Articles de revues : « Layered nanofillers »

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Galimberti, Maurizio, Valeria Cipolletti, Sara Musto, Serena Cioppa, Giulia Peli, Marco Mauro, Guerra Gaetano, Silvia Agnelli, Riccò Theonis et Vineet Kumar. « RECENT ADVANCEMENTS IN RUBBER NANOCOMPOSITES ». Rubber Chemistry and Technology 87, n^o 3 (1 septembre 2014) : 417–42. http://dx.doi.org/10.5254/rct.14.86919.

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ABSTRACT Nanocomposites were prepared via melt blending, based on organically modified clays (OC), carbon nanotubes (CNT), and graphitic nanofillers made by a few layers of graphene (nanoG). In particular, nanocomposites based on a hybrid filler system, with a nanostructured filler such as carbon black (CB), are examined. It is shown that low crystalline order in the interlayer space of a layered nanofiller (such as OC and nanoG) leads to easier delamination. Nanofillers give rise to filler networking at low concentration, particularly in the presence of CB. Hybrid filler systems lead to nanocomposites' having initial moduli that are much higher than those calculated through the sum of the initial modulus of composites containing either only CB or only the nanofiller. Nanofillers enhance the matrix modulus by a multiplication factor that depends only on the nanofiller type and content, regardless of whether the matrix is a neat or a CB-filled polymer. Furthermore, the filler–polymer interfacial area is shown to be a parameter able to correlate the mechanical behavior of both nano-CNT and nanostructured (CB) fillers. By plotting values of the composite initial modulus versus the filler–polymer interfacial area, points due to CB, CNT, and the hybrid CB-CNT system lie on the same curve.

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Mochane, Mokgaotsa Jonas, Sifiso Innocent Magagula, Jeremia Shale Sefadi, Emmanuel Rotimi Sadiku et Teboho Clement Mokhena. « Morphology, Thermal Stability, and Flammability Properties of Polymer-Layered Double Hydroxide (LDH) Nanocomposites : A Review ». Crystals 10, n^o 7 (14 juillet 2020) : 612. http://dx.doi.org/10.3390/cryst10070612.

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The utilization of layered nanofillers in polymer matrix, as reinforcement, has attracted great interest in the 21st century. This can be attributed to the high aspect ratios of the nanofillers and the attendant substantial improvement in different properties (i.e., increased flammability resistance, improved modulus and impact strength, as well as improved barrier properties) of the resultant nanocomposite when compared to the neat polymer matrix. Amongst the well-known layered nanofillers, layered inorganic materials, in the form of LDHs, have been given the most attention. LDH nanofillers have been employed in different polymers due to their flexibility in chemical composition as well as an adjustable charge density, which permits numerous interactions with the host polymer matrices. One of the most important features of LDHs is their ability to act as flame-retardant materials because of their endothermic decomposition. This review paper gives detailed information on the: preparation methods, morphology, flammability, and barrier properties as well as thermal stability of LDH/polymer nanocomposites.

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Zilg, Carsten, Frank Dietsche, Botho Hoffmann, Christoph Dietrich et Rolf M�hlhaupt. « Nanofillers based upon organophilic layered silicates ». Macromolecular Symposia 169, n^o 1 (mai 2001) : 65–77. http://dx.doi.org/10.1002/1521-3900(200105)169:1<65 ::aid-masy65>3.0.co;2-f.

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Maiti, Madhuchhanda, Mithun Bhattacharya et Anil K. Bhowmick. « Elastomer Nanocomposites ». Rubber Chemistry and Technology 81, n^o 3 (1 juillet 2008) : 384–469. http://dx.doi.org/10.5254/1.3548215.

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Abstract Recently, elastomer - nanocomposites reinforced with low volume fraction of nanofillers have attracted great interest due to their fascinating properties. The incorporation of nanofillers such as layered silicate clays, carbon nanotubes, nanofibers, calcium carbonate, metal oxides or silica nanoparticles into elastomers improves significantly their mechanical, thermal, dynamic mechanical, barrier properties, flame retardancy, etc. The properties of nanocomposites depend greatly on the chemistry of polymer matrices, nature of nanofillers, and the method in which they are prepared. The uniform dispersion of nanofillers in elastomer matrices is a general prerequisite for achieving desired mechanical and physical characteristics. In this review article, current developments in the field of elastomer nanocomposites reinforced with layered silicates, silica, carbon nanotubes, nanofibers and various other nanoparticles have been addressed. Attention has been paid to the structure and properties of such high-performance nanocomposites, along with the theories and models existing in this field.

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Pradhan, Sharmila, Ralf Lach, Wolfgang Grellmann et Rameshwar Adhikari. « Nanofiller Reinforced Polyolefin Elastomer : Effect on Morphology and Mechanical Properties of Composites ». Nepal Journal of Science and Technology 13, n^o 2 (8 mars 2013) : 103–8. http://dx.doi.org/10.3126/njst.v13i2.7721.

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The effect of different types of fillers on morphology and mechanical properties of polymer nanocomposites has been investigated using ethylene-1–octene copolymer (EOC), a polyolefin based elastomer, as matrix and various nanofillers {such as multi-walled carbon nanotubes (MWCNT), layered silicate (LS) and boehmite (OS2)}. The morphological structures were studied by scanning electron microscopy (SEM) while the mechanical properties were characterized by tensile testing and microindentation hardness measurements. It has been shown that the nature of the nanofiller may have significant influence on the mechanical properties of the samples. Among the nanocomposites studied so far, the MWCNT filled samples showed the highest reinforcing effect followed by layered silicate. The least reinforcing effect was obtained for the samples filled with boehmite nanoparticles. Nepal Journal of Science and Technology Vol. 13, No. 2 (2012) 103-108 DOI: http://dx.doi.org/10.3126/njst.v13i2.7721

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Enotiadis, Apostolos, Lamprini G. Boutsika, Konstantinos Spyrou, Cataldo Simari et Isabella Nicotera. « A facile approach to fabricating organosilica layered material with sulfonic groups as an efficient filler for polymer electrolyte nanocomposites ». New Journal of Chemistry 41, n^o 17 (2017) : 9489–96. http://dx.doi.org/10.1039/c7nj01416c.

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Wen, Shipeng, Rui Zhang, Zongchao Xu, Long Zheng et Li Liu. « Effect of the Topology of Carbon-Based Nanofillers on the Filler Networks and Gas Barrier Properties of Rubber Composites ». Materials 13, n^o 23 (28 novembre 2020) : 5416. http://dx.doi.org/10.3390/ma13235416.

