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The surface of nano silica was modified with anhydrous ethanol as dispersant, nano silica as silicon source and silane coupling agent KH-550 as surface modifier.The molecular structure, particle size distribution and microscopic morphology of the modified nano silica were characterized by Fourier infrared spectroscopy, particle size analyzer and transmission electron microscopy.The results showed that the number of hydroxyl groups on the surface of the modified nano silica decreased, and the agglomeration phenomenon decreased.The particle size distribution in water ranged from 70 nm to 80 nm.The results showed that when the solid-liquid ratio of the nano silica to the modifier was 1∶5 g/mL,the modification time was 3 h, the modification temperature is 70 ℃.Under this condition, the lipophilicity value of the modified nano silica is 41.2%,and the dispersion of the modified nano silica in water is improved. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, waste nitrile rubber (NBR) was radio-chemo-mechanically devulcanized and used as oil/seawater separator. Pure and surface modified silica nanoparticles were applied to the new and recycled NBR compounds at different contents (i.e. 1, 2, 3, 5 and 10 wt%). The surface modification of nanoparticles was performed using triethoxyvinylsilane (TEVS) at different concentrations (i.e. 1, 5 and 10X). The rheological/mechanical properties and water/oil contact angles (WCA/OCA) of the new and recycled NBR based nanocomposites were evaluated. The results showed that using modified silica nanoparticles (at 5 wt% loading content) caused increment in the WCA from 89.89 and 95.3° to 151.56 and 153.3° and decrease in the OCA from 73.39 and 71.3° to 14.1 and 11.1° for new and recycled NBRs, respectively. It was also found that durability of sorbent against oil absorption–desorption cycles declined using the recycled rubber instead of new NBR compound (i.e. from 1000 to 700 cycles), but the oil absorption capacity enhanced (i.e. from 2.2 to 2.4 g/g). The oil separation efficiencies (OSE) of the modified nanocomposites were more than 99%. It was shown that using modified nanoparticles in RNBR caused 50% decrement in the Payne effect and 33% enhancement in the chemical/physical bonds, respectively. [ABSTRACT FROM AUTHOR]

Owing to their convenient manufacture, transportation, low energy consumption, and environmental impacts, lightweight cement composites have been applied as building and construction materials. However, its decreased density is associated with a reduction in mechanical strength. In most existing investigations, attempts have been made to improve mechanical behaviours via supplementary cementitious or fibre materials, whereas limited studies have been implemented on the effects of nano additives, especially their synergic influence. In this study, industrial waste fly ash cenosphere (FAC) has been utilized as lightweight aggregate by 73.3% cement weight to fabricate sustainable lightweight cement mortar (LWCM). Carbon nanotubes (CNTs) at a dosage of 0.05%, 0.15%, and 0.45% and nano silica (NS) with the content of 0.2%, 0.6%, and 1.0% by cement weight have been applied as modifying additives. Experiments were carried out to test flexural strength, compressive strength, and water absorption. SEM, TG, and XRD analyses were conducted to evaluate microstructure and hydration characteristics. Based on the outcomes, the inclusion of CNTs and NS can effectively increase flexural and compressive strength and reduce absorbed water weight. The analysis of SEM, TG, and XRD reveals that the binary usage of CNTs and NS can improve pore structure and facilitate hydration reaction. [ABSTRACT FROM AUTHOR]

SiO2 has been widely used in the assembly of photonic crystals due to its excellent optical properties. Currently, many studies have been focused on the structural color of monodispersed silica photonic crystals, yet there are few reports on the poly-dispersed ones. In this study, SiO2 particles (450～650 nm) with normal size distribution was prepared by the improved St9ber method. Pouring self-assembly method was used for the film fabrication. Polyvinyl alcohol (PVA) with flexible macromolecular chains was introduced into the gap of SiO2 microspheres, and polyvinylpyrrolidone (PVP) with strong polar groups was introduced into the surface of the microspheres to enhanced film flexibility and better orderliness respectively. It was found that integral film is shown while the mass ratio of 0. 3% SiO2 to 8% PVA is 2∶1. Best iridescent film is shown at the PVP dosage of 1. 75%. The film fabricated in this paper has flat surface and good mechanical properties. The large and small silica microspheres are arranged alternately to form different photonic band gap, which results in iridescent color under point light, while colorless and transparent under natural light. The research results will provide potential application in optical anti-counterfeiting, optical encryption and decoration. [ABSTRACT FROM AUTHOR]

Superhydrophobic materials were prepared by sol-gel method using nano silica particles, n-octyl triethoxysilane (OTES) and silane coupling agent (KH560) as precursors SiO2 @OTES self cleaning coating. In acidic catalyst and organic solvent, OTES and KH560 modified the surface of nanoparticles from hydrophilic to hydrophobic. The influence of the content of nano-SiO2, OTES and KH560 on the wet- tability of the superhydrophobic coating was investigated. The result showed that when 3.5 g nano-SiO2, 8% OTES and 2% KH560 were doped, the coating achieved the best hydrophobic effect, with a contact angle of (154 +1)°, and the rolling angle of (3.3 ±0.5)°. The SEM, FTIR, and X-ray photoelectron spectroscopy (XPS) were used to analyze the superhydrophobic SiO2@OTES surface morphology and chemical composition of the materials were characterized. The experiment shows that the prepared super- hydrophobic SiO2@OTES self-cleaning coating has good self-cleaning, anti fouling, low temperature resistance and wear resistance, and the surface obtained by recycling the coating still has super hydrophobicity. [ABSTRACT FROM AUTHOR]

