Nano-sized Fillers Research Articles

Preparation of composite micro-nanofibers based on nano-sized magnetite by electrospinning

Composite materials with magnetic fillers play an important role in a number of industries, from functional coatings in electronics to electromagnetic wave absorption and microwave-shielding materials. An important feature is the selection of a magnetic nano-sized filler that does not cause increased degradation of the polymer binder, and the selection of a polymer that ensures the weather resistance of the nanocomposite material. In this study, composite samples of micro- and nanofibers based on fabricated particles of nanosized magnetite (Fe3O4) as a cheap electromagnetic wave absorption material were investigated. Magnetic polymer-dielectric fibers polystyrene-Fe3O4 were obtained by electrospinning. The X-ray diffraction analysis showed that the synthesized Fe3O4 nanoparticles have a cubic space group structure Fd3m with crystal lattice parameter a = 8.422±0.026 Å. The analysis of the ferromagnetic resonance spectrum showed the ferromagnetic nature of the obtained magnetite nanoparticles. It has been shown that during the production of composite fibers by electrospinning, a dispersion of nano-sized magnetite powder can be included in the spinning solution, which, as a result of the electrospinning process, allows obtaining magnetic composite micro- and nanofibers. The average size of the included magnetite particles was15±3 nm. The resulting non-woven magnetic material is predominantly composed of two types of fibers with an average diameter of 680±280 nm and larger associated fibers with a diameter of 1500±300 nm. Based on a certain frequency ependence of losses upon reflection RL in the frequency range 15 MHz – 7.0 GHz, the synthesized fibrous material can be considered to be an effective electromagnetic wave absorption material.

Probing the microstructural properties of metal-reinforced polymer composites

Abstract Microstructural analysis is an important technique to study the extent of interaction between metal fillers and polymers. The aim of this study is to review the investigations on the microstructural properties of metal-reinforced polymer composites. Scanning Electron Microscope (SEM) operating at a magnification range of 2,500× is typically used for examining the microstructure of the composites. Microstructural analysis reveals two key qualitative informations, dispersion and interfacial adhesion. It was observed from the review that flaky metal fillers will maximise dispersion and interfacial adhesion hence leading to improved mechanical, tribological, electrical, and thermal properties of the composites. Utilizing ternary metallic components helps to eliminate aggregation because the cohesion of metal particles is limited. It is important that future microstructural studies evaluate nano-sized fillers as compared to micro-sized ones. Also, it is important to quantitatively correlate the arrangement of the fillers to macro-scale properties and finite element analysis is an important tool that can help achieving this.

Characterization of extracted bio-nano particles from date palm agro-residues

Mechanical downsizing of waste lignocellulosic fibers to small-size particles is a promising way to produce efficient reinforcing elements for bio-composites, both from commercial and environmental perspectives. This study specifically aims to make nano-sized lignocellulosic fillers from date palm agro-residues using a mechanical ball milling technique supplemented with liquid Nitrogen. The researchers aimed to obtain efficient reinforcing elements for bio-composites by fragmenting and downsizing waste lignocellulosic fibers. Several tests were conducted to evaluate and characterize the fillers' properties. The morphological analysis using TEM and FE-SEM showed that the microparticles had irregularly shaped particles with sizes ranging from 0.6 to 0.8 μm for micro-untreated particles and 0.22–0.32 μm for micro-treated particles. The nanoparticles had smaller particle sizes, with nano-untreated particles ranging from 80 to 122 nm and nano-treated particles ranging from 32 to 55 nm. XRD analysis revealed a boost in crystallinity due to the treatment process; (45 %) for micro-treated and (67 %) for nano-treated. TGA analysis indicated that the chemically treated fillers contributed to the improved thermal stability of the samples. Specifically, MT showed the best thermal stability due to increased crystallinity and stronger binding among the cellulose chains than that of NT.

