Increase In Relative Viscosity Research Articles

Nucleic acid binding affinity and antioxidant activity of N-m-Tolyl-4-Chlorophenoxyacetohydroxamicacid.

Hydroxamic acids represent a group of weak organic acids, both naturally occurring and synthetically derived, characterized by the general formula RC(= O)N(R'OH). In this study, we investigated the binding behavior of N-m-tolyl-4-chlorophenoxyaceto hydroxamic acid with calf thymus DNA (ct-DNA) and torula yeast RNA (t-RNA) through a combination of techniques including UV-visible spectroscopy, fluorescence emission analysis, viscometry, and computational simulations using AutoDock4 software. Our findings reveal that the mode of binding between the compound and the nucleic acids is consistent with intercalation. Competitive binding experiments demonstrated that the complex competes effectively with ethidium bromide (EB) for binding to ct-DNA/t-RNA, displacing EB from its binding sites. Additionally, the introduction of the compound into the DNA-EB system resulted in a quenching of fluorescence emission peaks. Analysis of absorption spectra indicated a red shift and hypochromic shift when the compound interacted with DNA, further supporting the intercalative binding mode. The calculated binding constant (Kb) value for the compound is 6.62 × 104M-1 and 5.40 × 103M-1 indicating a strong interaction with ct-DNA and t-RNA respectively. We determined the Stern-Volmer constants for ct-DNA and t-RNA as 9.96 × 104M-1 and 8.13 × 105M-1, respectively. The binding free energy values for ct-DNA/t-RNA were calculated to be -3.741 × 107 and -5.425 × 108kcal/mol, respectively. Viscometric studies corroborated the UV results, showing a continuous increase in relative viscosity of ct-DNA/t-RNA solutions with the addition of the optimal hydroxamic acid concentration. Furthermore, we assessed the antioxidant activity of the compound using DPPH-radical scavenging and β-carotene linoleic acid assays. Gel electrophoresis results demonstrated the compound's remarkable efficacy in preventing DNA damage. Collectively, all experimental evidence supports the conclusion that N-m-tolyl-4-chlorophenoxyaceto hydroxamic acid binds to ct-DNA/t-RNA through an intercalative mechanism, which is consistent with our molecular docking simulations.

Thermophysical properties of the liquid organic hydrogen carrier system based on diphenylmethane with the byproducts fluorene or perhydrofluorene

Fluorene (H0-F) and perhydrofluorene (H12-F) represent process-related byproducts formed by a dehydrocyclization step in the liquid organic hydrogen carrier (LOHC) system based on diphenylmethane (H0-DPM) and dicyclohexylmethane (H12-DPM). The influence of these byproducts on the liquid viscosity, surface tension, and liquid density of the DPM-based system was experimentally determined by studying three dehydrogenated binary mixtures with H0-F mole fractions of 0.05, 0.10, and 0.20 as well as one hydrogenated binary mixture with an H12-F mole fraction of 0.10 close to 0.1 MPa from (283–573) K. The densities increase with increasing share of H0-F or H12-F by around 1% per added byproduct mole fraction of 0.1. For the surface tension, an increase relative to the values of H0-DPM or H12-DPM by up to 6% is found. The addition of H0-F to H0-DPM or H12-F to H12-DPM yields a relative increase in viscosity by up to 9% at the lowest temperature studied.

Multi-spectroscopic and free energy landscape analysis on the binding of antiviral drug remdesivir with calf thymus DNA

Remdesivir (REM) is an antiviral drug, which exercises its effect by targeting specifically RNA-dependent RNA polymerase. The interaction of REM with calf thymus DNA (CT-DNA) was investigated by multi-spectroscopic techniques (UV–Vis, fluorescence, circular dichroism and 31P NMR) in combination with different biophysical experiments and metadynamics simulation studies. UV–Vis and fluorescence spectroscopic analysis indicated formation of a complex between REM and CT-DNA, whose binding constant is in the order of 104 M−1. Competitive displacement assays with ethidium bromide (EB) and Hoechst 33258 shown that REM binds to CT-DNA via intercalation mode. Significant alteration in the band due to base stacking pairs at 274 nm in the circular dichroism spectrum, appreciable increase in relative viscosity of the biomolecule upon binding with REM and the results of potassium iodide quenching studies confirmed that REM intercalates into the base pairs of CT-DNA. Thermodynamic parameters revealed that the binding of REM to CT-DNA is a spontaneous process (ΔG0 < 0) and the main force which holds them together in the REM/CT-DNA complex is electrostatic interaction (ΔH0 < 0 and ΔS0 > 0). The up-field shift in the 31P NMR signal of REM on interaction with CT-DNA suggested that phenyl ring adjacent to the phosphate moiety of REM may involve in the intercalation process. This is well supported by the analysis of free energy surface landscape derived from metadynamics simulation studies.

