0NS120 and G3NS120, respectively. Particularly, the nanocomposite GelMA/NS hydrogels supported osteoblast adhesion well, and NS and DEX exhibited synergistic effect on osteoblast proliferation with 5.01 fold increase after 7 days of culture. Our results clearly showed that GelMA/NS nanocomposite hydrogels with tunable physiochemical and drug carrier properties could provide a favorable option for accelerating bone repair.

Tracking the adsorptive effect of nano silicate–ginkgo residue composite for Sr(II) and Cd(II) removal from aqueous solutions

Ginkgo biloba (Ginkgo)/calcium silicate nanocomposite (NG-CSA) was prepared as a novel sorbent. Nanomaterial was characterized using different techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, differential thermal analysis and thermal gravimetric analysis (DTA and TG). Adsorption of Sr(II) and Cd(II) ions was performed taking into account significant parameters such as initial pH of the solution, shaking time and initial concentration of metal ions as well as temperature. The acquired results were disclosed that the adsorption of both ions is notably improved using NG-CSA composite. The monolayer capacity of NG-CSA for Sr(II) and Cd(II) from binary system is 122.45 and 64.68 mg/g for Sr(II) and Cd(II), respectively. The kinetic studies exposed that the adsorption process followed nonlinear pseudo-first-order model. The isotherm studies show that the extended Langmuir model is more applicable than Freundlich model for binary system adsorption process. The value of diffusion coefficient for the Sr(II) and Cd(II) is in range 10−10 m2/s which indicates the chemisorption nature of the process. The maximum value of desorption for the Sr(II) and Cd(II) is 98.41% and 97.66 utilized 0.3 M of nitric acid. This indicated that NG-CSA composite can be regenerated and reused for further adsorption of Sr(II) and Cd(II) from wastewater.

Biocompatibility and antimicrobial activity of copper(II) oxide hybridized with nano silicate platelets

Nano-sized copper(II) oxide (CuO) is an interesting material with proficient antibacterial activities but limited due to its toxicity to mammalian cells. In this study, CuO nano-sized needles were coated on the surface of nano-silicate platelets (NSP), which were exfoliated from natural montmorillonite clays and with the thickness of about 1 nm, to form nanohybrids. Our findings indicate that NSPs can effectively prevent the aggregation of CuO needles, and significantly enhance antibacterial efficiency without affecting biocompatibility. An optimal antibacterial activity against Staphylococcus aureus exceeding 99% could be obtained, while that for Escherichia coli was about 88%. Electron paramagnetic resonance results suggest that •OH radicals, one of the reactive oxygen species generated by CuO/NSP, might damage the cellular components and thus result in the death of bacterial.

Nano Silicate Ceramic Coating Material Applied to Increase the Emissivity and Efficiency of Primary Reformer Radiant

Nano silicate ceramic material prepared in this research for coating the walls of the primary reformer unit in the state company of fertilizers. It is applied to increase the emissivity and thermal efficiency to improve the properties of insulation materials. Moreover, it is increasing the working operation time for catalyst tubes and reducing the carbon dioxide emissions. Nano coating materials were prepared by using different refractory materials that include silica, filed spar, alumina, manganese dioxide and magnesium oxide. The preparation method was done by, calcination and firing these materials then crashing to get extremely fine powder. The results show that coating materials consist mainly from quartz crystalline and glassy phase structure with a grain size of 158 nm and penetration between 10 to 20 mm when using different concentration 0.5 to 1.0 % for total mix. The emissivity of primary reformer insulation materials was increased with 30 % comparing with insulation materials without coating.

Nano-Silicate-Reinforced and SDF-1α-Loaded Gelatin-Methacryloyl Hydrogel for Bone Tissue Engineering.