In situ three-roll mill exfoliation approach for fabricating asphalt/graphite nanoplatelet composites as thermal interface materials

Thermal interface materials (TIMs) are vital to dissipate excess heat generated by electronic components with ever-growing power density to ensure their reliability and performance. However, the limited dispersibility of nano-sized thermal conductive fillers hinders further enhancement of thermal conductivity in TIMs. It remains challenging to manufacture high-performance TIMs with simultaneous high thermal conductivity, low cost, and capability of large-scale production. Herein, a solvent-free and scalable approach was adopted to fabricate asphalt/graphite nanoplatelets (GNPs) composites by in situ exfoliating graphite in asphalt melt using a three-roll mill. During exfoliation, asphalt was adsorbed onto the surface of GNPs via π-π interaction and improved their dispersibility. Hence, GNPs formed integrated thermal conductive pathways with reduced interfacial thermal resistance, which significantly improved the thermal conductivity of asphalt/GNP composites. At 25 vol% loading, the asphalt/GNP composite displayed a thermal conductivity of 1.95 W m−1 K−1, showing a 114 % increase compared to the asphalt/commercial GNP (c-GNP) composite prepared by conventional mechanical mixing. Moreover, the heat-resistant and mechanical properties of the asphalt/GNP composites were also enhanced due to the improved filler dispersion and filler-matrix interactions. Thus, the asphalt/GNP composites fabricated by in situ three-roll milling possessed remarkable advantages as TIMs compared with asphalt/c-GNP composites and commercial silicone rubber thermal pads.

Coarse-grained simulation of thermal conductivity of boron nitride/epoxy composites based on DPD and SPH method

In this study, thermal conductivity (TC) of BN/polymer composites is investigated utilizing dissipative particle dynamics (DPD) and smoothed-particle hydrodynamics (SPH) methods by establishing the coarse-grained (CG) models of boron nitride nanotube (BNNT) and boron nitride nanosheet (BNNS). The Iterative Boltzmann inversion (IBI) approach is employed to calculate the parameters of the potential function of the hexagonal boron nitride (h-BN) coarse grain model for DPD method. Mesoscopic simulations on the TC of BNNT/EP, BNNS/EP, and BNNT/BNNS/EP composites are performed using SPH and DPD simulations to investigate the effects of nanofiller ratio, aspect ratio, size, and orientation on TC. The CG models established for the BNNT and BNNS structures are proven to be efficient in DPD and SPH simulations for predicting the TC of h-BN/polymer composites. Furthermore, it is demonstrated that the TC of BNNT/BNNS/EP composites is superior to that of BNNT/EP and BNNS/EP composites at the same filler ratio due to the synergistic effect of BNNT and BNNS.

Structure-property relationship and emerging applications of nano- and micro-sized fillers reinforced sialon composites: a review

Oxonitridoaluminosilicates (SiAlON) are renowned in advanced ceramics for their exceptional properties: high temperature stability, excellent oxidation resistance, and good wear resistance. Incorporating micro- and nano-sized fillers into SiAlON matrices enhances their properties, yielding SiAlON composite materials with superior mechanical, tribological, and thermal characteristics. This review examines fabrication techniques for producing SiAlON micro/nanocomposites and the structure-property relationships governing their performance across different phase compositions (β, α, X, and O-phases). A comprehensive literature review scrutinized fabrication techniques and structure-property relationships from various databases and scholarly articles. Although SiAlON composites with micro/nano inclusions hold promise across applications, understanding their fabrication processes, structure-property relationships, and potential applications in different fields is crucial. The review highlights diverse fabrication techniques for SiAlON micro/nanocomposites and provides insights into their structure-property relationships. Additionally, emerging applications in structural domains, cutting tools, coatings, corrosion protection, solar cells, LEDs, biomedical realms, and filtration membranes are discussed. This review is a valuable resource for researchers and engineers interested in designing SiAlON products tailored for sophisticated applications. It emphasizes understanding fabrication processes and structure-property relationships to unlock SiAlON-based materials' full potential across industries.