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The topology of nanofillers is one of the key factors affecting the gas barrier properties of rubber composites. In this research, three types of carbon-based nanofillers, including spherical carbon black (CB), fibrous carbon nanotubes (CNTs), and layered graphene (GE) were chosen to investigate the effect of the topological structures of nanofillers on the gas barrier properties of styrene-butadiene rubber (SBR) composites. Results showed that the structure and strength of the filler networks in SBR composites were closely associated with the topology of nanofillers. When filled with 35 phr CB, 8 phr CNTs, and 4 phr GE, the SBR composites had the same strength of the filler network, while the improvement in gas barrier properties were 39.2%, 12.7%, and 41.2%, respectively, compared with pure SBR composites. Among the three nanofillers, GE exhibited the most excellent enhancement with the smallest filler content, demonstrating the superiority of two-dimensional GE in improving the barrier properties of rubber composites.

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Danowska, Magdalena, Łukasz Piszczyk, Michał Strankowski, Maria Gazda et Józef T. Haponiuk. « Rigid polyurethane foams modified with selected layered silicate nanofillers ». Journal of Applied Polymer Science 130, n^o 4 (20 mai 2013) : 2272–81. http://dx.doi.org/10.1002/app.39432.

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Prateek, Shahil Siddiqui, Ritamay Bhunia, Narendra Singh, Ashish Garg et Raju Kumar Gupta. « Interface modulation in multi-layered BaTiO3 nanofibers/PVDF using the PVP linker layer as an adhesive for high energy density capacitor applications ». Materials Advances 1, n^o 4 (2020) : 680–88. http://dx.doi.org/10.1039/d0ma00240b.

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In this work, we have studied the role of a linker across the interface in a multi-layered polymer nanocomposite-based capacitor using barium titanate (BT) nanofibers (NFs) as nanofillers and polyvinylidene fluoride (PVDF) as the polymer matrix.

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Zhou, Ke Qing, Zhou Gui et Yuan Hu. « MoS₂ : Advanced Nanofillers for Polymer Nanocomposites ». Advanced Materials Research 1105 (mai 2015) : 21–25. http://dx.doi.org/10.4028/www.scientific.net/amr.1105.21.

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Since discovery of graphene, great attention had been paid to other two dimensional (2D) layered materials. As a graphene-like layered nanomaterial, molybdenum disulfide (MoS2) had gained enormous attention from the materials fields which had been widely used in many areas such as solid lubricants, lithium ion batteries, photocatalysts, sensors or as conductive fillers in polymer composites. In this work, MoS2 nanosheets were incorporated into polymer matrix as nanofillers by three typical preparation methods, including solvent blending, in situ polymerization and melt blending method. The MoS2 nanosheets were dispersed well in the polymer matrices which improved the thermal stability, mechanical properties and reduced fire hazards of the composites obviously. The improvements in the thermal properties, fire resistance properties and mechanical properties of polymer/MoS2 nanocomposites were mainly attributed to good dispersion of MoS2, physical barrier effects of MoS2 and catalytic char function of MoS2 nanosheets.

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Cai, Guipeng, Aravind Dasari, Zhong-Zhen Yu, Xusheng Du, Shaocong Dai, Yiu-Wing Mai et Jiyang Wang. « Fire response of polyamide 6 with layered and fibrillar nanofillers ». Polymer Degradation and Stability 95, n^o 5 (mai 2010) : 845–51. http://dx.doi.org/10.1016/j.polymdegradstab.2010.01.026.

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Bujok, Sonia, Jiří Hodan et Hynek Beneš. « Effects of Immobilized Ionic Liquid on Properties of Biodegradable Polycaprolactone/LDH Nanocomposites Prepared by In Situ Polymerization and Melt-Blending Techniques ». Nanomaterials 10, n^o 5 (18 mai 2020) : 969. http://dx.doi.org/10.3390/nano10050969.

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The high capacity of calcinated layered double hydroxides (LDH) to immobilize various active molecules together with their inherent gas/vapor impermeability make these nanoparticles highly promising to be applied as nanofillers for biodegradable polyester packaging. Herein, trihexyl(tetradecyl)phosphonium decanoate ionic liquid (IL) was immobilized on the surface of calcinated LDH. Thus, the synthesized nanoparticles were used for the preparation of polycaprolactone (PCL)/LDH nanocomposites. Two different methods of nanocomposite preparation were used and compared: microwave-assisted in situ ring opening polymerization (ROP) of ε-caprolactone (εCL) and melt-blending. The in situ ROP of εCL in the presence of LDH nanoparticles with the immobilized IL led to homogenous nanofiller dispersion in the PCL matrix promoting formation of large PCL crystallites, which resulted in the improved mechanical, thermal and gas/water vapor barrier properties of the final nanocomposite. The surface-bonded IL thus acted as nanofiller surfactant, compatibilizer, as well as thermal stabilizer of the PCL/LDH nanocomposites. Contrary to that, the melt-blending caused a partial degradation of the immobilized IL and led to the production of PCL nanocomposites with a heterogenous nanofiller dispersion having inferior mechanical and gas/water vapor barrier properties.

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Pradhan, Sharmila, Ralf Lach, Hong Hai Le, Wolfgang Grellmann, Hans-Joachim Radusch et Rameshwar Adhikari. « Effect of Filler Dimensionality on Mechanical Properties of Nanofiller Reinforced Polyolefin Elastomers ». ISRN Polymer Science 2013 (26 juin 2013) : 1–9. http://dx.doi.org/10.1155/2013/284504.

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The object of this study has been to investigate the effect of filler dimensionality on morphology and mechanical properties of polymer nanocomposites using various kinds of nanofillers (such as multiwalled carbon nanotubes (1D filler), layered silicate (2D filler), and boehmite (3D filler)) dispersed in the matrix of ethylene-1-octene copolymer (EOC), a polyolefin-based elastomer. The morphological features were studied by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) while mechanical properties were characterized by tensile testing and depth sensitive recording microindentation hardness measurements. It has been demonstrated that the filler dimensionality may have dramatic influence on the mechanical properties of the samples. Based on the results obtained by tensile testing and microhardness measurements, the reinforcing effect of the nanofiller was found to follow the order: 1D filler > 2D filler > 3D filler.

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Todorov, Lyudmil V., Carla I. Martins et Júlio C. Viana. « Characterization of PET Nanocomposites with Different Nanofillers ». Solid State Phenomena 151 (avril 2009) : 113–17. http://dx.doi.org/10.4028/www.scientific.net/ssp.151.113.

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This study investigates the influence of various nanofillers of different shapes and sizes on the properties of PET nanocomposites. PET was reinforced with 0.3 wt.% of different nanoreinforcements, namely: (i) 1D platelet-like shape of organo-modified layered silicates (montmorillonite) (platelet size approx. 1 x 200 nm) with average agglomerate size of: (a) 30 μm and (b) 8 μm; (ii) 3D spherical shape particles of titanium oxide with an average size of 21 nm and (iii) 3D spherical shape silica with an average particle size of 12 nm. PET nanocomposites were prepared by melt blending in an asymmetric batch minimixer followed by compression moulding process. The effect of nanofillers upon thermal, mechanical and structural properties in comparison to the neat PET are discussed.

