Addition Of Silica Nanoparticles Research Articles

Enhancement of acetate production in hydrogen-mediated microbial electrosynthesis reactors by addition of silica nanoparticles

Microbial electrosynthesis (MES) is a promising technology for CO2 fixation and electrical energy storage. Currently, the low current density of MES limits its practical application. The H2-mediated and non-biofilm-driven MES could work under higher current density, but it is difficult to achieve high coulombic efficiency (CE) due to low H2 solubility and poor mass transfer. Here, we proposed to enhance the hydrogen mass transfer by adding silica nanoparticles to the reactor. At pH 7, 35 ℃ and 39 A·m− 2 current density, with the addition of 0.3wt% silica nanoparticles, the volumetric mass transfer coefficient (kLa) of H2 in the reactor increased by 32.4% (from 0.37 h− 1 to 0.49 h− 1), thereby increasing the acetate production rate and CE of the reactor by 69.8% and 69.2%, respectively. The titer of acetate in the reactor with silica nanoparticles (18.5 g·L− 1) was 56.9% higher than that of the reactor without silica nanoparticles (11.8 g·L− 1). Moreover, the average acetate production rate of the reactor with silica nanoparticles was up to 2.14 g·L− 1·d− 1 in the stable increment phase, which was much higher than the other reported reactors. These results demonstrated that the addition of silica nanoparticles is an effective approach to enhancing the performance of H2-mediated MES reactors.Graphical

Modification of gelatin and photocured 3D‐printed resin to prepare biomimetic phantoms for ultrasound‐guided minimally invasive surgeries

AbstractThe main challenge of ultrasound‐guided minimally invasive surgeries is to carry out treatments through small boreholes in the patient's body surface with sub‐millimetric accuracy and facility offered by ultrasound instruments. Thus, the phantoms' biomimetic appearances, acoustic characteristics, and mechanical properties are essential for healthcare professionals. In this study, gelatin and 3D‐printed photo‐resin phantoms were developed for hard and soft tissues, respectively. Using glutaraldehyde (GA) and formaldehyde (FA) to crosslink gelatin phantoms, the mechanical strength, ultrasound velocity, acoustic impedance, needle insertion forces, and antiseptic periods were improved, and the addition of silica nanoparticles raised the acoustic impedance. For 3D‐printed phantoms, the acoustic impedance ascended with hydrophilic polyethylene glycol diacrylate (PEGDA) oligomers. The additives applied in this study successfully made the gelatin and photo‐resin phantoms more mimetic to muscle and bone tissues, allowing their application in preoperative preparations.

Enhancement of bending strength of polyurethane foam reinforced with basalt fiber with silica nanoparticles in comparison with plain polyurethane foam

This research work is aims to improve the bending strength of novel Structured Insulating Panels (SIP Panel) made of polyurethane foam reinforced with basalt fibre (Sandwich composite). In recent times Structured Insulating Panels replaces conventional constructional materials such as brick, hollow block structures. The novel SIP Panel is developed with polyurethane foam as an inner core which is lighter in weight and acts as an insulating material and basalt fiber laminate as an outer hard skin. Further to strengthen the basalt laminate, silicon nanoparticles were added as additive material. The effect of silicon nanoparticles on bending strength is studied. For this experimental study, two groups are materials are taken for comparison. The 20 samples of plain polyurethane foam are considered as a control group and the 20 samples of polyurethane foam sandwich composite reinforced with basalt fibre with silicon nanoparticles as a filler material is taken as an experimental group. By the addition of silica nanoparticles, it is observed that there is 3% increase in the flexural strength of the SIP panel compared with plain polyurethane foam. Independent sample test between the control group and the experimental group with the significance level of 0.034. Within the limits of the study the polyurethane foam sandwich composite reinforced with basalt fiber with silica nanoparticles is compared with plain polyurethane foam. The reinforced panel seems better bending strength and strength and comparatively less in weight when compared with existing panels.

