Nanocomposite Gel Research Articles

A model for equilibrium swelling of the upper critical solution temperature type thermoresponsive hydrogels

AbstractThermoresponsive gels of the upper critical solution temperature (UCST) type shrink below their critical temperature and swell above it. Changes in water uptake by these gels are driven by thermally induced dissociation of hydrogen or ionic bonds between chains. A simple model is developed for the description of the equilibrium swelling of thermophilic gels with hydrogen bonds. To confirm its ability to describe observations, equilibrium swelling diagrams are fitted on poly(acrylamide‐acrylic acid) and poly(acrylamide‐acrylonitrile) macroscopic gels and microgels with various structures (copolymer gels, gels with interpenetrating networks, nanocomposite gels), as well as on biocompatible poly(N‐acryloyl‐glycinamide) and poly(allylurea‐co‐allylamine) gels. Numerical simulation reveals that material parameters evolve consistently with molar fractions of crosslinker, hydrophobic and hydrophilic comonomers in the feed, degree of ionization of functional groups, and concentration of nanofiller. It is shown that the model can also be applied to describe observations on thermophilic zwitterionic gels. © 2021 Society of Industrial Chemistry.

Ruthenium Red-functionalized sol-gel and multi-walled carbon nanotubes for electrochemical simultaneous detection of three dihydroxybenzene isomers

In this proof-of-concept study, sol–gel was functionalized with Ruthenium Red (RR) using 3-glycidoxypropyl trimethoxysilane as the coupling agent and multi-walled carbon nanotubes (MWCNTs) and characterized with FT-IR, SEM and TEM as well as electrochemical techniques. The functionalized sol–gel (fSG) nanocomposite was used for the modification of a graphite paste electrode (GPE/fSGRR-MWCNTs) for the speciation of dihydroxybenzene compounds, hydroquinone (HQ), catechol (CC), and resorcinol (RS) which are known as hazardous water pollutants. The DPV measurements were performed in phosphate buffer solution at pH 5.0 from −0.2 to 1.0 V vs. Ag/AgCl. The nanocomposite-modified electrode displayed stable and continuous three well-separated oxidation peaks at 0.20, 0.30 and 0.72 V for HQ, CC, and RS, respectively. The limit-of-detection (LOD) was determined to be 0.049, 0.008 and 0.015 μM for HQ, CC, and RS, respectively. The modified GPE/fSGRR-MWCNTs showed good stability, reproducibility, sensitivity, and selectivity properties to determine all three compounds. The electrochemical performance of the GPE/fSGRR-MWCNT has been evaluated for simultaneous determination of dihydroxybenzene isomers in creek water, residential wastewater, and commercial hair dye, with satisfactory recoveries between 95 and 104%. This modified GPE/fSGRR-MWCNTs showed better stability, reproducibility, sensitivity, and selectivity properties to determine all three compounds when compared with the similar modified electrodes recently reported in the literature. Therefore, this novel RR-containing nanocomposite-modified sensor can be a promising pre-screening tool for the inexpensive and rapid detection of HQ, CC, and RS in on-field environmental studies.

Porous polymer‐derived ceramics: Flexible morphological and compositional controls through sol–gel chemistry

AbstractPorous nonoxide ceramics have exhibited impressive progress in terms of synthesis and applications over the past few decades because of their unique characteristics distinguished from the oxide counterparts. From the synthetic aspect, the preceramic polymer route, where nonoxide ceramics such as carbides and nitrides are produced from molecular precursors, offers exceptional opportunities to elaborate and control the material shape as well as the micro‐ and nanostructures in concert with various techniques. This review presents monolithic ceramic materials based on various reduced phases bearing hierarchical porosity with a focus on those obtained from macroporous preceramic monoliths prepared via the one‐pot sol–gel process accompanied by spinodal decomposition. Here, we highlight two classes of preceramic inorganic–organic hybrid gels: organometallic crosslinked polymers based on poly(silsesquioxane)s and nonorganometallic hybrid networks related to Ti without Ti–C bonds. The polymer‐to‐ceramic conversion processes are discussed with concern for the crystal transition behaviors and the variation of pore properties in different length scales upon heating. In addition, although out of the preceramic polymer category, some examples of inorganic–organic nanocomposite gels with a carbonizable polymer and/or urea for yielding porous metal carbides and nitrides in a monolithic form are introduced as well, which provides extended versatility toward a variety of transition metal systems.