Molecular-scale interaction between sub-1 nm cluster chains and polymer for high-performance solid electrolyte

Organic-inorganic interface in composite solid electrolyte could lead to increased ion transport for solid-state lithium batteries; however, most inorganic fillers have much larger size than polymer chains, which results in severe aggregation of inorganic fillers and poor ionic conductivity. Herein, functional sub-1 nm inorganic cluster chains were integrated with polymer chains to fabricate composite solid electrolyte with enhanced ionic conductivity. Different from all other inorganic fillers, the sub-1 nm inorganic cluster chains with diameter <1 nm have similar size and geometry compared with polymer chains, exhibiting polymer-like solution properties. A transparent sub-1 nm inorganic filler/polymer mixed solution was generated to realize monodispersion of cluster chains as functional fillers in polymer matrix. Meanwhile, abundant oxygen vacancies on cluster chains interact with polymer chains and lithium salts at molecular-scale, which decreases the complexation of polymer segments with Li+ and promote the dissociation of lithium salts, thereby improving Li+ transport. As a result, the composite solid electrolyte exhibits high ionic conductivity (0.4 mS cm−1) and large mobile Li+ distribution (50.8 %). This work pushes the size of nanofillers down to <1 nm, which is a unique approach to the molecular-scale interaction between nanofillers and polymers to boost ion transport in solid electrolytes.

Regulating interfaces of composite polymer electrolyte via surface charge on fillers for stable solid-state lithium battery

The commercial potential of composite polymer electrolytes (CPEs) is significant due to their ability to combine the advantages of both inorganic and polymer solid electrolytes. However, the unstable interface and insufficient ionic conductivity remain important challenges in practical applications of CPEs for achieving high-performance solid-state lithium batteries (SLBs). Herein, we construct a double-layer composite polymer electrolyte (D-CPE) by incorporating nanosized TiO2 fillers with adjustable concentrations of oxygen vacancies into poly (ethylene oxide) (PEO)-based electrolyte composites. In the D-CPE structure, one CPE layer containing TiO2 fillers with oxygen vacancies exclusively interfaces with the LiFePO4 cathode, while the other CPE layer consisting of pristine TiO2 fillers (with negatively charged surfaces) solely contacts the lithium anode. This design of D-CPE achieves high ionic conductivity, a broad electrochemical window, and interfacial stability without additional resistance at the electrolyte-electrolyte interface simultaneously. The LiFePO4/D-CPEs/Li battery exhibits excellent cycling stability at 0.1 C, maintaining a capacity of 157.2 mAh g−1 with a capacity retention rate of 99.1% after 100 cycles. Furthermore, even at 0 °C, it delivers an impressive discharge capacity of 133.1 mAh g−1 at 0.1 C. This work presents a simple and effective approach to achieving superior polymer-based electrolytes for high-performance solid-state lithium batteries.

Optimum selection of nano-Al2O3, nano-SiO2, and nano-ZrO2 particulate fillers on physical, mechanical, and wear assessment of Al6061 nanocomposite using preference selection index

The present study investigated the role of three important nano-sized fillers such as nano-SiO2, nano-ZrO2, and nano-Al2O3 on mechanical and wear assessment of Al6061 alloy matrix composite and suggested the optimum compositions for the best performance for Al6067 alloy matrix composites. Preference selection index as optimization tool was used and attributes taken for optimizations were void content, hardness, tensile strength, flexural strength, fracture toughness, impact strength, specific wear rate at normal load of 25 and 55 N load, sliding velocities of 0.5 and 2 m/s, sliding distance of 500 and 2000 m, respectively. In general, all three nanofillers enhanced the mechanical and wear properties of Al6061 alloy matrix composite. In the steady state wear study, on increasing normal load from 25 to 55 N, the specific wear rate of Al6061, Al6061-3Al2O3, Al6061-3SiO2, and Al6061-3ZrO2 was increased by 58.7%, 33.2%, 15.4%, and 26.14%, respectively. On increasing sliding speed from 0.5 to 2 m/sec, the specific wear rate of Al6061, Al6061-3Al2O3, Al6061-3SiO2, and Al6061-3ZrO2 was increased by 27%, 13%, 6%, and 12%, respectively. On increasing sliding distance from 500 to 2000 m, the specific wear rate of Al6061, Al6061-3Al2O3, Al6061-3SiO2, and Al6061-3ZrO2 was increased by 41%, 36%, 9%, and 21%, respectively. Al6061-3SiO2 indicated the best composition in terms of mechanical and wear performance followed by Al6061-3Al2O3 and Al6061-3ZrO2. Hence, nano-SiO2 can be suggested as the best filler to enhance the mechanical and wear performance of Al6061-based nanocomposite. Therefore, nano-SiO2 reinforced Al6061 composite is indicated as the best suitable composite material for a large number of components in structural, automobile, marine, and aerospace industries.

