Dispersion Of Oxide Nanoparticles Research Articles

Study of the antibacterial activity of hybrid nanocomposites “metal oxide/alginate” synthesized for therapeutic purposes

IntroductionBacterial infections pose a significant health challenge, leading to chronic ailments and high mortality rates. Antibiotic resistance due to improper usage necessitates novel antimicrobial solutions. Metal oxide nanoparticles, particularly in nanocomposites with sodium alginate, offer promising antibacterial properties. This study aims to synthesize and evaluate metal oxide/alginate nanocomposites for enhanced antibacterial activity.Material and methodMetal oxide nanoparticles (ZnO, Ag2O, CuO, NiO, CoO, FeO, Fe2O3, Cr2O3) were synthesized using a precipitation method. Nanocomposites (MO-Alg) were formed by incorporating these nanoparticles into a sodium alginate matrix. The physicochemical properties, stability, and antibacterial activity of the nanocomposites were assessed through ATR-IR analysis, SEM imaging, granulometry analysis, and XRD patterns. Antibacterial tests were conducted against Gram-negative (Pseudomonas aeruginosa, Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis).Result and discussionCharacterization revealed well-defined metal oxide structures (ATR-IR) within the alginate matrix. SEM images showcased uniform dispersion and distinctive rod-like configurations of metal oxide nanoparticles. XRD patterns confirmed crystalline phases. Antibacterial tests demonstrated varying efficacy, the lowest inhibition concentration for (G +) samples was 65 µg/ml for ZnO-Alg and Ag2O-Alg NCs. For (G-) samples, inhibition of P. aeruginosa was observed at 65 µg/ml with Ag2O-Alg, FeO-Alg, and Fe2O3-Alg, and for E. coli, inhibition was observed with all NCs except ZnO-Alg, with 65 µg/ml for Ag2O-Alg, NiO-Alg, FeO-Alg, and Fe2O3-Alg.ConclusionThe study successfully synthesized and characterized metal oxide/alginate nanocomposites with promising antibacterial properties. The nanocomposites exhibited stability and bactericidal effects, highlighting their potential for diverse biomedical applications, including wound dressings, medical implants, and packaging materials. The findings contribute to advancing nanomaterials in biomedical fields, encouraging further exploration and development.

Enhancing mechanical strength and microstructural properties of alkali-activated systems through nano graphene oxide dispersion and polycarboxylate ether admixture

The dispersion of graphene oxide (GO) nanoparticles in alkali-activated concrete with / without superplasticizers can help in understanding the effect it has on its mechanical strength and microstructural properties. The dispersion of GO in alkali activator fluid of 10(M) and 12(M) with / without polycarboxylate ether (PCE) admixture has been explored in this study. The alkali activator solution of 10(M) NaOH solution with PCE shows better dispersion than 12(M) NaOH solution, as higher alkalinity leads to agglomeration of GO. The study investigated the effect of incorporating PCE in GO-based alkali-activated slag (AAS) mortar with 8(M), 10(M) and 12(M) of alkaline activator solution. The mechanical strength and microstructural characteristics of conventional AAS (without both GO and PCE), GO-based AAS (without PCE) and GO-based AAS with PCE of the respective molar concentration of activator fluid are analysed. The mechanical strength of the AAS mortars has been evaluated using compressive, flexural, and splitting tensile strength testing. The micro-structural and mineralogical characteristics of the binders are evaluated using Field Emission Scanning Electron Microscopy (FESEM with EDS), X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The addition of only GO (0.06 % of binder w/w) and the addition of both GO and PCE in AAS have shown up to 30 % and 40 % mechanical strength improvement with respect to conventional AAS, respectively. The effectiveness of PCE and percentages of strength improvement are higher with a lower molarity of activator fluid, and vice versa. Adding GO and PCE to the AAS system improves its hydration rate and denser microstructure, enhancing its strength.