Rheology of three-phase suspensions determined via dam-break experiments.

Three-phase suspensions, of liquid that suspends dispersed solid particles and gas bubbles, are common in both natural and industrial settings. Their rheology is poorly constrained, particularly for high total suspended fractions (≳0.5). We use a dam-break consistometer to characterize the rheology of suspensions of (Newtonian) corn syrup, plastic particles and CO2 bubbles. The study is motivated by a desire to understand the rheology of magma and lava. Our experiments are scaled to the volcanic system: they are conducted in the non-Brownian, non-inertial regime; bubble capillary number is varied across unity; and bubble and particle fractions are 0 ≤ ϕ gas ≤ 0.82 and 0 ≤ ϕ solid ≤ 0.37, respectively. We measure flow-front velocity and invert for a Herschel-Bulkley rheology model as a function of , , and the capillary number. We find a stronger increase in relative viscosity with increasing in the low to intermediate capillary number regime than predicted by existing theory, and find both shear-thinning and shear-thickening effects, depending on the capillary number. We apply our model to the existing community code for lava flow emplacement, PyFLOWGO, and predict increased viscosity and decreased velocity compared with current rheological models, suggesting existing models may not adequately account for the role of bubbles in stiffening lavas.

Physico-Chemical and Molecular Interactions in Sodium Dodecyl Sulfate+Acetamide, Formamide Aqueous Mixtures According to Dielectric Relaxation Spectroscopy Data at 303 K

Investigation of sodium dodecyl sulfate+acetamide, formamide aqueous mixtures of various concentrations has been performed by dielectric relaxation spectroscopy (TDR-time domain reflectometry) technique 303 K. The relaxation times were determined through the Debye method and relative viscosities of solution. The linear increase of relative viscosity has the same increasing trend as dodecyl sulfate concentrations up to 80 mM. The superposition of relaxation time between water and micelle through the rotation phenomena, whereas inside the micelle by hydrophobic phenomena, is found and discussed in light of obtained results and justified.

CO2 mobility control by small molecule thickeners during secondary and tertiary enhanced oil recovery

AbstractRecently, polymer thickeners have been considered for CO2 mobility control during enhanced oil recovery (EOR) processes. Despite that, the requirement of co‐solvents is a controversial challenge for the solution of high‐molecular weight thickeners in gases. This study is focused on small molecule thickeners for carbon dioxide EOR without adding co‐solvents. Polydimethylsiloxane (PDMS) was used as a CO2‐philic thickener in different low molecular weights. Cloud‐point pressure, relative viscosity, and interfacial tension (IFT) between intermediate crude oil and pure/thickened CO2 were measured at reservoir conditions. Also, the impact of PDMS‐CO2 thickener on gas mobility control was evaluated during the coreflooding experiments in secondary and tertiary modes. The experimental results show that PDMS caused an increase in relative viscosity up to 4.7‐fold and successfully thickened CO2. In addition, the minimum miscibility pressure of PDMS‐thickened CO2 was lower than that of pure CO2, and miscible PDMS‐CO2 thickener occurred at higher PDMS molecular weights. However, the gas breakthrough time can be considerably delayed if the PDMS‐thickened CO2 was flooded directly, which increased the oil recovery factor between 6% to 15% during tertiary recovery.

Linear Coordination Polymer Synthesis from Bis-Catechol Functionalized RAFT Polymers.

Catechol-Fe(III) complexes contain some of the strongest known metal-chelate coordination bonds. Despite this, they have until now not been utilized in (polymeric linker) linear coordination polymer (LCP) synthesis. With the view of generating catechol end-functional polymers, a new, symmetrical bis-catechol functionalized trithiocarbonate reversible addition fragmentation chain transfer (RAFT) agent is synthesized (CatDMAT). Acrylamide (AM) and dimethylacrylamide (DMA) polymerizations are conducted with CatDMAT using direct photoactivation RAFT polymerization to yield bis-catechol end-functionalized homo- and block-copolymers of molecular weight 10-15kDa. Catechol-Fe(III) LCPs are successfully formed from the telechelic catechol polymers by bis-complexation to Fe(III). The tetrahedral bis-complex is detected by UV-vis spectroscopy (λmax = 570nm), while increases in relative viscosity and Mn,GPC over their respective uncomplexed polymers confirm the occurrence of supramolecular polymerization. The catechol-LCPs are shown to undergo oxidation and crosslinking in aqueous solution after 24 h.