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Shen, Zhen-Qi, Li Chen, Ling Lin, Cheng-Liang Deng, Jing Zhao et Yu-Zhong Wang. « Synergistic Effect of Layered Nanofillers in Intumescent Flame-Retardant EPDM : Montmorillonite versus Layered Double Hydroxides ». Industrial & ; Engineering Chemistry Research 52, n^o 25 (18 juin 2013) : 8454–63. http://dx.doi.org/10.1021/ie4010546.

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Atif, Rasheed, et Fawad Inam. « Fractography analysis of 1.0 wt% nanoclay/multi-layer graphene reinforced epoxy nanocomposites ». Journal of Composite Materials 51, n^o 23 (29 novembre 2016) : 3281–90. http://dx.doi.org/10.1177/0021998316679017.

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The topographical features of fractured tensile, flexural, K1C, and impact specimens of 1.0 wt% multi-layered graphene/nanoclay-epoxy nanocomposites have been investigated. The topographical features studied include maximum roughness height ( Rmax or Rz), root mean square value ( Rq), roughness average ( Ra), and waviness ( Wa). Due to deflection and bifurcation of the cracks by nanofillers, specific fracture patterns are observed. Although these fracture patterns seem aesthetically appealing, however, if delved deeper, they can further be used to estimate the influence of nanofiller on the mechanical properties. By a meticulous examination of topographical features of fractured patterns, various important aspects related to fillers can be approximated such as dispersion state, interfacial interactions, presence of agglomerates, and overall influence of the incorporation of filler on the mechanical properties of nanocomposites. In addition, treating the nanocomposites with surfaces of specific topography can help improve the mechanical properties of nanocomposites.

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Zambrzycki, Marcel, Krystian Sokolowski, Maciej Gubernat et Aneta Fraczek-Szczypta. « Effect of Secondary Carbon Nanofillers on the Electrical, Thermal, and Mechanical Properties of Conductive Hybrid Composites Based on Epoxy Resin and Graphite ». Materials 14, n^o 15 (27 juillet 2021) : 4169. http://dx.doi.org/10.3390/ma14154169.

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In this work, we present a comparative study of the impact of secondary carbon nanofillers on the electrical and thermal conductivity, thermal stability, and mechanical properties of hybrid conductive polymer composites (CPC) based on high loadings of synthetic graphite and epoxy resin. Two different carbon nanofillers were chosen for the investigation—low-cost multi-layered graphene nanoplatelets (GN) and carbon black (CB), which were aimed at improving the overall performance of composites. The samples were obtained by a simple, inexpensive, and effective compression molding technique, and were investigated by the means of, i.a., scanning electron microscopy, Raman spectroscopy, electrical conductivity measurements, laser flash analysis, and thermogravimetry. The tests performed revealed that, due to the exceptional electronic transport properties of GN, its relatively low specific surface area, good aspect ratio, and nanometric sizes of particles, a notable improvement in the overall characteristics of the composites (best results for 4 wt % of GN; σ = 266.7 S cm−1; λ = 40.6 W mK−1; fl. strength = 40.1 MPa). In turn, the addition of CB resulted in a limited improvement in mechanical properties, and a deterioration in electrical and thermal properties, mainly due to the too high specific surface area of this nanofiller. The results obtained were compared with US Department of Energy recommendations regarding properties of materials for bipolar plates in fuel cells. As shown, the materials developed significantly exceed the recommended values of the majority of the most important parameters, indicating high potential application of the composites obtained.

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Casciola, Mario. « From layered zirconium phosphates and phosphonates to nanofillers for ionomeric membranes ». Solid State Ionics 336 (août 2019) : 1–10. http://dx.doi.org/10.1016/j.ssi.2019.03.005.

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Kedzierski, Michal, Zbigniew Boncza-Tomaszewski, Grazyna Jaworska et Anna Niska. « Layered double hydroxides as transesterification catalysts and nanofillers for polyester resin ». Polimery 60, n^o 03 (mars 2015) : 160–66. http://dx.doi.org/10.14314/polimery.2015.160.

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Kopecká, Kateřina, Ludvík Beneš, Klára Melánová, Vítězslav Zima, Petr Knotek et Kateřina Zetková. « Layered calcium phenylphosphonate : a hybrid material for a new generation of nanofillers ». Beilstein Journal of Nanotechnology 9 (20 novembre 2018) : 2906–15. http://dx.doi.org/10.3762/bjnano.9.269.

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The use of nanosheets of layered calcium phenylphosphonate as a filler in a polymeric matrix was investigated. Layered calcium phenylphosphonate (CaPhP), with chemical formula CaC6H5PO3∙2H2O, is a hybrid organic–inorganic material that exhibits a hydrophobic character due to the presence of phenyl groups on the surface of the layers. In this paper, various CaPhP synthesis methods were studied with the aim of obtaining a product most suitable for its subsequent exfoliation. The liquid-based approach was used for the exfoliation. It was found that the most promising technique for the exfoliation of CaPhP in an amount sufficient for incorporation into polymers involved using propan-2-ol with a strong shear force generated in a high-shear disperser. The filler was tested both in its unexfoliated and exfoliated forms for the preparation of polymer composites, for which a low molecular weight epoxy resin based on bisphenol A was used as a polymer matrix. The prepared samples were characterized by powder X-ray diffraction, atomic force microscopy, optical and scanning electron microscopy, and dynamic mechanical analysis. Flammability and gas permeation tests were also performed. The addition of the nanofiller was found to influence the composite properties – the exfoliated particles were found to have a higher impact on the properties of the prepared composites than the unexfoliated particles of the same loading

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Vol’fson, S. I., et A. A. Nikiforov. « Use of Zinc-Aluminum Layered Double Hydroxides as Nanofillers of Thermoplastic Vulcanizates ». Russian Journal of Applied Chemistry 93, n^o 8 (août 2020) : 1188–91. http://dx.doi.org/10.1134/s107042722008011x.

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Chausson, Sophie, Richard Retoux, Jean-Michel Rueff, Loïc LE Pluart, Pierre-Jean Madec et Paul-Alain Jaffres. « Elaboration and characterization of novel polyamide-12-layered titanoniobates nanocomposites ». Journal of Materials Research 24, n^o 11 (novembre 2009) : 3358–71. http://dx.doi.org/10.1557/jmr.2009.0410.

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This article describes the synthesis and the characterization of a polyamide-12 filled with a nanostructured organic/inorganic titanoniobate hybrid material. The pristine oxide KTiNbO5 has been successfully organomodified by N-alkyl amines via an acido-basic reaction after a cationic exchange step as shown by x-ray diffraction. Transmission electron microscope study and scanning transmission electron microscope observations have been used to describe the change of morphology of the nanofillers before and after processing; the micronic aggregates were changed into single sheets and dispersed in the polymer. Thermomechanical properties of the composites have been determined, and their analyses with structure-properties models are consistent with the exfoliation of the organomodified titanoniobates.