Mild steel panels were zinc phosphated employing environmentally safe nano silica as an accelerator and a series of four cationic surfactants as additives. The four cationic surfactants chosen were decyltriethyl ammonium bromide (C10TEAB), dodecyltriethyl ammonium bromide (C12TEAB), hexadecyltriethyl ammonium bromide (C16TEAB), and octadecyltriethyl ammonium bromide (C18TEAB). The length of the alkyl chain of the surfactant compounds influenced the quality of the coatings. The corrosion resistance of the coated panels was assessed using a salt spray test. The hydrophobicity of the coatings increased as the hydrocarbon chain length of the surfactants extended from C10 to C18. Porosity, adhesion, and roughness tests were used to examine the surface properties of the coated panels. The coating weight and thickness of the resultant coatings on the base metal were used to quantify coating quality. The results of the tests revealed that the presence of C16TEAB additive outperformed all other components in terms of coating efficiency, coating thickness, and corrosion inhibition performance. The optimal quantity of C18TEAB deposited had a maximum coating weight of 0.0430 g/mm2 that enhanced durability, appearance, and barrier qualities. [ABSTRACT FROM AUTHOR]

Construction demolition waste disposal is considered a serious concern across several countries and threatens the environment. Utilisation of those demolition wastes in the construction industry and recycle the wastes resolves the environmental problem. Sustainable solution to handle the construction demolition waste is the utilisation of partial/ full replacement for conventional coarse aggregate. Utilisation of non-renewable resources, carbon dioxide emission, high consumption of energy requirement of cement production motivates the researchers to find out the possible alternative to minimise the utilisation of cement in the building industry. Over the few decades, there is increased concern about using sugarcane bagasse ash as a partial replacement of cement is investigated in this paper along with other supplementary cementitious materials include GGBS and nano silica. Based on the previous studies, fixed proportion of 10% bagasse ash was used as a maximum replacement for cement. Different proportions of nano silica ranging from 1 to 6% by weight of cement were incorporated as an additive in concrete specimens. The influence of SCBA, recycled aggregate, GGBS and nano silica is presented in this paper on the mechanical and durability properties of concrete. [ABSTRACT FROM AUTHOR]

In construction industry the innovation and advancement technology has major scope in new inventions. Nano materials plays their role in the improvement of the construction sector by enhancing the material properties. Nano particles which are having high surface area compared to its volume. Nano materials are more reactive and improve the concrete mechanical properties. In order to study the performance of the nano silica concrete, the various mix ratios were used. The optimum dosage of nano silica in concrete was found. Various dosages of nano silica 0%, 1.5%, 2%, 2.5%, 4%, 6%, 8% were attempted. A constant water to cementitious materials ratio of 0.45 was kept for all mixtures. The results indicate that the incorporation of nano silica increased the compressive strength of the concrete when compared to control concrete. Compressive strength, Modulus of Elasticity and flexural strength of the nano silica-based concrete were also examined.

This work presents the mechanical characteristics of concrete enhanced with egg shell powder (ESP) and nano-silica (NS) along with steel fibres. Steel fibre reinforced concrete (SFRC) offers several benefits, including prevention of macro cracks, improving ductility and residual strength and increasing toughness. These benefits make SFRC a valuable choice for structural applications requiring enhanced durability, crack resistance, and resilience to mechanical stresses. To develop the modified concrete mixture the Ordinary Portland Cement (OPC 53 grade) was partially replaced with varying percentage such as 0%, 5%, 10%, and 15% of ESP and NS by weight of the total binder content. Steel fibers were merged into the concrete at a volume fraction of 1.5% by weight of concrete to boost the engineering characteristics of concrete. The effect of ESP and NS were observed on compressive, flexural and split tensiles trength of the concrete. The test was conducted after 7 and 28days of curing period. The inclusion of 10% and 15% percentage of ESP and NS gives high mechanical properties. The findings validated the suitability and efficacy of employing ESP and NS as partial substitutes for OPC, leading to substantial enhancements in the engineering characteristics of SFRC.

In the reported study, nano silica and nano clay were used to remove the residual color from effluent generated during the dyeing of wool fabric with basic violet. Various concentrations (0.1%, 0.25%, 0.5%, and 1.0%) of the nanoparticles were treated with dye effluent for different durations and the results are compared with the color removal of commercial activated carbon. The nanoparticles were characterized for their physical properties including particle size, FTIR, and TEM. Freundlich isotherm was used for the dye adsorption studies. The FTIR and TEM analysis depicted the characteristic peaks and crystal geometry for the selected nanoparticles. The treated effluent showed a significant reduction in color, biological, and chemical oxygen demand (more than 99%). The treatment was optimized for 1.0% adsorbent concentration for 60 minutes. The color removal efficiency of nano silica was found to be higher at low concentration; however, the efficiency of nano clay exceeded at a higher concentration of adsorbents.

In the reported work, the wool fabric was coated with epoxy resin by hand layup method to fabricate the wool-epoxy composites. Hydrophobic nanosilica was used as a filler to improve their mechanical characteristics. The physico-mechanical properties of the composites were analyzed using various analytical techniques. The surface morphology was examined with the aid of Scanning Electron Microscope. The biodegradability of the developed composites was determined by soil burial test. The presence of nanosilica in the composite was confirmed by Fourier Transform Infrared Spectroscopy (FTIR). According to the findings, up to 0.5% nanosilica content significantly increases the tensile and impact strength of the wool-epoxy composites. The contact angle measurement showed a slight enhancement in the hydrophobic properties of the composites due to the dispersion of hydrophobic nanosilica particles. The presence of nanosilica slightly reduced the water diffusivity in wool-epoxy-nanosilica composites when compared to wool-epoxy composites. The SEM images detected nanosilica inside the composites. After soil burial test, all the composites showed a weight reduction below 1.0%.

Traffic volume and loads have increased significantly in recent years, coupled with the high summer temperature and the low temperature in winter, premature failure in asphalt concrete pavement becomes the main challenge for pavement construction companies and engineers. The use of modifiers in asphalt concrete mixes become of considerable interest in the improvement of pavement performance and service life. With the advent and evolvement in nanotechnology, many researchers focused on how these materials could serve in rising the serviceability of pavement in terms of reducing rutting, fatigue cracking as well as moisture induced damage. In this study, nanomaterials, including nano silica (NS), nano carbonate calcium (NCC), nano clay (NC), and nano platelet hydroxyapatite (NP), were used to examine the prospect of enhancing the durability and resilience of asphalt mixtures. Specifically, this study aimed to evaluate the effect of adding nanomaterials as a modifier to the bitumen on the Marshall properties, resilient modulus as well as the durability of the asphalt concrete mixture, which was assessed for moisture susceptibility using indirect tensile strength (ITS) and permanent deformation using the uniaxial repeated load test. The investigated nanomaterial dosages were as follows; NS (1, 3 and 5%), NCC (2, 4 and 6%), NC (3, 5 and 7%), and NP (2, 4 and 6%), by weight of asphalt cement. The results were compared with the control mix (CM), i.e., an unmodified mix. The results revealed that nanomaterials significantly improved the properties of asphalt concrete. Also, this work provides a basis for producing more durable mixtures with higher resistance to distress.