Injectable Biocatalytic Nanocomposite Hydrogel Factories for Focal Enzyme-Prodrug Cancer Therapy.

Systemic enzyme-prodrug therapy (EPT) using nanofactories, nanoparticles encapsulating prodrug-activating enzymes, is a promising concept for anticancer therapy. However, systemic delivery systems can be problematic. As nanofactories are typically carried by the blood circulation to tissues throughout the body, conversion of anticancer drugs in normal tissues can cause severe side effects. To overcome this problem, we developed a novel focal EPT approach utilizing nanocomposite hydrogels composed of a poly(dl-lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(dl-lactide-co-glycolide) (PLGA-PEG-PLGA) copolymer, LAPONITE, and β-galactosidase (β-gal). The nanocomposite gels can be easily injected locally, and the inherent enzyme activity of β-gal can be preserved long-term. Prodrug 5-FU-β-gal readily permeated into the interior space of gels and was converted into the active anticancer drug 5-FU. Importantly, a single local injection of nanocomposite gels and prodrug 5-FU-β-gal provided long-lasting antitumor activity in vivo without observable side effects, demonstrating the potential utility of injectable biocatalytic hydrogel factories for novel focal EPT systems.

Graphene based sulfonated polyvinyl alcohol hydrogel nanocomposite for flexible supercapacitors

Graphene based sulfonated polyvinyl alcohol (PVA) hydrogel was synthesized and its performance as nanocomposite gel polymer electrolyte was investigated for application in quasi solid-state flexible supercapacitors. Hydrothermally reduced graphene (HRG) was synthesized through hydrothermal reduction of graphene oxide (GO). Sulfonated PVA hydrogel (SPVA) was synthesized with predetermined quantities of HRG to obtain nanocomposite gel polymer electrolytes coded as SPVA-HRG-x (x = content (wt.%) of HRG). The amorphous nature of SPVA-HRG-x was determined using X-ray diffraction (XRD) technique. The electrochemical performance of SPVA-HRG-x was evaluated using techniques like cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical spectroscopy (EIS) studies of a lab scale supercapacitor cell, fabricated using hydrothermally reduced carbon cloth (CCHy) current collectors coated with HRG (HRG-CCHy). In SPVA-HRG-0.5 electrolyte, HRG-CCHy exhibited specific capacitance of 200 F g-1 at 1 A g-1 and specific energy of 6.1 Wh kg-1 at specific power of 1 kW kg-1 and retained 93 % of its initial capacitance even after 5000 GCD cycles. The incorporation of SPVA with 0.5 wt.% of HRG-CCHy can be attributed to the increase in amorphous nature of SPVA-HRG-0.5, which in-turn lowers its impedance. This contributed to the remarkable supercapacitive behaviour of HRG-CCHy, demonstrating its potential as gel polymer electrolyte (GPE) for application in quasi solid-state flexible supercapacitors.

Dynamic Gelation of Conductive Polymer Nanocomposites Consisting of Poly(3-hexylthiophene) and ZnO Nanowires

The sol–gel transition of conductive nanocomposites consisting of poly(3-hexylthiophene) (P3HT) and ZnO nanowires in o-dichlorobenzene (o-DCB) has been investigated rheologically. The physical gelation of P3HT in o-DCB spontaneously occurs upon adding the small amount of ZnO nanowires. The rheological properties of the P3HT/ZnO nanocomposite gels have been systematically studied by varying factors such as polymer concentration, nanowire loading, and temperature. The nanocomposite gel exhibits shear-thinning in the low shear rate range and shear-thickening in the high shear rate range. The elastic storage modulus of the nanocomposite gel gradually increases with gelation time and is consistently independent of frequency at all investigated ranges. The isothermal gelation kinetics has been analyzed by monitoring the storage modulus with gelation time, and the data are well fitted with a first-order rate law. The structural analysis data reveal that the polymer forms the crystalline layer coated on ZnO nanowires. A fringed micelle model is proposed to explain the possible gelation mechanism.

