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The T g for polystyrene matrices and SiO 2 -PS com- posites. The composites are labeled with vol.% of SiO 2 only.
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Polymer nanocomposites have improved mechanical, optical and thermal properties compared to traditional thermoplastics. To study the impact of grafted brush–matrix interactions on the mechanical properties of nanoparticle filled polymers, uniaxial tensile testing with digital image correlation (DIC) was done on polystyrene (PS) grafted SiO2 in low...
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... for amorphous polymers the T g is very important. The T g values are shown in Table 2 below. The 100k PS composites and matrix T g values are within error of each other. ...
Similar publications
Surface functionalization of silica nanoparticles (SiNP) has gained attention as an efficient methodology in improving the properties of the proton exchange membrane (PEM). Here, we report the development of block copolymer grafted SiNP (BC-g-SiNP) as functional nanofiller which was further blended with oxypolybenzimidazole (OPBI) to prepare nanoco...
Citations
... Although some examples on the impact of HNPs on the mechanical properties of polymer-based NCs are reported in the literature [24][25][26][27][28][29], there are very few examples relating to elastomers. Bonnevide et al. reported the synthesis of SiO 2 NPs decorated with grafted polyisoprene (PI), polybutadiene (PB) and styrene-butadiene rubber (SBR) brushes through a grafting-from approach [30] and, in particular, investigated the morphologies of PI-grafted NPs aggregates in PI and SBR matrices, showing evidences of self-assembly process [31]. ...
... Although some Authors previously reported on the HNPs organization [52,53] for NCs based on polymer matrices with high Tg, such as polystyrene (PS) lled with PS-grafted HNPs, there is a lack of information on the preparation of HNPs having low Tg elastomers as hairs [34,40], such as PB [54,55] or PI [24,27]. ...
With the aim to identify possible strategies to reduce the environmental impact of tyre, we propose the use of advanced rubber materials based on silica hairy nanoparticles (HNPs), which consist of a core of silica surrounded by end-grafted rubber chains. The rational has been to impart unique surface reactivity to the silica NPs, usually used as reinforcing fillers, for coupling with the non-crosslinked host elastomer as well as the subsequent ability to employ coupling agents other than the conventional sulfur-bridged bis-alkoxy silanes. SiO2 HNPs, having polybutadiene (PB) chains as polymeric brushes, were prepared with different degrees of PB grafting density and embedded in elastomer to produce rubber nanocomposites (NCs), following the standard tyre formulation but without using silane coupling agents. A deep investigation on the relation between the mechanical properties of the NCs materials and HNPs self-assembling behavior was performed, showing a high degree of structural order and a significant percolative HNPs network. In fact, silica HNPs can build anisotropic energy-dissipation structures which act as additional cross-linking junctions reducing the chain relaxation and consequently enhancing the chain deformation.
The presence of self-assembled fillers domains induces a reduction in the mobility of the filler and consequently in the energy consumption due to the deformation of the microstructure of the rubber composite, with its breakage and subsequent recovery, not completely reversible. For this, the present study supports the use of HNPs as reinforcing filler for producing more sustainable rubber materials.
... An interesting suitable solution is the introduction of inorganic nanoparticles (NPs) endowed with high refractive index into polymer matrixes. 7 These systems, defined as polymer nanocomposites, 8 according to Rayleigh's law are transparent when the dispersed phase is smaller than 40 nm. 9 A family of nanocomposites widely reported in the literature is based on titanium dioxide NPs, since TiO 2 has a relatively large refractive index (n = 2.45 and 2.7 at 500 nm for anatase and rutile phases, respectively), 10 has no absorptions in the visible light range, and can be easily produced as nanocrystals with controlled size and shape. ...
Transparent nanocomposite films made of surface-modified titanium dioxide nanoparticles and thermoplastic polyurethane are prepared via film casting approach showing enhanced refractive indexes and mechanical properties. Two different sets of composites were prepared up to 37.5 wt % of inorganic nanoparticles with a diameter <15 nm, one set using particles capped only with oleic acid and a second one with a bimodal system layer made of oleic acid and mPEO-5000 as coating agents. All of the composites show significantly enhanced refractive index and mechanical properties than the neat polymeric matrix. The transparency of nanocomposite films shows the excellent dispersion of the inorganic nanoparticles in the polymeric matrix avoiding aggregation and precipitation phenomena. Our study provides a facile and feasible route to produce transparent nanocomposite films with tunable mechanical properties and high refractive indices for various applications.