New concepts for improving the performance of cementitious materials have recently surfaced due to the advancement in nanotechnology. In this context, nano silica (NS) and carbon nanotubes (CNTs) have been widely used in recent years. These nanomaterials significantly enhance the mechanical and durable performance of cement mixtures, although there are a few drawbacks related to high cost and workability issues. As a result, these components must be consumed at specific rates in order to achieve the desired qualities. This study aimed to create models to forecast the compressive strength (CS) for concrete mixed with two types of nanomaterials utilizing machine-learning-algorithms (MLA), such as the decision tree algorithm (DTA) and random forest algorithm (RFA). The results of both models were compared and verified by external K-fold cross-validation. A comprehensive database was collected containing 72 and 55 data points for the CS of CNTs and NS-modified concrete respectively. Four input variables such as fine aggregate (FA), cement content (CC), coarse aggregate (CA) and water-to-cement ratio (W/C) were used for the calibration of the models. Additionally, predicted results were checked through k-fold-cross-validation and other performance gauges such as mean-absolute-error (MAE), mean-squared-error (MSE), correlation coefficient (R2), root-mean-square-error (RMSE), relative-root-mean-square-error (RRMSE) and performance-index-factor (Pif). The RFA (CNTs and NS) models were found with better performance and accuracy than the DTA models by having the lowest MAE of 3.51, 4.17 RRMSE of 0.0783, 0.0584, and Pif of 0.0398 and 0.0299 respectively. In addition, the value of R2 for RFA models was observed higher such as 0.90 (CNTs) and 0.93 (NS), while for DTA models R2 was found as 0.88 (CNTs) and 0.86 (NS) respectively. The ensembled ML methods demonstrated a better generalization capability, which indicates their better ability for future prediction of CNTs and NS mixed concrete.

Present study assesses the durability performance of concrete mix with the addition of marble dust and Nano silica as partial replacement of cement. Concrete blends with 1 %, 2 %, and 3 % Nano silica and 5 %, 10 %, and 15 % marble dust powder were prepared at constant water to binder ratio of 0.4. The bulk density, water permeability, water absorption, carbonation depth, rapid chloride penetration test, and acid attack after curing for 28 days along with mineralogical and morphological tests were carried out. The carbonation depth was investigated after exposing the samples for a long duration of 90 days and 180 days, respectively. The durability tests revealed that the incorporation of Nano silica (2 %) and marble dust (5 %) together, resulting in a decrease in water absorption and permeability up to 26 %, and 57 %, respectively. A reduction of around 20 % in carbonation depth was also observed for concrete mixes containing 2 % Nano silica and 5 % marble dust powder. Nano silica and marble dust containing concrete mixes offer good resistance to acid attack. It was observed that the incorporation of fine particles of marble dust (5 %) and Nano silica (2 %) in cement enhanced the bulk density by reducing the pores inside the matrix and thus improves the overall durability properties of the concrete mix. The utilization of nano silica and marble dust as replacement of cement in concrete can lower the CO2 emission produced during the manufacturing of cement.

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sorbitol was employed as the grafting agent to modify nano-silica by the hyperbranched reaction. The obtained carrier was further used to prepare immobilized 4-dimethylaminopyridine (DMAP), which was successfully applied to produce vitamin E succinate. Two crucial steps were systematically investigated during the preparation of hyperbranched loadedDMAP: the epoxy-alcohol addition and N-alkylation reactions. For the epoxy-alcohol addition reaction, the maximum hydroxyl content reached 8.89 mmol/g when the molar ratio of sorbitol to epoxide was 2.5:1, the reaction temperature was 55 °C, the stirring ratewas 500 rpm, and the reaction timewas 8 h. In theN-alkylation reaction, when the reaction timewas 20 h, the reaction temperature was 130 °C, the molar ratio of MAP to K2CO3 was 1:1.5, the KI to MAP molar ratio was 1:1 and the stirring rate was 600 rpm, the highest loading of DMAP reached 5.17mmol/g. The catalytic performance of the loaded DMAP with different branching levels was evaluated by the acetylation reaction. The highest catalytic activity was observed in the hyperbranched catalyst, which reached 24.97 mmol/h·g. Moreover, the stability of the prepared immobilizedDMAPwas significantly enhanced. After being used for ten batches, 94.9% of the catalytic activity retention rate was obtained. [ABSTRACT FROM AUTHOR]

The use of enormous amounts of material is required for production. Due to the current emphasis on the environment and sustainability of materials, waste products and by-products, including silica fume and fly ash (FA), are incorporated into concrete as a substitute partially for cement. Additionally, concrete fine aggregate has indeed been largely replaced by waste materials like crumb rubber (CR), thus it reduces the mechanical properties but improved some other properties of the concrete. To decrease the detrimental effects of the CR, concrete is therefore enhanced with nanomaterials such nano silica (NS). The concrete mechanical properties are essential for the designing and constRuction of concrete structures. Concrete with several variables can have its mechanical characteristics predicted by an artificial neural network (ANN) technique. Using ANN approaches, this paper predict the mechanical characteristics of concrete constructed with FA as a partial substitute for cement, CR as a partial replacement for fine aggregate, and NS as an addition. Using an artificial neural network (ANN) technique, the mechanical characteristics investigated comprise splitting tensile strength (Fs), compressive strength (Fc), modulus of elasticity (Ec) and flexural strength (Ff). The ANN model was used to train and test the dataset obtained from the experimental program. Fc, Fs, Ff and Ec were predicted from added admixtures such as CR, NS, FA and curing age (P). The modelling result indicated that ANN predicted the strength with high accuracy. The proportional deviation mean (MoD) values calculated for Fc, Fs, Ff and Ec values were −0.28%, 0.14%, 0.87% and 1.17%, respectively, which are closed to zero line. The resulting ANN model's mean square error (MSE) values and coefficient of determination (R2) are 6.45 × 10−2 and 0.99496, respectively. [ABSTRACT FROM AUTHOR]

