Concentration Of SiO2 Nanoparticles Research Articles

Integrated physiological, transcriptomic, and metabolomic analyses of drought stress alleviation in Ehretia macrophylla Wall. seedlings by SiO2 NPs (silica nanoparticles).

With environmental problems such as climate global warming, drought has become one of the major stress factors, because it severely affects the plant growth and development. Silicon dioxide nanoparticles (SiO2 NPs) are crucial for mitigating abiotic stresses suffered by plants in unfavorable environmental conditions and further promoting plant growth, such as drought. This study aimed to investigate the effect of different concentrations of SiO2 NPs on the growth of the Ehretia macrophylla Wall. seedlings under severe drought stress (water content in soil, 30-35%). The treatment was started by starting spraying different concentrations of SiO2 NPs on seedlings of Ehretia macrophyla, which were consistently under normal and severe drought conditions (soil moisture content 30-35%), respectively, at the seedling stage, followed by physiological and biochemical measurements, transcriptomics and metabolomics analyses. SiO2 NPs (100 mg·L-1) treatment reduced malondialdehyde and hydrogen peroxide content and enhanced the activity of antioxidant enzymes under drought stress. Transcriptomic analysis showed that 1451 differentially expressed genes (DEGs) in the leaves of E. macrophylla seedlings were regulated by SiO2 NPs under drought stress, and these genes mainly participate in auxin signal transduction and mitogen-activated protein kinase signaling pathways. This study also found that the metabolism of fatty acids and α-linolenic acids may play a key role in the enhancement of drought tolerance in SiO2 NP-treated E. macrophylla seedlings. Metabolomics studies indicated that the accumulation level of secondary metabolites related to drought tolerance was higher after SiO2 NPs treatment. This study revealed insights into the physiological mechanisms induced by SiO2 NPs for enhancing the drought tolerance of plants.

Foliar application of SiO2 nanoparticles to increase shallot production under water stress as an effort to mitigate climate change

Global climate change has resulted in environmental stress which has the potential to reduce the production of various agricultural commodities. One of the reasons for the low production of shallot is because cultivated in land with limited water. An effort to minimize the impact of water stress on shallots is to use SiO2 nanoparticles. This study aims to determine the role of SiO2 nanoparticles to increase production of shallot under water stress. This research was conducted at the greenhouse of the Faculty of Agriculture from December 2022 to March 2023, using randomized block design. The first factor is water stress (80%, 60% and 40% field capacity) and the second factor is the concentration SiO2 nanoparticles (0 g/l, 6 g/l, 12 g/l and 18 g/l). The results showed the water stress treatment had significant effect reduced number of tubers and fresh and dry weight of tubers, the application of SiO2 nanoparticles had significant effect increased the number of tubers and fresh and dry weight of tubers. Interaction of application SiO2 nanoparticles and water stress conditions had a significant effect on increased the number of tubers in the combination of 80% field capacity with SiO2 nanoparticles concentration 12 g/l.

"Advanced Materials in Refrigeration Systems: An In-depth Analysis of Novel Additives and Their Influence on Heat Transfer Efficiency and Energy Consumption"

Abstract: This study explores the cutting-edge domain of nano refrigerants, aiming to boost the cooling performance of the widely used refrigerant R-134a by integrating a precisely balanced blend of CuO and SiO2 nanoparticles. The primary motivation for this research is the imperative to transform refrigeration systems, making them more energy-efficient and environmentally sustainable. The research methodology involves systematically creating a nano refrigerant by dispersing varying concentrations of CuO and SiO2 nanoparticles in R-134a. Selected for their exceptional thermal conductivity and stability, these nanoparticles have the potential to significantly enhance the heat transfer properties of the refrigerant. Initial stages encompass rigorous assessments of thermal conductivity improvements compared to the base R-134a, laying the groundwork for practical evaluations in a heat exchanger setup. In heat exchanger experiments, crucial parameters such as heat transfer coefficient, pressure drop, and overall heat transfer rate are precisely measured, providing a comprehensive understanding of the nano refrigerant’s real-world performance. The objective is not only to enhance thermal conductivity but also to optimize the nano refrigerant for effective and efficient heat exchange, thereby elevating the cooling capacity of R-134a. Stability studies are integral, ensuring the long-term viability of the nano refrigerant. Scrutinizing compatibility with commonly used refrigeration system materials and monitoring potential degradation over extended periods are essential.

