Effect of amino acid-functionalized multi-walled carbon nanotubes on the properties of dopamine-based poly(amide-imide) composites: An experimental study

Abstract

In a single-step, rapid microwave-assisted process, multi-walled carbon nanotubes were functionalized by S-valine amino acid. Formation of amino acid on nanotube surface was confirmed by Fourier transform-infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, field emission scanning and transmission electron microscopy techniques. The surface-modified nanotubes showed better chemical stability in common solvents such as N,N-dimethylacetamide. The effects of amino acid functionalization of multiwalled carbon nanotubes on the properties of nanotube/poly(amide-imide) nanocomposites were investigated. The functionalized carbon nanotubes (5-15 wt%) were dispersed homogeneously in the poly(amide-imide) matrix, while the structure of the polymer and the nanotubes structure were stable in the preparation process as revealed by microscopic observations. The properties of nanocomposites were characterized extensively using the aforementioned techniques. The composite films have been prepared by casting a solution of precursor polymer containing S-valine-functionalized carbon nanotubes into a thin film and its tensile properties were examined. The Young's modulus (elastic modulus) and tensile strength of the composite films were greatly improved by the incorporation of modified nanotubes. Keywords. Multi-walled carbon nanotubes; amino acids; nanocomposite; mechanical properties.

Study on CO2 facilitated separation of mixed matrix membranes containing surface modified MWCNTs

“…This feature also can be attributed to two possible reasons. On the one hand, the MWCNTs possessed good thermal conductivity, which facilitates heat dissipation in the MMMs and hence prevents the accumulation of heat at a certain point for degradation . On the other hand, the interaction between MWCNT and VA‐co‐VAm matrix can increase the thermal stability of MMMs.…”

“…Multiwalled carbon nanotubes (MWCNTs) were considered as an excellent filler due to its unique chemical, mechanical, and thermal properties . It has a nested structure with inter‐layer spacing of about 3.4 Å . Therefore, MMMs using MWCNTs as nanofillers have attracted a widespread attention for CO 2 gas separation.…”

Processing and characterization of extruded PET and its r-PET and MWCNT nanocomposite thin films by spin coating

“…The morphological studies reveal more compact and smooth surface of PET C and PET D nanocomposites as compared with PET A and PET B. This improved surface morphology of PET C and PET D could be due to decrease in chain entanglement density of r-PET [11,24]. The surface PET D samples show more compact and uniform globular structure as compared with PET C. This could be due to more nucleation sites produced by MWCNT which leads to small and more uniform structure [16,19].…”

“…Wrapping and better dispersion of MWCNT was reported by Hsiao et al [10] for preparing MWCNT/ polyethylene. Although there is tremendous importance for precipitation method, very less literature is available on dispersing of MWCNT and preparing polymer nanocomposites which leads to better thermal, mechanical, and decreased electrical and rheological threshold [11]. Dispersion of nanofiller is a big challenge and the precipitation method can play a very important role by producing polymer wrapped MWCNT which can in fact used as filler for preparing polymer nanocomposites.…”

Synthesis and studies of thermal, mechanical and electrical properties of MWCNT-cyclodextrin as a nanoparticle in polyamide matrix based on 2,2-Bis[4-(4-aminophenoxy)phenyl] propane

“…For solving this problem, several mechanical/physical methods and an additional functional group such as the hydroxyl group in the MWCNT to form MWCNT-functionalized were used. Thus, it is possible to obtain MWCNTs as an effective reinforcement in PA composites and ensure proper dispersion and appropriate interfacial adhesion between the MWCNTs and PA. [18,19] This functionalization process should contribute positively to the good dispersion of MWCNT in the PA matrix. Moreover, the introduction of several functional groups into the backbone of the aromatic polymer allows hydrogen bonding with functionalized MWCNTs.…”