Carbonaceous nanomaterials and their derivatives have been inspired tremendous enthusiasm in the scientific community. They have been excogitated as the encouraging attributes and the qualified dispersed phase to develop multi‐functional composites. Particularly, graphene and carbon nanotube (anisotropic fillers) have gained substantial research interest owing to their promising characteristics. This highlights an innovative technique to synthesize hybridized nanotube and nanosheet. Initially, parent materials have been synthesized: The pristine CNT has been modified by acid mixture solution, and reduced graphene oxide has been prepared by chemical reduction method. Henceforth, the self‐assembly in situ sol–gel technique has been endorsed here. The synthesized nanohybrids have been characterized by different spectroscopic techniques: FTIR, Raman, UV, and XPS to confirm the attachment of multifunctionalities; meanwhile, the composition and stability have been investigated from XRD and TGA plots. The magnitude of surface charge and particle size distribution have been evaluated for the parent and hybridized products; further, morphology of all the samples has been authenticated from FESEM and TEM. [ABSTRACT FROM AUTHOR]

This paper reviews the application of silica nanomaterials in the field of heavy metals, and mainly introduces the progress and development trend of mesoporous silica nanomaterials, functional group modified silica nanomaterials and composite silica nanomaterials. Silica nanomaterials have the advantages of low cost, high specific surface, good stability and multiple modification ways, which are important development direction of heavy metal pollution control. This work also analyzes the future development trend and potential value of silicon dioxide nanomaterials, and puts forward some opinions and suggestions on the solutions to the technical problems still existing in the application of silicon dioxide nanomaterials in the field of heavy metals. [ABSTRACT FROM AUTHOR]

Salinity inferiorly affects physiological and biochemical processes of wheat plants making grain yield economically drops. Ameliorative effects of some growth stimulants (control, humic acid, tocopherol, nano-silica and nitric oxide) on two wheat cultivars (Sakha 95 and Misr3) under saline soil conditions were investigated in this work. The experiment was conducted during 2019/2020 and 2020/2021seasons using split-plot design. Results disclosed that although Sakha 95 recorded higher value of grain yield than Misr 3 but there were insignificant differences between the two cultivars in almost all studied traits, except for relative water content, malondialdehyde content and catalase activity, where Misr 3 significantly superior Sakha 95 in these traits. Nano-silica or nitric oxide significantly affected water relations traits of the two studied cultivars, where the two treatments gave the lowest values of transpiration rate and the highest values of both stomata resistance and relative water content in both seasons. The two treatments also gave the highest activity of catalase and peroxidase enzymes and the lowest values of malondealdehyde. The highest increase in chlorophyll pigments (a and b) and yield as well as its attributes were obtained from spraying nano silica. It could be recommended that cultivation of Sakha 95 or Misr 3 treated with nano-silica or Sakha 95 with spraying any of the other studied stimulant substances (nitric oxide or humic acid or tocopherol) to obtain high productivity under saline soil conditions. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of nano SiO2silica and nano TiO2 on the dyeing of cotton fabric with madder dye was studied. The metal nanoparticles were prepared by sol-gel method from respective precursors. Various concentrations of the nanoparticles were added during the dyeing of cotton with madder. The effect of nanoparticles on the color values, fastness, and ultraviolet protection properties was studied. The characterization of the nanoparticles and the dyed fabric was studied using various analytical techniques. The dye was characterized by FTIR and phytochemical analysis. The post dyeing results inferred that there is a considerable improvement in the dye uptake and fastness properties of the dyed fabric after introducing metal nanoparticles. The SEM and EDX analysis confirmed the presence of SiO2 and TiO2nanoparticles on the fabric surface. The physico-mechanical properties of the fabric were found intact after dyeing. [ABSTRACT FROM AUTHOR]

Terminal blend (TB) rubberized asphalt is a popular technology in the production of rubberized asphalt. However, it always presents challenges regarding the inadequate high-temperature rutting performance of the binders. Additionally, crumb rubber (CR), a modifier of asphalt is a cross-linked material which presents poor compatibility between CR particles and bitumen. Incorporating nanomaterials and pretreating CR particles are two possible solutions to address this drawback. But the performance improvement and modification mechanism of the composite TB binders is not clearly understood. Therefore, the purpose of this research was to evaluate the high-temperature properties and reaction mechanism of the TB rubber/nano silica composite modified asphalt using microwave activated rubber. To achieve the research purpose, bitumen penetration grade 80–100 was first modified with 8% CR particles at elevated temperature to produce TB rubberized asphalt followed by the addition of 0.5, 1.5 and 3.0% weight percentage of nano silica to produce TB rubber/nano silica composite modified asphalt. Short and long-term aging tests were performed on samples by thin film oven test (TFOT) and pressure aging vessel (PAV) prior to chemical and rheological tests. The results of the study shows that nano silica has a great influence on the high temperature rutting resistance, storage stability and anti-aging properties of TB rubberized asphalt. Nano silica promoted good interaction and compatibility between CR particles and bitumen and improved the overall rheological properties of the binders. XRD test results revealed that the TB rubberized/nano silica composite modified asphalt samples were amorphous materials and did not have a crystalline structure. The reaction mechanism between rubber and asphalt was found to be physical, whereas nano silica interacted chemically with TB rubberized asphalt. In light of these findings, this research concluded that nano silica evidently improves the high-temperature rutting properties of TB rubberized asphalt, which deserves further exploration and application. [ABSTRACT FROM AUTHOR]