Elektrokimyasal Olarak Çöktürülmüş Metal Oksit Takviyelendirilmiş Ni Nanokompozit Kaplamaların Korozyon Performansı

The properties of traditional nickel coatings were enhanced by preparing Ni nanocomposite coatings reinforced with metal oxide nanoparticles by using electrodeposition technique. The impact of applied current density was investigated by changing SiO2 nanoparticle concentration. Phase structure study and morphological investigation of the samples were performed by X-Ray Diffractometer and Scanning Electron Microscopy, respectively. Vickers indentation method was utilized to determine the mechanical properties of obtained nanocomposite coatings. Potentiodynamic polarization technique was performed to evaluate electrochemical behavior of nanocomposite coatings. As a result, introducing SiO 2 nanoparticles to Ni matrix improves both mechanical and electrochemical properties of produced nanocomposite coatings.

Holographic Properties of Irgacure 784/PMMA Photopolymer Doped with SiO2 Nanoparticles.

To enhance the holographic properties, one of the main methods is increasing the solubility of the photosensitizer and modifying the components to improve the modulation of the refractive index in the photopolymer. This study provides evidence, through the introduction of a mutual diffusion model, that the incorporation of SiO2 nanoparticles in photopolymers can effectively enhance the degree of refractive index modulation, consequently achieving the objective of improving the holographic performance of the materials. Different concentrations of SiO2 nanoparticles have been introduced into highly soluble photosensitizer Irgacure 784 (solubility up to 10wt%)-doped poly-methyl methacrylate (Irgacure 784/PMMA) photopolymers. Holographic measurement experiments have been performed on the prepared samples, and the experiments have demonstrated that the Irgacure 784/PMMA photopolymer doped with 1.0 × 10-3wt% SiO2 nanoparticles exhibits the highest diffraction efficiency (74.5%), representing an approximate 30% increase in diffraction efficiency as compared to an undoped photopolymer. Finally, we have successfully achieved the recording of real objects on SiO2/Irgacure 784/PMMA photopolymers, demonstrated by the SiO2/Irgacure 784/PMMA photopolymer material prepared in this study, which exhibits promising characteristics for holographic storage applications. The strategy of doping nanoparticles (Nps) in Irgacure 784/PMMA photopolymers has also provided a new approach for achieving high-capacity holographic storage in the future.

Effect of Al2O3, SiO2, and ZnO Nanoparticle Concentrations Mixed with EG–Water on the Heat Transfer Characteristics through a Microchannel

Nanofluids have gained attention for their potential to solve overheating problems in various industries. They are a mixture of a base fluid and nanoparticles dispersed on the nanoscale. The nanoparticles can be metallic, ceramic, or carbon based, depending on the desired properties. While nanofluids offer advantages, challenges such as nanoparticle agglomeration, stability, and cost effectiveness remain. Nonetheless, ongoing research aims to fully harness the potential of nanofluids in addressing overheating issues and improving thermal management in different applications. The current study is concerned with the fluid flow and heat transfer characteristics of different nanofluids using different types of nanoparticles such as Al2O3, SiO2, and ZnO mixed with different base fluids. Pure water and ethylene glycol–water (EG–H2O) mixtures at different EG–H2O ratios (ψ = 0%, 10%, 30%, 40%) are used as the base fluid. Furthermore, a rectangular microchannel heat sink is used. Mesh independent study and validation are performed to investigate the current model, and a good agreement is achieved. The numerical analysis evaluates the influence on the heat transfer coefficient and flow characteristics of nanofluids for Reynolds numbers 500 to 1200 at a 288 K inlet flow temperature. The results show that ZnO nanofluid and 40% EG–H2O increase the heat transfer coefficient by 63% compared to ZnO–H2O nanofluid obtained at Re = 1200 and φ = 5%. Conversely, the pressure drop by ZnO is nearly double that obtained by Al2O3 and SiO2.

