SiO2 Nanoparticles Research Articles

Expression of Concern: Investigating the Effect of SiO2 Nanoparticle Addition and Thickness of Face-Coverings on COVID-19 Protection Using Molecular Dynamics Approach

Expression of Concern: Investigating the Effect of SiO2 Nanoparticle Addition and Thickness of Face-Coverings on COVID-19 Protection Using Molecular Dynamics Approach

Foliar spraying of different size SiO2 nanoparticles affected phenanthrene accumulation in amaranth (Amaranthus tricolor L.): A metabolomics insight

Silica nanoparticles (nSiO2) have attracted considerable attention in agricultural practices. However, their effects on polycyclic aromatic hydrocarbon (PAH) accumulation in plants remain largely unknown. Thus, this issue was tracked here with a 30-d pot experiment with foliar spraying different sizes of nSiO2 (100 mg L-1, 10 mL) on Amaranthus tricolor L. (amaranth). Results showed that 30 nm and 100 nm nSiO2 increased phenanthrene (PHE) contents in amaranth leaves by 242% ± 88.4% and 158% ± 29.6%, respectively, which was more significant than 2 µm particles (96.0% ± 29.2%). Metabolomics indicated that compared to nSiO2, 2 µm SiO2 more significantly boosted oxidative defense in amaranth leaves, enhanced cell membrane fluidity, and upregulated amino acid metabolism, glycolysis, and gluconeogenesis. In addition, the upregulation of discriminating metabolites was the most significant in 2 µm SiO2-treatment, followed by 100 nm and 30 nm. This is mainly because nSiO2 promoted amaranth growth and decreased average PHE content per unit biomass, namely “dilute effect”. Thus, slighter metabolic disturbances were observed in 30 nm and 100 nm SiO2-treated group. The present study revealed the possibility of PAHs accumulation enhancement in vegetables with nSiO2 foliar spayed. The results of this study provide theoretical guidance regarding to particle size selection for the safe agricultural application of nSiO2 in PAHs-contaminated areas.

Investigating the Potential of CO2 Nanobubble Systems for Enhanced Oil Recovery in Extra-Low-Permeability Reservoirs.

Carbon Capture, Utilization, and Storage (CCUS) stands as one of the effective means to reduce carbon emissions and serves as a crucial technical pillar for achieving experimental carbon neutrality. CO2-enhanced oil recovery (CO2-EOR) represents the foremost method for CO2 utilization. CO2-EOR represents a favorable technical means of efficiently developing extra-low-permeability reservoirs. Nevertheless, the process known as the direct injection of CO2 is highly susceptible to gas scrambling, which reduces the exposure time and contact area between CO2 and the extra-low-permeability oil matrix, making it challenging to utilize CO2 molecular diffusion effectively. In this paper, a comprehensive study involving the application of a CO2 nanobubble system in extra-low-permeability reservoirs is presented. A modified nano-SiO2 particle with pro-CO2 properties was designed using the Pickering emulsion template method and employed as a CO2 nanobubble stabilizer. The suitability of the CO2 nanobubbles for use in extra-low-permeability reservoirs was evaluated in terms of their temperature resistance, oil resistance, dimensional stability, interfacial properties, and wetting-reversal properties. The enhanced oil recovery (EOR) effect of the CO2 nanobubble system was evaluated through core experiments. The results indicate that the CO2 nanobubble system can suppress the phenomena of channeling and gravity overlap in the formation. Additionally, the system can alter the wettability, thereby improving interfacial activity. Furthermore, the system can reduce the interfacial tension, thus expanding the wave efficiency of the repellent phase fluids. The system can also improve the ability of CO2 to displace the crude oil or water in the pore space. The CO2 nanobubble system can take advantage of its size and high mass transfer efficiency, among other advantages. Injection of the gas into the extra-low-permeability reservoir can be used to block high-gas-capacity channels. The injected gas is forced to enter the low-permeability layer or matrix, with the results of core simulation experiments indicating a recovery rate of 66.28%. Nanobubble technology, the subject of this paper, has significant practical implications for enhancing the efficiency of CO2-EOR and geologic sequestration, as well as providing an environmentally friendly method as part of larger CCUS-EOR.

Effect of Disinfection on Tensile Strength and Rupture Elongation of Maxillofacial Silicone Reinforced with Nano-Filler Particles.

