Development of Conductive Polyelectrolyte-Triggered Polymer Nanocomposite Attached With MWCNT

Lightweight polymer composites have drawn a lot of interest because of their improved mechanical, electrical, and thermal properties, which make them perfect for cutting-edge engineering applications. This work reports the synthesis of hybrid polymer composites by integrating multi-walled carbon nanotubes (MWCNTs) into a polyvinylidene fluoride (PVDF) matrix. The synergistic effect of MWCNTs and graphite nanoparticles was explored to achieve improved structural and functional performance. The composites were synthesised using a solution casting method to ensure dispersion of the fillers within the polymer matrix. The fabricated composite was characterized using XRD, FTIR, EDS and FESEM to evaluate its structural, compositional, morphological and elemental properties. XRD confirmed the nanofillers' crystalline phases and structural integrity within the polymer matrix. FTIR spectroscopy identified the characteristic functional groups, verifying interactions between PVDF and the incorporated nanofillers. FESEM images revealed a fibrous CNT network blended within the PVDF polymer matrix and distinct graphite flakes, ensuring uniform dispersion and adhesion. EDS confirmed the elemental composition, highlighting the presence of carbon and fluorine as primary constituents. These combined techniques provide comprehensive insight into the composite's composition, structure and potential functional properties for advanced applications.

Structural organization of ionic liquids embedded in fluorinated polymers

The nanocomposites based on poly (styrene-b-ethylene butylene-b-styrene) (SEBS) and multiwalled carbon nanotubes (MWNTs) were prepared and electrical, thermal, and mechanical properties of the nanocomposites were investigated. SEBS is a block copolymer showing microphase separated morphologies and can be a matrix polymer for double percolation of MWNTs in nanocomposites. In order to facilitate the dispersion of MWNTs, pristine MWNTs were reduced with Li into anions and sulfonation of SEBS to prepare sulfonated SEBS (S-SEBS) was carried out. Furthermore, we have added poly (4-styrenesulfonic acid) (PSSA) to SEBS or S-SEBS and investigated properties of the nanocomposites based on the MWNTs, SEBS, and PSSA. Nanocomposites based on S-SEBS, PSSA, and the modified MWNTs showed threshold decrease of electrical resistivity due to the percolation of MWNTs at a lower content of the MWNTs compared with those based on SEBS, PSSA, and the MWNTs. The efficient percolation of the MWNTs in the nanocomposites of S-SEBS and PSSA is attributed to interactions between ionic moieties of MWNTs and S-SEBS and fine dispersion of the MWNTs. It was worthwhile to notice that the addition of PSSA into S-SEBS resulted in the decrease of the critical concentration of MWNTs (Pc) for the percolation in the nanocomposites. It is postulated that the decrease of Pc resulted from a double percolation of MWNTs by preferred location in sulfonated polystyrene phases of microphase separated S-SEBS in the nanocomposites. The nanocomposites based on S-SEBS showed large improvement of Young's modulus compared with the nanocomposites based on SEBS.

Multi-walled carbon nanotubes (MWNTs) nanocomposites with the polymer matrix composed of blends of poly(vinylidene fluoride) (PVDF) and polyurethane (PU) were prepared via functionalization of 3,4,5-triflouroaniline (TFA) on MWNTs. The MWNTs/polymer nanocomposites showed a dominantly enhanced elongation due to incorporation of PU molecules in PVDF matrix and the improved MWNTs dispersion in the polymer matrix resulting from functionalization of MWNTs with TFA. The functionalization of TFA on MWNTs was confirmed by the measurements of Raman, FT-IR spectra, SEM, and TEM images. In addition, the dielectric constant of nanocomposites increased with an increase of TFA-functionalized MWNTs in PVDF/PU/MWNTs nanocomposites. The polymer blend nanocomposites incorporating MWNTs may be available as an alternative potential route for the actuator materials.

Polymer dielectric capacitors have emerged as attractive energy storage solutions for pulsed power applications, attributed to their exceptional breakdown strength and superior processability. Nevertheless, the energy storage performance of polymers is limited by low polarization, making it crucial to develop rational strategies to enhance their energy storage density (Ue). In this article, Mg‐Al layered double hydroxide nanosheets (MALNS) were in‐plane oriented within a polyvinylidene fluoride (PVDF) matrix through spray‐coating, double‐folding, and hot‐pressing methods, forming the typical “3 + 2” layered composite, consisting of two oriented MALNS layers sandwiched between three PVDF matrix layers. Orientation regulation of positively charged MALNS can enhance their effective area of capturing free charges, which restrains the formation of breakdown paths. Furthermore, two polymethylmethacrylate (PMMA) ultrathin layers were coated onto the surfaces of the layered composites to reduce the defects at the dielectric‐electrode interface. Consequently, the PMMA‐covered layered composite filled with 1 mg oriented MALNS in PVDF achieves a high Ue of up to 11.9 J/cm3 under an electric field of 443.2 MV/m, which is 264% and 133% higher than that of pure PVDF (4.5 J/cm3 and 333.5 MV/m). This research presents a robust and effective strategy for the design and fabrication of high Ue energy storage devices.Highlights The in‐plane orientation of MALNS is achieved via the spray‐coating process. The overall polarization and Eb of the Vx composites have been enhanced. The M5000V1M5000 composite exhibits a high Ue of 11.9 J/cm3 and a η of 59.9%. The “3 + 2” orientation structure enhances the capture area for free charges. The multi‐layer structure interface suppresses the migration of space charges.

