SiO2 Filler Research Articles

Polymer-coated silica dual functional fillers to improve the performance of poly(ethylene oxide)-based solid electrolytes

The application of solid polymer electrolytes (SPEs) is mainly hindered by their low ionic conductivity and the limited mechanical properties. Adding functional small molecules and inorganic fillers are two of the simplest and most effective ways to improve the performance of SPEs. However, most of the time, both methods cannot be implemented concomitantly, and may even inhibit each other. Here, an original dual functional filler, consisting of hollow porous SiO2 nanospheres three-dimensionally wrapped by poly(2,2,6,6-tetramethylpiperidin-4-yl methacrylate) (PTMPM), is blended with poly(ethylene oxide) (PEO) and LiClO4 to obtain a composite solid electrolyte (CSE). Compared to the reference PEO SPE, the room-temperature ionic conductivity of the synthesized CSE is improved by 4 orders of magnitude reaching 1.3 × 10−4 S cm−1. Moreover, a lithium ion transference number value as high as 0.81 is obtained. The CSE membrane is further assembled with a Li anode and a standard LiFePO4 cathode to obtain an all-solid-state battery showing high capacity (149.3 mAh g−1 at 0.1 C) and long-term stability (0.68‰ loss of capacity per cycle, over 100 cycles). The peculiar structure of the PEO/PTMPM interface is thought to be at the origin of the enhanced LiClO4 dissociation and mobility of lithium ions. Remarkably, the well-known toughening effect of SiO2 fillers is preserved in the CSE.

PDMS‐silica composite gas separation membranes by direct ink writing

AbstractPolydimethylsiloxane (PDMS)‐based membranes containing amine‐functionalized and unfunctionalized silica particles were fabricated via direct ink writing for CO2/N2 gas separation. The printability of the inks was evaluated by rheological measurements, while spectroscopy, microscopy, thermal measurements, and mechanical testing were employed to characterize the printed membranes. The surface morphology of the membranes revealed the absence of voids, demonstrating their suitability for gas separation. The printed membranes also exhibited desirable thermal and mechanical properties (i.e., thermal degradation temperature of 518 °C and tensile strength as high as 1.178 MPa with 529% elongation). The PDMS‐based membranes generally displayed high permeability for CO2 but slightly low selectivity for the CO2/N2 gas pair. The best‐combined permeability‐selectivity performance of 8794 barrer and selectivity of 11.64 was demonstrated by the printed PDMS membrane containing no SiO2 fillers. The inclusion of unfunctionalized SiO2 particles generally increased the membrane's gas permeability but compromised the selectivity. In contrast, membranes with amine‐functionalized silica showed improved selectivity compared to membranes containing unfunctionalized silica. Overall, the performance and characteristics offered by the PDMS/silica composite membranes demonstrated the potential of 3D printing as an economical and sustainable fabrication approach to developing materials for carbon capture applications.

Enhanced surface insulation for SiO2/epoxy resin composites through co-modification of nanofiller with silane coupling agent and plasma

To enhance the surface insulation properties of SiO2/epoxy resin composites, the SiO2 filler is co-modified with a chemical method and dielectric barrier discharge plasma in this work. The effects on the micro-structures, electrical parameters and surface insulation properties of the materials are studied. The results show that chemical modification using the silane coupling agent (KH550) can effectively introduce organo-functional groups into SiO2 filler. On the other hand, plasma modification shows little effect on the organo-functional group but significantly increases the dispersity of the nanoparticles, therefore reducing filler conglobation in epoxy resin composite. The composite samples with SiO2 doping concentration of 1 wt.%, 2 wt.%, 3 wt.%, 5 wt.% and 7 wt.% are prepared and characterized. It is found that the synergy of chemical and plasma methods could significantly improve the surface insulation of composite samples. Through doping 2 wt.% of the co-modified SiO2 filler, the direct current flashover voltage of the composites in dry air at atmospheric pressure can be increased to 1.53 times of the pure epoxy. The enhanced surface insulation properties are explained by the trap effect and the change of electrical parameters through the co-modification process.

Inert Filler Selection Strategies in Li-Ion Gel Polymer Electrolytes.

