Showing papers on "Glass transition published in 2013"
TL;DR: In this article, a review of the features of secondary relaxations and their relations to other processes and properties in metallic glasses is presented. But the focus is on their current roles and future promise in understanding the glass transition phenomenon, mechanical properties and mechanisms of plastic deformation, diffusion, physical aging and stability and crystallization of metallic glasses.
278 citations
TL;DR: The remarkable kinetic slowdown experienced by liquids as they are cooled toward their glass transition is not accompanied by any obvious structural change Understanding the origin of this behavior is a major scientific challenge as discussed by the authors.
Abstract: The remarkable kinetic slowdown experienced by liquids as they are cooled toward their glass transition is not accompanied by any obvious structural change Understanding the origin of this behavior is a major scientific challenge At present, this area of condensed matter theory is characterized by an abundance of divergent viewpoints that attempt to describe well-defined physical phenomena We review representative theoretical views on the unusual kinetics of liquid supercooling, which fall into two broad competing categories: thermodynamic and kinetic In the former, an apparent “ideal,” thermodynamic, glass transition caused by rapid loss of entropy in the supercooled liquid underlies kinetic slowdown; in the latter, purely kinetic constraints are responsible for loss of ergodicity The possible existence of an ideal thermodynamic glass transition is discussed and placed in its proper statistical mechanical context
250 citations
TL;DR: It is reported that high-density amorphous ice at ambient pressure shows a distinct calorimetric glass transitions at 116 K and present evidence that this second glass transition involves liquid-like translational mobility of water molecules, related to the coexistence of two liquid phases.
Abstract: The glassy states of water are of common interest as the majority of H2O in space is in the glassy state and especially because a proper description of this phenomenon is considered to be the key to our understanding why liquid water shows exceptional properties, different from all other liquids. The occurrence of water’s calorimetric glass transition of low-density amorphous ice at 136 K has been discussed controversially for many years because its calorimetric signature is very feeble. Here, we report that high-density amorphous ice at ambient pressure shows a distinct calorimetric glass transitions at 116 K and present evidence that this second glass transition involves liquid-like translational mobility of water molecules. This “double Tg scenario” is related to the coexistence of two liquid phases. The calorimetric signature of the second glass transition is much less feeble, with a heat capacity increase at Tg,2 about five times as large as at Tg,1. By using broadband-dielectric spectroscopy we resolve loss peaks yielding relaxation times near 100 s at 126 K for low-density amorphous ice and at 110 K for high-density amorphous ice as signatures of these two distinct glass transitions. Temperature-dependent dielectric data and heating-rate–dependent calorimetric data allow us to construct the relaxation map for the two distinct phases of water and to extract fragility indices m = 14 for the low-density and m = 20–25 for the high-density liquid. Thus, low-density liquid is classified as the strongest of all liquids known (“superstrong”), and also high-density liquid is classified as a strong liquid.
244 citations
TL;DR: Results from calorimetric and stress relaxation experiments using a 20-million-year-old Dominican amber deviate dramatically from the expectation of classical theory and are consistent with some modern ideas, in which the diverging timescale signature of complex fluids disappears below the glass transition temperature.
Abstract: Fossil amber offers the opportunity to investigate the dynamics of glass-forming materials far below the nominal glass transition temperature. This is important in the context of classical theory, as well as some new theories that challenge the idea of an 'ideal' glass transition. Here we report results from calorimetric and stress relaxation experiments using a 20-million-year-old Dominican amber. By performing the stress relaxation experiments in a step-wise fashion, we measured the relaxation time at each temperature and, above the fictive temperature of this 20-million-year-old glass, this is an upper bound to the equilibrium relaxation time. The results deviate dramatically from the expectation of classical theory and are consistent with some modern ideas, in which the diverging timescale signature of complex fluids disappears below the glass transition temperature.
233 citations
TL;DR: In this article, a brief introduction to the enhanced glass forming ability and phase separation in metallic glass systems is given, and several thermodynamic aspects for decomposition by liquid-liquid phase separation which include stability conditions, decomposition in the multicomponent system, types of miscibility gap, calculation of bimodal and spinodal curves are introduced as a background for design of metallic glasses phase separating in the liquid state.
206 citations
TL;DR: In this article, a low transition temperature mixture (LTTM) formed by lactic acid and choline chloride is evaluated as solvent for separation of CO2, and the phase behaviour and Henry's constant for the pseudo-binary system composed of LTTM (lactic acid:choline chloride = 2:1) and CO2 are also studied.
194 citations
TL;DR: In this article, a broad frequency (10−1−106 Hz) and temperature range (178−423 K) was used to probe the polymer/silica interface and two relaxation processes were identified for the composites: one corresponding to the bulklike polymer and a second one related to polymer chains close to the silica surface.
Abstract: Samples with different amounts of poly(vinyl acetate) adsorbed on silica particles were prepared in order to study their interfacial interactions and dynamics. The interface of adsorbed polymers to a substrate plays an important role in many applications such as polymer nanocomposites, thin films, and coatings. Characterization of such interfaces is thus of high importance since they were found to differ from bulk properties. Thermogravimetric analysis (TGA) is applied to analyze the amounts of polymer adsorbed on silica particles. Broadband dielectric spectroscopy (BDS) is employed in a broad frequency (10–1–106 Hz) and temperature range (178–423 K) in order to probe the polymer/silica interface. Two relaxation processes can be identified for the composites: one corresponding to the bulklike polymer and a second one related to polymer chains close to the silica surface. For the latter the dynamic glass transition is shifted to higher temperature due to reduced mobility. This effect is investigated in dep...