A strategy of consistent X-ray and neutron double-difference pair distribution function analysis of nanoparticle dispersions

AbstractIt has been demonstrated that the X-ray pair distribution function (PDF) formalism allows for the identification of very small signal contributions in multi-component systems by the difference and double-difference PDF (dd-PDF) approach. Due to their stronger interaction with light elements compared to X-rays, neutrons are often beneficial or complementary for the characterization of modern materials. Here, it is demonstrated that the dd-PDF strategy previously developed for X-ray PDF data can successfully be applied to neutron PDF data despite much lower count rates compared to X-rays. The dd-PDF strategy was employed for the investigation of aqueous iron oxide nanoparticle (IONP) dispersions. At the Near and InterMediate Range Order Diffractometer (NIMROD) at ISIS, the IONPs could even be investigated in pure water, whereas at the Nanoscale Ordered Materials Diffractometer (NOMAD) at SNS, heavy water had to be used, but additional information could be retrieved from modelling the data of IONP powder in the dry state and with adsorbed (heavy) water. The simple and robust approach can easily be adapted for the use in other multicomponent systems, like heterogenous catalysts or battery systems. Graphical Abstract

Performance Improvement of Energy Efficiency in Heat Pipe Solar Collector with Nano Composite

The objective of this research is to investigate the performance increase of evacuated solar collector with nano fluid. Solar collector includes absorber unit to transfer the heat energy to a working fluid. In this research it was intended to evaluate performance considering with nano fluid. Improving the heat collection efficiency, efficient extraction of the heat from the solar collector, controlling the operating temperature, long maintenance free life of the device are some of the major challenges in collecting and extracting heat from the evacuated solar collectors. Using nano fluids as working fluids are interesting and challenging. Improvement in the performance of the evacuated heat pipe was obtained using heat transporting nano fluid consisting of aqueous dispersion (3 weight %) of Copper Oxide (CuO) nanoparticles; in comparison with the device without utilizing the nano fluid. From the past research, authors have analysed the performance with numerous trials. The result shows that evacuated tube heat pipe collector with nano fluid give the better result than heat pipe collector without nano fluid.

Poly(ε-Caprolactone)-Based Composites Modified With Polymer-Grafted Magnetic Nanoparticles and L-Ascorbic Acid for Bone Tissue Engineering.

The aim of this study was to develop multifunctional magnetic poly(ε-caprolactone) (PCL) mats with antibacterial properties for bone tissue engineering and osteosarcoma prevention. To provide good dispersion of magnetic iron oxide nanoparticles (IONs), they were first grafted with PCL using a novel three-step approach. Then, a series of PCL-based mats containing a fixed amount of ION@PCL particles and an increasing content of ascorbic acid (AA) was prepared by electrospinning. AA is known for increasing osteoblast activity and suppressing osteosarcoma cells. Composites were characterized in terms of morphology, mechanical properties, hydrolytic stability, antibacterial performance, and biocompatibility. AA affected both the fiber diameter and the mechanical properties of the nanocomposites. All produced mats were nontoxic to rat bone marrow-derived mesenchymal cells; however, a composite with 5 wt.% of AA suppressed the initial proliferation of SAOS-2 osteoblast-like cells. Moreover, AA improved antibacterial properties against Staphylococcus aureus and Escherichia coli compared to PCL. Overall, these magnetic composites, reported for the very first time, can be used as scaffolds for both tissue regeneration and osteosarcoma prevention.

Synthesis, dispersion, functionalization, biological and antioxidant activity of metal oxide nanoparticles: Review