The main role of inert fillers in polymer electrolytes is to enhance ionic conductivity. However, lithium ions in gel polymer electrolytes (GPEs) conduct in liquid solvent rather than along the polymer chains. So far, the main role of inert fillers in improving the electrochemical performance of GPEs is still unclear. Here, various low-cost and common inert fillers (Al2O3, SiO2, TiO2, ZrO2) are introduced into GPEs to study their effects on Li-ion polymer batteries. It is found that the addition of inert fillers has different effects on ionic conductivity, mechanical strength, thermal stability, and, dominantly, interfacial properties. Compared with other gel electrolytes containing SiO2, TiO2, or ZrO2 fillers, those with Al2O3 fillers exhibit the most favorable performance. The high performance is ascribed to the interaction between the surface functional groups of Al2O3 and LiNi0.8Co0.1Mn0.1O2, which alleviates the decomposition of the organic solvent by the cathode, resulting in the formation of a high-quality Li+ conductor interfacial layer. This study provides an important reference for the selection of fillers in GPEs, surface modification of separators, and cathode surface coating.

In Situ Nano-SiO2 Electrospun Polyethylene-Oxide-Based Nano-Fiber Composite Solid Polymer Electrolyte for High-Performance Lithium-Ion Batteries

Polyethylene oxide (PEO)-based composite polymer electrolytes (CPEs) containing in situ SiO2 fillers are prepared using an electrostatic spinning method at room temperature. Through the in situ hydrolysis of tetraethyl silicate (TEOS), the generated SiO2 nanospheres are uniformly dispersed in the PEO matrix to form a 3D ceramic network, which enhances the mechanical properties of the electrolyte as a reinforcing phase. The interaction between SiO2 nanospheres and PEO chains results in chemical bonding with a decrease in the crystallinity of the PEO matrix, as well as the complexation strength of PEO chains with lithium ions during the hydrolysis process. Meanwhile, the addition of SiO2 nanospheres can disturb the orderliness of PEO chain segments and further suppress the crystallization of the PEO matrix. Therefore, improved mechanical/electrochemical properties can be obtained in the as-spun electrolyte with the unique one-dimensional high-speed ion channels. The electrospun CPE with in situ SiO2 (10 wt%, ca. 45 nm) has a higher ionic conductivity of 1.03 × 10-3 S cm-1 than that of the mechanical blending one. Meanwhile, the upper limit of the electrochemical stability window is up to 5.5 V versus Li+/Li, and a lithium-ion migration number can be of up to 0.282 at room temperature. In addition, in situ SiO2 electrospun CPE achieves a tensile strength of 1.12 MPa, elongation at the break of 488.1%, and it has an excellent plasticity. All in all, it is expected that the electrospun CPE prepared in this study is a promising one for application in an all-solid-state lithium-ion battery (LIB) with a high energy density, long life cycle, and high safety.

Influence of the nanostructural characteristics of inorganic fillers on the physical properties of resin cements.

Light-curing resin cements, each comprising one of five different inorganic fillers (non-porous and porous spherical SiO2 particles, irregularly shaped glass and ZrO2 particles, and porous ZrO2 spheres), monomers, and polymerization initiators were prepared to determine the effect of filler morphology on the adhesive strength of the resin cement. The strength of adhesion to a computer-aided design/computer-aided manufacturing (CAD/CAM) resin block was investigated mechanically by measuring the tensile bond strength, flexural strength, and elastic modulus. The resin cement containing sub-micron porous ZrO2 spheres had significantly higher tensile bond strength than the other resin cements. The resin cement containing the porous ZrO2 spheres had markedly lower flexural strength and elastic modulus values than the resin cements containing SiO2 and glass fillers.