Construction industry is one of the biggest sectors globally and a wide variety of materials are used to carry out various works. Particularly, cement is a material that is used in the construction of various structures and it is also the major source of emission of CO2 gas into the atmosphere which results in global warming. Many researchers have identified various replacement materials for cement as a partial substitution and carried out experiments successfully. Nano silica is widely utilized as a partial replacement for cement and a lot of research is carried out. This paper reviews the past studies in which nano silica is utilized in various building materials such as cement mortars, normal concrete and special concretes. The fresh concrete properties, strength and durability of the material are the parameters reviewed and it is apparent that by incorporating nano silica in cement it absorbs more water, which makes the mix less workable and it imparts additional strength to the concrete and also provides better durability when compared with the control specimen. Hence it has been revealed that nano silica will be a good replacement for cement as it is pozzolanic in nature and also possessing good microstructure. [ABSTRACT FROM AUTHOR]

In the new era, development of high strength concrete demands good amount of cement content which is very exorbitant. Increase in grade of concrete results in escalating the amount of cement quantity. Therefore, by adding small amount of mineral admixtures to the concrete mix can boost the strength of concrete effectively. Focus of this research work is to develop the high strength self compacting concrete which can be self cured. The size of nano silica particles has a great influence on concrete characteristics while comparing it with other nano materials at suitable proportion. The combination of PEG and NS demands an extensive analysis as their contribution towards hydration process is significant. In the present study, Nano silica (NS) was used as mineral admixture, Polyethylene glycol (PEG) was used as self curing agent. Initially optimum content of NS was determined in order to attain the high strength self compacting concrete. Nano silica replaced with cement with the mass of cement and Polyethylene glycol replaced with water by different proportions to the mass of cement. The fresh properties of prescribed mixes satisfies the EFNARC guidelines. Permeability of concrete can be lowered by adopting mineral admixture like NS which helps to overcome chloride ion entry. For which, Durability tests like Rapid Chloride Permeability Test (RCPT) and water absorption and desorption tests were initiated to know the performance of Nano Silica in Self Compacting Concrete. The improved results I,e, optimum content was observed at 2% addition of NS and 3% addition of PEG.

The present study aims at assessing the ballistic impact behaviour of jute reinforced polyethylene glycol (PEG) and nano silica based shear thickening fluid (STF). Preparation of STF is achieved by dispersing the nano silica particles at different weight percentage loadings of 10%, 20%, 30% and 40% in PEG and the effect of various weight percentages loading of nano silica particles on ballistic performance of the proposed composites is studied experimentally. Rheological studies of the prepared STF’s showed that at all nanosilica loading shear thickening occurred and also the shear thickening was highest at higher loading of nano silica at lower rate of shear. The study reveals that the ballistic performance of the jute fabric is enhanced with impregnation of STF. The ballistic results indicate that energy absorption of the proposed composites is enhanced with increased loading of nano silica particles and at the same time, the effect of STF was reduced. Specific energy absorption (SEA) of the neat fabric and the proposed composites was made use of for the purpose of comparing the energy absorption capabilities. It is found that the SEA of proposed composites with 10% nano silica loading is lesser than the neat fabric both in case of 3 layers and 6 layers. It was also found that proposed composite with 40% nano silica loading exhibits highest SEA compared to neat fabric and its counterparts with its SEA being 3.21 and 3.76 times highest compared to three and six layers of neat fabrics respectively.

Glass is a transparent and geometrically ordered element in architecture. Glass bonding can be classified into adhesive, layered, and mechanical categories. One of the best bonding materials for glass applications is adhesive. The preparation and investigation of Ultraviolet (UV)-curable composites for glass-to-glass bonding is the goal of this research. The investigation focused on the effect of raw material type and weight percentage on mechanical properties. Epoxy acrylate resin was employed as an oligomer in this study. Trimethylolpropane triacrylate (TMPTA), tripropyleneglycol triacrylate (TPGDA), and pentaerythritol tetraacrylate (PETA) were used as monomers. As photoinitiators, were used bis (2,4,6 trimethylbenzoyl)-phenylphosphine oxide, hydroxycyclohexyl phenylketone, and 2,4,6-trimethylbenzoyl diphenyl phosphineoxide. Benzophenone, acrylic acid, nano silica, and trimethoxysilylpropyl methacrylate (TMSPMA) were used as the additives. The mechanical properties of the samples were studied using compressive and shear tests. The degree of conversion (DC) was obtained using Fourier transform infrared spectroscopy (FTIR). The mechanical behavior of the samples were measured as a function of temperature using dynamic mechanical thermal analysis (DMTA); and the distribution of nanoparticles was examined using scanning electron microscopy (SEM). The results showed that the sample containing 4 wt% nano silica, which also contained 24 wt% PETA and 7 wt% TMSPMA, has the best mechanical properties with 0.42 and 0.63 MPa compressive and shear strength, respectively. In the FTIR, was observed an increase of nano silica from the lowest (1 wt%) to the highest amount (5 wt%), the DC current decreased by 11 %. In the DMTA analysis, it was observed that an increase of nano silica from 1 to 5 wt%, the storage modulus increased by 41 %. The highest loss modulus and loss temperature were related to the samples containing 1 and 2 wt% nano silica with 221 MPa and 113.8 °C. Finally, the best distribution of nanoparticles was observed in the sample containing 1 wt% nano silica. In the SEM images, agglomeration of nanoparticles was seen in the sample containing 5 wt% nano silica. [Display omitted] • UV-curable composite adhesive based on epoxy acrylate was prepared to bonding glass to glass. • Presence of silanes containing acrylate groups in composite were increased adhesion between UV-curable composite and glass. • Presence of acrylic acid in UV-curable composite were decreased mechanical properties of composite in glass bonding. • With the increase of nanoparticles in UV-curable composite, degree of conversion was decreased. [ABSTRACT FROM AUTHOR]