A micromechanical modeling approach for predicting the piezoelectric and mechanical properties of piezoelectric fiber-reinforced multiphase composites containing CNT/GNP hybrids

This paper focuses on the prediction of piezoelectric coefficients, Young’s moduli and shear moduli of unidirectional piezoelectric fiber/carbon nanotube (CNT)/graphene nanoplatelet (GNP)-reinforced polymer composites using a novel micromechanics modeling technique. The multiphase composite configuration is that piezoelectric fibers are embedded within a polymer matrix filled by CNT/GNP hybrids. Agglomeration of hybrid nanofillers as a significant factor is identified and incorporated in the micromechanical calculation. Parametric studies are carried out to understand the effect of volume fraction, size and dispersion type of carbonous nanofillers as well as the piezoelectric fiber volume fraction on the effective material constants of multiphase composites. It is found that in comparison with the piezoelectric fibrous composite, the piezoelectric fiber multiphase composite containing CNT/GNP hybrids shows better elastic and piezoelectric properties. Also, further improvement in effective properties can be obtained by increasing the length and percentage of CNTs and GNPs. But, degradation in the elastic and piezoelectric constants is observed by the agglomeration of CNT/GNP hybrids. The current results are found to be in close proximity with the experimental data and other numerical results available in the literature.

Fumed nanosilica as filler for semi-rigid palm oil-based polyurethane foam: Mechanical, material, thermal, and fire response

Incorporating nano-sized fillers into bio-based polyurethane (PU) foams typically enhances their properties. In present investigation, palm oil-based PU foams are fabricated with varied loadings (0 to 5 wt%) of fumed nanosilica. The foams are then characterized for their fire-retardancy, thermal stability, foam morphology, and also mechanical properties. Marginal improvement in Limiting Oxygen Index (LOI) values, as well as failure to be rated under UL-94 Vertical Combustion Test indicate limited potential of fumed silica in improving flammability of organic polymeric foams; suggesting exorbitant amount is required for any distinguishable effect to manifest. Interestingly; results from Thermogravimetry Analysis (TGA) shows marked improvements in terms of char residue with more than seven-fold increase at 5 wt% filler loading, possibly owed to the inert filler nature of fumed nanosilica forming a char barrier and acting as fuel diluent. Filled PU foams displayed an increased open-cell content, likely because the filler functioned as a cell opener. Removing the influence of density, the normalized compressive properties showed notable improvement up until a certain loading, which could be credited to the increased stiffness imparted by the filler itself. The results portray the potential of fumed nanosilica as filler for bio-based PU foams, offering enhanced thermal stability and limited fire retardancy.