PurposeAutologous bone grafts are the gold standard for treating bone defects. However, limited bone supply and morbidity at the donor site restrict its extensive use. Therefore, developing bone graft materials as an alternative to autologous grafts has gained considerable attention. Injectable hydrogels endowed with osteogenic potential have the ability to fill irregular bone defects using minimally invasive procedures and have thus been attracting researchers’ attention. However, from a clinical perspective, most fabrication methods employed for the current injectable osteogenic hydrogels are difficult and inconvenient. In the current study, we fabricated an injectable osteogenic hydrogel using a simple and convenient strategy.Materials and MethodsGelatin-methacryloyl (GelMA) pre-polymer was synthetized. Nano silicate (SN) and stromal cell-derived factor-1 alpha (SDF-1α) were introduced into the pre-polymer to achieve injectability, controlled release property, excellent osteogenic ability, and efficient stem cell homing.ResultsThe GelMA-SN-SDF-1α demonstrated excellent injectability via a 17-G needle at room temperature. The loaded SDF-1α exhibited a long-term controlled release pattern and efficiently stimulated MSC migration and homing. The GelMA-SN-SDF-1α hydrogel amplified cell spreading, migration, osteogenic-related biomarker expression, and matrix mineralization. The GelMA-SN-SDF-1α hydrogel filled critical-sized calvaria defects in rats and demonstrated excellent bone regeneration ability, as assessed using micro-CT scanning and histomorphometric staining.ConclusionThe GelMA-SN-SDF-1α hydrogel provides a simple and convenient strategy for the fabrication of injectable osteogenic graft materials.

Flexible and Green Electronics Manufactured by Origami Folding of Nanosilicate-Reinforced Cellulose Paper.

Today's consumer electronics are made from nonrenewable and toxic components. They are also rigid, bulky, and manufactured in an energy-inefficient manner via CO2-generating routes. Though petroleum-based polymers such as polyethylene terephthalate and polyethylene naphthalate can address the rigidity issue, they have a large carbon footprint and generate harmful waste. Scalable routes for manufacturing electronics that are both flexible and ecofriendly (Fleco) could address the challenges in the field. Ideally, such substrates must incorporate into electronics without compromising device performance. In this work, we demonstrate that a new type of wood-based [nanocellulose (NC)] material made via nanosilicate (NS) reinforcement can yield flexible electronics that can bend and roll without loss of electrical function. Specifically, the NSs interact electrostatically with NC to reinforce thermal and mechanical properties. For instance, films containing 34 wt % of NS displayed an increased young's modulus (1.5 times), thermal stability (290 → 310 °C), and a low coefficient of thermal expansion (40 ppm/K). These films can also easily be separated and renewed into new devices through simple and low-energy processes. Moreover, we used very cheap and environmentally friendly NC from American Value Added Pulping (AVAP) technology, American Process, and therefore, the manufacturing cost of our NS-reinforced NC paper is much cheaper ($0.016 per dm-2) than that of conventional NC-based substrates. Looking forward, the methodology highlighted herein is highly attractive as it can unlock the secrets of Fleco electronics and transform otherwise bulky, rigid, and "difficult-to-process" rigid circuits into more aesthetic and flexible ones while simultaneously bringing relief to an already-overburdened ecosystem.

Halloysit Nanotüp Takviyeli Kopoliester Termoplastik Elastomer Kompozitler: Isıl ve Mekanik Özelliklerin İncelenmesi