Metal oxide nanoparticles (MONPs) have garnered significant interest due to their remarkable properties with applications in diverse fields like human health, agriculture, and general community health. This has led to their widespread use across various scientific and industrial sectors. We focused on four specific types of MONPs: iron oxide, gadolinium oxide, titanium dioxide, and zinc oxide nanoparticles due to their advantages over other metal oxides and noble metals, including cost-effectiveness, biocompatibility, and versatility. This review aimed to highlight examples of MONPs with various implementations and provide a comprehensive revision on the synthesis, dispersion, functionalization, biological and antioxidant activity of the selected MONPs. In this context, we demonstrated the applications of MONPs in various relevant domains and the impact of surface functionalization on the mechanical, optical, and electrical properties of MONPs, particularly in biological and antioxidant activities. Moreover, the volumetric, viscometric, and optical characteristics of MONPs dispersions and their stability challenges were significantly illustrated. The opportunities for MONPs in the global market based on market statistical studies were introduced in order to explore the current and future prospects for MONPs in the commercial market. This review paper offers a thorough and novel perspective on the synthesis, properties, functionalization, and applications of selected MONPs, along with their market potential, making it a valuable resource for researchers and industry professionals. Our revision has sparked interest in the scientific pursuit of uncomplicated and intuitive ideas that make use of regenerative options.

New dispersion mechanism for oxide dispersion-strengthened steels by liquid metallurgy

The use of oxide dispersion-strengthened (ODS) alloys in demanding applications can effectively reduce parts’ weights, extend life of use, and enhance overall energy efficiency. But, the current manufacturing of ODS alloys has remained impractical for decades due to poor scalability and extremely high costs. Mass production of ODS steels by liquid metallurgy is therefore crucial to decrease their costs by several orders of magnitude and expand their potential applications. However, oxide nanoparticle (NP) dispersion in molten alloys presents fundamental challenges for liquid metallurgy due to the vastly dissimilar atomic properties between ionocovalent oxides and metals. Here we show, for the first time, that Y2O3 NPs are able to be dispersed in liquid 316L with a 1 % Nb addition. It was discovered that Nb-enriched interfacial layers exist around the Y2O3 NPs in solidified steels after slow cooling. Theoretical analyses reveal that the Nb-enriched interfacial layer induces a higher energy barrier and a significantly lower van der Waals attraction between oxide NPs and liquid Fe for the successful dispersion of oxide NPs in liquid steels. Moreover, Y2O3 and Al2O3 NPs were successfully dispersed in lean steels, such as Fe-Nb and low-C steels. This new dispersion mechanism of oxide NPs opens an exciting pathway for the economical mass manufacturing of various ODS alloys by liquid metallurgy for numerous applications.

Secondary phases characterization by SANS and XAS of an ODS ferritic steel after thermal aging at 873 K

An ODS steel with nominal composition Fe–14Cr–2W–0.4Ti-0.3Y2O3 (wt.%) was produced by mechanical alloying and compacted by hot isostatic pressing (HIP) followed by hot cross rolling (HCR). To check the effects of thermal aging at relevant temperatures of operation in fusion power plants, the alloy was thermally aged at 873 K for 2000 h. In this work, small-angle neutron scattering (SANS) and X-ray absorption spectroscopy (XAS) techniques are used for the advanced characterization of secondary phases and the oxide nanoparticle dispersion. SANS results show that the oxide nanoparticles remain stable after the thermal aging treatment. Composition of the oxide nanoparticles was identified as Y2TiO5 or Y2Ti2O7 by SANS, while non-stoichiometry was found by XAS analysis. Laves phase precipitation after the thermal aging treatment is further confirmed by SANS, from the magnetic anisotropic contribution to the scattering intensity associated to this metallic phase, and by XANES.

High-performance composite transparent electrode composed of ultra-long silver nanowires and antimony-doped tin oxide nanoparticles

Composite transparent conductive electrodes (TCEs) consisting of silver nanowires (AgNWs) and conductive metal oxides are very promising for flexible optoelectronic devices due to their smooth surface morphology and high chemical stability. However, it is still challenging to ensure high optoelectronic performance and long-term stability in practical applications. Here, we solved these problems by coating antimony-doped tin oxide (ATO) nanoparticles dispersion on ultra-long AgNWs network using waterborne polyurethane (WPU) binder. Ultra-long nanowires occupy less wire-wire junctions and space than short nanowires, thus increasing the optoelectronic performance and flexibility of the composite TCE. WPU improves the adhesion and stability of ATO nanoparticles to the substrate and AgNWs network. The fabricated composite TCE showed a low sheet resistance of 11.9 Ω sq−1, good optical transmittance of 83% at 550 nm and a figure of merit (FOM) of 162 compared to PET/ITO electrode. It also showed excellent mechanical flexibility, adhesion to the substrate and solvent stability. Furthermore, the long-term conductivity was maintained under ambient conditions for 60 days.

