Taguchi L25 (54) Approach for Methylene Blue Removal by Polyethylene Terephthalate Nanofiber-Multi-Walled Carbon Nanotube Composite

A membrane composed of polyethylene terephthalate nanofiber and multi-walled carbon nanotubes (PET NF-MWCNTs) composite is used to adsorb methylene blue (MB) dye from an aqueous solution. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction techniques are employed to study the surface properties of the adsorbent. Several parameters affecting dye adsorption (pH, MB dye initial concentration, PET NF-MWCNTs dose, and contact time) are optimized for optimal removal efficiency (R, %) by using the Taguchi L25 (54) Orthogonal Array approach. According to the ANOVA results, pH has the highest contributing percentage at 71.01%, suggesting it has the most significant impact on removal efficiency. The adsorbent dose is the second most affected (12.08%), followed by the MB dye initial concentration of 5.91%, and the least affected is the contact time (1.81%). In addition, experimental findings confirm that the Langmuir isotherm is well-fitted, suggesting a monolayer capping of MB dye on the PET-NF-MWCNT surface with a maximum adsorption capacity of 7.047 mg g−1. Also, the kinetic results are well-suited to the pseudo-second-order model. There is a good agreement between the calculated (qe) and experimental values for the pseudo-second-order kinetic model.

UIO-66 as Nucleating Agent on the Crystallization Behavior and Properties of Poly(Ethylene Terephthalate)

In this study, not only was the similar terephthalate structure between UIO-66 and PET utilized to improve compatibility, but the Zr4+ exposed by defects of UIO-66 was also utilized to improve the interaction between PET and UIO-66. Furthermore, PET nanocomposites with different contents of UIO-66 were also fabricated. Due to the high specific surface area and coordination of Zr4+, UIO-66 has high nucleation efficiency in the PET matrix. Compared with pure PET, the crystallization rate of PET/UIO-66 nanocomposite is significantly increased, and the crystallization temperature of PET-UIO66-1 is significantly increased from 194.3 °C to 211.6 °C. In addition, the tensile strength of nanocomposites has also been improved due to coordination.

Interaction of Poly L-Lactide and Tungsten Disulfide Nanotubes Studied by in Situ X-ray Scattering during Expansion of PLLA/WS2NT Nanocomposite Tubes

In situ synchrotron X-ray scattering was used to reveal the transient microstructure of poly(L-lactide) (PLLA)/tungsten disulfide inorganic nanotubes (WS₂NTs) nanocomposites. This microstructure is formed during the blow molding process (“tube expansion”) of an extruded polymer tube, an important step in the manufacturing of PLLA-based bioresorbable vascular scaffolds (BVS). A fundamental understanding of how such a microstructure develops during processing is relevant to two unmet needs in PLLA-based BVS: increasing strength to enable thinner devices and improving radiopacity to enable imaging during implantation. Here, we focus on how the flow generated during tube expansion affects the orientation of the WS₂NTs and the formation of polymer crystals by comparing neat PLLA and nanocomposite tubes under different expansion conditions. Surprisingly, the WS₂NTs remain oriented along the extrusion direction despite significant strain in the transverse direction while the PLLA crystals (c-axis) form along the circumferential direction of the tube. Although WS₂NTs promote the nucleation of PLLA crystals in nanocomposite tubes, crystallization proceeds with largely the same orientation as in neat PLLA tubes. We suggest that the reason for the unusual independence of the orientations of the nanotubes and polymer crystals stems from the favorable interaction between PLLA and WS₂NTs. This favorable interaction leads WS₂NTs to disperse well in PLLA and strongly orient along the axis of the PLLA tube during extrusion. As a consequence, the nanotubes are aligned orthogonally to the circumferential stretching direction, which appears to decouple the orientations of PLLA crystals and WS₂NTs.

Poly(ethylene Terephthalate) Carbon-Based Nanocomposites: A Crystallization and Molecular Orientation Study

Hybrid polymeric materials incorporating carbon nanostructures or inorganic constituents stand as a promising class of materials exhibiting distinct but also complementary features. Carbon nanotubes have been proposed as unique candidates for polymer reinforcement; however, sustained efforts are further needed in order to make full use of their potential. The final properties of the reinforced polymer are controlled in part by the morphology and the eventual molecular orientation of the polymer matrix. In the present study, multiwall carbon nanotubes (MWCNTs) were utilized in order to reinforce polyethylene terephthalate (PET) composites. The effect of CNTs on the crystallization and the orientation of the structurally hybridized polymeric material has been investigated from the perspective of assessing their impact on the final properties of a relevant nanocomposite product. Functionalized MWCNTs were used to achieve their optimal dispersion in the polymer matrix. The physical properties of the composites (i.e., crystallinity and orientation) were characterized via differential scanning calorimetry, X-ray diffraction, and polarized Raman microscopy. The addition of well-dispersed CNTs acted as a nucleation agent, increasing the crystallization of the polyethylene terephthalate matrix and differentiating the orientation of both CNTs and macromolecular chains.

Effects of Reorientation of Graphene Platelets (GPLs) on Young's Modulus of Polymer Composites under Bi-Axial Stretching

Effects of bi-axial stretching induced reorientation of graphene platelets (GPLs) on the Young's modulus of GPL/polymer composites is studied by Mori-Tanaka micromechanics model. The dispersion state of the GPLs in polymer matrix is captured by an orientation distribution function (ODF), in which two Euler angles are used to identify the orientation of the GPLs. Compared to uni-axial stretching, the increase of the stretching strain in the second direction enhances the re-alignment of GPL fillers in this direction while it deteriorates the re-alignment of the fillers in the other two directions. Comprehensive parametric study on the effects of the out-of-plane Young's modulus, stretching strain, strain ratio, Poisson's ratio and weight fraction and GPL dimension on the effective Young's moduli of the composites in the three directions are conducted. It is found that the out-of-plane Young's modulus has limited effects on the overall Young's modulus of the composites. The second stretching enhances the Young's modulus in this direction while it decreases the Young's modulus in the other two directions. The results demonstrate the increase of Poisson's ratio is favorable in increasing the Young's modulus of the composites. GPLs with larger diameter-to-thickness ratio have better reinforcing effect on the Young's modulus of GPL/polymer nanocomposites.

Smarter-lighter-greener: research innovations for the automotive sector

This paper reviews the changing nature of research underpinning the revolution in the automotive sector. Legislation controlling vehicle emissions has brought urgency to research, so we are now noticing a more rapid development of new technologies than at any time in the past century. The light-weighting of structures, the refinement of advanced propulsion systems, the advent of new smart materials, and greater in-vehicle intelligence and connectivity with transport infrastructure all require a fundamental rethink of established technologies used for many decades-defining a range of new multi-disciplinary research challenges. While meeting escalating emission penalties, cars must also fulfil the human desire for speed, reliability, beauty, refinement and elegance, qualities that mark out the truly great automobile.

Melt processing and characterisation of polyamide 6/graphene nanoplatelet composites

The incorporation of graphene nanoplatelets into nylon (PA6)viamelt processing on an industrial scale significantly increases the crystallinity, stiffness, and electrical conductivity of the resulting composites.

Characterization and structure–property relationship of melt-mixed high density polyethylene/multi-walled carbon nanotube composites under extensional deformation

Disentanglement degree of nanotube agglomerates depends on the stretching mode, strain rate and stretching temperatures under extensional deformation.

Processability, structural evolution and properties of melt processed biaxially stretched HDPE/MWCNT nanocomposites

The HDPE/MWCNT nanocomposites show a structural evolution of MWCNT networks from 3D to 2D during biaxial stretching.