Rheological properties and swelling behavior of nanocomposite preformed particle gels based on starch-graft-polyacrylamide loaded with nanosilica

Rheological properties and swelling behavior of nanocomposite preformed particle gels based on starch-graft-polyacrylamide loaded with nanosilica

Nanofiber induced enhancement of electrical and electrochemical properties in polymer gel electrolytes for application in energy storage devices

In this article, a significant study on ionic conduction properties of novel nanocomposite polymer gel electrolytes (NCPGEs) is carried out using poly (methyl methacrylate) (PMMA) with nanofibers of silica (SiO2) complexed with lithium perchlorate (LiClO4) by combining experimental work and computational modelling. The compositional variation of SiO2 nanofibers in polymer electrolytes induces a visible alteration in different characteristics like ionic conductivity, electrochemical stability, interfacial stability, surface morphology and optical properties. Among all the compositions, NCPGEs containing 5 wt% nanofibers exhibit maximum ionic conductivity of 4.6 × 10−3 Scm−1 at room temperature. Fourier Transform Infrared Spectroscopy (FTIR) has shown a better interaction between lithium ions (Li+) with carbonyl group of PMMA in presence of SiO2 nanofibers. X-ray photoelectron spectroscopy (XPS) has confirmed various interactions among different constituents in NCPGEs. A combined molecular dynamics (MD) simulation and density functional theory (DFT) show a stable interaction between polymer with nanofiber filler and Li salt.

Improvement of light stability of DHR123 radio fluorogenic nano clay gel dosimeter by incorporating a new dispersant

A tissue-equivalent three-dimensional dosimeter is being developed to verify dose distributions for radiotherapy. Recently, we have reported a nanocomposite fluorescent gel (NC-RFG) dosimeter that enables readout by the fluorometry, which is more sensitive than absorption method in principle. However, irradiating by an excitation light for a dose information readout also produces fluorescent dyes and is not negligible in the low-dose irradiation range under 1 Gy. In this study, we investigate new additives to improve the NC-RFG’s light stability. We successfully suppressed the light-sensitive property of the NC-RFG to at least 10% of normal conditions by adding either N-vinylpyrrolidone or pyridine as a new dispersant that is presumed to break up aggregation of rhodamine 123 (RD123) and dihydrorhodamine 123 (DHR123) to stop photoexcited RD123 from oxidizing the adjacent DHR123. We also provide a detailed study of sensitivity characteristics such as dose rate dependence for fluorescent gel dosimeters.

Preparation and evaluation of soft preformed particle gels for conformance control in carbonate reservoir

In this paper, we studied on the nanocomposite preformed particle gels (PPGs) for conformance control in fractured-vuggy carbonated reservoirs. The nanocomposite PPGs were synthesized via free radical polymerization, consist of acrylamide (AM), N-vinylpyrrolidone (NVP). PPGs were evaluated at 130 °C and salinity of 2.2 × 105 mg/L. Swelling ratio (Sw) and storage modulus (G′) were measured as a function of aging time. A three-stage swollen history is discovered by means of fitting the power-law relation of modulus and volume fraction. It is inferred that the deviation is caused by stress relaxation and secondary cross-link, respectively. Experimental results show that increasing the concentration of monomer, cross-linker and clay leads to a higher swelling ratio and lower modulus during the aging term. PPGs with 30 wt% monomers, NVP: AM ratio of 6:4, 0.25 wt% cross-linker and 3.0 wt% clay exhibit optimum properties for conformance control at high temperature reservoirs. The propagation and blocking efficiency of PPGs were evaluated in an ideal fracture model. The match relation of particle size and fracture width was discussed. Industrial PPGs products with various sizes were prepared. Toughness measurements and infrared spectrum (IR) show that the properties of PPGs are stable during the scale up production. Finally, the field application in Tahe oil field is briefly introduced.

Nanocomposite gels of poloxamine and Laponite for β-Lapachone release in anticancer therapy

Nano-hybrid systems have been shown to be an attractive platform for drug delivery. Laponite® RD (LAP), a biocompatible synthetic clay, has been exploited for its ability to establish of strong secondary interactions with guest compounds and hybridization with polymers or small molecules that improves, for instance, cell adhesion, proliferation, and differentiation or facilitates drug attachment to their surfaces through charge interaction. In this work, LAP was combined with Tetronics, X-shaped amphiphilic PPO-PEO (poly (propylene oxide)–poly (ethylene oxide) block copolymers. β-Lapachone (BLPC) was selected for its anticancer activity and its limited bioavailability due to very low aqueous solubility, with the aim to improve this by using LAP/Tetronic nano-hybrid systems. The nanocarriers were prepared over a range of Tetronic 1304 concentrations (1 to 20% w/w) and LAP (0 to 3% w/w). A combination of physicochemical methods was employed to characterize the hybrid systems, including rheology, particle size and shape (DLS, TEM), thermal analysis (TG and DSC), FTIR, solubility studies and drug release experiments. In vitro cytotoxicity assays were performed with BALB/3T3 and MCF-7 cell lines. In hybrid systems, a sol-gel transition can occur below physiological temperature. BLPC exhibits the most significant increase in solubility in formulations with a high concentration of T1304 (over 10% w/w) and 1.5% w/w LAP, or systems with only LAP (1.5%), with a 50 and 100-fold increase in solubilisation, respectively. TEM images showed spherical micelles of T1304, which elongated into wormlike micelles with concentration (20%) and in the presence of LAP, a finding that has not been reported before. A sustained release of BLPC over 140 hours was achieved in one of the formulations (10% T1304 with 1.5% laponite), which also showed the best selectivity index towards cancer cells (MCF-7) over BALB/3T3 cell lines. In conclusion, BLPC-loaded T1304/LAP nano-hybrid systems proved safe and highly effective and are thus a promising formulation for anticancer therapy.