Objectives: Compare the tensile strength and rupture elongation of room temperature vulcanizing silicone (RTV), heat temperature vulcanizing silicone (HTV) and 3% SiO2 reinforced RTV and HTV following disinfection with various agents. Materials and Methods: According to ASTM D412, 384 samples were fabricated using HTV, RTV, RTV and HTV reinforced with 3% SiO2 nanoparticles. The control group received no disinfection treatment, while the other samples were disinfected for 10 minutes using neutral soap, 4% chlorhexidine, and ozone water, three times a day for 60 days. Additionally, accelerated aging was carried out for 252,504,1008 hours. Tensile strength and rupture elongation were assessed using a universal testing machine at 500 mm/min speed, and the mean values were analyzed using two-way ANOVA and Tukey HSD test (P<0.05). Results: The mean value of tensile strength of RTV (2.96 ± 0.41), 3%SiO2 RTV (3.26 ±0.33), HTV (3.30 ±0.36),3% SiO2 HTV (4.07 ±0.85) MPa which was statistically significant for control, neutral soap and 4% chlorhexidine at 252,504 ,1008 hours of aging. (P <0.05). The percentage of elongation of RTV (545 ±29.2),3%SiO2 RTV (617 ±30.5), HTV (735 ±48.7),3% SiO2 HTV (801 ±55.7) which was statically significant for control, neutral soap, 4% chlorhexidine and Ozone water for 252, 504 ,1008 hours of aging. (P <0.05). Conclusion: The HTV silicone showed more tensile strength and rupture elongation compared to HTV, RTV and RTV silicones reinforced with 3% SiO2 nanoparticles. Ozone water disinfection had least effect on tensile strength and rupture elongation of maxillo-facial silicone compared to other disinfectant.

Unveiling Hidden Hyperuniformity: Radial Turing Pattern Formation of Marangoni-Driven SiO2 Nanoparticles on Liquid Metal Surface.

Mastering the self-organization of nanoparticle morphologies is pivotal in soft matter physics and film growth. Silicon dioxide (SiO2) nanoparticles are an archetypical model of nanomotor in soft matter. Here, the emphasis is on the self-organizing behavior of SiO2 nanoparticles under extreme conditions. It is unveiled that manipulating the states of the metal substrate profoundly dictates the motion characteristics of SiO2 nanoparticles. This manipulation triggers the emergence of intricate morphologies and distinctive patterns. Employing a reaction-diffusion model, the fundamental roles played by Brownian motion and Marangoni-driven motion in shaping fractal structures and radial Turing patterns are demonstrated, respectively. Notably, these radial Turing patterns showcase hyperuniform order, challenging conventional notions of film morphology. These discoveries pave the way for crafting non-equilibrium morphological materials, poised with the potential for self-healing, adaptability, and innovative applications.

Experimental investigation on stability and thermal conductivity of SiO2 nanoparticles as green nanofluids for application thermal system

In the last few years, much research has focused on the stability and improvement of the thermo-physical properties of single-component nanofluids. Some studies have not made many improvements to the stability and thermophysical properties of various types of green nanofluids from several variations of nanoparticles. Green nanofluids must be developed to improve heat transfer performance from their stability and thermal conductivity factors. Stability and thermal conductivity of Nano-silicate suspended in a base mixture of water /ethylene glycol with the ratio of 60:40, different volume concentrations were investigated. The experiments carried out were the stability of the green nanofluids investigated for volume concentrations of 0.1~0.3% and temperature conditions from 30 to 70°C for thermal conductivity measurement using TEMPOS Thermal Properties Analyzer. The experimental results showed that the stability analysis of the green nanofluids prepared by the UV-Vis method was stable up to 30 days after preparation with a sonication time of 1 hour with a ratio of 70-80%. The evaluation of the zeta potential for green nanofluids obtained a value of 33.57 mV with a moderate stability classification. The highest thermal conductivity for the green nanofluids was obtained at 0.3%, and the maximum increase was 17% higher than that of the base liquid (W/EG). Green nanofluids with a concentration of 0.1% gave the lowest effective thermal conductivity of 1.09 time at 70°C.

