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A two-step methodology has been developed utilizing the models of Paul and Takayanagi to determine the modulus of polymer halloysite nanotube (HNT) products. Initially, HNTs and the adjacent interphase are considered as pseudoparticles, and their modulus is evaluated using the Paul model. Subsequently, the modulus of a nanocomposite, consisting of a polymer medium and pseudoparticles, is predicted by Takayanagi equation. The impacts of various factors on the modulus of the products are analyzed, and the results from the two-step method are compared with experimental data from different samples. It has been observed that the modulus of samples progressively increases with an increase in interphase depth. Also, a higher interphase modulus contributes to an enhanced modulus of samples. Nevertheless, excessively high interphase moduli (Ei > 60 GPa) result in only a marginal improvement in the modulus of nanocomposites. Additionally, narrower HNTs are advantageous for producing stronger samples, though the modulus of the nanocomposites slightly diminishes at very high HNT radii (R > 55 nm). The outputs of two-step method agree with the experimental moduli of various HNT-filled systems. [ABSTRACT FROM AUTHOR]

Abstract A two-step methodology has been developed utilizing the models of Paul and Takayanagi to determine the modulus of polymer halloysite nanotube (HNT) products. Initially, HNTs and the adjacent interphase are considered as pseudoparticles, and their modulus is evaluated using the Paul model. Subsequently, the modulus of a nanocomposite, consisting of a polymer medium and pseudoparticles, is predicted by Takayanagi equation. The impacts of various factors on the modulus of the products are analyzed, and the results from the two-step method are compared with experimental data from different samples. It has been observed that the modulus of samples progressively increases with an increase in interphase depth. Also, a higher interphase modulus contributes to an enhanced modulus of samples. Nevertheless, excessively high interphase moduli (Ei > 60 GPa) result in only a marginal improvement in the modulus of nanocomposites. Additionally, narrower HNTs are advantageous for producing stronger samples, though the modulus of the nanocomposites slightly diminishes at very high HNT radii (R > 55 nm). The outputs of two-step method agree with the experimental moduli of various HNT-filled systems.

Introduction. Development of formulations of multicomponent binder compositions with the use of mineral additives of different nature is an urgent task. Multicomponent binders, “Portland cement – mineral additive”, “Portland cement – mineral additive – plasticizer” allow to expand the range of binders, to find economical practical application of resource-intensive material, to reduce energy consumption for high-temperature processing, and all this not to the detriment of the operational indicators of concrete and reinforced concrete.Materials and methods. According to the regulatory and technical documents GOST 31108, GOST 20515, it is recommended to use finely dispersed additives of both natural and anthropogenic origin as a component of binding systems, which do not have a harmful effect on the properties of cement paste and stone.Results. Topological models of multicomponent binder system, which differ depending on the nature and granulometry of mineral powder. On the basis of the conducted researches, the models of the diffusion interphase zone of cement stone, consisting of reacted clinker and mineral components, are presented; the boundary layers of which are characterized by the presence of calcium hydrate silicates and micropores of different configuration in the composition of neoplasms. The qualitative composition of the boundary interphase zone is determined by the nature and reactivity of the filler.Conclusions. The analysis of the results showed that the appropriate chemical and mineralogical composition, the presence of ion-exchange centers and high activity coefficient contribute to an increase in the reactivity of mineral additives, which is important for the creation of strong binder, necessary for the organization of monolithic high-rise construction with structural elements of complex hermetic configuration.

To date, there have been a limited number of studies modeling the tensile modulus in the polymer halloysite nanotube (HNT) systems before or after percolation onset. In this paper, an equation for a composite's modulus post-percolation onset was developed for HNT-filled samples including the interphase and HNT network. The dispersed nanoparticles and adjoining interphase part were neglected, because they caused ineffective influences on the stiffness of the system after percolation onset. The developed model reflects the impacts of HNTs' size, interphase depth, percolation onset and the volume shares and moduli of the HNT network and its adjacent interphase on the modulus of HNT-based systems. The impacts of issues on the nanocomposite modulus are defendable, confirming the effectiveness of the developed model. HNT length, interphase depth, HNT concentration, net modulus and net portion directly influenced the stiffness, while the HNT radius and percolation onset had inverse effects. Results show that there was a 142% improvement in the modulus of samples at an interphase depth of 40 nm. Moreover, the stiffness improved by 60% at a net modulus of 200 GPa, but it later exhibited a 180% enhancement at a net modulus of 1000 GPa. In addition, the experimental data for the modulus of numerous composites display fine agreement to the predictions, confirming the validity of the developed model. [ABSTRACT FROM AUTHOR]