Advancements in micropropagation techniques facilitated the incorporation of nanoparticles in the propagation of many commercially important plants. Under in vitro conditions, the adventitious shoots are regenerated with undesirable structural disorders, which increase the rate of mortality of in vitro -produced propagules. In the present study, the effect of Silicon nanoparticles (SiNPs) along with the optimized plant growth regulators (PGRs) in the nutrient medium were tested for their growth-promoting effects on in vitro developing shoots of Cyperus rotundus L. Silicon NPs at 5.0 mg/L induced a higher number of shoots (23 shoots/culture vessel) with improved shoot morphology, rhizogenesis (7.0 roots with 4.0 cm root length), photopigments [(chl a - 474.0 μg/g fresh weight (FW); chl b - 509.0 μg/g FW)] and biomass (3.0 g FW), which were comparatively superior to the morphometric outcomes of the control experiments. The occurrence of morphometric and anatomical disorders in the leaves such as non-functional stomata with increased stomatal density, underdeveloped epidermal cells, undifferentiated costal and intercostal regions, and reduced mesophyll, sclerenchyma, xylem vessels, and phloem elements was observed in the controlled shoots. Silicon NPs at 5.0 mg/L in the medium reduced the in vitro- induced structural abnormalities and modulated foliar micro-morpho-structural differentiation of leaves by promoting positive structural alterations in the leaf thickness, differentiation of dermal tissues, Kranz anatomy, vascularization, stomatal complex, and mechanical tissues. These overall developmentssupported the hardening and survival of plantlets ex vitro. The present findings report the role of SiNPs as the 'structural stabilizer' during in vitro plantlet development of C. rotundus , as a target species and representative model for the C 4 plants. [Display omitted] • Silicon nanoparticles (SiNPs) were tested for their growth-promoting effects in plants. • SiNPs induced a higher rate of shoot proliferation of Cyperus rotundus in vitro. • The in vitro induced morpho-structural abnormalities were mitigated by SiNPs. • It resulted in the formation of structurally developed shoots and foliage. • SiNPs-derived plantlets performed better during acclimatization. [ABSTRACT FROM AUTHOR]

Incineration ash contains metallic aluminium that can react with cement alkalis, producing hydrogen gas, which can affect the strength of cementitious materials. In this study, we aimed to improve the technical properties of incinerated ash-based mortar using three different nanomaterials: carbon nanotubes, graphene nanoplatelets, and nano-silica. These nanomaterials were incorporated at concentrations of 0.025 wt%, 0.05 wt%, 0.1 wt%, 0.25 wt%, 0.5 wt%, and 1 wt% of the cement mass, respectively. Comprehensive analysis indicates that the type of nanomaterials and their doses play a significant role in early age hydration, shortening the induction period and promoting the formation of C-S-H. Study results show evidence up to a 45 % enhancement in compressive strength. Sustainability assessment reveals that a dose of 0.025 % graphene nanoplatelets is the most sustainable from an environmental perspective, with approximately a 25 % improvement in compressive strength of incinerated ash mortar. Findings of the study will contribute to the understanding of nanomaterial-reinforced cementitious systems incorporating incinerated ash and offer valuable guidance for improving the performance of incinerated ash-based cementitious materials in construction applications. • The type and doses of nanomaterial has remarkable effects on cement hydration. • The type of nanomaterials impacts mortar strength enhancement efficiency. • Nanomaterials provide nucleation and pore-filling effects. • The microstructure of incinerated mortar improved with nanomaterials. [ABSTRACT FROM AUTHOR]

The purpose of the present study is to offer an optimal model to predict the tensile index of the paper being consumed to make veneer impregnated with different weight ratios of modified starch (from 3.18 to 36.8%) to urea formaldehyde resin (WR) containing different formaldehyde to urea molar ratios (MR, from 1.16:1 to 2.84:1) enriched by different contents of silicon nano-oxide (NC, from 0 to 4%) using multiple linear regression (MLR) and adaptive neuro-fuzzy inference system (ANFIS) and compare the precision of these two models to estimate the response being examined (tensile index). Fourier-transform infrared spectroscopy (FTIR) and transmittance electron microscopy (TEM) were also used to analyze the results. The results of studying the adhesive structure using FTIR analysis showed that as the WR increased to the maximum level and MR increased to the average level (3%), more ether and methylene linkage forms due to cross-linking. TEM analysis also indicated that if an average level of silicon nano-oxide is applied, there will be more cross-linking due to the more uniform distribution and suitable interactions between the adhesive and nanoparticles. The modeling results showed that the ANFIS model estimates have been closer to the actual values compared to the MLR model. It can be concluded that the model offered by ANFIS has a higher potential to predict the tensile index of the paper impregnated with the combined adhesive of UF resin and modified starch. However, the MLR model could not offer a good estimate to predict the response. According to the preferred approach to predict the most effective property of resin coated paper, modelling would be useful to the research community and the results are beneficial in industrial applications without spending more cost and time. [ABSTRACT FROM AUTHOR]

Highlights: Micro silica and nano silica are found to yield similar effects in influencing the values of Young's modulus. The values of Young's modulus of hybrid silica particle are higher than single filler, at the same weight loading. The highest improvement in Young's Modulus was recorded 25 wt.% hybrid loading (12.5 wt.% micro silica + 12.5 wt.% nano silica). 1.1 weight percentage is applied for the hybrid composite, which makes equal distribution of weight for nano and micro. Epoxy nano composites containing micro and nano silica were prepared by varying the filler's weight loading as an attempt to investigate the effects of incorporating these fillers in influencing its mechanical properties. Mechanical properties characterizations include the evaluation of tensile. The mechanical properties of the epoxy composites were found to tremendously increase as both micro and nano silica were added together at a 1:1 wt.% ratio. For example, the highest values of Young's modulus were recorded to be 5.39 GPa for 25 wt.% loading (12.5 wt.% Micro + 12.5 wt.% nano), while Young's modulus values of 5.22 MPa and 5.32 MPa were recorded for micro and nano silica, respectively, at the same weight loading. The most outstanding results were observed at 25 wt.% hybrids (12.5 wt.% micro silica + 12.5 wt.% nano silica), where the values of Young's modulus were increased by 228% compared to the neat epoxy. This study successfully demonstrated synergistic effects demonstrated by combining micro and nano silica fillers, which created an interaction that significantly enhanced the Young's modulus of epoxy composites. [ABSTRACT FROM AUTHOR]