Preparation of intelligent corrosion resistant coatings based on pH-responsive silica nanocontainers

This work introduces the synthesis of smart silica nanoparticles loaded with a corrosion inhibitor (2-mercaptobenzothiazole) and embedded in composite organosilane coatings for corrosion protection of carbon steel. Through the BET test, the results show that the mechanically stabilized silica nanoparticles have the characteristics of large specific surface area, narrow pore size distribution and large pore volume. This also provides conditions for sufficient loading of the corrosion inhibitor (CI). Further, smart nano-containers are prepared by encapsulating CI in a layer-by-layer (LBL) self-assembly manner. The anticorrosion properties of the coatings were investigated by electrochemical impedance spectroscopy (EIS) and polarization curve characterization methods. The results indicate that the addition of smart silica nanoparticles can improve the corrosion resistance of the coating. This method simplifies the synthesis process of nanocontainers, which will be widely used in the fabrication of novel nanocontainers and opens up new prospects for active anticorrosion.

Strength, Durability and Permeability Studies on Cement Concrete with and without Nano-Silica

The application of nanomaterials in cement/concrete has resulted in the development of smart materials which are durable, sustainable and high performance oriented apart from being eco-friendly. Several types of nanomaterials are being used by researchers all over the world to improve the properties of cementitious system, amongst them silica nanoparticles (SNPs) have been credited with high pozzolanic reactivity and pore filling effects. It is also very well known that permeability is the major factor for deteriorations of concrete structures in the long term thus affecting its durability. A thorough study was performed on cement mortar composites and standard grade concrete with the additions of colloidal silica nanoparticles(SNPs) in various dosages starting from 0.5%,0.75%,1.0%,1.25% and 1.5% by weight of cement(b.w.c.) to understand the impact from micro-structure improvement to macro-level property enhancement. The results show that in presence of colloidal SNPs (Indian branded) having 35-40% active nano content with 5-40nm particle size the strength increase at 28 days is 32% increasing to 59% at 90 days. An influence on durability is also observed with strength increasing from 4% to 8% with the addition of more SNPs from 0.75% to 1.0% b.w.c. The microstructural investigations reveal that silica nanoparticles refines the pore structure due to accelerated hydrated mechanisms leading to the creation of more hydration products and thus to a more denser microstructure. A M-40 grade standard concrete was prepared as per IS:10262 with the addition of optimized SNPs as found for cement mortar composites strength results at 28 days maximum strength keeping the water-cement(w/c) ratio fixed at 0.4. Tests were conducted on concrete to find out the compressive strength and permeability of concrete. The compressive strength of concrete containing nano materials were found to be 24% more than that of normal cement concrete (NCC) of M-40 grade. The permeability values were found to be decreased by 57% with the addition of nano silica particles to concrete.

Tensile performance and viscoelastic properties of rubber nanocomposites filled with silica nanoparticles: A molecular dynamics simulation study

Understanding the relationship between the macro-properties and microstructure of rubber and rubber nanocomposites (RNCs) is crucial for the design and optimization of relevant rubber composite products. Herein, we explore the mechanical and viscoelastic properties of rubber and RNCs filled with silica nanoparticles by using atomistic molecular dynamics simulation. It is found that increasing cross-linking density can greatly enhance the tensile performance of pure rubber, and reduce the permanent deformation and hysteresis loss. The addition of silica nanoparticles causes significant changes in the static distribution, movement, and bond orientation, and the Tg of RNCs increases by more than 6% when the volume fraction of NPs reaches 10%. At fixed volume fraction of NPs, decreasing the NP size can further enhance the mechanical properties of RNCs, and the maximum tensile stress can increase by 50%. In addition, cross-linking in the RNCs can improve the viscoelastic properties, and more highly crosslinked RNCs present larger storage modulus and loss modulus, and smaller loss angle. This work gives an in-depth understanding of the effect of microstructure on the mechanical properties of RNCs.