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Kim, G. M., D. H. Lee, B. Hoffmann, J. Kressler et G. Stöppelmann. « Influence of nanofillers on the deformation process in layered silicate/polyamide-12 nanocomposites ». Polymer 42, n^o 3 (février 2001) : 1095–100. http://dx.doi.org/10.1016/s0032-3861(00)00468-7.

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Sadeghipour, Hojjatollah, Farshid Ghorbani, Mohammad Reza Jafari Felavarjani, Hassan Ebadi-Dehaghani, Davoud Ashouri et Saman Mousavian. « Polycarbonate Nanocomposites via Melt Compounding : The Relation between Compatibility and Rheological Properties ». Advanced Materials Research 739 (août 2013) : 117–22. http://dx.doi.org/10.4028/www.scientific.net/amr.739.117.

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The effect of several types of nanoparticles on the rheological properties of polycarbonate (PC) was compared. Four polycarbonate nanocomposites containing 5 wt% of layered silica (SiO2), Iron oxide (Fe3O4), Iron oxide (α-Fe2O3), cupric oxide (CuO) nanoparticles were prepared via melt compounding at 260 °C. Compression molded samples were prepared and the dynamic rheological properties of the nanocomposites were investigated. The incorporation of the nanoparticles increased the storage modulus and consequently decreased the damping factor. In the Cole-Cole plot, PC filled layered silica and Fe2O3 nanoparticles showed more semi-circle pattern comparing to that of other nanocomposites implied more compatibility between PC and layered silica and also Fe2O3 nanofillers. While other nanocomposites showed more deviation from this pattern. Rotational mode in rheological studies showed that at low shear rate the viscosities of nanocomposites are higher than that of pure Polycarbonate. While at higher shear rate the viscosity of filled samples tend to approach the viscosity of pure PC.

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Elloh, V. W., Soni Mishra, A. Yaya et Abhishek Kumar Mishra. « First-principles calculations on structure and electronic properties of α-zirconium hydrogen phosphate ». MRS Advances 4, n^o 50 (2019) : 2699–707. http://dx.doi.org/10.1557/adv.2019.309.

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AbstractLayered zirconium hydrogen phosphate intercalation compounds can be easily tuned, leading to potential applications in many fields, specifically by introducing them in different polymeric composites as nanofillers. Employing first-principles density functional theory based calculations, we have investigated ground state electronic structure properties of α-zirconium hydrogen phosphate (α-ZrP). We discuss the structure and electronic band structure, where projected density of states calculations have been discussed to understand the different atomic orbitals contributions to electronic bands. ZrP has numerous properties of interest for use in many semiconductor device structures, specifically, layered zirconium hydrogen phosphate has substantial promise for both optical devices and for high power electronics due to its large direct band gap. Our structural calculations suggest that layered zirconium hydrogen phosphate exhibits monoclinic structure. The calculated structural parameters and band gap are in good agreement with available experimental data.

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Morici, Elisabetta, Giulia Infurna et Nadka Tz Dintcheva. « Ecofriendly Biopolymer-Based Nanocomposite Films with Improved Photo-Oxidative Resistance ». Materials 15, n^o 16 (21 août 2022) : 5778. http://dx.doi.org/10.3390/ma15165778.

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The interest towards high performance biopolymer-based materials increases continuously and, to guarantee appropriately industrial applications, the photo-oxidative resistance and stability of these materials must be adequately addressed. In this study, innovative biopolymer-based nanocomposites, i.e., Polyamide 11 (PA11), containing ad-hoc modified Layered Double Hydroxides (LDH), were successfully formulated and characterized. Particularly, LDH were considered carriers for hindered amine light stabilizing molecules, so two different hindered amine moieties (HALS1 and HALS2) were anchored on LDH layered internal structures and/or outer surfaces. The presence of HALS1 and HALS2 in LDH were confirmed by X-ray diffraction, spectroscopy, and thermogravimetric analysis. Then, the novel LDH-HALS nanofillers (here named LDH-HALS1 and LDH-HALS2) were introduced into a PA11 matrix by melt mixing at 5 wt.%; the produced nanocomposites were characterized by differential scanning calorimetry, rheological, and morphological analysis. All obtained results suggest that the LDH-HALS1/HALS2 nanofillers were very well dispersed into the PA11 matrix. Additionally, the photo-oxidative resistance of the PA11-based nanocomposite films was evaluated by subjecting thin films to UVB exposure and the degradation process was monitored by spectroscopic analysis over time. The photo-oxidative resistance of the PA11/LDH-HALS1/HALS2 was compared to that of PA11-based nanocomposites containing unmodified LDH and the commercial hindered amine UV-stabilizer (Cyasorb® UV-3853). It was established that by anchoring the hindered amine moieties to the LDH, the PA11 nanocomposites were successfully protected against UVB exposure. This was because the hindered amine light stabilizing molecules were available to act at the critical zone where the degradation phenomena occur, which is at the interface between the matrix and the inorganic particles.

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Tajuddin, Muhammad Hanis, Norhaniza Yusof, Norfadhilatuladha Abdullah, Muhammad Nidzhom Zainol Abidin, Wan Norharyati Wan Salleh, Ahmad Fauzi Ismail, Takeshi Matsuura, Nur Hanis Hayati Hairom et Nurasyikin Misdan. « Incorporation of layered double hydroxide nanofillers in polyamide nanofiltration membrane for high performance of salts rejections ». Journal of the Taiwan Institute of Chemical Engineers 97 (avril 2019) : 1–11. http://dx.doi.org/10.1016/j.jtice.2019.01.021.

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Ganter, Markus, Wolfram Gronski, Peter Reichert et Rolf Mülhaupt. « Rubber Nanocomposites : Morphology and Mechanical Properties of BR and SBR Vulcanizates Reinforced by Organophilic Layered Silicates ». Rubber Chemistry and Technology 74, n^o 2 (1 mai 2001) : 221–35. http://dx.doi.org/10.5254/1.3544946.

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Abstract Rubber compounds based on butadiene rubber (BR) or styrene—butadiene rubber (SBR) containing organophilic layered silicates were prepared. Organophilic silicates were swollen in a rubber/toluene solution. Matrix—filler reactive bonding was performed by adding bis(triethoxysilylpropyl)-tetrasulfan (TESPT) during swelling. Excellent dispersion of organoclay nanofillers in rubber matrices was demonstrated by transmission electron microscopy (TEM) and atomic force microscopy (AFM) exhibiting intercalated and partially exfoliated silicate layers. Matrix—filler interfacial coupling by TESPT led to reduced strain at break and reduced hysteresis for both organoclay and silica-based vulcanizates as expected for successful matrix filler coupling. Organoclay vulcanizates exhibited enhanced hysteresis when compared to silica compounds. This is related to orientation and sliding of anisotropic silicate layers, as determined by online wide-angle X-ray scattering (WAXS) measurements during cyclic tensile testing.