Taking acrylic acid (AA) and acrylamide (AM) as monomers, and then introducing nano-silica (nano-SiO2),with ammonium persulfate as the initiator, N,N-methylenebisacrylamide (NMBA) as the crosslinking agent, using the addition of polyvinyl alcohol to make the system have an interpenetrating network structure, P (AA-AM) /Nano-SiO2/PVA organic/inorganic composite interpenetrating network superabsorbent resin was prepared by aqueous solution polymerization method, and the crosslinker dosage and initiator were investigated. Effect of nano-silica addition on resin water absorption magnification. The results show that the addition of hydrophilic nano-silica has a negative effect on the water absorption performance of the water-absorbing resin, and the water absorption rate of the composite resin reaches 360 g/g at a particle size of 20～80 mesh. P (AA/AM) /PVA resin water absorption multiple of 477 g/g; test its water absorption capacity in distilled water and 0. 9% sodium chloride solution, respectively; the addition of nano-silica makes the composite resin have good water retention performance, and the resin is dried for 5 h at 80 ℃,and its water retention rate reaches 92. 7%. [ABSTRACT FROM AUTHOR]

Calcium carbide residue (CCR) is generated from acetylene gas production, and it is highly alkaline and contains a very high amount of calcium. Nano silica (NS), on the other hand, is mostly used in combination with other pozzolanic materials in concrete to ignite the reactivity of the material and to improve the properties of the concrete. This study investigated the effect of CCR incorporated in concrete mixtures to partially replace cement content at 0 to 30% (interval of 7.5%). NS was used as an additive by weight of binder at levels 0 to 4% in increment of 1%. Thus, response surface methodology (RSM) was employed to investigate the effects of CCR and NS on the properties of the concrete, including compressive strength, flexural strength, splitting tensile strength, modulus of elasticity (MoE), and water absorption. The RSM was used for model development predicted concrete's properties and carried out mixture multi-objective optimization by maximizing strengths, MoE, and minimizing water absorption. The results showed that using up to 15% CCR improved the strengths, MoE, and water absorption of the concrete. Adding up to 3% NS further enhanced the strengths, MoE, and water absorption significantly. The developed models for predicting the properties of the concrete using RSM were highly efficient with high degree of correlation. The optimization solutions indicated that the best optimum or best mix combination based on maximum strengths and MoE with minimum water absorption was achieved by replacing 10.6% cement with CCR and adding 1.95% NS by the weight of cementitious materials. [ABSTRACT FROM AUTHOR]

Coating technology is widely recognized as the most cost-effective and efficient method of preventing metal corrosion. Polymers have been regarded as a powerful coating material owing to their excellent barrier qualities, simplicity of modification, and large-scale production. Nanomaterials differ significantly from their physical and chemical properties, and have been hailed as highly promising functional materials in a wide range of applications, affecting nearly every aspect of science and technology. The addition of organic or inorganic nanofiller particles to polymer nanocomposite coatings may improve corrosion protection and lower the possibility of blistering or delamination. High hardness for polymer coatings, on the other hand, could be achieved by forming hard nanocrystalline phases inside the matrix. This article provides an overview of recent developments in polymer nanocomposite coatings in terms of their history, coating methods, properties, features, and drawbacks. [ABSTRACT FROM AUTHOR]

Synthetic silica has a special place to improve the properties of silicone rubber coatings. Good hydrophobicity can be achieved by modifying these nanoparticles and incorporating them into a suitable polymer matrix. Conventional methods of synthesizing silica nanoparticles are expensive and not eco-friendly. Tetraethyl orthosilicate has been used to synthesize silica nanoparticles, although it is not the best source of silica production due to its high cost. One of the cost-effective sources is sodium silicate (water glass). This study used cheaper materials such as water glass, hydrochloric acid, ethyl acetate and cetyl trimethyl ammonium bromide (CTAB) as a surfactant, to synthesize silica in three different methods based on water glass. The phase of the synthesized particles was investigated by X-ray diffraction, and scanning electron microscopy was conducted to determine their particle size and morphology. Surface modification with fluorinated hydrocarbons or silanes is expensive and harmful to the environment and human health. Therefore, the nanoparticles were modified with inexpensive stearic acid, and then they were incorporated into RTV (room temperature vulcanizing) silicone rubber as fillers. The results showed that with increasing silica content from 0 to 3 wt%, the water contact angle of the nanocomposite increased by 19°. The changes in mechanical and electrical properties of RTV with addition of modified synthesized silica nanoparticles were also investigated. [ABSTRACT FROM AUTHOR]

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In field, the research has been extended to the usage of Nano material in concrete and thereby enhancing the performance of the structure. It has been identified that incorporating a trifling amount of Nano material in concrete can modify the properties of cement at Nano level which makes the concrete much sustainable. Among the various Nano materials, Nano Silica has gained the attention in contemporary days because it offers high SSA and good pozzolanic reactivity even better than the other conventional mineral admixtures. Due to its high SSA, Nano Silica extended its advantages as a better filler, which makes the concrete less porous and thus enhances the durability. Early-age strength gain is due to the accelerated Nano Silica – Cement hydration which ends up in the formation of complex microstructural C-S–H gel. Accelerated hydration is the result of high pozzolanic reactivity of Nano Silica. For the better rheological properties, concrete with Nano Silica requires the higher dosage of super plasticizers to promote the rolling effect of Nano particles and also to avoid the agglomeration of Nano particles in concrete even at high water-cement ratio (0.45) when paralleled with conventional one. Moreover, dispersion type, particle size distribution and densification of concrete with Nano Silica particles plays a vital role in enhancing the strength parameters of the concrete. This review paper presents the study on how Nano Silica in concrete at different dosages can alter the properties of the concrete. [ABSTRACT FROM AUTHOR]

Sulfate attack is one of the main concerns of cement-based materials. In this research, the magnesium sulfate attack resistivity of cement-based materials modified with nano silica (NS) and supplementary cementitious materials (SCMs) i.e., silica fume (SF), fly ash (FA) and ground granulated blast-furnace slag (GGBS) was studied up to 500 days. The effects of the initial curing time (7 and 28 days) on the mechanical property and volume stability of the cement mortars under magnesium sulfate attack were studied. The results showed that the NS has a better capability of improving the magnesium sulfate attack resistivity of the cement mortar compared with traditional supplementary materials, and a longer initial curing time contributed to the higher resistivity. The higher pozzolanic reactivity of NS led to a denser structure of the cement mortar and retarded the magnesium sulfate attack process. FA-added samples had poor resistance to magnesium sulfate attack due to the low pozzolanic reactivity. The resistance of the GGBS-added samples to magnesium sulfate attack was moderate among the samples.