PDMS/TiO2 and PDMS/SiO2 Nanocomposites: Mechanical Properties' Evaluation for Improved Insulating Coatings.

The use of nanoparticles (NPs) as reinforcements in polymeric coatings allows for direct interaction with the polymeric chains of the matrix, resulting in a synergistic process through physical (electrostatic forces) and chemical interactions (bond formation) for the improvement of the mechanical properties with relatively low weight concentrations of the NPs. In this investigation, different nanocomposite polymers were synthesized from the crosslinking reaction of the hydroxy-terminated polydimethylsiloxane elastomer. Different concentrations (0, 2, 4, 8, and 10 wt%) of TiO2 and SiO2 nanoparticles synthesized by the sol-gel method were added as reinforcing structures. The crystalline and morphological properties of the nanoparticles were determined through X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). The molecular structure of coatings was through infrared spectroscopy (IR). The crosslinking, efficiency, hydrophobicity, and adhesion degree of the study groups were evaluated with gravimetric crosslinking tests, contact angle, and adhesion tests. It was observed that the crosslinking efficiency and surface adhesion properties of the different nanocomposites obtained were maintained. A slight increase in the contact angle was observed for the nanocomposites with 8 wt% compared to the polymer without reinforcements. The mechanical tests of indentation hardness and tensile strength following the ASTM E-384 and ISO 527 standards, respectively, were performed. As the nanoparticle concentration increased, a maximum increase of 157% in Vickers hardness, 71.4% in elastic modulus, and 80% in tensile strength was observed. However, the maximum elongation remained between 60 and 75%, ensuring that the composites did not become brittle.

Green preparation of 3D micronetwork eugenol-encapsuled porous starch for improving the performance of starch-based antibacterial film

In order to find a non-enzymatically treated alternative wall material with effective encapsulation properties, and to reduce the use of conventional non-biodegradable plastics, a novel 3D-micronetwork porous starch (3D-MPS) was created via a modified sacrificial template method to encapsulate eugenol (3D-EMPS) and used to incorporate with TiO2-starch film, for significantly improving the performance of starch-based antibacterial film. At the template SiO2 nanoparticles concentration of 0.1 %, the 3D-MPS exhibited anticipated alveolate structure with internal aperture of approximately 10 μm confirmed by SEM. With addition of 3D-EMPS, higher tensile strength (29.70 Mpa) and water barrier property (924 g/cm2·24 h) of the composite film was obtained. Moreover, molecular docking technique was used to model the intermolecular forces, which showed that the major forces maintaining the internal bonding of the composite film were hydrogen bonding and the interaction between eugenol and 3D-MPS skeleton in 3D-EMPS. Meanwhile, the composite film demonstrated the expected eugenol retardation and antimicrobial capacity against S. aureus, E. coli, and B. subtilis. Finally, the composite films were used for evaluating the feasibility in the actual food, which largely extended its shelf life compared to the negative control. This high-performance film revealed their potential for packaging materials application.

Analysis of the interfacial tension of cationic imidazolium-based ionic liquid, twin-branched tailed anionic surfactant, and a non-ionic emulsifier in the presence of SiO2 nanoparticle and amphiphilic oleic components using response surface method