High density bromide-based nanocomposite gel for temporary plugging in fractured reservoirs with multi-pressure systems

The coexistence of blowout and lost circulation in multi-pressure fractured reservoirs has always been a huge challenge to the oil industry. Although the use of high-density kill fluids can ensure the safety of well control, the problem of lost circulation in low pressure layer is still troublesome. Gel is widely used as a temporary plugging system, but the conventional gel plugging system will float when used in combination with high-density kill fluid, resulting in failure of temporary plugging. In this paper, a novel high-density bromide-based nanocomposite gel (HDGEL) was developed, the gel formation mechanism was explored, and its performance was evaluated in the laboratory. The gel is weighted by sodium bromide (NaBr), and cross-linked by covalent bonds, density 1.2–1.5 g/cm 3 adjustable, and its temperature resistance can reach 160 °C. Rheological tests show that the gel solution has low initial viscosity and easy to pump. The gelation time can be adjusted from 8 to 12 h, which can be directly broken by the drill or regular jetting nozzle and then flowed back. It can be used in combination with high-density kill fluid to ensure temporary plugging effect. In the fractures with tip sizes (0.014 cm), the maximum bearing pressure of HDGEL is 17.52 MPa, and the regained-permeability recovery can reach 86.81% without the use of gel breaker. This paper introduces a new gel system for multi-pressure reservoirs that can be used in combination with high-density kill fluid and makes recommendations for its engineering application. • High-density bromide-based nanocomposite gel (HDGEL) was developed. • HDGEL will not float in high density well killing fluid. • HDGEL combined with high density well killing fluid can work in multi-pressure reservoir. • HDGEL performs high pressure bearing performance and low damage to the fractured core.

Studies on ionic liquid based nanocomposite gel polymer electrolyte and its application in sodium battery

A nanocomposite gel polymer electrolyte system comprising porous membrane of poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/TiO2 immobilizing a liquid electrolyte of sodium trifluoromethanesulfonate (NaCF3SO3) in 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMImCF3SO3) ionic liquid is reported in the paper. The porous gel polymer electrolyte membranes are prepared by phase-inversion technique. The electrolyte membranes are characterized by various physical and electrochemical techniques. The TiO2 nanoparticles display interaction with the anion (CF3SO3−) of the liquid electrolyte and enhance amorphicity in the polymer network. The optimized membrane displays maximum room temperature ionic conductivity as ~0.4 mS cm−1 with improved electrochemical stability window of ~4.3 V and Na+ ion transport number as ~0.27. A proto-type sodium battery using the optimized membrane is fabricated and characterized. The battery delivers a stable open circuit potential of ~2.2 V and shows a discharge capacity ~200 mA h g−1 at 25 mA g−1 drain current.

Facile synthesis of temperature-resistant hydroxylated carbon black/polyacrylamide nanocomposite gel based on chemical crosslinking and its application in oilfield