Impact of viscosity on photo-induced bimodal emission, decay profile and energy transfer in lanthanide based hybrid nanostructure

The effect of viscous media on fluorescence intensity and lifetime of hybrid nanoparticles (HNPs) have been investigated in order to design viscosity sensor. HNPs are developed by using of Eu(TTA)3Phen (ETP) coordination compound and NaGd0.78Er0.02Yb0.20F4 fluoride nanoparticles. Here ETP gives strong emission in orange-red region at 611 nm wavelength by absorbing ultraviolet (UV) {240–450 nm) photons (known as downshifting process, DS) and NaGd0.78Er0.02Yb0.20F4 nanoparticles give strong emission in green region at about 540 nm wavelength by absorbing near-infrared (980 nm) photons (known as Upconversion process, UC). Small amount of HNPs are dispersed in glycerol-water medium (concentratioñ 10−6 M) and its fluorescence intensity and lifetime are monitored. The viscosity of the system is varied by taking different ratios of glycerol (C3H8O3) and distilled water (H2O). The fluorescence intensity of the colloidal solution is measured by exciting it with UV as well as 980 nm diode laser and found enhancement in emission intensity as a function of increase in relative viscosity. Similarly lifetime also increases with the increase in the relative viscosity of the solvent in both DS and UC processes. The viscosity vs emission intensity/lifetime show exponential increment upon increasing glycerol concentrations. Therefore, the HNPs can serves as fluorescent probe for quantitative measurements of the micro viscosity of environment and thus, it could be extremely useful for the study of biological systems.

Shear rate dependence of viscosity and normal stress differences in ferrofluids

In this work we investigate numerically the viscosity and normal stress differences of mono and polydisperse ferrofluids undergoing a simple shear flow in the presence of a transverse applied magnetic field. The simulations are carried out by means of a Brownian Dynamics integration algorithm. For all simulations we assume that the dipole moments are fixed to the magnetic particles. In the case of polydisperse suspensions the particles present a typical log-normal distribution of magnetic diameters which are covered with a layer of surfactant of constant width. The long-range dipolar interaction between the magnetic moments are computed by Ewald summation technique and the surfactant influence is modeled as a steric repulsive force between pairs of particles. The attractive van der Waals force is also incorporated in the numerical simulations. The numerical procedure is validated by comparing the simulation results of the non-dimensional relative viscosity increase as a function of the magnetic field intensity with experimental data. The present numerical simulations show that the non-dimensional relative viscosity increment as a function of the non-dimensional shear rate is strongly influenced by the particle volume fraction and the strength of the dipolar interactions parameter. By examining the suspension microstructure into the numerical box, we can see anisotropic structures like chains of particles for the low shear rate regimes, specially in the polydisperse cases. The results also indicate the presence of a suspension shear-thinning behavior with two different non-dimensional shear rate dependence. In addition, non-dimensional normal stress differences are observed even in the absence of dipolar interactions, as a consequence of stress anisotropy produced by the repulsive forces during the particle collisions induced by the imposed steady-shear flow. The dipolar interactions increase these non-dimensional normal stress differences and make their dependence on the non-dimensional shear rate non-monotonic. For low non-dimensional shear rates, the dipolar interactions dominate and the formation of large-structures like chains oriented in the direction of the magnetic fields leads to an increase in the non-dimensional first normal stress difference. For very high non-dimensional shear rates, the flow breaks the anisotropic structures and the effects of polydispersity and dipolar interactions become unimportant. The numerical simulations provide a useful tool for understanding the complex microphysical and rheology of real ferrofuids under shear flows.