Nano dolgular polimerlerin ısıl ve mekanik özelliklerini geliştirmek için sıklıkla kullanılan malzemelerdir. Halloysit (HNT) içi boş tüp şeklinde doğal bir alümina silikat nano dolgudur. Bu çalışmada, termoplastik elastomer ailesinin bir üyesi olan kopoliester (COPE) polimerinin ısıl ve mekanik özellikleri organofilik yüzey modifikasyonu yapılmış HNT (Org-HNT) dolgusu ile geliştirilmeye çalışılmıştır. Değişik oranlarda (3,5 ve 7 phr) Org-HNT içeren kompozitler bir dahili karıştırıcı yardımıyla eriyik harmanlama metodu ile hazırlanmıştır. Elde edilen kompozitlerin morfolojik, reolojik, ısıl ve mekanik karakterizasyonları saf COPE ile karşılaştırmalı olarak incelenmiştir. Taramalı elektron mikroskobu (SEM) analizi, 3 ve 5 phr Org-HNT içeren kompozitlerin matris içinde göreceli daha homojen ve ince bir dağılım sergilediğini, 7 phr Org-HNT kullanıldığında ise nanotüplerin agregat şeklinde kaldığını göstermiştir. Org-HNT varlığında COPE’nin erime sıcaklığı artma eğilimi göstermiş ve bununla birlikte nanotüplerin nükleasyon ajanı etkisi ile kristalizasyon sıcaklığı yaklaşık 8°C artmıştır. Kompozitlerin elastik modül değerleri ve Shore sertlikleri Org-HNT miktarının artması ile doğru orantılı olarak artarak, 7 phr Org-HNT içeren kompozitte saf COPE ile karşılaştırıldığında yaklaşık %55’lik modül artışı bulunmuştur. COPE’nin başlangıç bozunma sıcaklıkları Org-HNT’lerin iyi dağılım gösterdiği 3 ve 5 phr kompozitlerinde gelişme gösterirken 7 phr kompozitinde azalmıştır. Bununla birlikte bütün kompozitlerin maksimum bozunma hızları saf COPE’den daha düşük değerler almıştır.

Experimental Evaluation of Nano Silica Effects to High Performance Concrete Strength in Early Age

Nano silicate SiO2 (NS) in the high-performance concrete (HPC) mixture is becoming great interest because it improves the mechanical properties of concrete. As the ultra-fine SiO2 particles with a very high ratio of surface area to mass, NS can tightening the structure and produces better quality gel products and thus concrete strength increases. However, the optimal rate of NS in high-performance concrete has not been investigated. This study experimentally evaluates the influence of NS on compressive strength and flexure strength of HPC of which nominal strength is 70MPa. Seven mixtures of HPC at NS rate of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% over the total weight of the adhesive were conducted. Each mixture provides six samples for compressive tests and six samples for flexure tests. Total samples are 336 samples for four ages of concrete. Reliability of test results was carried out and results shown that at the early stage of HPC, an NS ratio of 1.5% shows the optimal value to improve the performance of concrete. This result also helps to apply NS in HPC in quality control in site application.

ENHANCED OIL RECOVERY THROUGH WETTABILITY ALTERATION USING NANOTECHNOLOGY TECHNIQUE FOR ABU ROACH C AND D MEMBERS INBADR AL-DIN 15 FIELD AT NORTH WESTERN DESERT, EGYPT

The majority of enhanced oil recovery mechanisms purposefully alter the wettability of the reservoir rock from oil-wet to water-wet; to increase the amount of oil recovered from it. Wettability is the ability of a fluid to stick to a solid surface in the presence of other immiscible fluids. Wettability alteration is crucial as it affects the amount of oil recovered from a given reservoir. It was concluded that the Nano silicate and aluminum were the best Nano concentration from 1.0 to 4.0 g/L and Nano scale 28-32 nm to change the rock wettability form oil wet to water wet .By doing so these will be reflect on the amount of producing oil. So it can be increased oil productivity by wettability change from oil wet to water wet which was the target of our research.

Cold crystallization kinetics of biodegradable polymer blend; controlled by reactive interactable and nano nucleating agent

Poly(lactic acid) (PLA) is famous for its crystalline nature and ability to show exothermic crystallization (cold crystallization) peak during heating cycle of differential scanning calorimetric study. To get an insight into the mechanism of cold crystallization of PLA in its promising forms like biodegradable blend and biodegradable blend nanocomposite, a kinetic study has conducted and reported in the present study. Biodegradable blend of PLA has prepared with poly(hydroxybutyrate) (PHB). Subsequently, blend nanocomposite has prepared using organically modified layered nano silicate. Maleic anhydride has used as a reactive compatibilization agent to modify the interface of the partially miscible blend of PLA and PHB. Kinetics and mechanism of crystallization have monitored through isothermal cold crystallization method on the basis of Avrami relationship. Avrami exponent ‘n’ and equilibrium rate constant ‘K’ value has taken into consideration to quantify the crystallization rate. The half-life of crystallization and equilibrium melting point also has estimated as additional findings to confirm the estimated rate of crystallization. Variation in the energy of activation (Ea) using Arrhenius relation and regime transitions during crystallization process through Lauritzen–Hoffman (L-H) equation also have been reported.

