Exploring the Interfacial Phase and π–π Stacking in Aligned Carbon Nanotube/Polyimide Nanocomposites

Abstract

To characterize the interfacial microstructure and interaction at a nanoscale has a significant meaning for the interface improvement of the nanocomposites. In this study, the interfacial microstructure and features of aligned multiwalled carbon nanotube (MWNT) and conjugated polymer polyimide (PI) with three molecular structures were investigated using small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), and fluorescence emission spectroscopy. It was found that aligned MWNT/PI nanocomposites had a nonideal two-phase system with the interfaces belonging to long period stacking ordered structure. Attributed to the π–π stacking effect, MWNT/BTDA-MPD presented the most regular arrangement verified by fractal dimension. By adopting a one-dimension correlation function, each phase dimension in aligned MWNT/PI nanocomposites was calculated and verified by high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The π–π stacking was demonstrated to be an important interaction between MWNT and PI via WAXD and fluorescence emission spectroscopy, and it was influenced by the linkage bond between benzene rings in PIs. This work is of significance to reveal the interfacial features between conjugated polymer and carbon nanotubes (CNTs), which is favorable for the interface design of CNT-based high performance nanocomposites.

Effect of Humidity on Gas Sensing Performance of Carbon Nanotube Gas Sensors Operated at Room Temperature

“…This peak can also be the result of parallel stacking of carbon tube layers. It has been shown that peak (002) intensity decreases in aligned CNTs [39]. The distance between the carbon nanotube plates and the type of nanotube formation can affect the (002) peak [36].…”

Electrochemical and Spectroelectrochemical Studies on the Reactivity of Perimidine–Carbazole–Thiophene Monomers towards the Formation of Multidimensional Macromolecules versus Stable π-Dimeric States

“…Generally, two-, three- and multidimensional molecular network can be organized based on types of monomer linking (covalently, coordinating and/or supramolecular), where can indicate such as: covalent organic frameworks (COF) [ 5 , 6 ], coordination polymers [ 7 ], metal-organic frameworks (MOF) [ 8 ] and supramolecular polymers [ 9 , 10 , 11 ]. Supramolecular structures are self-assembled small molecules held together by reversible noncovalent interactions, such as hydrogen bonds [ 12 , 13 ], coordination [ 14 ], π–π stacking [ 15 , 16 ], and host-guest interactions [ 17 , 18 ], etc. It is noteworthy that supramolecular polymers do not comply with classical Carothers’ definition of a polymer as a single macromolecule but rather the idea of polymers as colloidal aggregates.…”

Review about the Application of Fractal Theory in the Research of Packaging Materials

“…The normally used method to extract the fractal feature of packaging materials is to employ the material micromorphology in the preparation process, surface, or fracture morphology of packaging material, and the test data in the property change process of packaging material (e.g., acoustic emission (AE) signal [ 18 ]) to carry out image gray processing and noise reduction processing, respectively. Common methods for calculating fractal dimension include the box counting method [ 19 ], correlation dimension method [ 20 ], Hurst index method [ 21 ], slit island method [ 22 ], yard stick method [ 23 ], area-perimeter method [ 24 ], Sierpiński carpet method [ 25 ], semi-variance method [ 26 ], and power spectral density [ 27 ] (PSD) method. The main methods to obtain object image are scanning electron microscope [ 28 ] (SEM), transmission electron microscope [ 29 ] (TEM), atomic force microscope [ 30 ] (AFM), and other imaging techniques.…”