Statistical investigation for developing a new model for rheological behavior of ZnO–Ag (50%–50%)/Water hybrid Newtonian nanofluid using experimental data

In this paper, the test results, along with the results of data analysis, are presented by graphs and tables. The effect of volume fraction and temperature on viscosity of a hybrid nanofluid, i.e. ZnO–Ag (50%–50%)-Water, is presented. Finally, a model for calculating nanofluid’s viscosity is based on available data was proposed. The results show that the dynamic viscosity decreases with increasing temperature and increases with increasing volume fraction of nanoparticles. Also, an increase in volume fraction at all temperatures is associated with an increase in relative viscosity. This increase was reported modest and linear in very low volume fractions. The margin of deviation between laboratory results and extracted experimental equations is equal to 1.8%.

Statistical investigation for developing a new model for rheological behavior of Silica–ethylene glycol/Water hybrid Newtonian nanofluid using experimental data

In this experimental investigation, we developed a new model for rheological behavior of Silica–Ethylene glycol/Water (30: 70 vol. %) hybrid Newtonian nanofluid. The tests were carried out in volume fractions of 0.1%, 0.25%, 0.5%, 0.75%, and 1.5%, the temperature range from 25 °C to 50 °C, and in the shear rate range 24.48 s−1 to 73.44 s−1. It can be deduced that the obtained correlation is a suitable model for estimating the desired nanofluid viscosity. Also, as the volume fraction increases, the relative viscosity increases due to the greater dispersion of the nanoparticles in the base fluid. The maximum marginal deviation values in this graph are shown to be equal to 1.37%. This value is acceptable for an experimental correlation. We find that the relationship between shear stress and shear rate is linear; then the desired fluid is Newtonian. At the maximum volume fraction, the percentage of loss of viscosity from the minimum temperature to the maximum temperature is 89%. In addition, at maximum operating temperature, the percentage increase in relative viscosity in the maximum volume fraction relative to the minimum fraction is 48%.

Miniaturized Measurement of Drug-Polymer Interactions via Viscosity Increase for Polymer Selection in Amorphous Solid Dispersions.

Drug-polymer interactions have a substantial impact on stability and performance of amorphous solid dispersions (ASD) but are difficult to analyze. Whereas there are many screening methods described for polymer selection based for example on glass forming ability, drug-polymer miscibility, supersaturation, or inhibition of recrystallization, the distinct detection of physico-chemical interactions mostly lacks miniaturized techniques. This work presents an interaction screening assessing the relative viscosity increase between highly concentrated polymer solutions with and without the model drug ketoconazole (KTZ). The fluorescent molecular rotor 9-(2-carboxy-2-cyanovinyl)julolidine was added to the solutions in a miniaturized setup in μL-scale. Due to its environment-sensitive emission behavior, the integrated fluorescence intensity can be used as a viscosity dye within this screening approach (FluViSc). Differences in relative viscosity increases through addition of KTZ were proposed to rank polymers regarding KTZ-polymer interactions. Absolute viscosities were measured with a cone-plate rheometer as a complimentary method and supported the results acquired by the FluViSc. Solid-state nuclear magnetic resonance (ss-NMR) relaxation time measurements and Raman spectroscopy were utilized to investigate drug-polymer interactions at a molecular level. Whereas Raman spectroscopy was not suited to reveal KTZ-polymer interactions, ss-NMR relaxation time measurements differentiated between the selected polymeric carriers hydroxypropylmethylcellulose acetate succinate (HPMCAS) and polyvinylpyrrolidone vinyl acetate 60:40 (PVP-VA64). Interactions were detected for HPMCAS/KTZ ASD while there was no hint for interactions between KTZ and PVP-VA64. These results were in correlation with the FluViSc. The findings were correlated with the dissolution performance of ASD and found to be predictive for supersaturation and inhibition of precipitation during dissolution.

Thermal, mechanical and physical properties of chain extended recycled polyamide 6 via reactive extrusion: Effect of chain extender types

Chain extenders having different structures such as: alternating copolymer of ethylene and maleic anhydride (EMA), multi-functional epoxy-based oligomeric chain extender (EPO), polyester wax with reactive caprolactam groups (CW) and dimeric 2,4-toluene diisocyanate (DTDI), were melt compounded with recycled polyamide6 (rPA6) in various amounts via a twin screw extruder. DTDI, which is generally used for polyurethane applications, was used as a chain extender for rPA6 for the first time. In order to evaluate the effects of chain extender's structural differences on the chain extension behavior of the resulting materials, differential scanning calorimetry (DSC) measurements, heat deflection temperature (HDT) measurements, vicat softening temperature (VST) measurements, relative viscosity measurements and mechanical tests including tensile and impact tests were performed. The results showed that mechanical properties were improved by all chain extenders, however the highest improvement was achieved with EMA. The addition of EMA increased relative viscosity by 41%, HDT 12.4%, elongation at break by 6.3 times and impact strength by 26%. DTDI showed 22% increase in relative viscosity, 10% increase in HDT, 23% increase in impact strength and it also increased elongation at break by 6.1 times, making it a very good chain extender candidate for rPA6.