Although various surface active agents have been proposed, there is still no straightforward and clear understanding of the effect of cationic imidazolium-based ionic liquid (IL), twin-branched tailed anionic surfactant, and a non-ionic emulsifier in the presence of SiO2 nanoparticle and amphiphilic oleic components on the interfacial tension (IFT) reduction. So, in this work, the performance of cationic imidazolium-based IL ([C12mim][Cl], anionic surfactant (AOT)), and non-ionic surfactant (Tween 80) on the IFT value were studied through the design of experiment approach and the response surface method. Experiments were designed using a face-centered composite design (FCCD) with the independent variables of surfactant concentration (175–525 ppm) and nanoparticle concentration (25–75 ppm) as numerical ones, and surfactant type and synthetic oil (8 wt% of asphaltene and resin fractions dissolved in heptol (mixture of n-heptane: toluene with the volume ratio of 30:70)) with various volume ratios of asphaltene to resin (1:0, 2:1, 1:1, and 1:2) as categorical ones. According to the analysis of variance (ANOVA) and 156 measured IFT experimental data points, the effects of each factor were evaluated. As a result, the suggested quadratic model with R2 (0.9986) and adjusted R2 (0.9984) values indicated that the fitted model can accurately predict the response variable (IFT) values. The best performance (lower IFT and critical micelle concentration) was obtained for [C12mim][Cl] without being affected by the amphiphilic nature of asphaltene and resin fractions and the concentration of SiO2 nanoparticles. The appropriate surface activity of IL was attributed to the effective polar head group of imidazolium and the presence of nitrogen in the aromatic ring.

Effect of SiO2 nanoparticles on the hardness and corrosion resistance of NiW/SiO2 nano composite coating prepared by electrodeposition

In this paper, NiW/SiO2 composite coatings were prepared on Q235B steel using the electrodeposition technique. The relationship between the concentration of SiO2 nanoparticles in the plating solution and the properties of NiW/SiO2 composite coating was investigated. The results show that the addition of an appropriate amount of SiO2 nanoparticles in the plating solution can enhance the cathode current, increase the surface hardness, improve the corrosion resistance, and reduce the roughness of the composite coating. The SiO2 nanoparticles covered on the coating surface can penetrate the lattice of NiW alloy to induce heterogeneous nucleation, and play a role in refining grain. However, when the SiO2 nanoparticles in the plating solution reaches 8 g/L, the agglomeration phenomenon occurs due to excessive nanoparticles, which will increase the roughness and decrease the compactness, resulting in the decrease of hardness and corrosion resistance. The NiW/SiO2 composite coating electrodeposited from the solution containing 6 g/L SiO2 nanoparticles exhibits the best hardness (643.23 HV) and the greatest corrosion resistance with the smallest corrosion current density (9.7 μA/cm2).

Effect of Concentration of SiO2 Nanoparticles in the Electrolyte on the Composition and Properties of Oxide Layers Formed by Plasma-Electrolytic Oxidation on Silumin AK7

Effect of Concentration of SiO2 Nanoparticles in the Electrolyte on the Composition and Properties of Oxide Layers Formed by Plasma-Electrolytic Oxidation on Silumin AK7

Design and spraying-preparation of the gradient coatings with various diameters and contents of SiO2 nano-particles for the enhanced anti-impact and thermal insulation performance

Composites used in aircraft are vulnerable to mechanical and thermal damage during particle impact at high speeds. In this paper, a series of gradient polyurethane silica coatings with different silica particle sizes and concentration gradients were prepared on epoxy resin matrix composites by pneumatic spraying process. The results of corundum impact and thermal insulation performance experiments indicated that multi-layer gradient coatings improved the particle impact resistance and thermal insulation. The damage was reduced to <1 % of surface damage area and thickness loss under the protection of enhanced gradient coatings, showing excellent particle impact resistance. Under unidirectional heating conditions, the temperature difference between the heating plate and the sample surface was four times that of the unprotected sample, from 2.2 °C to 9.4 °C, and the total thermal conductivity of the protected sample was reduced by 91.73 %. The coatings remained intact under high-speed particle collision of 300 A plasma flow, which verified the protection performance of the coatings simulating the situation that the coatings were impacted by particles and heated simultaneously. The as-prepared gradient coatings can effectively enhance the anti-impact and thermal insulation performance of composites, exhibiting wide application prospects.