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Regmi, Chhabilal, Jalal Azadmanjiri, Vipin Mishra, Zdeněk Sofer, Saeed Ashtiani et Karel Friess. « Cellulose Triacetate-Based Mixed-Matrix Membranes with MXene 2D Filler—CO2/CH4 Separation Performance and Comparison with TiO2-Based 1D and 0D Fillers ». Membranes 12, n^o 10 (22 septembre 2022) : 917. http://dx.doi.org/10.3390/membranes12100917.

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Mixed-matrix membranes (MMMs) possess the unique properties and inherent characteristics of their component polymer and inorganic fillers, or other possible types of additives. However, the successful fabrication of compact and defect-free MMMs with a homogeneous filler distribution poses a major challenge, due to poor filler/polymer compatibility. In this study, we use two-dimensional multi-layered Ti3C2Tx MXene nanofillers to improve the compatibility and CO2/CH4 separation performance of cellulose triacetate (CTA)-based MMMs. CTA-based MMMs with TiO2-based 1D (nanotubes) and 0D (nanofillers) additives were also fabricated and tested for comparison. The high thermal stability, compact homogeneous structure, and stable long-term CO2/CH4 separation performance of the CTA-2D samples suggest the potential application of the membrane in bio/natural gas separation. The best results were obtained for the CTA-2D sample with a loading of 3 wt.%, which exhibited a 5-fold increase in CO2 permeability and 2-fold increase in CO2/CH4 selectivity, compared with the pristine CTA membrane, approaching the state-of-the-art Robeson 2008 upper bound. The dimensional (shape) effect on separation performance was determined as 2D > 1D > 0D. The use of lamellar stacked MXene with abundant surface-terminating groups not only prevents the aggregation of particles but also enhances the CO2 adsorption properties and provides additional transport channels, resulting in improved CO2 permeability and CO2/CH4 selectivity.

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Ding, Peng, Sheng Fu Tang, Hui Yang et Li Yi Shi. « PP/LDH Nanocomposites via Melt-Intercalation : Synergistic Flame Retardant Effects, Properties and Applications in Automobile Industries ». Advanced Materials Research 87-88 (décembre 2009) : 427–32. http://dx.doi.org/10.4028/www.scientific.net/amr.87-88.427.

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The structure, thermal behavior and flame retardant properties of polypropylene (PP) nanocomposites treated with complex flame retardants composed of layered double hydroxides (LDH) and ammonium polyphosphate (APP)/pentaerythritol (PER) intumescent flame retardant systems have been investigated by XRD, TEM, LOI, UL-94, and TGA analysis. The results showed that introduction of LDH nanofillers into the samples can obtain good flame retardant synergistic effects with APP/PER additives at appropriate LDH loadings. Such synergism between LDH and APP/PER in PP matrix can be explained by a proposed condensed phase flame retardant mechanism. And based on this study, different types of modified PP products were developed in a ten-thousand-ton scale to be used for the automobile industries, such as car bumpers and dashboards.

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Gao, Yanshan, Qiang Wang et Weiran Lin. « Ammonium Polyphosphate Intercalated Layered Double Hydroxide and Zinc Borate as Highly Efficient Flame Retardant Nanofillers for Polypropylene ». Polymers 10, n^o 10 (9 octobre 2018) : 1114. http://dx.doi.org/10.3390/polym10101114.

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We found in our previous study that layered double hydroxides (LDHs) which undergo aqueous miscible organic solvent treatment (AMOST) can tune the hydrophobicity surface of LDHs to be hydrophobic, and then the solvent mixing method can be used to prepare polymer/LDH nanocomposites. However, flame retardant property is not very high if LDHs are only used. In this present work, ammonium polyphosphate (APP) intercalated LDHs and zinc borate (ZB) was incorporated into a polypropylene (PP) matrix using the solvent mixing method. The structures, morphologies, and performance of the composites were characterized carefully. The peak heat release rate (PHRR) reduction of PP containing 10 and 20 wt % APP-LDH reached 27% and 55%, respectively, which increased up to 63% compared with PP/CO3-LDH. After incorporating 2 wt % ZB in the PP/APP-LDH system, the flame retardant property was further improved. Polypropylene composites with 20 wt % APP-LDH and 2 wt % ZB showed a 58% PHRR reduction. In addition, thermogravimetric analyzer (TGA) results indicated that the addition of APP-LDH and ZB improved the temperature at 50% weight loss (T50%) and the char formation of the materials significantly.

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Hu, Dongtao, Qianqian Zhou et Keqing Zhou. « Combined effects of layered nanofillers and intumescent flame retardant on thermal and fire behavior of ABS resin ». Journal of Applied Polymer Science 136, n^o 46 (8 juillet 2019) : 48220. http://dx.doi.org/10.1002/app.48220.

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Tang, Xue Gang, Meng Hou, Jin Zou et Rowan Truss. « Effect of Nano-Filler Network on the Rheological Behaviours of Poly(vinylidene fluoride) Nanocomposites ». Advanced Materials Research 328-330 (septembre 2011) : 1232–38. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.1232.

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A nano-filler network constructed by layered silicates and multi-wall carbon nanotubes (MWCNTs) has been prepared. The structure of the network was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), and dynamic rheological test. The results showed that a plateau in the storage modulus at low frequency occurred, which indicated the pseudo solid-like behaviour for the sample with nano-filler network, and the jamming effect due to the nano-filler network dominated the viscoelatic behaviour at low frequency. This effect was sensitive to the frequency and decreased quickly with the increase of frequency. At the same time, the introduction of nanofillers and the presence of nano-filler network affected the complex viscosity and shear thinning too, especially at low frequency.

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Piszczyk, Łukasz, Magdalena Danowska, Michał Strankowski, Iwona Gibas et Józef Tadeusz Haponiuk. « Physical and Mechanical Properties of Rigid Polyurethane Faoms Modified with Selected Flame Retardants or Layered Silicates ». Advanced Composites Letters 20, n^o 3 (mai 2011) : 096369351102000. http://dx.doi.org/10.1177/096369351102000302.

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The flame retardants: expandable graphite, decabromodiphenyloxid, triethylphosphate and nanofillers: natural montmoryllonite [MMT] – Nanofil®116, natural MMT modified with a quaternary ammonium salt - Cloisite®10A, synthetic layered silicate – Laponite®RD has been used in rigid polyurethane foams (PUFs). The influence of fillers amounts on processing parameters, physical–mechanical properties (compression strength, density, water absorption, brittleness, mass loss and volume change) and thermal properties (thermal stability and storage modulus in DMA methods) of such foams has been analysed. The morphology has been characterized by X-ray diffraction and scanning electron microscopy (SEM). The X-ray diffraction of the polyurethane nanocomposite foams has been indicated the partial exfoliation of the clay in the polyurethane matrix. The flame retardancy and the thermal stability of all polyurethane modified systems was improved by an addition of flame retardants or nanoclays. Best results, in comparison for pure polyurethane foam, was obtained for polyurethane modified with organically modified montmorillonite (Cloisite 10A).