... This results in reduced weight, improved fuel efficiency, and enhanced overall performance of aerospace systems [48]. The incorporation of CeAlO 3 nanoparticles in the synthesis of CeAlO 3 nanoparticles and nano-CeAlO 3 epoxy composite materials is aimed at enhancing the composite's properties and expanding its applications across various fields [49]. The integration of nanofillers into polymer matrices represents a promising strategy to enhance resistance against chemical degradation and environmental challenges. ...
This study explores enhancing epoxy polymers with cerium aluminate (CeAlO3) nanoparticles via a solution combustion process. CeAlO3 loading (0.5 to 2.5 wt.%) significantly influences resulting composite properties. Characterization techniques confirm CeAlO3 presence, porous spherical morphology, and formation. FTIR spectroscopy identifies functional groups, while TGA shows excellent thermal stability below 200 °C, with minimal mass loss, and stability at 900 °C. The composites exhibit enhanced properties, with maximum tensile strength at 0.5 wt.%, a linear increase in tensile modulus up to 2.5 wt.%, and maximum compressive strength at 0.5 wt.%, with increasing modulus at higher filler loadings. These findings suggest CeAlO3-filled epoxy composites hold promise for high-temperature applications, emphasizing the importance of low filler concentrations for optimal structural properties. Overall, this research underscores the potential of CeAlO3 nanoparticles in advancing epoxy-based materials across various industries.
... Giovino et al. [105] grafted polystyrene (PS) on the surface of nano SiO 2 particles. In this study, two types of polystyrene were grafted to particle surface: (I) polystyrene brush with MW ¼ 8 kg/mol and graft density ¼ 0.25 chains/nm 2 , and (II) polystyrene brush with MW ¼ 110 kg/mol and graft density ¼ 0.07 chains/nm. ...
... As a result, the gluecoated scanning probe provides better compliance at the contact when it is pushed against the sandpaper under a normal load. Meanwhile, mixing the nanoparticles into the glue reduces the adhesion of the probe to the sandpaper and strengthens the mechanical properties of the glue 43 . ...
Friction between two rough solid surfaces often involves local stick-slip events occurring at different locations of the contact interface. If the apparent contact area is large, multiple local slips may take place simultaneously and the total frictional force is a sum of the pinning forces imposed by many asperities on the interface. Here, we report a systematic study of stick-slip friction over a mesoscale contact area using a hanging-beam lateral atomic-force-microscope, which is capable of resolving frictional force fluctuations generated by individual slip events and measuring their statistical properties at the single-slip resolution. The measured probability density functions (PDFs) of the slip length δxs, the maximal force Fc needed to trigger the local slips, and the local force gradient k′ of the asperity-induced pinning force field provide a comprehensive statistical description of stick-slip friction that is often associated with the avalanche dynamics at a critical state. In particular, the measured PDF of δxs obeys a power law distribution and the power-law exponent is explained by a new theoretical model for the under-damped spring-block motion under a Brownian-correlated pinning force field. This model provides a long-sought physical mechanism for the avalanche dynamics in stick-slip friction at mesoscale.
... Chemical interactions with PS are facilitated by incorporating appropriately functionalized POSS, as in the case of POSS cages with vinyl or vinylidene moieties. The mechanical properties of SiO 2 -PS composites with grafted chain conformation were dependent on the P/N ratio [118], where P is the degree of polymerization of the matrix and N is the degree of polymerization of the grafted brush. High composite strength is expected at N~P, with swollen grafted chains. ...
... Chemical interactions with PS are facilitated by incorporating appropriately functionalized POSS, as in the case of POSS cages with vinyl or vinylidene moieties. The mechanical properties of SiO2-PS composites with grafted chain conformation were dependent on the P/N ratio [118], where P is the degree of polymerization of the matrix and N is the degree of polymerization of the grafted brush. High composite strength is expected at N ~ P, with swollen grafted chains. ...