In the current article, Kolarik model is progressed for the tensile modulus of a polymeric system containing dispersed halloysite nanotubes (HNT) and adjacent interphase section. The progressive model correlates the nanocomposite's modulus to HNT concentration (volume fraction and weight percentage), the extents of HNT and nearby interphase section in addition to the densities of polymer medium and HNT. The productions of the progressive model are linked to the tentative results and the influences of all variables on the modulus of system are justified. The modulus of system reduces as HNT radius increases, but HNT weight percentage directly controls the nanocomposite's modulus. The modulus of samples maximizes by 47% by the deepest interphase section of 20 nm establishing a straight link among nanocomposite's modulus and interphase thickness. The increment of polymer matrix density improves the modulus of samples, but there is an opposite relation between the modulus of system and HNT density. Furthermore, the calculations exactly match to the experimental facts of numerous examples representing the accurateness of the progressed model. [ABSTRACT FROM AUTHOR]

In this work, we focus on the minimum interfacial shear modulus (Sc) and interfacial shear modulus (Si) controlling the efficiency of interphase zone in polymer clay nanocomposites, since the stress transferring through interphase section handles the stress bearing of samples. The roles of "Sc" and "Si" in the effective thickness and concentration of interphase zone are clarified. Moreover, a model based on Kolarik system is developed for modulus of clay‐reinforced nanocomposites, which reflects the efficiency of interphase zone. The experimental data of tensile modulus for many samples display good matching with the predictions of the advanced model. Also, all model parameters properly manipulate the nanocomposite's modulus. Thick clay (t > 4 nm) cannot generate the interphase zone in the samples. A poor "Sc," high "Si," and thin clay improve the modulus of nanocomposites, but very high "Sc," extremely poor "Si," or thick clay cause a poor nanocomposite. A high value of Sc = 0.21 GPa deteriorates the reinforcing efficiency of clay in nanocomposites. Furthermore, low Si < 35 GPa produces a poorer nanocomposite than the polymer matrix. Additionally, complete exfoliation of thin clay (t = 1 nm) causes 900% improvement in the nanocomposite's modulus. [ABSTRACT FROM AUTHOR]

To date, there have been a limited number of studies modeling the tensile modulus in the polymer halloysite nanotube (HNT) systems before or after percolation onset. In this paper, an equation for a composite’s modulus post-percolation onset was developed for HNT-filled samples including the interphase and HNT network. The dispersed nanoparticles and adjoining interphase part were neglected, because they caused ineffective influences on the stiffness of the system after percolation onset. The developed model reflects the impacts of HNTs’ size, interphase depth, percolation onset and the volume shares and moduli of the HNT network and its adjacent interphase on the modulus of HNT-based systems. The impacts of issues on the nanocomposite modulus are defendable, confirming the effectiveness of the developed model. HNT length, interphase depth, HNT concentration, net modulus and net portion directly influenced the stiffness, while the HNT radius and percolation onset had inverse effects. Results show that there was a 142% improvement in the modulus of samples at an interphase depth of 40 nm. Moreover, the stiffness improved by 60% at a net modulus of 200 GPa, but it later exhibited a 180% enhancement at a net modulus of 1000 GPa. In addition, the experimental data for the modulus of numerous composites display fine agreement to the predictions, confirming the validity of the developed model.

