Synthesis of carbon nanotubes/titanium dioxide and study of its effect on the optical, dielectric, and mechanical properties of polyvinyl alcohol/sodium alginate for energy storage devices

Abstract

Summary In this system, the solvent casting technique was used to prepare polymer nanocomposites from the multiwalled carbon nanotubes (MWCNTs)/TiO2 nanoparticles (as nanofiller)‐doped polyvinyl alcohol/sodium alginate (PVA/SA) blend. The modification in the structure of the nanocomposites is proved by the studies of X‐ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra. The transmission electron microscopy (TEM) analysis evidenced that the MWCNTs/TiO2 nanoparticles were incorporated in the PVA/SA polymer. The optical energy gap of the polymer blend is reduced after incorporating the MWCNTs/TiO2. The thermogravimetric analysis (TGA) has demonstrated the nanocomposites' excellent thermal stability compared to pure blend, as well as its enhancement with the addition of MWCNTs/TiO2 nanoparticles. The AC conductivity and dielectric properties of the nanocomposite enhanced as compared to pure PVA/SA. Also, the electrical properties were higher due to the loading of MWCNTs/TiO2 nanoparticles. The increase in elongation at the break and higher tensile strength of nanocomposites compared to pure polymer blends suggested that MWCNTs/TiO2 nanoparticles in the polymer matrix provided greater reinforcement. Thus, it was generally concluded that the polymer nanocomposite is better than the pure blend due to its superior dielectric constant, thermal, optical, and mechanical properties, which make them useful in the manufacture of nanoelectronic devices of high energy storage.

Structural, optical, thermal, and dielectric properties of carboxymethyl cellulose/sodium alginate blend/lithium titanium oxide nanoparticles: Biocomposites for lithium‐ion batteries applications

“…Also, this increasing in the values of σ and σ dc suggested that the NPs formed a three-dimensional conductive pathway within the polymeric nanocomposite samples. 2,5,8 Thus, these σ dc results can be indicated that these polymer nanocomposite samples may be considered as a potential candidate for microelectronic devices as flexible polymeric nanodielectric and for the preparation of novel nanocomposite SPEs with the addition of various alkali metal salts. )…”

“…The strength of the peaks was changed with doping indicating greater interactions between the polymeric chains and the NPs. 5,9,18,21,28…”

“…8,34 The enhancement of electrical conductivity after adding the nanofiller was because of the increase of the number of dopants, where the nanofiller molecules begin to bridge the gap between two localized-states and lower potential barriers separating them, thus the transfer of charges F I G U R E 4 (αhν) 1/2 vs photon energy (hν) of pure blend and nanocomposite samples carriers is easy between them. 2,5 Further, this enhancement was attributed to the high conductivity of added NPs and the increase of charge mobility because of the increase of amorphous regions within the filled samples. 8,9 On the other hand, the σ value increased by raising temperature due to the increase the interfacial polarization effect and raising the charges carrier mobility 30,34 implying the thermally activated σ behavior of this nanocomposite sample.…”

“…[1][2][3] Therefore, these types of combinations can be used in various optoelectronic and discharge energy devices. [4][5][6][7] The spinel Li 4 Ti 5 O 12 NPs are cheap, environment friendly, 8,9 and has good lithium ions mobility as well as high lithiumion insertion/extraction with potential at 1.55 V. 10 Also, these NPs possess a high structure stability "zero-strain" in charge/discharge cycles and have the potency to reinforce the performance for secondary Li-ions batteries due to their short diffusion paths and high surface area. 11,12 Due to these novel physicochemical properties of Li 4 Ti 5 O 12 NPs, it has gained increasing importance to reinforce the performance PV cells, some semiconductor devices, catalysis, and next-generation Li + -batteries.…”

“…19,20,24 Because of these fascinating properties, SA polymer can be used in various applications as electrical devices, paper making, medicine, wound dressing, and food packing. 5,19,[23][24][25] Thus, the CMC/SA blend displays high miscibility and compatibility because of hydrogen bond formation between the functional groups present within the repeat units of CMC and SA polymers. Also, these groups are found exceedingly compatible with various nanofillers and dopants to frame the innovative nanocomposites and composites.…”