Fabrication of a robust superhydrophobic coating from the aqueous self-assembly of perfluoropolyether-based triblock copolymers

Five types of poly(hydroxyethyl methacrylate)m-perfluoropolyether-poly(hydroxyethyl methacrylate)m triblock copolymers (HFHm) with different poly(hydroxyethyl methacrylate) chain lengths were synthesized successfully. The as-synthesized HFHm can self-assemble into micelles in water with perfluoropolyether core surrounded by poly(hydroxyethyl methacrylate) corona under a dilute concentration. By casting the mixture of the HFHm micelles in water, hydrophilic silica nanoparticles and hydrophilic polyisocyanates as a cross-linking agent, a robust superhydrophobic surface can be obtained on smooth substrates. The addition of silica nanoparticles and polyisocyanates enhances the surface roughness and mechanical durability of the coatings. Due to the high surface roughness (Ra = 889 nm) and the high surface fluorine content (41.9 wt%), the cross-linked HFHm superhydrophobic coating can reach a water contact angle of 157.8 ± 0.7° and a water sliding angle of 3.5 ± 0.6°. After 30 abrasion cycles or immersion for 22 h in strong acid (pH 2) and weak alkaline (pH 9) solutions, the coating still maintains its superhydrophobicity. These phenomena indicate that the HFHm can be used as a kind of environment-friendly coatings with superhydrophobicity.

Study the Properties of High-Density Polyethylene with Nano Particles Silica Composite

In this research work high density polyethylene (HDPE) and silica nanoparticles (SiO2 NPs) were studied. Samples having 0-10 % composition variation were prepared by injection molding. HDPE and Sio2 NPs constituents were combined at microscopic level and they are insoluble into each other. This phase is called as “Reinforcing” Phase. Soft and ductile phase is called Matrix phase. Matrix phase provides base support to the reinforcing phase and it is protecting the reinforcing phase from the hot environment against the degradation of Polymer Matrix Composites (PMC). Silica dioxide Particle in the form of powder was examined by Electron microscopic method (46.69% silica &53.31% oxygen) with size 2-20 nm. It has large specific surface area/surface energy. Sample of HDPE/SiO2 NPs composites were characterized by mechanical and thermal analysis. It was concluded that the including the SiO2 NPs into HDPE resulted in higher tensile and flexural properties. It has increased the impact strength of composite by 23.58% (5% by wt. addition of silica nanoparticles) and 46.42% (10% by wt. addition of silica nanoparticles).

Influencing foam properties of aqueous bis(2-ethylhexyl)sulfosuccinate solutions by addition of polypropylene-glycol-modified and amino-modified silica nanoparticles

The effect of silica nanoparticle (SiO2NP) addition on the air-water interfacial rheology and foam properties was investigated in aqueous solutions of bis(2-ethylhexyl)sulfosuccinate (AOT), an anionic surfactant. Two types of SiO2NPs were prepared: polypropylene-glycol-modified SiO2NPs (PPG-SiO2NPs) and amino-modified SiO2NPs (NH2-SiO2NPs). The addition of SiO2NPs stabilized the foam in the aqueous AOT solution in all cases, but the effect on the air-water interfacial behavior differed depending on the SiO2NP type. Adsorption of NH2-SiO2NPs to the air-water interface improved the air-water interfacial dilational viscoelasticity (E), enhancing foam stability. Although PPG-SiO2NPs did not adsorb to the air-water interface, the movement of AOT molecules to the air-water interface was partially suppressed by hydrophobic interaction with PPG-SiO2NPs in the bulk aqueous solution. This event limited the decrease in E, thereby stabilizing the foam.