SBA-15 with short-sized channels modified with Fe2O3 nanoparticles. A novel approximation of an efficient adsorbent for As removal in contaminated water

The urgent need for technologies to ensure health standards, as per the Sustainable Development Goals established by the United Nations, has prompted research into addressing human health problems associated with chemical contaminants in air, water, and soil. Heavy metals, particularly arsenic, pose significant health risks, with millions of people worldwide exposed to concentrations exceeding recommended limits. Nanostructured materials, including ordered mesoporous substrates such as SBA-15, have shown promise for arsenic removal due to their high surface area and pore characteristics. This study aimed to synthesize a silica mesoporous material with reduced pore channel length to enhance surface area and active sites, thereby improving arsenic removal efficiency. By exploring various surfactant-to-silica precursor ratios, a suitable value was identified to promote the production of shortened SBA-15 particles. These shortened pore channels facilitated the dispersion of iron oxide nanoparticles (Fe2O3) on the SBA-15 surface, resulting in an effective adsorbent that achieved over 95% arsenic removal. The combination of the modified SBA-15 substrate and Fe2O3 nanoparticles demonstrated high efficiency in arsenic removal from aqueous effluents, offering a promising solution to address water pollution and associated health risks.

Spiral-template from waste tea-leaf to design hierarchical dispersed zinc oxide nanocatalyst for boosting their photocatalytic carbon dioxide reduction

The utilization of cellulose-based templates to enhance the dispersion of zinc oxide (ZnO) nanoparticles represents an effective approach for enhancing their photocatalytic carbon dioxide (CO2) reduction activity. However, the limited availability of surface active sites on linear cellulose fiber has posed a significant challenge for loading ZnO nanoparticles. The present study introduces a technique for segregating spiral vessel (SV) from waste tea-leaves and employing them as templates for in-situ self-assembled ZnO nanoparticles. Due to the inherent three-dimensional (3D) stability of the spiral structure, ZnO nanoparticles exhibit excellent dispersion and maintain a stable hierarchical spiral morphology even after template removal. With the help of a field emission scanning electron microscope (FE-SEM), it could be observed that SV-loaded ZnO nanospheres extracted from waste Pu 'er tea-leaves retained the best spiral morphology after removing the template. The photocatalytic CO2 conversion over spheroidal ZnO with SV as templates (ZnOSS) significantly enhanced yields of CO and CH4, reaching 6.700 and 1.666 μmol·g−1h−1, respectively, surpassing those of other synthesized catalysts. The results obtained from the free radical scavenging experiment and electron paramagnetic resonance (EPR) test demonstrate the pivotal involvement of superoxide radicals (∙O2−) and hydroxyl radicals (∙OH) in the photocatalytic reduction of CO2. Quantum mechanical simulation further verified that the ZnO (0 0 2) crystal face was the best reaction interface with CO2. The design of a cellulose-based spiral template not only facilitates the valorization of waste biomass but also offers a novel perspective for the synthesis of efficient photocatalysts.

Microstructure and mechanical properties of oxide dispersion strengthened FeNiMnCr high-entropy alloy fabricated by spark plasma sintering