An Interaction of Anionic- and Cationic-Rich Mixed Surfactants in Aqueous Medium through Physicochemical Properties at Three Different Temperatures

The mixed micellization of aqueous binary mixtures of DTAB-rich and SDS-rich surfactants, comprising sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) is studied in aqueous solution by using the physicochemical properties (PCPs) at three different temperatures (T = 293.15, 298.15, and 303.15 K) andP=0.1 MPa. The DTAB concentration is varied from 0.0001 to 0.03 M/mol·L−1in the ∼0.01 M/mol·L−1SDS solution, while the concentration of SDS is varied from 0.001 to 0.015 M/mol·L−1in the ∼0.005 M/mol·L−1DTAB. The stable formulations have been obtained by employing the DTAB-rich and SDS-rich surfactants solutions in 3 : 1 ratio. Therefore, different phases and aggregated states formed in the ternary combinations of DTAB/SDS/H2O have been identified and described. The calculated PCPs have been utilized for determining the nature of the solute-solvent interaction (SLS0I). With increasing surfactants concentration, the polarisation of the solution also increases along with an increase in relative viscosity (ηr), viscous relaxation time (τ), and surface excess concentration (Γmax). However, the surface area of the molecule (Amin), hydrodynamic volume (Vh), and hydrodynamic radius (Rh) decrease along with an increase in surfactants concentration.

Drug Effect of Thulium(III)-Arsenazo III Complex on Herring Sperm DNA

To assess the potential cytostatic properties of the thulium(III)-arsenazo III complex as a probe of rare earth complex antitumor drugs, the interaction information of the thulium(III)-arsenazo III complex with DNA was obtained by using spectroscopy, viscosity measurements, and voltammetric methods. The thermodynamic functions demonstrated that the binding constants of the thulium(III)-arsenazo III complex with DNA were Kθ298.15K = 4.84 × 106 L·mol−1 and Kθ308.15K = 4.48 × 106 L·mol−1, and the binding process was enthalpy driven. The increase in relative viscosity of DNA with the addition of the thulium(III)-arsenazo III complex and the results from Scatchard and voltammetric methods showed that the interaction mode between the thulium(III)-arsenazo III complex and DNA was groove binding along with weak intercalative binding.

DNA influence on norfloxacin fluorescence

The emission properties of norfloxacin, a quinolone antibiotic, in presence of salmon sperm DNA were studied at room temperature and in conditions of acid, alkaline and neutral pH. It was found that norfloxacin molecules are inserted between the DNA base pairs, as evidenced by the emission spectra features and the significant increases in relative viscosity of DNA by the addition of norfloxacin. The fluorescence quenching process was characterized by Stern–Volmer plots which display a positive deviation from the linearity. The analysis was performed in terms of the Stern-Volmer modified equations including both dynamic and static quenching. The use of the finite sink approximation model showed that the process of quenching of the norfloxacin fluorescence with DNA was diffusion limited, irrespective to the pH of the work solution. At the same time, relying on the formation of the ground state complex model and the sphere of action static quenching model, we concluded that the quenching reaction from the norfloxacin - DNA system is due to the combined effect of both dynamic and static quenching processes.

The DNA-binding behavior and DFT calculation of ruthenium(II) complexes [Ru(phen)2L](ClO4)2 (L = HMOPIP and MOHPIP)

Two ruthenium(II) complexes, [Ru(phen)2HMPIP]2+ (1) and [Ru(phen)2MHPIP]2+ (2), have been synthesized and characterized by elemental analysis, ESI-MS, and 1H NMR spectroscopy. The DNA-binding properties of 1 and 2 have been investigated by electronic and emission spectra and viscosity experiments. The results show that both 1 and 2 can bind to DNA in intercalating mode, with 1 exhibiting stronger binding affinity. These were confirmed by the strong hypochromism at IL and MLCT absorption bands in both complexes when DNA was added into solution, and the increase in relative viscosity of CT-DNA in the presence of both complexes. Moreover, the calculated intrinsic binding constant for 1 and 2 from the decay of electronic spectra is 3.82 × 105 and 2.06 × 105 M−1, respectively. Finally, the effects of the substituent groups on the DNA-binding behavior of ruthenium(II) complexes have also been rationally discussed by computer calculation of density functional theory (DFT) methods.