Fabrication of superior flame-retardant phosphorylated chitosan biobased porous composites reinforced by superhydrophobic silicone interpenetrating crosslinking networks

Chitosan-based porous materials have potential to develop into a new generation of high performance sustainable thermal insulation materials. In this study, hydrophobic and enhanced phosphorylated porous materials (PCSM) were constructed by the in-situ crosslinking of methytrimethoxylsilane (MTMS), and modified SiO2 nanoparticles (H-SiO2) were further incorporated into the crosslinking networks to fabricate superhydrophobic and reinforced PCSM-H-SiO2 porous composites. The morphology of PCSM-H-SiO2 porous materials exhibited special micro-nanoscale “pearl string-like” rough and interpenetrating pore wall structure, which endowed them superhydrophobicity and self-cleaning ability. The water contact angles (WCAs) of PCSM-H-SiO2 porous composites achieved up to 150o, and the compressive and specific moduli of PCSM2-H-SiO2–2 porous composite significantly increased to 11.0 MPa and 89.6 m2·s−2, 5.39 and 1.74 times higher than those of PCS porous material, respectively. The limited oxygen index (LOI) values of PCSM2-H-SiO2–2 porous composite were above 80 %. The cone calorimeter test result demonstrated the peak heat release rate and total heat release rate values of PCSM-H-SiO2–2 porous composite were lower than those of PCS porous material. The ultra-high flame-retardant PCSM-H-SiO2–2 porous composite with superhydrophobicity and excellent compressive property is a promising biodegradable thermal-insulation material as replacement of petroleum-based material.

Controllable preparation of carbon nanofiber membranes for enhanced flexibility and permeability

The electrospinning-produced carbon nanofiber membranes (CNFM) have been applied in many fields for their three-dimensional porous networks, however, the natural fragility impedes their practical applications. Introducing plasticizers into carbon fibers has been proven an efficient way to increase the flexibility of CNFM but the extent is limited. This work explored dual plasticizers strategy to improve the flexibility of CNFM. The addition of zinc acetate and tetraethyl orthosilicate leads to bigger carbon nanofibers and higher mean pore diameters. They can be transformed into SiO2 and ZnO nanoparticles that embed in the carbon fibers, and act as plasticizers to inhibit stress diffusion. The Young's modulus of the optimal SZCNFM-2.0-1.5-700 is 31.0 MPa, which is lower than single plasticizer can reduce. The mechanism of dual plasticizers collaboratively improving the flexibility of SZCNFM was proved based on the characterization results. The SZCNFM-2.0-1.5-700 with well flexibility also revealed high permeability, for instance, the gravity-induced cyclohexane flux is 486.67 L m−2 h−1. Furthermore, the SZCNFM-2.0-1.5-700 requires only half the time compared to the commercial filter membrane when separating the same amount of Pd@CN suspension in the suction filter.

Breaking the boundaries of wound closure: A novel polyurethane tissue adhesive with enhanced healing properties.

Over the past few decades, there have been advancements in the development of high-performance tissue adhesives as alternatives to traditional sutures and staples for rapid and effective wound closure post-surgery. While tissue adhesives offer advantages such as ease of use, short application time, and minimal tissue damage, they also face challenges related to biocompatibility, biodegradability, and adhesive strength. In this study, L-lysine diisocyanate (LDI) and trimethylolpropane (TMP) were utilized as the primary raw materials to produce a prepolymer terminated with NCO, resulting in the development of a new biocompatible polyurethane tissue adhesive (TMP-LDI). Additionally, SiO2 nanoparticles were incorporated into the prepolymer, significantly enhancing the adhesive strength of the TMP-LDI tissue adhesive through the "nanobridging effect," achieving a strength of 170.4 kPa. Furthermore, the SiO2/TMP-LDI tissue adhesive exhibited satisfactory temperature change during curing and degradation performance. In vitro and in vivo studies demonstrated that SiO2/TMP-LDI exhibited good biocompatibility, efficient hemostasis, antimicrobial properties, and the ability to promote wound healing. This research presents a novel approach for the development of tissue adhesives with superior adhesive performance.