Effect of Nanosilica Incorporation on Flexural Strength, Shear Bond Strength, and Color of Veneering Porcelain after Thermocycling

AIM: The focus of this research was to see how silica nanoparticles changed veneering porcelain over a zirconia core affected flexure strength, shear bond strength, and color. METHODS: A total number of 30 zirconia core veneer samples were constructed and classified according to silica nanoparticles modification of veneering porcelain into two groups: Group 1 (control group) veneering porcelain without any modification (n = 15) and Group 2 (modified group) veneering porcelain modified by silica nanoparticles (n = 15). Silica nanoparticles were added to the veneering porcelain powder at a rate of 5% by weight. Silica nanoparticles powder and veneering porcelain powder were manually crushed for about 10 min using a pestle and mortar then the mixed powder was combined with the porcelain moldings liquid to make a paste. After thermal cycling, each group was examined for flexural strength, shear bond strength, and color measurement (n = 5). Universal testing equipment was used to determine flexural and shear bond strength. The color shift was measured using a spectrophotometer. RESULTS: Flexural strength levels in the modified group (280.9 ± 29.85 Mpa) were substantially higher than in the control group (431.78 ± 22.73 Mpa). Shear bond strength values in the modified group (34.31 ± 5.6) were significantly higher than in the control group (26.97 ± 4.03). Color change was within the clinical acceptable range (1.71 ± 0.32). CONCLUSIONS: The addition of silica nanoparticles to veneering porcelain improved the flexural and shear bond strength, as well as, color change was within the clinical acceptable limits.

Stiffness enhancement of magnetorheological foam by structural modification using silica nanoparticles additive

Magnetorheological (MR) foam is a newly developed porous smart material that is able to change its properties continuously, actively, and reversibly in response to controllable external magnetic stimuli. Unfortunately, the stiffness or also known as storage modulus of MR foam is still rather low and insufficient, in the range of below 100 kPa only, due to weak interparticle interaction between CIPs and the foam matrix, which consequently restricts the potential of MR foam to be used in future sensor applications or in other semi-active devices. Therefore, the aim of this research is to enhance the structural and storage modulus of MR foam by adding silica nanoparticles as an additive. Consequently, MR foam samples with different compositions of silica nanoparticles in the range of 0–5 wt% were prepared via an in situ method. The rheological properties were tested under an oscillatory shear mode with the absence and presence of magnetic fields using a rheometer, with the input parameters of strains between 0.001% and 10% and range of magnetic flux density between 0 and 0.73 T for a magnetic field sweep test. The rheological findings show that with the addition of silica nanoparticles, particularly at 4 wt%, have enhanced the storage modulus of MR foam by 260%, which attributed to the highest stiffness from 45 to 162 kPa. Meanwhile, the change of storage modulus under the influence of magnetic fields (0 T–0.73 T) somehow showed small increment, about ∆1 kPa for each concentration of silica nanoparticles in MR foams, due to non-magnetic behavior of silica. The morphological characteristics of MR foams were described by an elemental analysis carried out by a using variable pressure scanning electron microscope (VPSEM) equipped with energy dispersive x-ray spectroscopy (EDX). The micrographs demonstrated large open-cell pores for MR foam, while MR foam with silica nanoparticles exhibited more closed-cell pores, associated with the enhancement of its storage modulus. It indicates that the silica nanoparticles have encouraged well dispersion of the particles in the foam matrix, which improved and strengthened the microstructure of MR foams through formation of silane coupling bonds of silica in the filler-matrix structure. Overall, incorporation of silica nanoparticles as an additive in the MR foam could provide advantage in enhancing the structure and mechanical properties of MR foam, for various future smart devices.

A Review on the Heightened Mechanical Features of Nanosilica-Based Concrete and the Response of Human Fibroblasts to Nanosilica

Cement is utilized extensively in the manufacturing of concrete, which makes it the most common material used in building construction. However, the usage of a great deal of cement results in a great deal of CO2 emissions, which leads to the greenhouse effect. Numerous studies have developed the use of nano-SiO2 in concrete materials to lower the cement content of concrete mixtures while improving mechanical properties. Additionally, a number of studies have demonstrated that silica NPs trigger an inflammatory response in pulmonary fibroblasts. The main cells that produce and maintain the extracellular matrix (ECM) in the connection of the tissue are fibroblasts. Fibroblasts are involved in processes including tissue regeneration and wound healing. Similar to angiogenesis, inflammation, cancer, and pathological and physiological tissue fibrosis, fibroblasts act as intermediaries. The effect of silica nanoparticles on the mechanical properties of concrete (compressive strength, split tensile strength, and flexural strength) was succinctly presented in this paper. Likewise, a number of studies on the reaction of human fibroblasts to silica nanoparticles were evaluated. Numerous research on the addition of silica nanoparticles to concrete revealed that doing so significantly enhanced the material's mechanical properties. The controlled interaction of silica nanoparticles with human fibroblast cells was demonstrated to have potential in a number of applications, including aesthetics, intracellular drug release systems, improving scar tissue, determining the fate of biomaterials in vivo, and designing potential prosthetics and implant surfaces to reduce bacterial adhesion.