High-entropy alloys (HEAs) strengthened by dispersed oxide nanoparticles are considered potential structural materials used in advanced nuclear reactors. Herein, a novel Y-Si-O nanoparticle-strengthened near-equiatomic FeNiMnCr HEA was prepared via the powder metallurgy method. Microstructural characterizations revealed that the oxide dispersion-strengthened (ODS) FeNiMnCr HEA consisted of the face-centered cubic (FCC) matrix and high-density Y-Si-O nanoparticles (Y2SiO5 and Y2Si2O7). The average diameter and volume fraction of the nanoparticles were counted to be 21.3 nm and 1.02%, respectively. The grain size was reduced from 10.13 μm of the FeNiMnCr HEA to 0.79 μm of the ODS FeNiMnCr HEA. The ODS FeNiMnCr HEA showed a yield strength of 1125 MPa, an ultimate tensile strength of 1137 MPa, and a moderate elongation of 8.3% at room temperature. At 500°C, the ODS FeNiMnCr HEA also had a high yield strength of 662 MPa. Theoretical calculation showed that the high strength of the ODS FeNiMnCr HEA was mainly due to the grain boundary strengthening, dislocation strengthening, and precipitation strengthening.

Mitigating hydrogen evolution reaction and corrosion of zinc in electrically rechargeable zinc-air batteries using nanofluid electrolytes

Among various metal-air batteries, zinc-air batteries (ZABs) have received tremendous attention owing to their abundant resources, cost-free fuel from the atmosphere and ease of fabrication. The performance of ZABs depends on the bifunctional electrocatalyst deployed at the air-cathode and the hydrogen evolution reaction (HER) occurring at the anode. While the rate of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) improve the performance of ZAB, HER causes zinc corrosion and thereby affects the performance of ZAB. The corrosion of zinc is attributed to the fact that HER is thermodynamically favoured since the standard reduction potential of zinc is more negative than hydrogen. Herein, the onset and overpotential of HER are increased by the uniform dispersion of metal oxide nanoparticles in the native electrolyte (6 M KOH), thereby reducing zinc corrosion. Dispersion of 0.1 wt% of SiOx or ZnO nanoparticles increases the HER overpotential to 547 and 679 mV, respectively. The microscopic investigations confirm the inhibition of corrosion and dendritic growth of zinc. Besides these, nanofluid electrolytes enhance the kinetics of ORR and OER, thereby improving the performance of electrically rechargeable ZABs. Also, nanofluid electrolytes are stable over three months.

Understanding and predicting the environmental dispersion of iron oxide nanoparticles: a comprehensive study on synthesis, characterisation, and modelling

This study assesses the dispersions of iron oxide nanoparticles (IONPs), unveiling their environmental impacts via CCRD predictive models.

Effect of Y2O3 nanoparticles on enhancing microstructure and mechanical properties of oxide dispersion strengthened W alloy

Dispersion of oxide nanoparticles in W, leading to the dispersion strengthening of W alloys, has emerged as a viable strategy to overcome the brittleness of W. In particular, the introduction of stable Y2O3 as a secondary phase refines the grain and enhances the densification of W, leading to an increase in the density of sintered alloy. Thus, analyzing the composite effects of Y2O3 on the alloy, which has homogeneous dispersion of Y2O3 nanoparticles, can allow enhanced mechanical properties of the W-Y2O3 alloy. However, to date, most studies have focused on synthesis methodology for nanocomposites, which is advantageous to grain refinement and dispersion. It is worth paying attention to the interaction in the W-Y2O3 system, such as the ternary oxide system (W-Y-O) with a low eutectic temperature and the possibility of liquid-phase sintering, which has been reported a few. In this study, the effect of Y2O3 nanoparticles on the microstructure and micro-Vickers hardness of W was experimentally evaluated. W-Y2O3 alloys with precisely controlled compositions from 1 wt% to 10 wt%Y2O3 were successfully fabricated using an ultrasonic spray pyrolysis process and a subsequent spark plasma sintering. The proposed process yielded Y2O3 nanoparticles with uniform dimensions and distributions even after sintering. Furthermore, the formation of Y2WO6 and a liquid-phase sintered structure, as products of the interaction between W and Y2O3 depending on the Y2O3 fraction, were observed, and thermodynamical formation routes were suggested. Evidently, the W-2wt%Y2O3 sintered alloy, with uniformly dispersed Y2O3 nanoparticles (<50 nm), exhibited an improved hardness of 7.21 ± 0.15 GPa, as the W grains were refined to approximately 760 nm, and their density increased to 96.48%.