The effects of agglomerate on the piezoresistivity of conductive carbon nanotube/polyvinylidene fluoride composites

Construction of recoverable Ag2SeO3/Ag3PO4/MWCNT/PVDF porous film photocatalyst with enhanced photocatalytic performance for degrading Indigo carmine dye in continuous flow-loop photoreactor

Nanocomposites based on poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) and multiwalled carbon nanotubes (MWNTs) were prepared. In order to facilitate the dispersion of MWNTs in the nanocomposites, the pristine MWNTs were reduced by Li to anions and SEBS was sulfonated. Poly(4-styrenesulfonic acid) (PSSA) was also added to either SEBS or S-SEBS and the morphology and properties of the nanocomposites were examined. Nanocomposites prepared from S-SEBS, PSSA, and the modified MWNTs showed a threshold decrease in electrical resistivity due to the percolation of MWNTs at a critical MWNT content (P(c)) lower than those for the nanocomposites based on SEBS, PSSA, and the MWNTs. It was found that the P(c) decreased with increasing the concentration of PSSA in the nanocomposites containing S-SEBS. The efficient percolation of MWNTs in the S-SEBS/PSSA nanocomposites was attributed to interactions between the ionic moieties of MWNTs and S-SEBS and the fine dispersion of the MWNTs. Nanocomposites based on S-SEBS showed large increase of rubbery plateau modulus compared with those based on SEBS. PSSA played the role of plasticizer of sulfonated PS blocks above T(g) of PS blocks in S-SEBS.

Effect of functional groups on the properties of multiwalled carbon nanotubes/polyvinylidenefluoride composite membranes

Synchronous removal and separation of multiple contaminants by poly (vinylidene fluoride)/polyaniline ultrafiltration membrane

Effect of the selective localization of carbon nanotubes in polystyrene/poly(vinylidene fluoride) blends on their dielectric, thermal, and mechanical properties

Functionalized BaTiO3 enhances piezoelectric effect towards cell response of bone scaffold

A ternary system based on blends of poly(vinylidene fluoride)(PVDF) and polycaprolactone (PCL) and made the multi-walled carbon nanotubes (MWNT) selective distribution in PCL phases via melt blending has been studied. The stud- ies on conductivity of MWNT/PCL/PVDF composites with different proportions of PVDF and PCL showed that the con- ductivity was good in the mass ratio range of PVDF/PCL from 70/30 to 40/60 and that of other matching was poor. The scanning electron microscope (SEM) observation of the composites revealed co-continuous morphologies of PVDF and PCL were formed in composites under suitable proportion of PVDF to PCL. The interfacial tensions of PVDF and PCL melts was tested at mixing temperature of 200°C, the calculated wetting coefficient indicated that MWNT would selectively distribute in PCL phase owing to interfacial effects. Transmission electron microscope (TEM) observation further confirmed that co-continuous morphologies of PVDF and PCL could appear with the increase of PCL content, as indicated by MWNT selective localization in PCL.As the result, the desired structure of double percolation was built in MWNT/PCL/PVDF composites, which have much higher conductivity than that of PVDF or PCL composites with the same MWNT content. Through a strategy of selective localization of MWNT, PVDF based material with low percolation threshold (<0.5 wt%) was acquired which held promise for potential use in large-scale industrial applications.

Poly(vinylidene fluoride) (PVDF) composites containing multiwalled carbon nanotubes (MWNTs) in the range from 0.1 to 5 wt% were prepared at 220 °C using a melt-mixer. The storage modulus (G′) of the PVDF/MWNT composites increased with increasing MWNT content. In particular, there was a significant increase in G′ between 1 and 3 wt%. In the Cole-Cole plot, the PVDF composites with up to 1 wt% MWNTs exhibited a single master curve with a slope of 1.25, but the composites containing 3 and 5 wt% MWNTs showed a decreased slope of 1.13 and 1.03, respectively. From the addition of 3 wt% MWNTs, the yield of the PVDF composites was observed in complex viscosity versus complex modulus plot with little dependence on the loss tangent (tan δ) on the frequency was shown. Both the induction time and crystallization time obtained from the G′ versus time plot decreased with increasing MWNT content. The promoting effect of the MWNTs on the overall crystallization behavior was more profound at higher crystallization temperatures. Pure PVDF and PVDF with 0.1 wt% MWNTs showed only α phase crystals, but the PVDF composites with high concentrations of MWNTs (1–5 wt%) appeared to contain a mixture of β and γ phases in addition to the α phase. Open image in new window

The existing study focused more on one-dimensional nanostructures such as nanotubes and nanofibers for various potential applications, but less on evaluation of their mechanical properties. Therefore, this study mainly concentrates on near-field electrospinning (NFES) and hollow cylindrical near-field electrospining (HCNFES) process to fabricate permanent piezoelectricity of polyvinylidene fluoride (PVDF)/multi-walled carbon nanotube (MWCNT) nanofibers. Comparing NFES and HCNFES, it can be seen that HCNFES was fabricated under high electrical field with in-situ strong mechanical stretching for possible alignment of dipoles along the longitudinal direction of PVDF nanofiber. Therefore, PVDF nanofibers fabricated using HCNFES can be of smaller diameters and higher contents of β-phase with excellent piezoelectricity. In addition, the crystallization and mechanical behaviors of PVDF nanofibers were influenced by the PVDF solution concentration and addition of MWCNT. The tensile test shows that the yield strength increases with increasing 0.03% MWCNT and 16% PVDF solution.