Effect of Silica Nanoparticle Dispersion on Flexural Strength of Sand Mold with Sodium Silicate Binder

Sodium silicate solutions are used as an eco-friendly binder in the casting process. However, the strength of sand molds using the sodium silicate solutions is reduced because of their low humidity resistance. In this study, silica nanoparticles were added to a sodium silicate solution with a constant SiO2/Na2O ratio to improve the humidity resistance of the inorganic binder. The effects of the dissolution times and particle size of the silica on the flexural strength of the molds was also investigated. The physiochemical properties of the inorganic binders were characterized by viscometer, Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). Sand molds for the flexural strength test were prepared by mixing artificial sand and inorganic binders. The addition of silica nanoparticles reduced the viscosity and water evaporation rate of the inorganic binders and improved the humidity resistance of the molds due to an increase in the SiO2/Na2O ratio. The flexural strength of the molds increased as the size of the silica nanoparticles increased, due to formation of discrete silica aggregates with high surface area. However, as the dissolution times of the silica nanoparticles increased, the strength of the molds decreased due to an enhanced Q2/Q3 ratio. Therefore, we suggest that the addition of silica nanoparticles will improve the humidity resistance of molds, and that varying the particle size and dissolution time of the silica nanoparticles affects the strength of the molds.

Influence of Nano Silica Particles on Quasistatic Mechanical and Low Velocity Impact Properties of Carbon-Glass-Sunn Hemp/Epoxy in Intra-Inter Ply Hybrid Composites

Increasing fuel prices and emission norms have favoured the automobile man- ufactures to use of lightweight materials. Land fill regulations imposed by many environmental governing agencies encourage the use of products which will decompose easily or which will require lesser energy for recycling. In this scenario an attempt has been made in this work to develop natural fiber hybrid composites with natural and synthetic fibers to address the issue of harm to the environment and energy spent on recycling. In this work the flexural, compres- sion, interlaminar shear stress and low velocity impact properties of natural fiber hybrid composite reinforced with carbon +E-glass intra plies, unidirec- tional sunn hemp mat interplies and nano silica particles are investigated for possible application in automobiles. It is found that the addition of nano silica particles enhances the flexural, compression, interlaminar shear strength and low velocity impact properties of the composite.

Rheological and adhesive properties of nanocomposite bitumen binders based on hydrophilic or hydrophobic silica and modified with bio-oil

Improved adhesive and cohesive properties of bitumen blends with bio-oil and two types of silica nanoparticles having either hydrophilic or hydrophobic surface were studied. The morphology of the modified bitumen and its rheological properties at normal and elevated temperatures were also investigated in detail. The addition of 5–20 wt% bio-oil leads to the appearance of a small yield stress in the bitumen melt and a reduction in the loss tangent for the cooled mixture. At the same time, the addition of 5% bio-oil is the most optimal, as it results in an increase of the thermodynamic work of adhesion and the measured adhesive strength of the bitumen binder to the silicate surface by 16–21%. The addition of silica nanoparticles in quantities up to 15 wt% causes a more significant increase in the yield stress as well as an even greater improvement in the stiffness and elasticity of the bitumen binder at normal temperature. Moreover, the nanoparticles increase the cohesive strength of the bitumen binder up to 60% and bidirectionally change its adhesion characteristics, depending on the nature of their surface. At a concentration of 15 wt%, the hydrophobic silica doubles the adhesion of the binder to steel, whereas the hydrophilic one conversely halves it.