Investigation of CeO2 nanoparticles on the performance enhancement of insulating oils

Integrating nanotechnology in dielectric fluid significantly inhibits losses and boosts overall dielectric fluid performance. There has been research done on the effects of introducing various nanoparticles, such as titania, alumina, silica nanodiamonds, etc. In this paper, a novel nanoparticle, Ceria (CeO2), has been used, and its properties were examined using the FTIR (Fourier Transform Infrared) spectrum, the XRD (X-ray Diffraction) spectrum, the SEM (Scanning Electron Microscopy), and the TEM (Transmission Electron Microscopy). This paper illustrates an efficient dielectric fluid prepared by the successful dispersion of Cerium Oxide (CeO2) nanoparticles in various concentrations into four commercial oils, namely mineral oil, rapeseed oil, synthetic ester oil, and soybean oil, to enhance and improve their dielectric characteristics. The performance investigation emphasises breakdown strength enhancement and other dielectric properties of the colloidal solution comprising different nanoparticle (NP) concentrations. Various commercial oils are used as a base in nano-oil to diversify their applicability as dielectric fluids by measuring the correlation in dielectric parameters and statistically assessing their applicability with normal and Weibull distributions. The obtained experimental data sets were analyzed using the Statistics and Machine Learning Toolbox in MATLAB. The aging measurement has been done only on mineral oil, and results were matched using a predictive model of statistics and the Machine Learning Toolbox in MATLAB. Well-dispersed CeO2 NPs in the insulating oils lead to a significant increase in AC breakdown strength. The effect of ageing on the dielectric properties of nano oils yields better results than conventionally aged oil. It has been observed that the breakdown voltage is enhanced by up to 30% for mineral oil at an optimal concentration of 0.01 g/L, 9% for synthetic ester oil at 0.03 g/L, 18% for rapeseed oil at 0.02 g/L, and 19% for soybean oil at 0.03 g/L nanoparticle concentration. Following the dispersion of CeO2 nanoparticles, the dielectric constant of all insulating oils has also significantly improved.The overall experimental results are promising and show the potential of the CeO2 NPs-based nano oil as an efficient and highly performing dielectric oil for different power applications.

Analysis of interparticle spacing and nanoparticle radius on the radiative alumina based nanofluid flow subject to irregular heat source/sink over a spinning disk

The analysis of the nanofluid flow across a spinning disc has great significance due to its wide range of applications, i.e. cancer treatments, nanoscience, chemotherapy, drug delivery, biosensors, food sciences, electronics and biomedicines. Based on the above applications, the nanofluid flow over a spinning disc is modeled. The magneto-hydrodynamic (MHD) nanofluid flow has been studied under the consequences of viscous dissipation, non-uniform heat source, and thermal radiation. The nanofluid is prepared by the dispersion of aluminum oxide (Al2O3) nanoparticles (nps) in the water. The effects of Al2O3 nps radius and inter-particle spacing (IPs) on the 2D flow of nanoliquid are also studied. The modeled equations are reset into non-dimensional form of ODEs using the similarity conversions. The numerical approach parametric continuation method “PCM” is used to tackle the reduced form of ODEs. The energy and velocities distributions are analyzed versus the discrete flow constraints and figured out for the large and IPs (h = 10 and h = 1/) and for large and small radii (Rp=5/2 and Rp=3/2) of Al2O3 nps. It has been noticed that the fluid velocity is amplified due to the rising effect of the suction factor for both large and small radii of Al2O3 nps. Moreover, it is observed that the energy conduction rate is higher when the nanoparticle volume fraction and Eckert number is rises for both cases (linear and nonlinear) of radiation.

Ethanol-water motifs-A re-interpretation of the double-difference pair distribution functions of aqueous iron oxide nanoparticle dispersions.