Investigation of mechanical properties of repair mortars containing high-volume fly ash and nano materials

Innovations for mineral and chemical additives used in concrete cause a rapid development in concrete technology. Thus, high-performance fiber-reinforced cement composites (HPFRCC) that exhibit ductile behavior under axial loads are produced. With the development and widespread use of nano technology, the production of nano materials that can be used in concrete has led to the development of concrete properties. The first studies about nano and fiber materials used in concrete show that the performance of the concrete develops when they are used together in concrete. In this study, two basic mixtures were designed as fly ash (55% by weight of total cementitious material) and without fly ash mixture. In both of two basic mixtures, HPFRCC mixtures were prepared using the ratio of nano materials (nano silica, nano alumina, and nano calcite) determined by the preliminary test and the additive materials. According to results for all mixtures, the highest compressive and flexural strengths belong to the mixture containing 0% fly ash and nano silicate which is 109.7 and 17 MPa at 90 days, respectively, and the lowest compressive and flexural strengths belong to the mixture containing 55% fly ash and without nano materials which is 23.36 and 12.02 MPa at 1 day, respectively. The results show that mixtures containing nano materials improve the compressive and flexural strengths.

Fracture properties prediction of clay/epoxy nanocomposites with interphase zones using a phase field model

We predict the macroscopic tensile strength and fracture toughness of fully exfoliated nano silicate clay epoxy composites accounting for the interphase behavior between the polymeric matrix and clay reinforcement. A phase field approach is employed to model fracture in the matrix and the interphase zone of the polymeric nanocomposites (PNCs) while the stiff clay platelets are considered as linear elastic material. The effect of the interphase zones, e.g. thickness and mechanical properties (Young’s modulus and strain energy release rate) on the tensile strength, and fracture parameters of the composite is studied in detail. The dissipation energy due to fracture in the PNCs is extracted for different thicknesses and properties of the interphase zones. We show through numerical experiments that the interphase thickness has the most influence on the tensile strength while the critical strain energy release rate of the interphase zones affects the dissipation energy depending on the interphase zone thickness.

Interfacial bond assessment of clay-polyolefin nanocomposites CPNC on view of mechanical and fracture properties

Interfacial bond between dry nanoclay (NC) powders and melted high density polyethylene (HDPE) powders is currently studied for clay/polymer nanocomposite (CPNC) made of montmorillonite (MMT) nanoclay (NC) and polyolefin (HDPE). Conceptual approach is proposed for evaluating bi-material interfacial bonding process by means of practical measurements of bond results. Enhanced mechanical and fracture properties are important results of achieving the bond and vice versa. Cracks and failure are direct result of de-bonding. Bond between natural layered silicate-aluminum particles NC and polyolefin such as HDPE has main role of creation of properties of final product. It controls mainly each of mechanical and fracture properties rather than other properties like thermal, chemical and physical. Several parameters share strongly in producing strong bond between nanoclay particles and polymer chains. It is believed that each of nano and micro size, surface area, structure will control the bond. Since there are no direct experimental measurements of interfacial bond, the mechanical and fracture properties can indirectly indicate and predict bond or de-bond process. Therefore, current research shows how mechanical and fracture parameters can explain the assessment of bi-interfacial bond between polymer chains and nano silicate aluminum. Experimental work and characterizations by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and chemical composition analysis (EDS) are carried out for investigating that phenomenon. The results verify the concept of proposed approach for evaluating bond process.