Durable, transparent and superhydrophobic coating with temperature-controlled dual-scale roughness by self-assembled raspberry nanoparticles

This study focuses on creating a superhydrophobic, durable, and exceptionally transparent coating with dual-scale roughness by naturally formed raspberry-like particles. This approach facilitates the management of surface roughness at both single and dual scales through variations in surface functionalization temperature. We illustrated that adjusting the temperature of organosilanes functionalization on the surface allows for various reactions, such as the direct grafting of metallic precursors or their polymerization on the surface, resulting in the formation of large raspberry-like particles.We investigated the impact of nanoparticle concentration, functionalization duration, and reaction temperature on surface properties. Our results reveal that a concentration of 1.5 % SiO2 nanoparticles, combined with surface functionalization using TCMS for 4 h at 3 °C, provides the optimal conditions for creating a surface that combines superhydrophobicity, transparency, and acceptable durability. The resulting surface exhibits an impressive contact angle of 158.9°, a sliding angle of 2°, and a transmittance rate of 82 %.Furthermore, the coating demonstrates remarkable resistance to abrasion for up to 35 cycles and can withstand temperatures up to 280 °C. It also offers enhanced protection against UV radiation for 50 h and improved resistance to sand abrasion for up to 30 s, enduring bombardment pressures of up to 6 bars. Moreover, the coating presents several advantages in terms of surface cleaning.

Synthesized Polymeric Nanocomposites with Enhanced Optical and Electrical Characteristics Based on SiO2 Nanoparticles for Multifunctional Technological Applications

Synthesized Polymeric Nanocomposites with Enhanced Optical and Electrical Characteristics Based on SiO2 Nanoparticles for Multifunctional Technological Applications

Synthesis and Characterization of SiO2 Nanoparticles for Application as Nanoadsorbent to Clean Wastewater

By way of the sol–gel chemical synthesis method, it is possible to synthesize SiO2 nanoparticles with a defined specific particle size, a surface area, and a defined crystal structure that can be effectively used as a nanoadsorbent to remove various organic dyes. SiO2 nanoparticles were synthesized by the sol–gel method using sodium silicate (Na2SiO3) by a green method without using a tetraethyl orthosilicate (TEOS) precursor, which is very expensive and highly toxic. This sol–gel process involves the formation of a colloidal suspension (sol) and solid gelation to form a network in a continuous liquid phase (gel). In addition, it requires controlled atmospheres. XRD indicates the presence of an amorphous phase with a diffraction angle of 2θ = 23°, associated with SiO2. UV-Vis spectroscopy reveals an absorbance value in the region of 200 nm to 300 nm, associated with SiO2 nanoparticles. The application as a nanoadsorbent to remove dyes was measured, and it was found that the nanoparticles with the best performance were those that were synthesized with pH 7, showing a 97% removal with 20 mg of SiO2 nanoparticles in 60 min. Therefore, SiO2 nanoparticles can be used as a nanoadsorbent, using a low-cost and scalable method for application to remove methylene blue in an aqueous medium.

Nano coating containing SiO2 nanoparticles with non-stick properties for easy peeling of car paint from mild steel surfaces

Non-stick latex coating enhanced with mesoporous silica nanoparticles (SiO2 NPs) showed promising peeling properties. In order to see the effect of SiO2 NPs, coatings with and without SiO2 NPs applied on pieces of a hollow section mild steel beam as substrate. The grain size, crystal phase structure, specific surface area (SSA) and pore size distribution of the SiO2 NPs was determined using transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern and Brunauer-Emmett-Teller (BET) analysis. Field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDS) was used to observe the surface morphology and composition of the coated samples. The contact angle was measured for three different liquids on the surface of the samples namely, 1-bromonaphthalene (nonpolar), formamide and distilled water (polar) in order to calculate the surface energies per unit area and hysteresis contact angles. The result showed that adding SiO2 NPs increases the hydrophobicity and decreases the surface energy of the surface. One of the applications of such a coating is to protect the surface from paint sticking to it. For this purpose, the coating with and without SiO2 NPs is applied on a mild steel substrate and then painted by resin-based automotive paint. The pull off test showed that the adhesion is reduced by addition of SiO2 NPs. In addition, to see this application in industry, the coating with SiO2 NPs is applied to a skid and placed in the painting line of an automotive factory for 12 working days. After removing from the line, the coating and the paint on it were easily peeled from the skid either manually with a spatula or by a water jet cleaning machine (100 bar at spraying angle of 45°) compared to a bare skid.