Improving corrosion resistance of epoxy coating by optimizing the stress distribution and dispersion of SiO2 filler

The steel fiber textile overcomes mostly the shortcomings of traditional reinforcement materials. However, the poor corrosion resistance severely limits service life. In this study, based on the mechanism of stress corrosion and electrochemical corrosion, the epoxy resin anti-corrosion coating was designed and prepared. First, the von Mises stress distribution of lamellar and spherical fillers in epoxy resin was studied by finite element simulation, which confirmed that the stress distribution of spherical SiO2 filler was more uniform when it was stressed. In addition, to optimize the dispersion of spherical SiO2 in epoxy resin, the spherical polyaniline@SiO2 (PANI@SiO2) composites with core-shell structure were produced with in situ polymerization method. Ultrasonic C scanning results showed that the addition of PANI@SiO2 nano-filler can effectively reduce the defects in epoxy resin. Compared with bare steel fiber, the composites coating of 2 wt% PANI@SiO2/epoxy showed the most excellent resistance to stress corrosion and electrochemical corrosion. The capacitance diameter is two orders of magnitude higher, which has good stability in simulated concrete pore solution. This is due to the fact that the addition of PANI@SiO2 nanomaterials improves the physical shielding properties of epoxy, creating a labyrinth effect, and that PANI can produce passivation on the metal surface.

Influence of SiO2 Filler Addition on the Types I and II Shear Fracture Toughness of Hemp Fiber-Reinforced Epoxy Mixtures

Natural fiber composites are now more costly than traditional building materials. Currently, industries are moving from traditional materials to natural fiber composites, and the price of natural fiber should be reduced through greater utilization of industrial production. This work aims to determine how matrix alteration affects the interlaminar characteristics of a hemp fiber-reinforced epoxy composite containing nano silicon oxide particles. Interlaminar modulus of rupture in Types I and II is assessed using dual cantilevered beams and end-notched deformation testing samples. Mechanical mixing and sonication are used to blend nanoscale SiO2 (30 nm) into the resin at concentrations of 0, 0.2, 0.4, and 0.6 wt%. The composites were made using the compression molding method. The composites were tested according to the American Society for Testing and Materials standards after manufacturing. The findings show that adding nanoparticles enhances interlaminar toughness values. Interlaminar fracture toughness improved by 20.25% and 30.35% for 0.4 wt% SiO2, respectively. The fiber matrix interaction and failure causes are examined using scanning electron microscope images.

Effect of SiO2 microstructure on ionic transport behavior of self-healing composite electrolytes for sodium metal batteries

Batteries matched with flexible intelligent electronic devices are required in the future to supply dense and reliable power security. In addition to energy storage performance, functionalized design of batteries with good mechanical properties and self-healing ability is critical to the development of flexible intelligent electronic devices. The polymer with quadruple hydrogen bonds can give materials the ability to repair mechanical damage and restore the original mechanical properties. The incorporation of inorganic fillers into polymer electrolytes can improve the electrochemical properties and stability of the electrolytes. Optimization of the geometry of inorganic materials could further improve the electrical conductivity of composite electrolytes. In this work, a flexible self-healing polymer electrolyte (Poly (ethylene glycol)-co-ureidopyrimidinone), PEG-UPy) was synthesized. Three different microstructures of SiO2 fillers (solid, mesoporous, and hollow mesoporous) with UPy modified were designed to improve the sodium ion transport performance of the PEG-UPy self-healing polymer electrolyte for sodium ion batteries. The PEG-UPy electrolyte filled with hollow mesoporous SiO2 (PEG-UPy@hSiO2) exhibits an excellent electrochemical performance due to its unique structure among the samples. The PEG-UPy@hSiO2 electrolyte shows the highest ionic conductivity, sodium ion transference number, and appropriate self-healing property. The discharge capacity of NVP/PEG-UPy@hSiO2-NaTFSI (HCPE)/Na cell could reach 110.5 mAh g−1 at 0.1C and the capacity retention rate could reach more than 77.6% after 200 cycles at 60 °C.

XRD Measurement for Particle Size Analysis of PMMA Polymer Electrolytes with SiO2

PMMA-based polymer electrolytes with LiCF3SO3 lithium salt, EC plasticizer, and SiO2 filler are prepared using the solution cast method. SiO2 filler sizes at 10 ?m and 63 ?m are used to estimate the particle size in the polymer electrolytes syste

Localizing the cross-links distribution in elastomeric composites by tailoring the morphology of the curing activator