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Saha, Tuhin, Anil K. Bhowmick, Takeshi Oda, Toshiaki Miyauchi et Nobuhiko Fujii. « Influence of layered nanofillers on the mechanical properties and thermal degradation of polyacrylicester polymer : Theoretical and experimental investigations ». Composites Part B : Engineering 169 (juillet 2019) : 65–78. http://dx.doi.org/10.1016/j.compositesb.2019.03.084.

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Martínez, L. A., R. Perera et L. Tarife. « Quantitative and qualitative analysis of segmental dielectric relaxations and space charge by TSDC in nanocomposites of natural rubber/clay ». Revista Mexicana de Física 66, n^o 2 Mar-Apr (1 mars 2020) : 127. http://dx.doi.org/10.31349/revmexfis.66.127.

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The effect of adding three different layered clays, a sodium montmorillonite and two commercial modified montmorillonites, on the morphology and molecular dynamics of natural rubber characterized by Transmission Electron Microscopy and Thermally Stimulated Depolarization Currents (TSDC) was studied. Carbon black was employed as reinforcing filler in a standard compound prepared and used for comparison purposes. The morphological results revealed that the sample with Cloisite\circledR 15A displays the highest degree of exfoliation, which suggests a stronger compatibility between the organic and inorganic phases. When the dispersion degree increases, a decrease of the activation energy was found from the quantitative analysis of the space charge dielectric relaxations. From the qualitative analysis of the dipolar dielectric relaxations around $T_{g}$, changes in the dielectric relaxation profile and in the peak localization were attributed to probable interactions between the nanofillers and the elastomer in the glass transition region of the NR.

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Reincke, Katrin, Wolfgang Grellmann et Gert Heinrich. « Investigation of Mechanical and Fracture Mechanical Properties of Elastomers Filled with Precipitated Silica and Nanofillers Based upon Layered Silicates ». Rubber Chemistry and Technology 77, n^o 4 (1 septembre 2004) : 662–77. http://dx.doi.org/10.5254/1.3547843.

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Abstract The aim of this paper is to show possibilities of experimental methods of polymer diagnostics and fracture mechanics for quantitative characterization of crack initiation and propagation properties of elastomeric materials. At first, a general overview of methods of technical fracture mechanics is given. This is followed by a short discussion of some possibilities for determination of tearing energy T for elastomers. In the main part, results of various mechanical and fracture mechanics experiments on filled natural rubber vulcanizates are shown. The vulcanizates were filled with different contents (5–70 phr) of two filler types. The fillers were precipitated silica and an organic-modified nano-disperse layered silicate. Th aim of the experiments was to prove possibilities of several fracture mechanics testing methods for quantifying the influence of the filler content, filler type and additionally the specimen direction on the deformation and fracture behavior. Tear-analyzer results were used to assess the crack propagation behavior under fatigue-like loading conditions. Furthermore, instrumented tensile-impact tests were performed for the characterization of the crack resistance of the materials under impact-like loading conditions. To obtain information about the initiation and propagation of a stable crack, a quasi-static fracture mechanics test was applied, and crack resistance curves were recorded. Here, specimens with various thicknesses were investigated. Additionally, conventional tear tests were done and the results were compared to that of the fracture mechanics test. Generally, it was found that all methods are useful for the description of the fracture properties. Furthermore, the fracture behavior is influenced positively especially by high filler contents. Strong differences of several parameters were found depending on the filler type. Another important result is that again differences were found between the crack initiation and propagation behavior.

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Wang, Yuan, Laipan Zhu et Cuifeng Du. « Progress in Piezoelectric Nanogenerators Based on PVDF Composite Films ». Micromachines 12, n^o 11 (20 octobre 2021) : 1278. http://dx.doi.org/10.3390/mi12111278.

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In recent years, great progress has been made in the field of energy harvesting to satisfy increasing needs for portable, sustainable, and renewable energy. Among piezoelectric materials, poly(vinylidene fluoride) (PVDF) and its copolymers are the most promising materials for piezoelectric nanogenerators (PENGs) due to their unique electroactivity, high flexibility, good machinability, and long–term stability. So far, PVDF–based PENGs have made remarkable progress. In this paper, the effects of the existence of various nanofillers, including organic–inorganic lead halide perovskites, inorganic lead halide perovskites, perovskite–type oxides, semiconductor piezoelectric materials, two–dimensional layered materials, and ions, in PVDF and its copolymer structure on their piezoelectric response and energy–harvesting properties are reviewed. This review will enable researchers to understand the piezoelectric mechanisms of the PVDF–based composite–film PENGs, so as to effectively convert environmental mechanical stimulus into electrical energy, and finally realize self–powered sensors or high–performance power sources for electronic devices.

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Bokobza, Liliane. « Natural Rubber Nanocomposites : A Review ». Nanomaterials 9, n^o 1 (22 décembre 2018) : 12. http://dx.doi.org/10.3390/nano9010012.

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This paper reviews studies carried out on natural rubber filled with nanofillers such as spherical silica particles (generated by the sol gel reaction), clays and carbon nanostructures. It is shown that the mechanical response of NR is influenced by several parameters including the processing conditions, the state of filler dispersion, the polymer-filler interactions and the filler morphological aspects. Even if the sol gel process conducted in vulcanized rubber yields almost ideal dispersions, rod-shaped particles such as clay, carbon fibers or carbon nanotubes are by far more efficient in terms of mechanical reinforcement on account of their anisotropic character and their ability to orientate in the direction of stretch. The efficiency of layered fillers such as clays or graphitic structures clearly depends on the way they are dispersed (exfoliated) in the rubber. Complete exfoliation still remains difficult to achieve which limits the tremendous nanoreinforcement expected from a single layer of clay or graphite. In all cases, the onset of crystallization is observed at a lower strain value than that of the unfilled matrix due to strain amplification effects.

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Liu, Guoshuai, Kang Shi et Hui Sun. « Research Progress in Hemicellulose-Based Nanocomposite Film as Food Packaging ». Polymers 15, n^o 4 (16 février 2023) : 979. http://dx.doi.org/10.3390/polym15040979.