A Comprehensive Examination of Low GO-Silica Loading in Pebax1657/PEI Thin Film Nano-composite Membranes for Gas Dehydration

The aim of this study was to assess the effectiveness of blending Pebax1657 polymer with SiO2-GO nanoparticles in the production of TFN membranes for N2 gas dehydration. By utilizing dip coating, nanoparticles were incorporated at varying concentrations. The resulting nanocomposites were subjected to thorough analysis to investigate their chemical structure, physical morphology, surface topology, and thermal stability. This examination encompassed the application of FTIR, SEM, CA, AFM, and TGA techniques. The results demonstrated that the samples displayed good thermal stability and a highly hydrophilic surface. The investigation concluded that the dehydration properties of TFN membranes are influenced by a variety of factors, such as morphology, plasticization, and hydrophilic attributes. The effectiveness of the system is contingent upon the contribution made by each individual nanoparticle. The impact of SiO2 nanoparticles in their pure form is clearly evident in the 0.5 wt% loaded composite membrane membrane. When 0.5% of SiO2 nanoparticles are introduced into the composite membrane, the morphology closely resembles the ideal state due to the non-porous nature of SiO2 and the low concentration of nanoparticles, hence a selectivity of ~560 is experienced. Fortunately this selectivity is beyond the need of the industries. Consequently, there was a reduction in water vapor and nitrogen permeability, resulting in a heightened selectivity ratio. These discoveries hold considerable importance in industrial settings, as they offer a more comprehensive understanding of the topic.

Biosynthesis of SiO2 nanoparticles from bamboo leaves for tanning wastewater treatment and mechanical properties of HMPC-SiO2 nanocomposite

Biosynthesis of SiO2 nanoparticles from bamboo leaves for tanning wastewater treatment and mechanical properties of HMPC-SiO2 nanocomposite

Shear‐Rheological‐Assisted MXene Dispersion in Epoxy Resin for Efficient Electromagnetic Absorption

AbstractMXenes, a burgeoning family of 2D materials with high conductivity and large specific surface area, are ideal electromagnetic absorbing materials. However, the ample polar functional groups lead to poor dispersion in the non‐polar matrix, limiting its application in non‐polar‐polymer‐based composites. With the help of the shear rheological properties of SiO2, the conflict is resolved here by directly dispersing MXene aqueous dispersion into the non‐polar resin. Water is locked dynamically through SiO2 nanoparticles among the MXene@SiO2 nanosheets, suppressing MXene's self‐restacking and aggregation in the resin matrix. Therefore, the fabrication of uniform MXene/non‐polar polymer composites is achieved. Meanwhile, this method allows different nanoparticles (Fe3O4, etc.) to be evenly dispersed among the MXene nanosheets to further improve the composites' electromagnetic parameters. The as‐prepared composites achieve remarkable absorbing performance with a low MXene concentration (≤5 wt.‰). The SMEP‐h achieves the maximum reflection loss value of over 60 dB at 12 GHz (at the thickness of 2.15 mm), and the SMEP‐F possesses a broad effective absorbing bandwidth of over 6.18 GHz (at the thickness of 1.75 mm). The shear‐rheological‐assisted MXene dispersion method in the non‐polar matrix paves an avenue for the design of outstanding MXene‐based electromagnetic absorbing composites.

Surface modification of CNTs through the SiO2 coating to increase the intragranular reinforcement content in Al matrix composites

Surface modification of CNTs with SiO2 coating was proposed to fabricate Al matrix composite with high-content intragranular reinforcements. The deposition of SiO2 nanoparticles on the surface of CNTs improved their compatibility with the Al matrix and thus increased the penetration of CNT@SiO2 reinforcements into Al grain interiors during powder processing. The intragranular reaction during the sintering process converted the CNT@SiO2 hybrid reinforcements into Al4O4C nanoparticles, leading to a remarkable increment in reinforcement content. As a result, incorporating CNT@SiO2 reinforcements (0.5 wt% CNT coated with 2 wt% SiO2) into Al resulted in a final composite with 9 vol% nanoreinforcement, of which 85 % were located in the grain interiors. The high-content intragranular reinforcements greatly improved dislocation storage capability and strain hardening rate, resulting in a significant increase in strength while retaining good ductility. The composite's yield strength and tensile strength increased to 370 MPa and 472 MPa, respectively, which were about 66 % and 67 % higher than those of the CNT-Al composite with the same CNT content.