The localization of the rubber vulcanization reaction close to the silica filler surface was investigated in isoprene rubber composites (IR NCs): the main goal was to highlight the role of curing agents’ dispersion and filler surface features on the spatial propagation of the rubber cross-links and the resulting mechanical behavior of the material. The study was realized by tailoring the morphology of the curing activator, i.e. by vulcanizing IR NCs with Zn@SiO2 double function filler, composed of Zn(II) single sites anchored on SiO2 filler, in comparison to silica filled IR NCs vulcanized with microcrystalline ZnO . The microscopic cross-links distribution was measured by Transmission Electron Microscopy for network visualization (NVTEM) and Time Domain Nuclear Magnetic Resonance (TD-NMR). Besides the NCs mechanical behavior was characterized both at small strain and at fracture. In the presence of Zn@SiO2, higher cross-link density in proximity to SiO2 particles was evidenced, which gradually spreads from the filler surface to the bulk, induced by localization of the Zn(II) centers. IR NCs with Zn@SiO2 resulted stiffer (+45%) and with a lower fracture toughness (less than one third), compared to m-ZnO based NCs, which shows a quite homogeneous structure of the rubber cross-links network. The results highlighted the correlation between the composites structural features and their macroscopic behavior, paving the way to modulating the mechanical properties of elastomeric materials by tuning the nature of the curing agents.

Silan Kaplı SiO2 Nanopartiküllerin Cam FRP Kompozitlerin Sertlik Değerlerine Etkisi

In this study, silane-coated SiO2 nanoparticles (as-received) were used as secondary reinforcement for glass fiber-reinforced polymer (FRP) composites, and the microhardness values of the developed composites were investigated. The nanoparticles were dispersed within the polymer epoxy at 1.5 wt.% and 3 wt.% ratios, respectively. Two different types of silane coating were used that were KH550 and KH570. The mixture of the epoxy resin and nanoparticles were subjected to ultrasonic homogenization to achieve a fine dispersibility of the SiO2 nanoparticles. Then the matrix was prepared with a suitable hardener at a weight ratio of 100:25. The strengthened polymer matrix was reinforced by woven glass fiber fabrics (primary reinforcing element). The vacuum bag method was applied to produce silane-coated nano SiO2 filled glass FRP composites. A digital microhardness testing device was used to determine the Vickers hardness values. While the pure glass/epoxy composite has resulted in a hardness of 20.69 HV, the maximum hardness value was recorded as 36.56 HV and it was obtained with 3 wt.% KH550-SiO2 filled glass/epoxy. The incorporation of silane-coated SiO2 nanoparticles has provided dramatic enhancements, approximately from 28% to 77%. The microscopic examination was also conducted via an optical microscope and the images were found helpful to explain the test results. Therefore, the findings of this study have shown that silane-coated nano SiO2 filler can be used as secondary reinforcement where high hardness and better wear resistance are desired for glass/epoxy composite applications.

Preparation of polypropylene-based thermally conductive composites via multiple injection compression molding method

With the increasing power consumption of electronic devices, this leads to a huge challenge in terms of heat dissipation. In order to solve the problem of heat dissipation in electronic equipment and to improve the stability and life of electronic equipment. This paper reports polypropylene (PP)/carbon fiber (CF)/Al2O3, PP/CF, PP/CF/SiO2 composites with excellent properties, which are prepared by two different methods: injection molding (IM) and injection compression (IC). The PP/CF/Al2O3 and PP/CF/SiO2 composites contain a constant 5 wt% of Al2O3 and SiO2 fillers. Different processing methods are used to prepare the composites in order to investigate the effect of different processing methods on the mechanical properties and thermal conductivity of the composites. The PP/CF/Al2O3 composite (0.475 W/(m⋅K)) prepared by IC method (6 × 0.5 mm) has good thermal conductivity, 15.90% higher than that of the PP/CF/Al2O3 composite (0.410 W/(m⋅K)) prepared by IM method. In addition, the PP/CF/Al2O3 composite has good mechanical properties (tensile strength and elongation at break are 4.22% and 14.176 MPa respectively). This method of IM has great potential for the continuous production of thermally conductive composites.

Toughening and Heat-Resistant Modification of Degradable PLA/PBS-Based Composites by Using Glass Fiber/Silicon Dioxide Hybrid Fillers.