The Effect of Se ect of Several Electric Cigar al Electric Cigarette Puffs on Nanohybrid ette Puffs on Nanohybrid Composite Resin Surface Roughness

Nanohybrid composite resin is a dental restorative material comprising micro and nano-sized fillers. When accompanied by smoking habits, it can alter the surface roughness of composite resin. Objective: This study aimed to determine the effect of several electric cigarette (e-cigarette) puffs on the surface roughness of nanohybrid composite resin. Methods: This study was conducted in the experimental laboratory with a pretest-posttest control group design using 48 nanohybrid composite resin specimens divided into six groups. Subsequently, the experimental groups were exposed to 75, 150, 225, 300, and 450 puffs of e-cigarette, and the control group was given artificial saliva immersion without exposure for 21 days. The surface roughness of specimens was measured with a surface roughness tester and evaluated through statistical analysis, including One-Way ANOVA and Post-Hoc LSD. Results: The average pre-test and post-test differences between groups I, II, III, IV, V, and VI were 0.013, 0.022, 0.033, 0.044, 0.065, and 0.005 μm. These results showed a significant difference in the surface roughness of nanohybrid composite resin (p &lt; 0.05), with variations between all groups. Conclusion: This study showed that the number of e-cigarette puffs had a significant effect on the surface roughness of nanohybrid composite resin. Specifically, an increase in the number of e-cigarette puffs led to a rise in the surface roughness value of nanohybrid composite resin.

Nanosize Filler Effect on Propagation of Electron Avalanche in Terms of Waveform Characteristics of Partial Discharge

Nanocomposite materials have excellent insulating properties, such as improved treeing resistance. The propagation properties of electrical trees are often determined using optical observations and partial discharge (PD) characteristics regarding phase angle distribution patterns. There is a limit to confirming the effects of physical barriers on the PD by optical observation alone. Conversely, there is a high possibility that the PD waveform reflects the characteristics of the electron avalanche in the discharge space. In this study, we constructed a PD measurement system with the widest possible frequency range and acquired 1000 PD waveforms along the time series. Although the acquired waveforms have a single peak or multiple peaks, adding nano-fillers increased the observation ratio of the waveform with multiple peaks. Furthermore, the multiple peaks suggested that the electron avalanche progresses with difficulty considering that the nano-fillers easily captures electrons. We investigated the effect of adding nano-fillers from the viewpoint of the waveform characteristics. The time difference between the peaks and the peak ratio is also supported by the property changes in the electron avalanche because of the electron capture by nano-fillers.

Investigation of the influence of nano-sized particles on the entanglement distribution of a generic polymer nanocomposite using molecular dynamics

The addition of nano-sized filler particles to polymers leads to significant improvements in their mechanical properties. These can be traced back to the matrix–filler interactions of the interphase, which can be analyzed using molecular dynamic simulations. Usually, research in this context studies the general number of entanglements or the radius of gyration. However, this publication presents a novel approach by investigating the radial distribution of entanglements in an effort to characterize the interphase. To this end, we employ a coarse-grained model for a generic polymer composite and study multiple systems with varying particle radius and matrix–filler adhesion. Furthermore, the highly customizable and computationally efficient nanocomposite system developed during this research serves as a foundation for the further characterization of polymer nanocomposites and their interphases.

Studying the mechanical behavior of a generic thermoplastic by means of a fast coarse-grained molecular dynamics model

Polymers play an emerging role in modern engineering applications due to their comparatively low cost, low density, and versatile manufacturing. The addition of nano-sized fillers further enhances the polymer’s properties but also induces a strong dependence on the resulting microstructure, particularly the matrix-filler interphase. Since an experimental characterization of this nano-sized interphase is extremely difficult, molecular dynamics (MD) simulations are used to study the effects at such small scales. However, MD’s high computational costs usually limit the scope of a mechanical characterization. Therefore, this study presents the methodology and tools to generate and analyze samples of an efficient generic thermoplastic model. In this first contribution, we focus on the neat polymer and introduce a versatile and numerically stable self-avoiding random walker with adjustable linearity of chain growth. Moreover, we verify our equilibration procedure by preparing samples in liquid and solid state which behave physically sound. Finally, we perform uniaxial tensile tests with a maximum strain of 10 % to evaluate the mechanical properties. In the liquid case, the polymer chains are sufficiently mobile, such that the tensile stresses fluctuate only around zero, while the solid exhibits an almost linear elastic regime followed by a nonlinear part. This contribution forms the basis for a thorough mechanical characterization of polymer nanocomposites which we will address in future studies. The methodology and tools introduced are not limited to our generic polymer, but applicable to many coarse-grained models.