Ultrasonic Preparation of Nano-CaCO3 Templates and Hollow Mesoporous SiO2 Nanoparticles for Voriconazole Loading

CaCO3 nanoparticles (nano-CaCO3) as nano-templates were prepared using CaCl2 and Na2CO3 solutions under controlled sonication (19.5 kHz). Using the same ultrasonic device, subsequently, hollow mesoporous silica nanoparticles (HMSNs) were obtained by the hard template of nano-CaCO3. HMSNs were selected as carriers for the antifungal drug voriconazole (VOR) loading to overcome poor water solubility. Three-dimensional CaCO3 nanosheets HMSNs were obtained under gentle sonication. Three-dimensional CaCO3 nanosheets of 24.5 nm (hydrodynamic diameter) were obtained under 17.6 W for 3 min. HMSNs were synthesized by double-template method with nano-CaCO3 as the hard template. Transmission electron microscopy measurements showed that the prepared HMSNs possess hollow structures with particle size between 110 and 120 nm. Nitrogen physisorption at -196 °C revealed that the HMSNs had high surface area (401.57 m2/g), high pore volume (0.11 cm3/g), and uniform pore size (2.22 nm) that facilitated the effective encapsulation of VOR in the HMSNs. The loading capacity of VOR (wt%) on the HMSNs was 7.96%, and the total VOR release amount of VOR-HMSNs material was 71.40% at 480 min. The kinetic model confirmed that the release mechanism of HMSNs nanoparticles followed Fickian diffusion at pH = 7.4 and 37 °C. Moreover, the cumulative VOR release at 42 °C (86.05%) was higher than that at 37 °C (71.40%). The cumulative release amount of VOR from the VOR-HMSNs material was 92.37% at pH = 5.8 at the same temperature. Both nano-CaCO3 templates and HMSNs were prepared by sonication at 19.5 kHz. The as-prepared HMSNs can effectively encapsulate VOR and released drug by Fickian diffusion.Graphical Nano-CaCO3 Templates and Hollow Mesoporous SiO2 Nanoparticles

Thermal performance evaluation of the parabolic trough solar collector using nanofluids: A case study in the desert of Algeria

The use of Parabolic Trough Solar Collector (PTSC) is currently the best option for widespread application in industries operating at temperatures from 60 to 400 °C. Numerous studies have been conducted to enhance the thermal performance of the PTSC using synthetic oils as heat transfer fluids. In this study, the thermal performance of parabolic collectors was enhanced using Metallic Oxide Nanofluids (CuO, SiO2, Al2O3, TiO2) based on Therminol VP-1™ at 4 % volumetric concentration as heat-transmitting fluids. A thermal model was developed and validated through experimental and theoretical study, while the results showed good compatibility in the outlet temperature with an error rate of 0.184 % for experimental and 0.29 % for theoretical studies. Moreover, various theoretical models of the thermal properties of nanofluids were analyzed to determine the model that matches and simulates this study. The findings indicated that nanofluids enhanced the thermal efficiency of the PTSC system compared to pure Therminol VP-1™. Specifically, CuO/Therminol VP-1™ demonstrated the most significant improvement, increasing thermal efficiency by 1.03 %. Furthermore, the results also showed that the addition of CuO, TiO2, Al2O3, and SiO2 nanoparticles led to an increase in outlet temperature by 9.57 %, 6.04 %, 5.21 %, and 3.08 %, respectively.

Improvement of the mechanical properties of the cement mortar by the incorporation of silica particles with low and high surface area

In recent years, nanoaprticules with different sizes have been incorporated in the cement mortar in order to improve their mechanical characteristics. The present work focuses onto the influence of the silica nanoparticles (SiO2) with low and high surface area over the stability and mechanical properties of the cement mortar. The quantities of nanosilica added into the cement mortar to ameliorate their mechanical characteristics vary from 0.5 % to 1.5 %wt. The obtained material after the incorporation of the SiO2 nanoparticles have been characterized by several techniques such as TG, DTG, DSC and their morphologies were determined by using SEM analysis. The workability, water absorption, compressive and flexural strengths of these materials have also been evaluated. The results obtained show that the introduction of the SiO2 nanoparticles into the cement mortar has been greatly improved their compressive and flexural strengths, and the specimens incorporated by nanosilica with high surface area are found more effective than those containing the silica nanoparticles with low surface area, suggesting that the specific surface play a crucial role in the improvement of their mechanical properties. The results show also that the appropriate dosage of silica nanoparticles in the cement mortar to have a maximum enhancement of their mechanical properties was found around 1.5 wt% by weight of cement for the nanosilica with high surface area.