In this paper, to enhance the toughness and heat resistance properties of polylactic acid (PLA)/polybutylene succinate (PBS) composites, the PLA/PBS matrix was modified by different glass fiber (GF), GF/SiO2, and GF/(Polyaluminium chloride) PAC fillers. Additionally, the effect of filler type, filler content, components interaction and composite structure on the mechanical and thermal properties of the PLA/PBS composites was researched. The results showed that the addition of GF, GF/SiO2 and GF/PAC make the PLA/PBS composites appear significantly higher mechanical properties compared with the pristine PLA/PBS composite. Among the different inorganic fillers, the 10%GF/1%SiO2 fillers showed excellent strengthening, toughening and heat resistant effects. Compared with the pristine PLA/PBS matrix, the tensile strength, elastic modulus, flexural strength, flexural modulus and Izod impact strength improved by 36.28%, 70.74%, 67.95%, 66.61% and 135.68%, respectively. Considering the above, when the weight loss rate was 50%, the thermal decomposition temperature of the 10%GF/1%SiO2 modified PLA/PBS composites was the highest 412.83 °C and its Vicat softening point was up to 116.8 °C. In a word, the 10%GF/1%SiO2 reinforced PLA/PBS composites exhibit excellent mechanical and thermal properties, which broadens the application of biodegradable materials in specific scenarios.

Erosion wear behavior of bamboo fiber-reinforced high-density polyethylene composites with nano silicon dioxide filler subjected to rotary water jet

The erosion wear behavior of bamboo fiber-reinforced high-density polyethylene (HDPE) composites with silicon dioxide (SiO2) nanoparticles filler was investigated based on the sand-carrying water (a mixture of water and garnet sand) jets (SCWJ). The composites consisted of varying weight percentage of SiO2 fillers were prepared through press molding technology. Based on the rotating water jet technique, the erosion wear performance of composites was considered with varying erosion times and shooting distances. The results showed that composites filled with SiO2 possessed better resistance to SCWJ erosion. The erosion resistance of the composites highly corresponds to their impact strength. The maximum erosion rate occurred at a shooting distance of 0.5 cm and an erosion duration of 180 s. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis further demonstrated that the erosive wear mechanisms mainly included the pulverization of bamboo fibers, brittle fracture of HDPE matrix, and increase in oxygen content.

Synergistically Active Piezoelectrical H2 O2 Production Composite Film Achieved from a Catalytically Inert PVDF-HFP Matrix and SiO2 Fillers.

Local and decentralized H2 O2 production via a piezoelectrical process promises smart biological utilization as well as environmental benefits. However, stable, bio/environmentally safe, and easily applied H2 O2 generation materials are still lacking. Here, we report a novel flexible H2 O2 generation polymeric film composed of catalytically inert PVDF-HFP (Poly(vinylidene fluoride-co-hexafluoropropylene)) matrix and SiO2 nanoparticle fillers. The film is bio-/environmentally benign at resting states, but effectively produces H2 O2 upon ultrasonic motivation at a production rate of 492 μmol in one hour. Experimental and simulation methods in combination indicate that the effective H2 O2 generation capabilities stem from the synergistic existence of piezoelectrical fields and the air-liquid-solid three-phase regions around the porous film. The chemical conversions are motivated by the adsorbed charges. The silicon hydroxyl groups properly stabilize the *OOH intermediate and facilitate the chemical conversions of 2e- ORR of ambient O2 . We expect the report to inspire H2 O2 piezoelectrical generation materials and promote the novel production strategies of H2 O2 as well as piezoelectrical functional materials.

High-throughput finite-element design of dielectric composites for high-frequency copper clad laminates

Dielectric substrates with low dielectric constant and good thermal stability are highly desired for high-frequency and high-speed signal transmission. It is however challenging to rationally design the demand-satisfied polymer-based composites due to the inadequate understanding of the contradictory effect of inorganic fillers on modulating dielectric-thermal-mechanical properties. In this work, taking Polytetrafluoroethylene (PTFE)-SiO2 composite as the example, we perform high-throughput finite-element calculations to systematically study the filler effects on the dielectric constant of composites εrcomposite and the coefficient of thermal expansion of composites (CTE-c). A series of influencing factors including intrinsic property, volume fraction, shape, distribution, and orientation of fillers have been considered in our models to establish the structure-property mapping of dielectric composites. It is found that CTE-c is more sensitive to the filler structure of PTFE-SiO2 composites than εrcomposite. Finally, guided by the calculation results, a skeleton structure is proposed to realize the performance targets of εrcomposite< 2.3 and CTE-c < 60 ppm/K with lower SiO2 filler content. This work provides a universal data-driven strategy for the rational design of dielectric composites with multi-objective requirements, and it is expected to spark more experimental efforts to design novel dielectric composites for high-quality signal transmission.