Several environmental and techno-economic assessments highlighted the advantage of placing polystyrene-based materials in a circular loop, from production to waste generation to product refabrication, either following the mechanical or thermochemical routes. This review provides an assortment of promising approaches to solving the dilemma of polystyrene waste. With a focus on upcycling technologies available in the last five years, the review first gives an overview of polystyrene, its chemistry, types, forms, and varied applications. This work presents all the stages that involve polystyrene’s cycle of life and the properties that make this product, in mixtures with other polymers, command a demand on the market. The features and mechanical performance of the studied materials with their associated images give an idea of the influence of recycling on the structure. Notably, technological assessments of elucidated approaches are also provided. No single approach can be mentioned as effective per se; hybrid technologies appear to possess the highest potential. Finally, this review correlates the amenability of these polystyrene upcycling methodologies to frontier technologies relating to 3D printing, human space habitation, flow chemistry, vertical farming, and green hydrogen, which may be less intuitive to many.
... For comparison, the water absorption of epoxy resin-based biocomposites with expanded graphite was decreased with an increased amount of the hydrophobic filler [23]. In order to thoroughly investigate the relationship between internal structure of composites and their macroscopic properties, the scanning electron microscopy images of their cross-sections should be taken [29]. This could provide an insight into a such bulk phenomena as aggregation, dispersion, and orientation of microparticles which would allow researchers to estimate interactions at the microparticle/epoxy resin matrix interface. ...
The aim of the research presented in the paper was to obtain new polymer composites with strong functional properties on the Epidian 5 epoxy resin matrix. The polymer composites contained admixtures of expanded graphite, powder graphite, birch bark containing botulin, and yellow dextrin in set amounts of 20% by weight. Their various mechanical parameters and physicochemical properties were investigated. The research involved determining the effect of a constant magnetic field with magnetic induction B, under the influence of which the parameters and properties of polymer composites have been changed. For example, in a constant magnetic field with an induction of B = 0.5 T there was an increase in the hardness of the composite with an admixture of birch bark from 24.01 to 26.96 N/mm² (12.3%), or in the composite with the addition of yellow dextrin from 26.12 to 29.93 N/mm² (14.6%). It was also found, for example, that the water absorption of the resin itself decreased from 0.18% to 0.13%, and the composite with graphite powder from 0.48% to 0.46%. Changes in these parameters, often beneficial, may be important in terms of potential application of those new materials in industry as alternatives.
... The shape, properties, and extent of the constituent, as well as the interfacial interactions of the matrix and the dispersed phase, all influence the properties of composites. Nanoparticles, [5] nanofibers, [6] and nanoclays [7] are types of nanomaterials used in fabrication composites. When the size of one of the constituents of the composite is on a nanometric scale, the word nanocomposites (NCs) suits more. ...
Polymer nanocomposites are materials that are prepared by incorporating nanoparticles into polymer matrices. In the last few decades, polymer nanocomposites have been investigated extensively and had undergone tremendous advancements. Transparent nanocomposites are of particular interest among several polymer nanocomposites due to the wide variety of applications. Therefore, this article aims to provide consolidated and in-depth knowledge about the capabilities of transparent polymers when combined with various nanoparticles like metal oxide, metal, semiconductor, carbon-based nanocomposites, etc. Challenges and future scope are also covered along with the synthesis, characterization and applications.
... Many researchers have reported that polymer-brush modifications result in changes in the morphology and surface properties of SiO 2 , such that the particles are arranged into an ordered array. 14,18,20,22,23 Moreover as a result of polymerbrush-modification, changes in particle properties, optical characteristics, and dielectric characteristics have been reported. [24][25][26][27][28][29] However, the effect of polymer-brush-modification on surface reactions have hardly been investigated. ...