With the continuous extraction and consumption of light oil resources, heavy oil is of growingly importance for industrial development. However, conventional displacement methods are not suitable for heavy oil due to its high viscosity, resulting in low oil recovery. Steam flooding is one of the most effective means to exploit heavy oil reservoir, and the injection profile greatly influences its oil production. As the most powerful plugging agent, the high temperature steam (200 °C) and complex mechanical environment in formation require gel to have good temperature resistance and shear resistance for profile control. In this work, we synthesized a HCB (hydroxylated nano carbon black) by grafting hyperbranched polyester onto its surface, and crosslinked it with polyacrylamide (PAM) by chemical reaction to prepare a high-strength temperature-resistant hydrogel HCB/PAM for profile control. In contrast to the conventional reinforcing filler (such as SiO2 and ordinary carbon black nanoparticles) physically crosslinked in gel, HCB can be uniformly dispersed in PAM gel through covalent bond connection between its surface terminal hydroxyl groups and PAM amide groups, and form a chemical crosslinking composite gel composed of carbon material and polymer. As such, the strong chemical bonding can effectively improve temperature resistance, mechanical properties and water retention capacity of HCB/PAM gel. On the other hand, compared with the highly crosslinked PAHHP (Polyacrylamide-hexamethylenetetramine-hydroquinone-polyethyleneimine) gel previously reported, HCB/PAM-0.5 gel (the optimal sample), being of good profile control ability, can effectually mitigate formation damage caused by steam flooding. Core flooding experiments showed that in comparison with PAHHP, the HCB/PAM-0.5 had larger plugging intensity and scope due to its robust 3D network and soft nature, leading to higher oil production. Meanwhile, without crosslinking agent, core permeability and porosity were decreasingly impacted by HCB/PAM-0.5. Generally, HCB/PAM-0.5 gel has better profile control ability and lower formation damage. These findings of this study can help better understand the relationship of gel flexibility and strength, thus offering references for enhancing oil recovery and handling formation damage.

Fabrication of a highly efficient new nanocomposite polymer gel for controlling the excess water production in petroleum reservoirs and increasing the performance of enhanced oil recovery processes

A new nanocomposite polymer gel is synthesized for reduction of excess water production in petroleum reservoirs at real operating conditions. This new nanocomposite gel contains SiO 2 nanoparticles, partially hydrolyzed polyacrylamide (HPAM) and chromium triacetate. High pressure and high temperature tests using porous carbonate core are carried out to evaluate the effects of nanoparticles on the synthesized polymer gel performance. It is shown that the residual resistance factor ratio of water to oil using the synthesized polymer gel nanocomposite in this work is much higher than that of the ordinary polymer gels. The presented results confirm the high performance of the synthesized nanocomposite polymer gel for decreasing the water flow through porous carbonate bed. A mathematical model for description of oil and water flow behavior in the presence of synthesized nanocomposite polymer gel is also presented. The presented nano polymer gel leads to considerable cost saving in enhanced oil recovery (EOR) processes.

Nanocomposite polymer gel with dispersed alumina as an efficient electrolyte for application in supercapacitors

A nanocomposite polymer gel electrolyte (NCPGE) has been synthesized from polyvinylidene fluoride co-hexafluoropropylene (PVDF-HFP) as the host polymer, ethylene carbonate (EC)/propylene carbonate (PC) as plasticizers, and tetraethylammonium tetrafluoroborate (TEABF4) as an ionic salt by a solution-casting technique, followed by the addition of Al2O3 nanoparticles. The optimal loading of Al2O3 giving the highest ionic conductivity of 6.0 × 10−3 S cm−1 was found to be 18 wt%. An activation energy of 0.107 eV has been calculated from a temperature-dependent conductivity plot, which shows Arrhenius behavior. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) characterizations have been applied to investigate the morphology and structure. The semi-crystalline and porous nature of the NCPGE has been confirmed by SEM and XRD analyses. The ionic transference number was calculated as 0.98 by the DC polarization technique, confirming the dominant ionic nature of the prepared electrolyte. The electrochemical potential window of the NCPGE of about 3.4 V, as estimated by linear sweep voltammetry, makes it suitable for supercapacitor applications.

Exploring the role of Muscovite in poly(alkyl methacrylate)-based ternary nanocomposite cryogels with selective functional groups: formation via cryogelling with the aid of inorganic clay.