SiO2 nanoparticles-containing slippery-liquid infused porous surface for corrosion and wear resistance of AZ31 Mg alloy

A slippery liquid-infused porous surface (SLIPS) was developed, based on MgAl-layered double hydroxide (LDH), in order to improve the corrosion and wear resistance of AZ31 Mg alloys. In particular, different concentrations of SiO2 nanoparticles were incorporated into the silicone oil to further ameliorate the performances of Mg alloys, which can effectively seal the nanopores constructed by MgAl-LDH. With increasing SiO2 nanoparticle concentration, the nanosheet microstructure of MgAl-LDH was gradually covered by the hierarchical structure of SiO2 nanoparticles. The formed composite SiO2-SLIPSs exhibited good surface hydrophobicity and superior corrosion and wear resistance. When the concentration of SiO2 nanoparticle was 10 mg mL−1, the composite SLIPS showed the best performances, with the lowest corrosion current density of 2.43 × 10-10 A cm−2 and wear volume of 0.041 mm3. The developed composite SLIPSs could find wide applications in effective corrosion and wear protection of Mg alloys in industry.

Thermal and Tribological Properties Enhancement of PVE Lubricant Modified with SiO2 and TiO2 Nanoparticles Additive

The addition of nanoparticles may have a positive or negative impact on the thermal and tribological properties of base lubricant. The objective of this paper is to investigate the effect of nanoparticle dispersion in lubricant base in relation to its application in refrigeration system compressors. An investigation of tribological and thermal properties of nanolubricants for rolling piston rotary systems was carried out through four-ball tribology tests and thermal conductivity measurements. Nanolubricants dispersed with SiO2 and TiO2 nanoparticles were tested at various concentrations and temperatures. The changes in thermal conductivity and coefficient of friction (COF) were analyzed while wear weight loss was also calculated from wear scar size. A regression model of thermal conductivity enhancement was proposed for both types of nanoparticles. Zeta potential results show that nanolubricants have excellent stability. The thermal conductivity increases by the increment of nanoparticle concentration but decreases by temperature. The R-square for the regression model is more than 0.9952 with an average deviation not more than 0.29%. The COF for SiO2/PVE nanolubricant at 0.003 vol.% reduced 15% from the baseline. The COF for nanolubricants exceeds the result for base lubricants when the concentration is more than the threshold value. The optimum concentration of SiO2 and TiO2 nanoparticles improved the thermal and tribological properties of PVE lubricant and may offer an advantage when applied to refrigeration systems.

Application of machine learning to determine the shear stress and filtration loss properties of nano-based drilling fluid

A detailed understanding of the drilling fluid rheology and filtration properties is essential to assuring reduced fluid loss during the transport process. As per literature review, silica nanoparticle is an exceptional additive to enhance drilling fluid rheology and filtration properties enhancement. However, a correlation based on nano-SiO2-water-based drilling fluid that can quantify the rheology and filtration properties of nanofluids is not available. Thus, two data-driven machine learning approaches are proposed for prediction, i.e. artificial-neural-network and least-square-support-vector-machine (LSSVM). Parameters involved for the prediction of shear stress are SiO2 concentration, temperature, and shear rate, whereas SiO2 nanoparticle concentration, temperature, and time are the inputs to simulate filtration volume. A feed-forward multilayer perceptron is constructed and optimised using the Levenberg–Marquardt learning algorithm. The parameters for the LSSVM are optimised using Couple Simulated Annealing. The performance of each model is evaluated based on several statistical parameters. The predicted results achieved R2 (coefficient of determination) value higher than 0.99 and MAE (mean absolute error) and MAPE (mean absolute percentage error) value below 7% for both the models. The developed models are further validated with experimental data that reveals an excellent agreement between predicted and experimental data.

Improve the performance of solar thermal collectors by varying the concentration and nanoparticles diameter of silicon dioxide