Oxygen permeation of perovskite‐type ceramics consists of three elementary processes: oxygen absorption, bulk oxygen diffusion, and oxygen desorption. In most cases, the rate‐determining step is the oxygen diffusion step, and the use of thin films improves the oxygen permeation rate of perovskite‐type ceramics. Polymer‐brush‐modification is a useful technique to produce thin films. Grafted PMMA‐brushes exhibit a screening effect for attractive interactions between core ceramic particles, thereby inducing repulsive forces on them. This results in the formation of a densely packed ordered array. Modification of the polymerization‐initiator and polymer‐brushes should affect the oxygen permeation properties of the ceramic particles, especially surface oxygen adsorption and desorption. In this paper, it is demonstrated that these modifications change the cation chemical states and lower the oxygen desorption rate, while increasing the desorption peak temperature. The surface of La–Sr–Co–Fe perovskite‐type oxides was modified only with the polymerization initiator, (2‐bromo‐2‐methyl)propionyloxyhexyltriethoxysilane (BHE) because there is no direct interaction between the polymer‐brush and the substrate, while the initiator is directly modified to the substrate. The oxygen desorption behavior of BHE‐modified oxides indicates that its oxygen desorption property is impeded without modification with PMMA. The investigation of BHE‐modified oxide cation chemical states and oxygen desorption behaviors imply that the BHE‐modifying site and change in chemical states have selectivity depending on cation species. Although sintering causes the formation of silicate and ceramic decomposition, this step can eliminate the harmful effects of BHE‐modification in total. When conventional La–Sr–Co–Fe perovskite‐type ceramics are used, sintering is preferable for the recovery of thin‐film surface reactions. However, if we utilize site selectivity of BHE‐modification, the harmful effects of those modifications can be avoided by modifying BHE onto sites that hardly participate in surface reactions.
... The fracture surface of the composites exhibited short and disorderly cracks when the content of KH550-AlOOH was 0.6 wt%, as shown in Fig. 10d, and KH550-AlOOH evenly dispersed in the matrix and the strong interaction made the crack directions of the composite change and present arborization when the composite was subjected to external forces. The reasons were possible, first of all, nanoparticles as the stress concentration point, it pinned craze and kept it from developing cracks [36,37], and at the same time, a large number of craze and shear zones were formed which expended a lot of fracture energy, and the toughness of the material had been observably improved [38]. Secondly, KH550-AlOOH@GO existed in the matrix with a special lamellar structure, and when composite was subjected to the external force, the stress was absorbed by the lamella through the interface between composite and particles, and the residual stress fractured at the sharp corners of the lamella to produce holes and a large number of micro-cracks, and the stress field interacted strongly around the nanoparticles. ...
Graphene oxide (GO) was obtained by improved Hummers method; the pseudoboehmite (AlOOH) nanoparticles were prepared with aluminum isopropoxide by Sol–Gel method and modified by the silane coupling agent (KH-550) to get KH550-AlOOH. GO was coated by KH550-AlOOH to gain KH550-AlOOH@GO component. In the meantime, the matrix (E51-BCE) was synthesized from epoxy resin (E51) and bisphenol A cyanate (BCE). KH550-AlOOH@GO/E51-BCE composites were prepared via in situ polymerization, E51-BCE as the matrix and KH550-AlOOH@GO as the reinforcement. The micro-morphology of KH550-AlOOH@GO was investigated by Fourier transform infrared spectrometer (FT-IR) and transmission electron microscope (TEM), and the results showed that KH550-AlOOH was well distributed on the GO sheet and with abundant hydroxyl groups on its surface. The X-ray diffraction (XRD) and scanning electron microscope (SEM) of KH550-AlOOH@GO/E51-BCE composites indicated that KH550-AlOOH@GO was uniformly dispersed in E51-BCE matrix and there was a good interaction between them, which was conducive to the performances of the composite material. Mechanical and dielectric properties of composite also were tested and analyzed. The highest bending strength, bending modulus, and impact strength of KH550-AlOOH@GO/E51-BCE composites were 158.23 MPa, 2.37 GPa, and 46.96 kJ/m², respectively, when the content of KH550-AlOOH@GO was 0.6 wt%, which were 15.72%, 22.42%, and 198.22% higher than those of the matrix resin, respectively. The dielectric constant and dielectric loss of the composite were 3.12 and 0.0027 at 100 Hz.