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As the main component of agricultural and forestry biomass, hemicellulose has the advantages of having an abundant source, biodegradability, nontoxicity and good biocompatibility. Its application in food packaging has thus become the focus of efficient utilization of biomass resources. However, due to its special molecular structure and physical and chemical characteristics, the mechanical properties and barrier properties of hemicellulose films are not sufficient, and modification for performance enhancement is still a challenge. In the field of food packaging materials preparation, modification of hemicellulose through blending with nanofibers or nanoparticles, both inorganic and organic, has attracted research attention because this approach offers the advantages of efficient improvement in the expected properties and better cost efficiency. In this paper, the composition of hemicellulose, the classification of nanofillers and the research status of hemicellulose-based nanocomposite films are reviewed. The research progress in modification of hemicellulose by using layered silicate, inorganic nanoparticles and organic nanoparticles in food packaging is described. Challenges and outlook of research in hemicellulose-based nanocomposite film in food packaging is discussed.

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Beneš, Hynek, Jana Kredatusová, Jakub Peter, Sébastien Livi, Sonia Bujok, Ewa Pavlova, Jiří Hodan, Sabina Abbrent, Magdalena Konefał et Petra Ecorchard. « Ionic Liquids as Delaminating Agents of Layered Double Hydroxide during In-Situ Synthesis of Poly (Butylene Adipate-co-Terephthalate) Nanocomposites ». Nanomaterials 9, n^o 4 (16 avril 2019) : 618. http://dx.doi.org/10.3390/nano9040618.

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Currently, highly demanded biodegradable or bio-sourced plastics exhibit inherent drawbacks due to their limited processability and end-use properties (barrier, mechanical, etc.). To overcome all of these shortcomings, the incorporation of lamellar inorganic particles, such as layered double hydroxides (LDH) seems to be appropriate. However, LDH delamination and homogenous dispersion in a polymer matrix without use of harmful solvents, remains a challenging issue, which explains why LDH-based polymer nanocomposites have not been scaled-up yet. In this work, LDH with intercalated ionic liquid (IL) anions were synthesized by a direct co-precipitation method in the presence of phosphonium IL and subsequently used as functional nanofillers for in-situ preparation of poly (butylene adipate-co-terephthalate) (PBAT) nanocomposites. The intercalated IL-anions promoted LDH swelling in monomers and LDH delamination during the course of in-situ polycondensation, which led to the production of PBAT/LDH nanocomposites with intercalated and exfoliated morphology containing well-dispersed LDH nanoplatelets. The prepared nanocomposite films showed improved water vapor permeability and mechanical properties and slightly increased crystallization degree and therefore can be considered excellent candidates for food packaging applications.

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Guo, Xincheng, Mengqi Tang, Na Wang, Lingtong Li, Yifan Wu, Xiaolang Chen, Jun Qin, Kun Zhang et Xiong Lu. « The synthesis of organically modified layered double hydroxide and its effect on the structure and physical properties of low-density polyethylene/ethylene–vinyl acetate blends ». Polymers and Polymer Composites 27, n^o 5 (5 mai 2019) : 287–98. http://dx.doi.org/10.1177/0967391119846218.

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Organically modified layered double hydroxide (OM-LDH) was synthesized via anion exchange reaction and potassium monolauryl phosphate (MAPK) was used as an intercalator. The OM-LDH nanofillers were embedded into low-density polyethylene/ethylene–vinyl acetate (LDPE/EVA) via melt blending process which provided LDPE/EVA/OM-LDH nanocomposites. The structure and properties of the fabricated samples were characterized through Fourier transform infrared spectroscopy, X-ray diffraction techniques, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and tensile testing. The results showed that the organic anion was intercalated into the interlayer region of LDH and enlarged the interlayer distance. The TGA results of the nanocomposites showed significantly improved thermal stability at a higher temperature when containing 6 wt% OM-LDH due to the good dispersion of OM-LDH in the matrix. The DSC data indicated that the degree of crystallinity was increased obviously due to the incorporation of OM-LDH in the matrix. The formation of organic side chains on the OM-LDH surface also contributed to an improvement in the interfacial adhesion, resulting in enhanced tensile strength and elongation at break compared with LDH.

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Liu, Ang, Huiwen Tian, Xiaodan Ju, Wei Wang, Peng Han et Weihua Li. « In-situ growth of layered double hydroxides nanosheet arrays on graphite fiber as highly dispersed nanofillers for polymer coating with excellent anticorrosion performances ». Journal of the Taiwan Institute of Chemical Engineers 104 (novembre 2019) : 330–40. http://dx.doi.org/10.1016/j.jtice.2019.09.006.

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Bugatti, Valeria, Luigi Vertuccio, Federica Zuppardi, Vittoria Vittoria et Giuliana Gorrasi. « PET and Active Coating Based on a LDH Nanofiller Hosting p-Hydroxybenzoate and Food-Grade Zeolites : Evaluation of Antimicrobial Activity of Packaging and Shelf Life of Red Meat ». Nanomaterials 9, n^o 12 (3 décembre 2019) : 1727. http://dx.doi.org/10.3390/nano9121727.

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Layered double hydroxide (LDH) nanofillers were considered as hosts of p-hydroxybenzoate as an antimicrobial molecule for active coating. A food grade resin with LDH-p-hydroxybenzoate and two different types of food grade zeolites was used to prepare active coatings for Polyethylene terephthalate (PET) trays. The release kinetics of the active molecule were followed using UV spectrophotometry and the experimental results were analyzed with the Gallagher–Corrigan model. The thermal properties of the coating mixtures and the PET coating were analyzed and found to be dependent on the coating’s composition. On the basis of CO2 transmission rate and off-odors tests, the best coating composition was selected. Global migration in ethanol (10% v/v), acetic acid (3% w/v), and vegetable oil, and specific migration of p-hydroxybenzoic acid revealed the suitability of the material for food contact. Antimicrobial tests on the packaging demonstrated a good inhibition against Salmonella spp. and Campylobacter jejuni. Red meat was packed into the selected active materials and results were compared to uncoated PET packaging. Color tests (browning of the meat) and analysis of Enterobacteriaceae spp. and total viable count evolution up to 10 days of storage demonstrated the capability of the considered active packaging in prolonging the shelf life of red meat.

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Sypaseuth, Fanni D., Emanuela Gallo, Serhat Çiftci et Bernhard Schartel. « Polylactic acid biocomposites : approaches to a completely green flame retarded polymer ». e-Polymers 17, n^o 6 (26 octobre 2017) : 449–62. http://dx.doi.org/10.1515/epoly-2017-0024.