The Investigation of Effects of Temperature and Nanoparticles Volume Fraction on the Viscosity of Copper Oxide-ethylene Glycol Nanofluids

In the present article, the effects of temperature and nanoparticles volume fraction on the viscosity of copper oxide-ethylene glycol nanofluid have been investigated experimentally. The experiments have been conducted in volume fractions of 0 to 1.5 % and temperatures from 27.5 to 50 °C. The shear stress computed by experimental values of viscosity and shear rate for volume fraction of 1% and in different temperatures show that this nanofluid has Newtonian behaviour. The experimental results reveal that in a given volume fraction when temperature increases, viscosity decreases, but relative viscosity varies. Also, in a specific temperature, nanofluid viscosity and relative viscosity increase when volume fraction increases. The maximum amount of increase in relative viscosity is 82.46% that occurs in volume fraction of 1.5% and temperature of 50 °C. Some models of computing nanofluid viscosity have been suggested. The greatest difference between the results obtained from these models and experimental results was down of 4 percent that shows that there is a very good agreement between experimental results and the results obtained from these models.

The influence of crystallization on the flow of coal ash-slags

Numerous technical applications in the energy and metallurgical industries demand a fundamental knowledge of the flow of slags. In particular, the operation of an entrained flow gasifier is challenging, as the oxide slag has to be reliably discharged. Crystallization in the slag influences strongly the flow behavior of the slag because precipitations occur. In this study, the process of crystallization during flow of two coal ash slags was investigated. Therefore, isothermal viscosity measurements were conducted in order to examine the rheological evolution over time caused by the crystallization. It has been demonstrated that the evolution of viscosity of a sub-liquidus melt depends strongly on time, as well as on temperature and composition. Using a rotational high-temperature viscometer to investigate coal slags, it was found that the crystallization during flow could be separated into three time regimes: a lag-time, in which the undercooled melt behaved as an Arrhenius-liquid; the kinetic-driven crystallization; and, finally, the rheological equilibrium that is represented by a constant viscosity. Furthermore, an increase of relative viscosity caused by crystallization was accompanied by a shift from Newtonian to non-Newtonian flow; here, pseudoplastic flow indicated the existence of precipitations. The results demonstrate that the flow behavior has to be divided into dilute, semi-concentrated and concentrated particle bearing fluids. A view into the morphology of the partly crystallized slag was taken by scanning electron microscope. Differential thermal analysis of the slags was conducted, to underline the results of the isothermal viscosity measurements. The degree of supercooling promotes the kinetics of crystallization. Our results demonstrate that time-dependency has to be considered for an accurate description of flow during crystallization, as well as the influence of degree of supercooling.

Viscoelastic properties and physical gelation of poly (butylene adipate-co-terephthalate)/graphene nanoplatelet nanocomposites at elevated temperatures

Abstract A series of biodegradable nanocomposites were prepared by dispersing graphene nanoplatelets (GNPs) in poly (butylene adipate-co-terephthalate) (PBAT). Variations of dynamic and steady shear rheology of the nanocomposites with GNP loading and temperature were investigated via oscillatory measurements. Viscoelastic properties of the matrix exhibited significant enhancement with GNP addition. Solid-like flow behaviour was observed for highly filled samples while pure PBAT and nanocomposites with low GNP loadings showed liquid-like behaviour. Interestingly, the liquid-solid transition was found to occur at lower GNP concentrations with increasing temperature; dropping from 11.5 wt% at 160 °C to 7 wt% at 220 °C. Furthermore, in contrast to ideal melts, viscoelastic properties of some of the nanocomposites increased with increasing temperature. These observations suggest that the percolation did not originate only from network formation between the platelets but may be related to a combined GNP-PBAT gelling network, which enhanced with increasing temperature, leading to a more solid-like response at elevated temperatures. Variation of shear viscosity of nanocomposites with temperature also showed that increasing GNP loading reduces the temperature sensitivity of viscosity, leading to an increase in relative viscosity of nanocomposites with increasing temperature.