Easy fabrication of inorganic clay muscovite (MUS) embedded poly(2-acrylamido-2-methyl-1-propane sulfonic acid-co-diethylaminoethyl methacrylate-co-hydroxyethyl methacrylate) (PADH) nanocomposite cryogels with dual temperature/pH dependent catalytic potential was reported. Nanocomposite cryogels were fabricated by a method involving cryogelation and free radical crosslinking of aqueous systems containing MUS ranging from 0% to 1.50% (w/v). The changes in the properties of polybasic PADH networks were investigated to explain how the network parameters and gel properties were affected by the addition of clay, with the formation of a single terpolymer-MUS structure. The potential of the addition of different amounts of MUS to strengthen the prepared terpolymer matrix was investigated by uniaxial compression tests. By lowering the polymerization temperature or increasing the MUS content, the PADH/MUS nanocomposite cryogels became more elastic and compressible with stronger entanglement of terpolymer chains between the clay layers. With the addition of 1.50% (w/v) MUS, the swelling capacity was reduced by 50%, resulting in a two-fold increase in compression elasticity. The nanocomposite gels showed a strong pH-dependence, and when the pH of the swelling medium decreased from 9.8 to 2.1, there was a significant increase in the degree of swelling with increasing protonation of tertiary amine groups. Under an acidic environment, the swelling capacity of the nanocomposite gel containing 1.10% (w/v) MUS increased by 49.5%. In temperature dependent swelling between 15 and 75 °C, all ternary PADH/MUS-Ngels showed a tendency to swell at low and high swelling temperatures, by the predominance of DEAEM units at low temperatures and HEMA monomers at high temperatures, respectively. As the temperature was increased to 55 °C, the swelling decreased and reached a minimum, and then the nanocomposite gels tended to swell again. The obtained results provide an insight into the effect of MUS addition on the properties of poly(alkyl methacrylate)-based ternary nanocomposite gels and demonstrate a simple and efficient way to produce multiple response systems with enhanced elasticity.

Characteristics of self-healable laponite-poly(N-isopropylacrylamide) hydrogels prepared by γ-ray irradiation

There have been many strategies and efforts to develop nanocomposite gels for wide applications that display desirable strength and properties, such as self-healing. In this study, self-healable laponite-poly(N-isopropylacrylamide) hydrogels were prepared by γ-ray radiation employing stepwise processes that provide gelation without any chemicals for crosslinking and initiation. This method achieved self-healable properties similar to that of typical gels crosslinked using crosslinkers and initiators. We found that the main factor of the property is the homogeneous distribution of laponite particles, based on comparisons of samples prepared using various synthetic strategies. Regarding the relationship between synthetic methods and their respective properties, the samples were characterized via swelling ratios, rheological properties, cross-sectional images, and nanostructures. The uniformity of the networks was evaluated with mesoscopic structures associated with large inhomogeneities and nanostructures described with interparticle distances at different swelling ratios. The results indicate that the stepwise process of the radiation method generates dense networks with uniform structures, which leads to self-healing ability. Consequently, we suggest that gelation by γ-ray irradiation can provide better properties via effective chemical controls.

Fabrication Tough and Electrically Conductive Graphene-Based Nanocomposite Gels with Self-Oscillating Performance

Stimulus-responsive polymer gel materials were studied and applied widely in many fields in recent years. However, the poor electrically conductive property and even with poor toughness largely limit their extensive applications in more expanded fields. Herein, we report a novel kind of self-oscillating gels poly(acrylamide-co-acrylic acid-co-Fe(phen)3)/reduced graphene oxide (poly(AM-co-AC-co-Fe(phen)3)/RGO) with excellent electrical conductivity, and compressive strength via an in-situ polymerization accompanied by an ultrasonic assisted method. The dispersed reduced graphene oxide (RGO) improved the conductive and mechanical properties of the prepared materials remarkably. The conductivity of gel reached to 16.88 S·m−1 with the content of 0.34 wt% RGO and the maximum fracture pressure was 4.1 MPa, which is as high as human cartilage. Besides, the prepared gels exhibited the self-oscillating behavior in the Belousov-Zhabotinsky (BZ) solution free of catalyst. Therefore, the prepared materials have potential applications as artificial cartilage and soft electron instrument.

Study of electrical and electrochemical properties of P(VdF-HFP)-MMT based nanocomposite gel polymer electrolytes for application in energy storage devices

The present study reports synthesis and analysis of different characteristics of montmorillonite (MMT) clay loaded nanocomposite gel polymer electrolytes (NCGPEs) based on poly (vinylidene fluoride hexafluoropropylene) [(P(VdF-HFP)] as host matrix and LiPF6 as salt. AC impedance analysis shows that the ionic conductivity of NCGPEs increases first with the increase of clay content and attains a maximum value of 9 X10-3 Scm−1 at 5 wt% of clay content, and then it decreases. TEM result shows a clear intercalation of polymer into the galleries of MMT clay. The variation of pore size in NCGPEs upon addition of MMT has been studied by SEM. XRD patterns show that MMT clay reduce the crystallinity of NCGPEs. The interaction among the various components of NCGPEs and its effect on ionic conductivity has been studied by FTIR. The interfacial and electrochemical stabilities are also found to be enhanced upon the addition of clay in P(VdF-HFP) matrix.