ZnO Quantum Photoinitiators as an All-in-One Solution for Multifunctional Photopolymer Nanocomposites.

Nanocomposites are constructed from a matrix material combined with dispersed nanosized filler particles. Such a combination yields a powerful ability to tailor the desired mechanical, optical, electrical, thermodynamic, and antimicrobial material properties. Colloidal semiconductor nanocrystals (SCNCs) are exciting potential fillers, as they display size-, shape-, and composition-controlled properties and are easily embedded in diverse matrices. Here we present their role as quantum photoinitiators (QPIs) in acrylate-based polymer, where they act as a catalytic radical initiator and endow the system with mechanical, photocatalytic, and antimicrobial properties. By utilizing ZnO nanorods (NRs) as QPIs, we were able to increase the tensile strength and elongation at break of poly(ethylene glycol) diacrylate (PEGDA) hydrogels by up to 85%, unlike the use of the same ZnO NRs acting merely as fillers. Simultaneously, we endowed the PEGDA hydrogels with post-polymerization photocatalytic and antimicrobial activities and showed their ability to decompose methylene blue and significantly eradicate antibiotic-resistant bacteria and viral pathogens. Moreover, we demonstrate two fabrication showcase methods, traditional molding and digital light processing printing, that can yield hydrogels with complex architectures. These results position SCNC-based systems as promising candidates to act as all-in-one photoinitiators and fillers in nanocomposites for diverse biomedical applications, where specific and purpose-oriented characteristics are required.

Effect of Nano-sized Hydroxyapatite Filler on Remineralization Efficacy of an Adhesive Resin: an in vitro study

Aim The aim of this study was to evaluate the remineralization efficacy of an adhesive resin containing nano-sized hydroxyapatite filler. Methodology The study consisted of four groups: control (without filler), 2% hydroxyapatite (HA), 5% HA, and 7% HA. Nano-hydroxyapatite powder was mixed with Scotchbond Multi-Purpose®. The teeth were sectioned to expose the midcoronal dentine. Bonding agents and resin composite restorations were applied. Teeth were incubated in simulated body fluid for 24-h, 30-day, and 90-day intervals. After incubation, the teeth were sliced. Hardness and elasticity modules were obtained for the three different time periods (for a total of n = 360 samples). The detection and measurement of mineral deposition areas were obtained by confocal laser scanning microscopy (CLSM) (for 120 samples). Elemental analysis was performed with energy-dispersive X-ray spectroscopy (EDS) (n = 360 samples). The statistical analysis of each parameter was performed using two-way ANOVA and group comparisons by post hoc tests. Results Study groups and storage periods affected the hardness (p = 0.00) and elasticity scores (p = 0.00). The CLSM results showed that increasing the storage periods and amount of HA resulted in mineral deposition areas (p = 0.02). The calcium and phosphor ion values of dentine that were obtained using EDS were increased (p = 0.00). Conclusion Hydroxyapatite fillers positively affect the remineralization activity of adhesive resins. In terms of remineralization efficacy, the best results were obtained in the 7% HA group.

Comparative analysis between size and mass ratio of nano-Al2O3 in the performance of dental composite and finding the optimum composition

Dental composites provide better bonding with tooth tissue as compared to other traditional materials such as amalgam. However, the development of dental composites relies on experimental results of physical, mechanical and thermal properties of the dental composite obtained after applying the strategy of filler technology, i.e., changing size, shape, surface modification and mass ratio of filler or reinforcement. In the present research, nano-Al2O3 particle size and filler mass ratio were varied to study their effect on the physical, mechanical and thermal behaviour of dental composite. The particle size was varied in the range of 30 nm, 50 nm and 70 nm. Nano-Al2O3 filler mass ratio was varied in the range of (0, 5, 10 and 15 wt. %). Fourier transform infrared analysis was done to check variations in absorption peak and band in the spectrum due to variation in the filler mass ratio and size. Physical properties, mechanical properties and thermal properties were investigated. It was observed that hardness, compressive strength, diametral tensile strength, flexural strength and stress intensity factor were increased by 133%, 13.6%, 27.4%, 25% and 20%, respectively, on adding 5 wt. % of nano-Al2O3 and decreased by 13.5%, 8.1%, 15.3%, 13.9% and 10.3%, respectively, on increasing particle size from 30 nm to 50 nm. The thermal degradation temperature was increased by 31.8% and 36% on adding 5 wt. % and increasing particle size from 30 nm to 50 nm, respectively. It can be concluded that in the case of nano-sized particulate filler, mass ratio played a more significant role than filler size in regards to optimization of physical, mechanical and thermal properties.