Abstract The influence of different concentrations and nanoparticles’ diameter of silicon dioxide nanoparticles on the Nusselt number enhancement ratio and friction factor for solar thermal collector (STC) was examined numerically. The CFD model was designed to show the influence of the flow of water/SiO2 and pure water inside the pipe on the enhancement of the performance of the STC. Different concentrations of SiO2 nanoparticles are used (ϕ = 1–4%) with several nanoparticle diameters (dp = 20–50 nm). The water/SiO2 and pure water flow under different Reynolds numbers ranging from 5,000 to 30,000. The average Nusselt numbers Nuavg improved by increasing the Reynolds numbers for both fluids. The Nuavg increases with the increase in the concentration of SiO2 nanoparticles. The water/SiO2 with nanoparticle concentration of (ϕ = 5%) and nanoparticle diameter of (dp = 20 nm) has the highest Nusselt number. The Nuavg enhances 25% with water/SiO2 nanofluid flow at Re = 5,000 and 15% flow at Re = 30,000. It is noted that the skin friction factor decreases with the increase in the Reynolds number for both fluids. Water/SiO2 nanofluid has a higher skin friction factor than pure water. The Nuavg improved by 31% at the lowest Reynolds number by using water/SiO2 nanofluid as the working fluid with a change in the concentration of SiO2 nanoparticles from (ϕ = 1%) to (ϕ = 4%) and improved by 42% at the highest Reynolds number of 30,000. The decrease in the nanoparticle diameter led to an increase in the Nusselt number across all Reynolds numbers. The lowest size SiO2 nanoparticles (dp = 20 nm) provides the highest Nusselt number. The lowest size SiO2 nanoparticles (dp = 20 nm) provide the highest ratio of enhancement for the Nusselt number in STC. This investigation has confirmed that the flow of water/SiO2 with AL2O3 nanoparticles of 5% (diameter of 20 nm) has a significant influence on heat transfer enhancement to improve the thermal efficiency of STC.

Effect of SiO2 nanoparticles concentration on the corrosion behaviour of solar salt-based nanofluids for Concentrating Solar Power plants

Recently, corrosion of nanoparticles molten salt-based nanofluids studies have emerged as Concentrating Solar Power plants provide a low carbon alternative to produce electricity. Enhancing the heat capacity and thermal conductivity of molten salts by using inorganic nanoparticles has been targeted as a strategy to decrease the overall investment cost of CSP systems. However, there is scarce and insufficient information about their effect on the corrosion behaviour of nanofluids, whether the nanoparticle content increases it or have no significant effect. The scatter data found show no clear agreement and the measurements are done under different conditions (temperature, time, impurities, nanoparticle's chemical nature and concentration, metal and alloy composition, testing method). In this context, the authors evaluated the effect of SiO 2 nanoparticles concentration in an industrial-grade Solar Salt in contact with four different alloys; AISI 1045, 304H, 316L and Inconel 600 by isothermal tests, 500 °C up to 2160 h. The effect of nanoparticles, 0.5% and 1% wt., was evaluated in comparison with Solar Salt industrial grade. The corrosion rate of the samples decreased in the following order AISI 1045 > 304H > 316L > Inconel 600 and nanoparticles increased in general and to a different extent the corrosion rate of the alloys. The one that experiences the highest nanoparticle effect is stainless steel 304H, followed by AISI 1045 and Inconel. For 316L, no significant differences can be seen. The applicability assessment carried out has shown that molten salt nitrate-based nanofluids can be used with Inconel 600, 304H and 316L in long-term service high-temperature applications such as CSP. • SiO 2 nanoparticles affect the corrosion behaviour of molten salt nitrates. • Nanoparticles increase the corrosion rate of the studied alloys. • The increase of nanoparticles from 0.5 to 1 % wt. does not affect significantly corrosion. • 304H, 316L and Inconel 600 can be used for long-term service with 1 % wt. SiO 2 Solar Salt.

Designing triple-layer superhydrophobic/hydrophobic/hydrophilic nanofibrous membrane via electrohydrodynamic technique for enhanced anti-fouling and anti-wetting in wastewater treatment by membrane distillation