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AbstractBasic paths towards fully green flame retarded kenaf fiber reinforced polylactic acid (K-PLA) biocomposites are compared. Multicomponent flame retardant systems are investigated using an amount of 20 wt% such as Mg(OH)2 (MH), ammonium polyphosphate (APP) and expandable graphite (EG), and combinations with silicon dioxide or layered silicate (LS) nanofillers. Adding kenaf fibers and flame retardants increases the E modulus up to a factor 2, although no compatibilizer was used at all. Thus, in particular adding EG and MH decreases the strength at maximum elongation, and kenaf fibers, MH, and EG are crucial for reducing the elongation to break. The oxygen index is improved by up to 33 vol% compared to 17 vol% for K-PLA. The HB classification of K-PLA in the UL 94 test is outperformed. All flame retarded biocomposites show somewhat lower thermal stability and increased amounts of residue. MH decreases the fire load significantly, and the greatest reduction in peak heat release rate is obtained for K-PLA/15MH/5LS. Synergistic effects are observed between EG and APP (ratio 2:1) in flammability and fire properties. Synergistic multicomponent systems containing EG and APP, or MH with adjuvants offer a promising route to green flame retarded natural fiber reinforced PLA biocomposites.

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Valentina, Iozzino, Askanian Haroutioun, Leroux Fabrice, Verney Vincent et Pantani Roberto. « Poly(Lactic Acid)-Based Nanobiocomposites with Modulated Degradation Rates ». Materials 11, n^o 10 (11 octobre 2018) : 1943. http://dx.doi.org/10.3390/ma11101943.

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In the field of biodegradable polymers such as poly(Lactic Acid) (PLA), it is quite well known that their kinetics of hydrolysis strongly depend on the pH of the hydrolyzing medium. The idea explored during this study focused on PLA, is the addition of additives that are able to control the pH of water when it diffuses inside the polymer. For instance, acids (i.e. succinic acid, also used as food additive) are bio- and eco- friendly additives that are able to play this role. In order to control the release of these molecules and their dispersion inside the polymer, their intercalation in biocompatible nanofillers like layered double hydroxides (LDH) is here considered. The additives have been dispersed in the polymer by melt compounding, commonly used in the plastic industry. Several composites of PLA (4032D) and LDH intercalated with organic acids (succinic, fumaric, and ascorbic acid) have been obtained by an extrusion process. From all extruded materials, PLA films obtained by compression molding were then subjected to hydrolysis tests. The results showed that the mentioned molecules, dispersed in the polymer, are able to control the rate of hydrolysis, and experimental results show an increase of degradation time for samples containing LDH-organic acid (in particular with LDH-succinic acid), making such hybrid additives an appropriate and efficient solution for PLA.

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Kislitsyn, V. D., K. A. Mokhireva, V. V. Shadrin et A. L. Svistkov. « Research and Modeling of Viscoelastic Behavior of Elastomeric Nanocomposites ». PNRPU Mechanics Bulletin, n^o 2 (15 décembre 2021) : 76–87. http://dx.doi.org/10.15593/perm.mech/2021.2.08.

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The paper presents results of studying mechanical properties of polymer composites depending on types of filler particles (granular - carbon black, nanodiamonds; layered - graphene plates; fibrous - single-walled nanotubes). These nanofillers differ greatly from each other in their structure and geometry. A significant difference in behavior of nanocomposites was revealed even with little introduction of particles into the elastomer. The highest level of reinforcement of the matrix was obtained when single-wall nanotubes and detonation nanodiamonds were used as fillers. The viscoelastic properties and the Mullins softening effect [1-4] were investigated in experiments performed with material samples subjected to complex uniaxial cyclic deformation. In these experiments, the amplitude of deformations was changed step by step; and at each step a time delay was specified to complete rearrangement processes of the material structure. It was found that a pronounced softening effect after the first cycle of deformation and significant hysteresis losses occur in the material filled with single-walled nanotubes. These characteristics are insignificant for the rest of nanocomposites until elongation increases twofold. In accordance with the obtained results, a new version of the mathematical model to describe properties of the viscoelastic polymer materials was proposed. The constants of the constitutive relations were calculated for each material; the theoretical and experimental load curves were compared. As a result, the introduced model is able to describe the behavior of elastomeric nanocomposites with a high accuracy. Moreover, this model is relatively easy to use, suitable for a wide range of strain rates and stretch ratios and does not require the entire history of deformation as needed for integral models of viscoelasticity.

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Lee, Juchul, Kwang Hoon Lee, Daehum Kim, Soonho Lim et Sang-Soo Lee. « Layered nanofiller-reinforced polyketone composites ». Macromolecular Research 21, n^o 11 (1 juillet 2013) : 1270–73. http://dx.doi.org/10.1007/s13233-013-1173-8.

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Ziadeh, M., B. Chwalka, H. Kalo, M. R. Schütz et J. Breu. « A simple approach for producing high aspect ratio fluorohectorite nanoplatelets utilizing a stirred media mill (ball mill) ». Clay Minerals 47, n^o 3 (septembre 2012) : 341–53. http://dx.doi.org/10.1180/claymin.2012.047.3.05.

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AbstractThe potential of platy nanofillers like clays in polymer nanocomposites is mostly determined by their aspect ratio. The degree of improvement that may be achieved in respect to reinforcement, gas-barrier properties and flame retardancy critically depends on the aspect ratio. Thus, increasing the aspect ratio is highly desirable in order to explore the full potential of the clay filler. Mechanical shear stress as generated in the grinding chamber of a stirred media mill (ball mill) induced an efficient exfoliation of highly hydrated and therefore ‘shear-labile’ synthetic Mg-fluorohectorite in aqueous dispersion. The attainable degree of exfoliation can be tuned and controlled through the shear forces applied by changing process parameters such as solid content and grinding media diameter. Characterization and evaluation of the exfoliation efficiency during milling was achieved by combining and cross-validating data obtained by powder X-ray diffraction (XRD), static light scattering (SLS), specific surface area measurements applying the Brunauer-Emmett-Teller (BET) equation, and scanning electron microscopy (SEM). This led to the identification of optimal processing parameters, allowing for control of the degree of exfoliation and, consequently, the aspect ratio of the nanoplatelets. Not surprisingly, besides exfoliation, increasing the magnitude of the shear stress also resulted in some reduction in platelet size.The clay platelets obtained showed a high average aspect ratio (>600), several times greater than that of original synthetic fluorohectorite. The increase of aspect ratio was reflected in a significant enhancement of both specific surface area and cation exchange capacity (CEC) of the external basal surfaces. This method has substantial advantages compared to microfluidizer processing with respect to feasibility, batch size and particle diameter size preservation. The exfoliated nanoplatelets obtained by milling have great potential to improve mechanical properties of polymer layered silicate nanocomposites (PLSN).

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Hajibeygi, M., M. Shabanian, H. Moghanian, H. A. Khonakdar et L. Häußler. « Development of one-step synthesized LDH reinforced multifunctional poly(amide–imide) matrix containing xanthene rings : study on thermal stability and flame retardancy ». RSC Advances 5, n^o 66 (2015) : 53726–35. http://dx.doi.org/10.1039/c5ra05565b.

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New exfoliated poly(amide–imide)/Zn–Al layered double hydroxide (LDH) nanocomposites were synthesized by solution intercalation using synthesized organo-modified LDH (OLDH) as nanofiller obtained by one-step method.

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