Phosphorylated chitosan/poly(vinyl alcohol) based proton exchange membranes modified with propylammonium nitrate ionic liquid and silica filler for fuel cell applications

In our previous work, phosphorylated chitosan was modified through polymer blending with poly(vinyl alcohol) (PVA) polymer to produce N-methylene phosphonic chitosan/poly(vinyl alcohol) (NMPC/PVA) composite membranes. The aim of this work is to further investigate the effects of a propylammonium nitrate (PAN) ionic liquid and/or silicon dioxide (SiO2) filler on the morphology and physical properties of NMPC/PVA composite membranes. The temperature-dependent ionic conductivity of the composite membranes with various ionic liquid and filler compositions was studied by varying the loading of PAN ionic liquid and SiO2-PAN filler in the range of 5–20 wt%. As the loading of PAN ionic liquid increased in the NMPC/PVA membrane matrix, the ionic conductivity value also increased with the highest value of 0.53 × 10−3 S cm−1 at 25 °C and increased to 1.54 × 10−3 S cm−1 at 100 °C with 20 wt% PAN. The NMPC/PVA-PAN (20 wt%) composite membrane also exhibited the highest water uptake and ion exchange capacity, with values of 60.5% and 0.60 mequiv g−1, respectively. In addition, in the single-cell performance test, the NMPC/PVA-PAN (20 wt%) composite membrane displayed a maximum power density, which was increased by approximately 14% compared to the NMPC/PVA composite membrane with 5 wt% SiO2-PAN. This work demonstrated that modified NMPC/PVA composite membranes with ionic liquid PAN and/or SiO2 filler showed enhanced performance compared with unmodified NMPC/PVA composite membranes for proton exchange membrane fuel cells.

Adhesion mechanism between mold resin and sputtered copper for electromagnetic wave shield packages

As mobile information and communication terminals become smaller and more sophisticated, electronic device manufacturers are increasingly demanding that electromagnetic interference measures be added to individual electronic components assembled on high-density printed circuit boards. Therefore, semiconductor device products require a process for forming electromagnetic wave shielding film. Sputtered film deposition methods with stable processes are increasingly used for the formation of shield films. Although Cu is often used as the shield film, there has been little discussion of the adhesion mechanism with the mold resin used in semiconductor device products. In this work, Cu film was sputter-deposited onto mold resin under a variety of conditions, and the factors that influence adhesion were investigated. The results show that it is necessary to carry out degassing in the sputtering equipment at temperatures higher than 180°C, above which the amount of degassing increases. No clear relationship was found between surface roughness and adhesion. The exposure ratio of the SiO2 filler was found to be related to adhesion. The mechanism of adhesion between the mold resin and sputter-deposited Cu film was considered from the experimental results, and the following models are proposed. Plasma etching exposes SiO2 filler at the surface of the mold resin and increases the surface free energy. The surface becomes activated, which is thought to create adhesion between the Cu and SiO2 filler.

Sea water effect on the mechanical properties of glass reinforced composite with Sio2 and Tio2 fillers

In this project we determine the moisture absorption behavior and mechanical properties of GFRP composites filled with Sio2 & Tio2. The composite prepared with glass reinforced vinyl ester with silicon Dioxide and Titanium oxide as a filler Materials by hand lay-up technic. The specimens are submerged for 56 days in artificial sea water then tested for mechanical properties. The studies show that Sio2 and Tio2 can be used for vinyl ester resin as a toughening modifier. After long term ageing of dry specimen the ultimate tensile strength is decreased by 28.46% & flexural strength decreased by 36.32%.