Modeling of density of state for polyethylene–nanotubes nanocomposites

Abstract

At the nanoscale system, the efficiency of carbon nanotube (CNT) reinforcement between the CNTs and polymer matrices in terms of interfacial load transferring is assessed for both nonfunctionalized and functionalized interfaces. The simulations of the mechanical properties (stress-strain) of polyethylene (PE)/CNT nanocomposites by the molecular dynamics are currently an area of discussion in the literature. In this work, PE considered as a thermoplastic material is studied, in which the characterization of its nanoscale load transfer has been carried out through the classification of representative nanoscale interface elements for nonfunctionalized CNTs for the diverse values of lengths and diameters. First, the main evaluations based on the density functional theory and the molecular dynamics method were used with the aim to examine the effect of PE monomers. Then, the effect of the diameter of CNTs with nonfunctionalization content on the electronic and mechanical properties of single-walled carbon nanotubes was examined. The findings reveal that the density of states highlights the absence of orbital hybridization between the PE monomers and nanotubes, whereas the Mulliken charge analysis depicts that the PE polymer produces a positive charge that is directly proportional to the number of monomers with many chains of PE and different diameters of CNTs. The decrease in diameters implies an increase in nanocomposites stress. In addition, the results show that the reinforcements in the longitudinal direction are more promising than those in the transverse direction.

Polymer composites–Special issue review for additive manufacturing of composites

“…This issue is highlighted by several review articles detailing recent advances in the additive manufacturing technology space including advances in the area of smart materials, 1 coatings of bio-polymer systems, 2 applications with natural materials for the matrix and the fiber, 3 recent advances in the performance of fiber filled polymer systems for the FFF process. 4 Papers in this special issue range from the use of bio and bio-inspired materials, 2,3,5-12 materials and material systems that benefit from nanoscale enhancements, [13][14][15][16][17][18][19][20][21][22][23] advances in the medical field, [24][25][26] additive material systems utilizing thermosets, [27][28][29] large scale additive manufacturing, [30][31][32] and some rather novel applications in AM. 1,[33][34][35] Several articles focus on improvements for characterization, [36][37][38][39] and quite a few seek to identify parameters to enhance the final part performance through processing improvements.…”

“…CNTs, graphene, and other similarly scaled systems. Several authors 13,14,20,21 enhance the final part performance through the integration of CNTs, with Li et al 14 enhancing fracture toughness, Han et al 20,21 focusing on processing enhancements, and Kessaissia et al 13 looking at the nanoscale to better understand interfacial properties between the CNTs and the surrounding matrix. Several authors focus on enhancements using nanoparticles beyond classical structural improvements, with Relinque et al 18 increasing the conductivity of an ABS system, Aktitiz et al 19 modify the polymer matrix with Fe 2 O 3…”

“…A continual focus for advancing additive manufacturing is through the use of nano‐scale materials, such as CNTs, graphene, and other similarly scaled systems. Several authors 13,14,20,21 enhance the final part performance through the integration of CNTs, with Li et al 14 enhancing fracture toughness, Han et al 20,21 focusing on processing enhancements, and Kessaissia et al 13 looking at the nanoscale to better understand interfacial properties between the CNTs and the surrounding matrix. Several authors focus on enhancements using nanoparticles beyond classical structural improvements, with Relinque et al 18 increasing the conductivity of an ABS system, Aktitiz et al 19 modify the polymer matrix with Fe 2 O 3 nanoparticles to improve the mechanical, magnetic and thermal properties, and Brooks et al 23 enhance the conductivity for biodegradable polymers for direct ink applications using a graphite material.…”

In situ polymerization of ethylene with functionalized multiwalled carbon nanotubes using a zirconocene aluminohydride system in solution

“…[11] On the other hand, improving the properties of materials is an essential key to industrial performance and also for maximizing the usage of multiphase materials where the matrix guarantees the connection between each component and the reinforcement provides the technical functions. [22] In this context, He and Zhang prepared composites of MWCNT/HDPE by a master batch method, melt-blending a commercial HDPE with an MWCNT/HDPE master batch obtained through in situ polymerization and compared these results with those composites prepared by direct meltblending method. Their investigation suggests that the HDPE covering on the MWCNT surfaces as a result of in situ polymerization was useful to achieve a homogeneous distribution, enhanced properties, and an effective method to obtain advanced polyolefin-based composites.…”