Effects of silica nanoparticles addition on formation of oxide layers on Al[sbnd]Si alloy by plasma electrolytic oxidation: The origin of stishovite under ambient conditions

The effects of different amorphous silica nanoparticles (NPs) with average particle size of 48 nm – n−SiO2(48) and 100 nm – n−SiO2(100) added to the electrolyte under plasma-electrolytic oxidation (PEO) of AlSi alloy 361.0 (9.8 wt. % Si) on the oxide layers structure, phase composition and properties were investigated. Unexpected formation of high pressure (HP) SiO2-phase – stishovite was detected in the oxide layers formed using n−SiO2(48) under ambient conditions. This HP-phase was not detected while using n−SiO2(100) and the electrolyte without nanoparticles. It was found that the addition of the n−SiO2 resulted in significant increase in the oxidizability, and, accordingly, in the thickness of the PEO-formed oxide layers, their wear resistance (by ~1.5 times) and thermal resistivity (by ~4 times) as compared to the oxide layers obtained without NPs. It also resulted in crystallite size reduction and an increase of the amorphous phase fraction, both effects are more pronounced while using n−SiO2(48) despite the equal initial concentrations of the nanopowders in the electrolyte (3 g/l). To explain these effects, a novel approach to the NPs/oxide layer interaction and the corresponding quantitative model were introduced. The interaction was considered as the colliding with the rigid oxide layer surface of rapidly moving charged NPs accelerated by electric field in the vapour-gas bubbles (VGB) formed in porous channels prior micro-arc discharge. During elastic/inelastic collision, the particle kinetic energy transforms to compressive strain energy, heating of the particle and/or to kinetic energy of the bounced off particle providing different interaction scenarios depending on the particle size. The developed model makes it possible to predict the HP SiO2-phase formation, an increase in the fraction of amorphous phases and reduction in the crystallite size in the PEO-formed layers in the presence of NPs, which can result in improvement of protective and mechanical properties of the layer.

Weakened PAM/PEI Polymer Gel for Oilfield Water Control: Remedy with Silica Nanoparticles.

Polymer gel treatment is one of the most popular conformance control methods used in the petroleum industry. The advantage of the polymer gel system used in harsh reservoir conditions is an integrated process that must take into account all elements of gelation kinetics. In high-temperature applications, NH4Cl has been selected as a retarder to extend the gelation time of a PAM/PEI gel system. However, the gel network loses gel strength when salt and retarder increase, resulting in a weak gel structure, and becomes susceptible. The combination of these two variables leads to the development of a weak gel network, making it fragile and susceptible. To strengthen the weakened PAM/PEI polymer gel, the addition of silica nanoparticles (silica NP) is considered an effective remedy. This article presents the performance of PAM/PEI polymer gel strengthened with silica NP, especially the performance in terms of viscosity, gelation time, and gel strength, as well as performance in porous media. For example, the results exhibited a high storage modulus, G′, which is almost 800 Pa, compared to the loss modulus, G″, throughout the frequency and strain range, indicating solid-like behavior, at significantly high amounts of silica NP. This finding provides a better understanding and knowledge on the influence of solid particles in enhancing the performance of PAM/PEI polymer gel that has been weakened by salinity and retarder.

Enhancing temperature resistance of polymer gels by hybrid with silica nanoparticles