Synthesis, structure, and optical studies of nanocomposites based on copoly (arylidene cyclohexanone) and CdS nanoparticles for photocatalytic and white LED applications

For various optical applications, the fabrication of nanocomposites of co-polyarylidene (cyclohexanone/4-tertiary butyl cyclohexanone) CoP6 with various-sized cadmium sulfide CdS nanoparticles via in situ polymerization has been investigated (CoP6-CdS NCs). Several techniques like FT-IR, XRD, XPS, SEM, TGA, TEM, UV–vis, and fluorescence emission have been used to investigate, characterize, and study nanocomposites' structural and optical characteristics. The optical band gap of NCs was found to have a slight redshift, from 2.81 to 2.71 eV, with no alteration to the absorption peak. The crystallinity and phase formation were studied by XRD, which showed that the produced NCs with larger (CdS) particles retain some crystalline structure. The NCs generated were characterized by SEM and TEM, revealing their aggregation inside the polymer matrix. The thermal stability of the produced nanocomposites varies with the size of the nanoparticles, with larger NPs being less stable than CoP6 in the first two stages of thermal degradation and smaller NPs showing better stability in the first stages. Their outstanding optical properties make them be used in solar cells and photocatalysts. According to the photophysical analysis, new CoP6-CdS NCs have excellent optical quality with 95% optical transparency and low absorption in the visible region; the light transmittance in the UV region is reduced as the size of the CdS NP increases. There is a potential for using CoP6-CdS NCs in white LED applications in the visible region by varying CdS nanofiller size. However, because the nanocomposites exhibit enhanced absorption in the UV region, they can be used as a material for UV protection.

Effects of nano-sized BaTiO3 on microstructural, thermal, mechanical and piezoelectric behavior of electrospun PVDF/BaTiO3 nanocomposite mats

Polyvinylidene fluoride (PVDF) is a good candidate for use in wearable electronics due to its flexibility, ease of processing, and ability to generate electrical charge in response to applied mechanical stress. In this work, low-density polyvinylidene fluoride (PVDF) nanocomposites containing nano-sized BaTiO3 with cubic symmetry were fabricated by electrospinning process, aiming to generate dominant electroactive β polar phase. The influence of nano-sized filler content on the microstructure, total degree of crystallinity, β phase content, and piezoelectric properties of the electrospun PVDF/BaTiO3 nanocomposites was systematically studied. The crystallinity and the thermal stability were evaluated using differential scanning calorimetry (DSC), x-ray diffraction (XRD) and thermogravimetric analysis (TGA). The content of evolved piezoactive β phase was determined by FTIR spectroscopy. It was shown that the electrospinning process is primarily responsible for very high content (up to 99.4%) of the developed piezoactive crystalline phase. High degree of crystallinity (up to 56.4%) was determined in PVDF/BaTiO3 nanocomposites, confirming the nucleation ability of the nanofiller. Maximum tensile strength of 55.5 MPa (127% higher than PVDF nanofiber mat) and maximum d33 coefficient of 18 pC N−1 were determined for the nanofiber mat containing 20 wt% BaTiO3. We believe that this work provides an important insight into the nanoparticles’ distribution and their agglomeration (SEM and TEM analyses) influence on the final properties of PVDF/BaTiO3 webs, generated via electrospinning.