Developing high-performance membranes for membrane distillation (MD) to treat highly saline industrial wastewater is of great significance. In this work, a superhydrophobic/hydrophobic/hydrophilic triple-layer membrane combining an electrosprayed superhydrophobic top layer, an electrospun hydrophobic nanofibrous intermediate layer and a hydrophilic microporous membrane substrate was fabricated by using electrohydrodynamic techniques. The top superhydrophobic surface possesses a unique surface morphology composing of hydrophobic SiO2-polymer microbeads with nanoscaled protrusions and interconnected thin nanofibers, which contributed to the enhanced water flux for desalination in direct contact MD. By tuning the concentrations of hydrophobic SiO2 nanoparticles and polyvinylidene fluoride-co-hexafluoropropylene for electrospraying the top layer, the triple-layer membrane showed both enhanced anti-fouling and anti-wetting properties due to the reduced liquid-solid contact area and stable Cassie-Baxter state. The triple-layer membrane exhibited stable MD performances when using real seawater and industrial flue gas desulfurization wastewater as the feed solutions, while no obvious fouling and wetting being observed even at 60% water recovery. This study provides an effective approach for fabricating a high-performance triple-layer superhydrophobic/hydrophobic/hydrophilic membrane for potential practical MD applications for industrial wastewater treatment.

Effect of Low Concentration of SiO2 Nanoparticles on Grape Seed Essential Oil/PBAT Composite Films for Sustainable Food Packaging Application

Active packaging material has been used in the food industry to maintain the quality of packaged foods. The use of conventional polymers has serious environmental consequences due to improper disposal or recycling methods. Therefore, active packaging films based on biopolymers have been developed due to their excellent biocompatibility, degradability, and eco-friendliness. Amongst all essential oils, grape seed oil is considered to be a promising antimicrobial agent. It comprises large quantities of flavonoids, tocopherols, and other antimicrobial compounds. Grape seed essential oil has good antimicrobial and antioxidant activity. As a film, it is used to preserve food items such as poultry products, fish, and tomatoes. This work aimed to develop a polybutylene adipate terephthalate (PBAT) biocomposite film incorporated with natural grape seed essential oil (GEO) in addition to silica nanoparticles (SiO2 NPs) using the solution casting process. To achieve the desired packaging properties of the prepared PBAT-based film, the concentrations of grape seed essential oil as a plasticizer and nanosilica as a filler material were varied. The optical, physical, barrier, mechanical, surface hydrophobicity, and antibacterial properties of the PBAT/GEO/SiO2NP films were assessed. The FT-IR and XRD results indicated that GEO had effective miscibility with the PBAT/SiO2NP matrix. The addition of GEO increased the film flexibility, opacity, and antimicrobial activity, but the incorporation of SiO2NPs in the PBAT/GEO blend increased the tensile strength, thermal stability, and antimicrobial activities. The PBAT/GEO/SiO2NP films exhibited excellent antibacterial activity against food spoilage microorganisms. Finally, due to improved antimicrobial activities, film flexibility, optical, and heat resistance properties, the PBAT/GEO/NP nanocomposite films were found to have high potential for usage in active food packaging applications.

A super-toughened poly(lactic acid)-based thermoplastic vulcanizate through incorporating modified SiO2 nanoparticles

Renewable and biodegradable poly(lactic acid) (PLA) has received great interest in the last decade. However, PLA exhibits high stiffness but low toughness, which largely restricts its applications. Blending with elastomers is a simple and effective method to improve the toughness of poly(lactic acid) (PLA), but the tensile strength of PLA generally decreases after adding elastomers. In this work, we manufacture the PLA/natural rubber (NR) (80/20) thermoplastic vulcanizate (TPV) with balanced stiffness-toughness through incorporating the modified SiO2 nanoparticles. The result of transmission electron microscopy, differential scanning calorimetry, and dynamic mechanical analysis shows that SiO2 nanoparticles modified by appropriate Bis-(3-triethoxysilylpropyl) tetrasulfide (TESPT) uniformly disperse in the interface, which not only enhances the strength of NR phase but also improves the interfacial compatibility of the PLA/NR TPV. Therefore, the toughness of the TPV could be improved (71.6 kJ/m2 at room temperature and 7.61 kJ/m2 at −30 °C) by adding low content of SiO2 nanoparticles (15 parts per hundreds of rubbers (phr) in NR or 3 phr in the TPV), while the tensile strength of the TPV remains at 34.6 MPa. Further, the co-continuous PLA/NR/SiO2@TEPST TPVs have a potential to be applied in 3D printing field.