The steam channeling channel formed during steam huff and puff can be blocked by temperature-resistant gel to improve the steam stimulation effect. In this study, a terpolymer prepared by the polymerization of acrylamide, N-Vinyl-pyrrolidone, and 2-acrylamide-2-methypropanesulfonic acid was selected as gelatinizer, hydroquinone, and hexamethylene tetramine were used as cross-linking agents to prepare gel. The stabilization time of the gel at 175 °C was dramatically extended from 3 days to more than 50 days by adding nanoparticles. The gel prepared with 0.6 wt% polymer, 0.1 wt% hydroquinone, 0.1 wt% hexamethylene tetramine, and 0.9 wt% silica nanoparticles can exist stably for 70 days at 175 °C, which provided a potential choice for plugging the steam channeling channel. The rheological experiments showed that the addition of nanoparticles increased the elastic tendency of the polymer solution to improve the structural strength of the heterogeneous network chain. Dynamic light scattering experiments showed that nanoparticles contribute to the dispersion of polymers in water. The micrographs of the gel were observed by scanning electron microscope, verified that the addition of silica nanoparticles strengthened the gel grid structure and increased the gel grid density, which might be one of the main factors to improve the thermal stability of gels.

Mechanical, barrier, thermal, surface hydrophobicity, optical and antibacterial properties of PBAT biopolymer after addition of natural plasticizer and silica nanoparticles

PurposeThe purpose of this study is to develop active package films using clove essential oil (CEO) and biodegradable polybutylene adipate terephthalate (PBAT) with varying weight percentages of SiO2 nanoparticles (SiO2NPs), as well as to investigate the mechanical, barrier, thermal, optical, surface hydrophobicity and antibacterial properties of PBAT incorporated with CEO as a natural plasticizer and SiO2NPs as a nanofiller.Design/methodology/approachPBAT-based bio-composites films were fabricated with different weight percentage of CEO (5% and 10%) and nanosilica (1% and 3%) by solution casting method. The packaging performance was investigated using universal testing machine, spectrophotometer, contact angle goniometer, oxygen and water vapour permeability tester. The antibacterial properties of PBAT-based nanocomposite and composite films were investigated using the ISO 22196 by zone of inhibition method.FindingsThe mechanical results exhibited that the addition of 10 Wt.% of CEO into PBAT increases the percentage of elongation, whereas, the addition of 3 Wt.% of SiO2NPs increases the tensile strength of the composite film. The presence of CEO in PBAT exhibits a good barrier against water permeability and SiO2NPs in the PBAT matrix help to reduce the opacity and hydrophobicity. The antimicrobial and thermal results revealed that the inclusion of 10 Wt.% of CEO and 3 Wt.% of SiO2NPs into PBAT polymer improved antimicrobial and thermal resistance properties.Originality/valueA new PBAT-based active packaging film developed using natural plasticizers CEO and nanofiller SiO2 with a wide range of applications in the active food packaging applications. Moreover, they have good surface hydrophobicity, thermal stability, mechanical, barrier and antibacterial properties.

Influence of photooxidation on ionic reversible interactions of ionic poly(ether urethane)/silica hybrids

Organic-inorganic hybrids that combine the reversible nature of electrostatic interactions present in ionic systems with the reinforcement ability of nanoparticles in nanocomposites have the potential to revolutionize a wide spectrum of technologies. However, the prediction of their service lifetime under photooxidative conditions has remained elusive. In this paper, the accelerated environmental ageing of ionic hybrid materials made by combining imidazolium-functionalized poly(ethylene glycol)-based polyurethane (im-PU) and surface-modified sulfonate silica nanoparticles (SiO2-SO3H) is addressed. Since the resulting ionic nanocomposites are dynamic, the present contribution aims to elucidate their temporal behavior and precisely distinguish the contribution of the nanoparticles addition to the photochemical behavior. Although the addition of SiO2-SO3H nanoparticles within im-PU matrix led to faster photooxidative degradation, the ionic imidazolium-sulfonate crosslinks are thought to be sustained under photooxidative conditions. The results further suggest that the molecular weight loss and the resulting ductile-to-brittle transition for the ionic hybrid under atmospheric ageing conditions are attributed to severe chain scissions into the im-PU backbone in the presence of SiO2-SO3H nanoparticles. Overall, the present investigation suggests that the silica nanoparticles addition is responsible for the prodegradant effect rather than the presence of reversible ionic interactions in the system. The present work thus provides a deeper understanding about the crucial role of the incorporation of dynamic linkages within ionic nanocomposites during photochemical ageing and can aid the future design and use of these systems.