The special particle grading properties of silt lead to the strong water sensitivity and low soil strength of silt sites, many of which are severely damaged and urgently need to be repaired. This article takes the powder soil from a certain burial site area in Xizhu Village, Luoyang as the research object, which is improved by adding nanosilica and potassium methylsilicate. The modified soil is studied through mechanical and waterproof performance tests, and the mechanism of action of the modified material is analyzed through SEM and XRD. The experimental results show that the mechanical properties and waterproof properties of the composite modified soil were improved when the nanosilica content was 2% and the potassium methylsilicate content was 0.5%; the durability of the composite modified soil is improved, making this the optimum ratio. The mechanical properties and water resistance of the silty soil were significantly improved by adding the appropriate amount of nanosilica and potassium methylsilicate. Nanosilica can be evenly dispersed in the soil matrix, absorb a small amount of water to form a gel state, fill the pores in the silt aggregates, and improve soil compactness. In addition, nanosilica aggregates can attach to the surface of the soil particles and extend from the particle surface to the particle edge. By increasing the contact between soil particles and increasing the particle size, the mechanical properties of the modified soil are improved. When potassium methylsilicate solution is added to the soil, it reacts with water and carbon dioxide, decomposes into methylsilicate, and quickly generates a polymethylsiloxane film to cover the surface of soil particles, forming a waterproof film on the surface and thereby improving the waterproof performance of modified soil. Our research results can provide a reference for the restoration and protection of silty and silt-like sites. The next step is to apply the composite modified soil in engineering restoration through field tests in order to study the repairing ability of composite modified soil and its actual protective effects.

The effect of nano silica (50 mL L−1) and melatonin (75 µM) individually or in combination in foliar applications on the morphophysiological, biochemical and yield properties of pea plants under salinity stress conditions was evaluated. Salt stress caused a remarkable decrease in the growth and yield characteristics; for example, the plant dry weight, plant height, number of flowers plant−1, number of pods plant−1, weight of 100 green seeds and protein concentration in the pea plants during both seasons were decreased compared with the control. Similarly, their physiobiochemical characteristics were negatively affected; chlorophyll a, chlorophyll b and the relative water content (RWC) were significantly reduced in the stressed pea plants. However, malondialdehyde (MDA), hydrogen peroxide, the electrolyte leakage (EL%), super oxide and the antioxidant components (catalase (CAT), superoxide dismutase (SOD), peroxidase (POX) and total phenolic compounds) were significantly increased when the plants were under salt stress compared with the control plants. On the other hand, the foliar application of nano silica and melatonin individually or in combination enhanced the physiobiochemical characteristics, morphological characteristics and yield of the stressed pea plants. The best treatment was the combination treatment (nano silica + melatonin), which caused significant increases in the plant dry weight, plant height, number of flowers and pods plant−1, weight of 100 green seeds, protein concentration, chlorophyll concentrations and RWC in the stressed pea plants. Additionally, the combination treatment significantly decreased the EL%, MDA, O2⋅− and H2O2 and adjusted the upregulation of the antioxidant enzymes, proline and total phenolic compounds in the stressed plants compared with the stressed untreated pea plants. Generally, it can be suggested that the co-application of nano silica (50 mL L−1) + melatonin (75 µM) plays a positive role in alleviating the adverse impacts of salinity on pea plants by modifying the plant metabolism and regulating the antioxidant defense system as well as scavenging reactive oxygen species.

The application of nanotechnology in cement mortar has added a new dimension to improving the mechanical performance of cementitious materials. Huge amounts of waste silica generated as a byproduct from aluminum fluoride industries poses heavy economic and environmental challenges. The objective of this study is to investigate the effect of replacement of cement with waste nano-silicas (NS) on the characteristics of cement mortar mainly the compressive strength, flexural strength, workability, density, and heat of hydration. Cement was replaced with NS with percentage of (0.5,1,1.5,2,2.5%, 4, 6, 8, 10%), with a constant water-tocement ratio (C/W) of 0.5. Depending on the obtained results, it has been observed that substitution of cement with NS has insignificant adverse impact on the characteristic of the mixture at low content of NS. Slight decrease (5.5%) in the compressive strength occurred at 7 days at low substitution percentage (0.5%), and 11.5% at 28 days. Flexure strength decreased by 23% and 55%, workability increased slightly by 1.33% and 6.8% at substitution percentage of 0.5%, and 2.5% respectively. Also, substitution resulted in significant reduction in the mortar weight up to 18.49% at substitution percentage of 10%, while insignificant impact on the hydration rate was observed for all substitution percentages. It can be concluded that recycling of waste NS in cement mortar mixture provided an attractive option to reduce the impact of waste on the environment, reduce cement consumption, reduce concrete weight, conserve natural resources and save the environment. [ABSTRACT FROM AUTHOR]

In the reported study, nano silica and nano clay were used to remove the residual color from effluent generated during the dyeing of wool fabric with basic violet. Various concentrations (0.1%, 0.25%, 0.5%, and 1.0%) of the nanoparticles were treated with dye effluent for different durations and the results are compared with the color removal of commercial activated carbon. The nanoparticles were characterized for their physical properties including particle size, FTIR, and TEM. Freundlich isotherm was used for the dye adsorption studies. The FTIR and TEM analysis depicted the characteristic peaks and crystal geometry for the selected nanoparticles. The treated effluent showed a significant reduction in color, biological, and chemical oxygen demand (more than 99%). The treatment was optimized for 1.0% adsorbent concentration for 60 minutes. The color removal efficiency of nano silica was found to be higher at low concentration; however, the efficiency of nano clay exceeded at a higher concentration of adsorbents. [ABSTRACT FROM AUTHOR]