The paper studies the structure and phase characteristics of the interphase zone diamond/matrix in dressers made by thermal diffusion metallization of a diamond combined with matrix sintering based on WC–Co and Cu impregnation. The compact arrangement of chromium powder particles around diamond grains and the shielding effect of copper foil create favorable conditions for thermal diffusion metallization of diamond at matrix sintering. A metallized coating chemically bonded to diamond and consisting of chromium carbide and solid solution of cobalt in chromium phases provides a strong diamond retention in the carbide matrix. It is shown that it is formed on the surface of the diamond under the conditions specified in the experiment and the temperature–time sintering mode. The specific productivity of experimental dresser made by hybrid technology at straightening the green silicon carbide grinding wheel equaled 51.50 cm3/mg, exceeding that of the control dresser made without metallization of diamonds by sintering with copper impregnation by 44.66%. [ABSTRACT FROM AUTHOR]

The present paper is aimed to study the buckling and postbuckling response of functionally graded carbon nanotube (FG-CNT)- magnesium (Mg) nanocomposite plate with interphase effect. Interphase zone is characterized by employing a cohesive zone model for its elastic modulus and thickness. An equivalent solid fiber (ESF) of CNT and interphase is modeled and dispersed into the matrix material by utilizing random sequential adsorption (RSA) technique. The effective elastic properties of the nanocomposite are computed by finite element method (FEM) based numerical homogenization technique. The obtained elastic properties of nanocomposite are utilized to investigate the buckling and post-buckling behaviour of different functionally graded (i.e., FG) nanocomposite plates modeled by varying the volume fraction of CNT/ESF along thickness direction, under in-plane compressive loads. The non-linear formulation is based on first-order shear deformation theory and von Karman's assumptions. It is found that considering the interphase between CNT and Mg matrix would result in decrease in buckling load and postbuckling strength of FG-CNT-reinforced nanocomposite plate as compared to nanocomposite without interphase. It is also reported that the higher volume fraction of CNTs near top and bottom surfaces than the middle portion of nanocomposite plate provide better resistance to buckling and postbuckling. [ABSTRACT FROM AUTHOR]

We predict the macroscopic tensile strength and fracture toughness of fully exfoliated nano silicate clay epoxy composites accounting for the interphase behavior between the polymeric matrix and clay reinforcement. A phase field approach is employed to model fracture in the matrix and the interphase zone of the polymeric nanocomposites (PNCs) while the stiff clay platelets are considered as linear elastic material. The effect of the interphase zones, e.g. thickness and mechanical properties (Young’s modulus and strain energy release rate) on the tensile strength, and fracture parameters of the composite is studied in detail. The dissipation energy due to fracture in the PNCs is extracted for different thicknesses and properties of the interphase zones. We show through numerical experiments that the interphase thickness has the most influence on the tensile strength while the critical strain energy release rate of the interphase zones affects the dissipation energy depending on the interphase zone thickness. [ABSTRACT FROM AUTHOR]

There are limited equations for determining the mechanical performance of halloysite nanotubes (Hal)/polymer samples, and these equations ignore the reinforcing efficacy of the interphase zone. In this article, the Kolarik system is used to determine the tensile strength of Hal-reinforced nanocomposites by Hal size, Hal concentration, and interphase properties. In addition, Pukanszky model is modified for this material type to account for effective Hal concentration based on the advanced Kolarik model. Numerous sets of experimental data for several samples and parametric inspections endorse the developed models. Both interphase depth and power directly govern the nanocomposite's strength and the interphase factor "A" in the advanced Kolarik model. The lowest ranges of interphase properties lead to the lowest level of "A," and at this level, there is no strengthening of the nanocomposites. The Hal radius (R) of 10 nm and Hal length (l) of 3 μm lead to the highest "A" of 50 and the maximum relative strength of 4.5 (350% improvement in nanocomposite's strength), whereas Hal with R > 50 nm and l < 1.5 μm cannot reinforce the sample. Moreover, the Hal content, interphase parameter "B," and interphase thickness have a direct relationship with nanocomposite's strength according to the developed Pukanszky model, whereas the Hal radius has an inverse relationship. • Kolarik system is advanced for tensile strength of HNT-reinforced nanocomposites. • Pukanszky model is progressed for these nanocomposites by effective HNT concentration. • Experimental data for several samples and parametric inspections endorse the models. • Both interphase depth and strength directly manage the nanocomposite's strength. • The extremely low ranges of interphase properties cannot strengthen the samples. [ABSTRACT FROM AUTHOR]