The effect of organoclay platelets on morphologies of three blend compositions (80/20, 20/80, and 99.5/0.5 w/w) of nylon-6 (N6) and poly(ethylene-ran-propylene) rubber (EPR) has been studied by scanning and transmission electron micrographs. For the 80/20 (w/w) N6/ERP blend, the dispersed domain size (D) of EPR phase in the N6 matrix decreased significantly even if a small amount of the organoclay was added. The extent of the decrease in D in this blend was similar to N6/EPR blend with an in-situ reactive compatibilizer of EPR-g-maleic anhydride. The D of the blend with the clay did not change upon further annealing at high temperatures, which suggests that the clay seems to be an effective compatibilizer. But, for the 20/80 (w/w) N6/EPR blend, dispersed N6 domain did not decrease with increasing the amount of the clay up to 2 wt %. Moreover, the dispersed N6 domains were not stable against further annealing at high temperatures; thus, coalescence of N6 domains was observed. Furthermore, for 99.5/0.5 (w/w) N6/EPR blend dispersed EPR domains did not change with the amount of the clay. The results indicate that as long as the clay becomes exfoliated in the matrix, the exfoliated clay plates effectively prevent the coalescence of the dispersed domains.

In this work, we report the superior piezoelectric energy harvester ability of a non-electrically poled Fe-doped reduced graphene oxide (Fe-RGO)/poly(vinylidene fluoride) (PVDF) nanocomposite film prepared through a simple solution casting technique that favors the nucleation and stabilization of ≈99% relative proportion of polar γ-phase. The piezoelectric energy harvester was made with non-electrically poled Fe-RGO/PVDF nanocomposite film that gives an open circuit output voltage and short circuit current up to 5.1 V and 0.254 μA by repetitive human finger imparting. The improvement of the output performance is influenced by the generation of the electroactive polar γ-phase in the PVDF, due to the electrostatic interactions among the -CH2-/-CF2- dipoles of PVDF and the delocalized π-electrons and remaining oxygen functionalities of Fe-doped RGO via ion-dipole and/or hydrogen bonding interactions. Fourier transform infrared spectroscopy (FT-IR) confirmed the nucleation of the polar γ-phase of PVDF by electrostatic interactions and Raman spectroscopy also supported the molecular interactions between the dipoles of PVDF and the Fe-doped RGO nanosheets. In addition, the nanocomposite shows a higher electrical energy density of ≈0.84 J cm(-3) at an electric field of 537 kV cm(-1), which indicates that it is appropriate for energy storage capabilities. Moreover, the surface of the prepared nanocomposite film is electrically conducting and shows an electrical conductivity of ≈3.30 × 10(-3) S cm(-1) at 2 wt% loading of Fe-RGO.

chemical) available in our surrounding, mechanical energy (variable frequency and amplitude) is the most urgent valuable energy because of its greater accessibility anywhere and anytime. [ 1,4 ] Several approaches have been reported to harvest mechanical energy from different mechanical energy sources, such as movement of body (fi nger imparting, pushing, stretching, bending, twisting, etc.), talking, breathing, air fl owing, vibration, friction, water falling, and hydraulic forces (ocean waves, blood fl ow, etc.) to power up various portable electronic devices. [4][5][6][7][8][9][10][11] Thus, human motion based energy harvesting technology is of great interest due to its emergent trends to power up portable smart electronic devices. [ 12,13 ] Recently, piezoelectric nanogenerators (PNGs) and triboelectric nanogenerators (TENGs) have attracted great attention for harvesting mechanical energy under different small mechanical and biomechanical actions with variable amplitude and frequency present in our living environment. [ 12,14 ] Although, TENGs have exhibited high output with high energy conversion efficiency up to ≈55%, they are unfavorable for long term uses (low durability) due to wear and tear at the two contact surfaces and industrial packaging problem in open environment for humidity. [ 15,16 ] Thus, to realize fully independent, scalable, sustainable, and wireless operation of low power-consuming self-powered devices and systems, development of PNGs with large power generating performance, high sensitivity and energy conversion effi ciency, and prominent mechanical durability is highly important. A lot of research works have been reported to fabricate PNGs using various semiconducting nanomaterials, e.g., ZnO, InN, GaN, Te, and lead based Pb(Zr,Ti)O 3 , (PZT) and lead free ceramics (BaTiO 3 , ZnSnO 3 , NaNbO 3 , KNbO 3 ) with superior energy conversion effi ciency. [17][18][19][20][21][22][23][24][25][26] But they have limitations, e.g., brittle, heavy weight, poisonous, low durability compared to piezoelectric polymers which retain their fl exibility and higher strain level to Till date, fabrication of piezoelectric nanogenerator (PNG) with highly durable, high power density, and high energy conversion effi ciency is of great concern. Here a fl exible, sensitive, cost effective hybrid piezoelectric nanogenerator (HPNG) developed by integrating fl exible steel woven fabric electrodes into poly(vinylidene fl uoride) (PVDF)/aluminum oxides decorated reduced graphene oxide (AlO-rGO) nanocomposite fi lm is reported where AlO-rGO acts as nucleating agent for electroactive β-phase formation. The HPNG exhibits reliable energy harvesting performance with high output, fast charging capability, and high durability compared with previously reported PVDF based PNGs. This HPNG is capable for harvesting energy from a variety and easy accessible biomechanical and mechanical energy sources such as, body movements (e.g., hand folding, jogging, heel pressing, and foot striking, etc.) and machine vibration. The HPNG exhib...

Today, we stand at the edge of exploring carbon nanotube (CNT) and graphene based polymer nanocomposites as next generation multifunctional materials. However, irrespective of the methods of composite preparation, development of electrical conductivity with high electromagnetic interference (EMI) value at very low loading of CNT and (or) graphene is limited due to poor dispersion of these nanofillers in polymer matrix. Here, we demonstrate a novel technique that involves in-situ polymerization of styrene/multiwalled carbon nanotubes (MWCNTs) in the presence of suspension polymerized polystyrene (PS)/graphite nanoplate (GNP) microbeads, for the preparation of electrically conducting PS/MWCNT/GNP nanocomposites with very high (~20.2 dB) EMI shielding value at extremely low loading of MWCNTs (~2 wt %) and GNP (~1.5 wt %). Finally, through optimizing the ratio of PS-GNP bead and MWCNTs in the nanocomposites, an electrical conductivity of ~9.47 × 10(-3) S cm(-1) was achieved at GNP and MWCNTs loading of 0.29 and 0.3 wt %, respectively. The random distribution of the GNPs and MWCNTs with GNP-GNP interconnection through MWCNT in the PS matrix was the key factor in achieving high electrical conductivity and very high EMI shielding value at this low MWCNT and GNP loadings in PS/MWCNT/GNP nanocomposites. With this technique, the formation of continuous conductive network structure of CNT-GNP-CNT and the development of spatial arrangement for strong π-π interaction among the electron rich phenyl rings of PS, GNP, and MWCNT could be possible throughout the matrix phase in the nanocomposites, as evident from the field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) studies.

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