In dispersion, nanoparticles can interact with the surrounding dispersion medium, such that an interfacial region with a structure differing from that of the bulk exists. Distinct nanoparticulate surfaces induce specific degrees of interfacial phenomena, and the availability of surface atoms is a crucial prerequisite for interfacial restructuring. Here, we investigate the nanoparticle-water interface of 0.5-10 wt. % aqueous iron oxide nanoparticle dispersions of 6nm diameter in the presence of 6 vol. % ethanol with x-ray absorption spectroscopy (XAS) and atomic pair distribution function (PDF) analysis. The absence of surface hydroxyl-groups in XAS spectra is in accordance with the double-difference PDF (dd-PDF) analysis, due to a fully covered surface from the capping agent. The previously observed dd-PDF signal is not stemming from a hydration shell, as postulated in Thomä et al. [Nat Commun. 10, 995 (2019)], but from the residual traces of ethanol from nanoparticle purification. With this article, we provide an insight into the arrangement of EtOH solutes in water at low concentration.

Dispersion and Demineralization Inhibition Capacity of Novel Magnesium Oxide Nanoparticles Varnish on Enamel Surfaces against Streptococcus mutans (an In Vitro Study)

This research analyzed the dispersion and impact of magnesium oxide nanoparticles (MgONPs) varnish on inhibiting enamel demineralization. A novel MgONPs varnish was prepared in absolute ethanol with rosin in 10%, 5%, 2.5%, and 1.25% concentrations. The samples were classified into six groups, including four tested with MgONPs varnish, one commercial 5% NaF varnish, and control groups of non-protected and sound dental enamel groups. Each group included five enamel samples and three broths of 20 mL per sample. The examinations were started by applying different concentrations of varnishes on the enamel surfaces, which were then exposed to Streptococcus mutans (S. mutans) in three sequences of time for 144 h. A scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to examine the MgONPs’ dispersion. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to quantify the calcium (Ca) released from the enamel. The SEM and EDX evaluations of the enamel samples showed a significantly increased dispersion for the 5% MgONPs varnish, with the highest median. The ICP-OES test showed significant inhibition levels of the Ca release capacity in the 2.5% and 1.25% MgONPs varnishes, similar to the 5% NaF varnish. The MgONPs varnish revealed increasing dispersion of MgONPs, from 1.25% to 5%, and the maximum protection capacity was associated with the 1.25% and 2.5% varnishes, which was similar to the 5% NaF varnish in inhibiting the demineralization effect on enamel.

A novel formulation of active hexagonal‐compact nano packed composite system using emerging technology for food packaging applications

AbstractWe report the nanoformulation of the active hexagonal‐compact nano‐packed composite system with iron oxide nanoparticles and glossy glutinous chitosan‐tapioca starch biopolymer solution (CTS‐S) for improved potential benefit in food packaging applications. The high pressure processing (HPP) treatment at various pressure level ranging from 100 to 500 MPa at constant time 120 s and optimized the formation of hexagonal nano‐packed system at 500 MPa. The UV–vis spectrophotometer (UV), Fourier transform infrared spectroscopy (FTIR), x‐ray diffraction (XRD) and Zeta potential analysis suggested uniform dispersion of iron oxide nanoparticles and formulated an effective stable nano‐packed composite structure. The XRD analysis of HPP treated sample confirmed the enhancement in material properties with high degree of crystallinity nature. Further studies on antimicrobial effects for HPP treated nano‐packed composite solution exhibited an excellent antimicrobial property and examined over a period of 1 month against microbial deterioration. The study revealed that the novel nano‐packed composite solution could be used as an antimicrobial food packaging material.Practical applicationThe research focused to the development of novel formulation of active hexagonal nano‐packed composite system using non‐thermal high pressure pascalization (HPP) technology. For the first time the design of compact nano structural pattern from the composite solution was developed which expresses an anti‐microbial characteristic even after exposed to environmental condition for a month. The experimental results revealed the practical application of formulated nano‐packed composite system with improvement bio‐physical properties and material characteristics has created an interest toward the food‐borne microbial barrier coating material which can be used in food packaging applications as well as promoting longer shelf life of food products with fabrication of nano‐packaging material as a commercial beneficial aspect in food packaging industries.