180 citations
TL;DR: A new metallic glass created by vapour deposition at an appropriately high substrate temperature shows exceptional thermal stability, and enhanced glass transition temperature and elastic modulus, which demonstrates the formation of ultrastable glassy materials correlates to the important concept of fragility.
Abstract: A new metallic glass, which was created by vapour deposition at an appropriately high substrate temperature, shows exceptional thermal stability, and enhanced glass transition temperature and elastic modulus. Comparing this new material with other organic glasses prepared by similar routes and known as ultrastable glasses demonstrates the formation of ultrastable glassy materials correlates to the important concept of fragility.
161 citations
TL;DR: The results, while leaving open the question of the divergence of the relaxation time and that of a thermodynamic singularity at a finite temperature, reveal a complex scenario of glassy dynamics.
Abstract: We investigated the kinetics of enthalpy recovery of several glass-forming polymers at temperatures significantly below the glass transition temperature (Tg) and for aging times up to one year. We find a double-step recovery at relatively low aging temperatures for the longest investigated aging times. The enthalpy recovered after the two-step decay approximately equals that expected by extrapolation from the melt. The two-step enthalpy recovery indicates the presence of two time scales for glass equilibration. The equilibration time of the first recovery step exhibits relatively weak temperature dependence, whereas that of the second step possesses pronounced temperature dependence, compatible with the VogelFulcher-Tammann behavior. These results, while leaving open the question of the divergence of the relaxation time and that of a thermodynamic singularity at a finite temperature, reveal a complex scenario of glassy dynamics.
159 citations
TL;DR: In this article, castor oil-based two hyperbranched polyurethanes (HBPUs) were synthesized via A2+B3 approach using castor oils or monoglyceride of the castor oils as the hydroxyl containing B3 reactant and toluene diisocyanate (TDI) as an A2 reactant along with 1,4-butane diol (BD) as the chain extender and poly(ɛ-caprolactone) diol as a macroglycol.
159 citations
TL;DR: In this article, the glass transition temperature of the insulating polystyrene (PS) block and the width of the conducting poly(ethylene oxide) (PEO) channel were investigated.
Abstract: The ionic conductivity and glass transition temperatures of nanostructured block copolymer electrolytes composed of polystyrene-b-poly(ethylene oxide) (SEO) doped with lithium bis(trifluoromethanesulfone)imide (LiTFSI) were studied in the small molecular weight limit (between 2.7 and 13.7 kg mol–1). In this range, the annealed conductivity exhibits a nonmonotonic dependence on molecular weight, decreasing with increasing molecular weight in the small molecular weight limit before increasing when molecular weight exceeds about 10 kg mol–1. We show that annealed electrolyte conductivity is affected by two competing factors: the glass transition temperature of the insulating polystyrene (PS) block and the width of the conducting poly(ethylene oxide) (PEO) channel. In the low molecular weight limit, all ions are in contact with both PS and PEO segments. The intermixing between PS and PEO segments is restricted to an interfacial zone of width, λ. Our experiments suggest that λ is about 5 nm. The fraction of io...
TL;DR: In this paper, the surface functionality of the silica nanoparticles is manipulated by the phosphoric acid (H3PO4)-doped conductive polyaniline (PANI) via a surface initiated polymerization (SIP) method.
Abstract: Epoxy resin nanocomposites reinforced with silica nanoparticles have been prepared at different nanoparticle loading levels. The surface functionality of the silica nanoparticles is manipulated by the phosphoric acid (H3PO4)-doped conductive polyaniline (PANI) via a surface initiated polymerization (SIP) method. The improved glass transition temperature (Tg) and enhanced mechanical properties of the cured epoxy resin nanocomposites filled with the functionalized silica nanoparticles are observed compared with those of the cured pure epoxy resin. The flammability and thermal stability behaviors of these nanocomposites are evaluated using microscale combustion calorimeter (MCC) and thermogravimetric analysis (TGA). The heat release rate (HRR) peak of the epoxy filled with functionalized silica nanoparticles is observed to decrease dramatically with increasing functionalized silica particle loadings, indicating a flame-retardant performance from the phosphoric acid-doped PANI.
TL;DR: In this paper, EGS esters of epoxidized fatty acids derived from soybean oil (EGS) and linseed oil (ELO) have been used for fabrication of structural and structurally complex epoxy composites.
Abstract: Glycidyl esters of epoxidized fatty acids derived from soybean oil (EGS) and linseed oil (EGL) have been syn- thesized to have higher oxirane content, more reactivity and lower viscosity than epoxidized soybean oil (ESO) or epoxi- dized linseed oil (ELO). The EGS and ESO, for comparison, were used neat and in blends with diglycidyl ether of bisphenol A (DGEBA). Thermosetting resins were fabricated with the epoxy monomers and either BF3 catalyst or anhy- dride. The curing behaviors, glass transition temperatures, crosslink densities and mechanical properties were tested. The results indicated that polymer glass transition temperatures were mostly a function of oxirane content with additional influ- ence of glycidyl versus internal oxirane reactivity, pendant chain content, and chemical structure and presence of saturated components. EGS provided better compatibility with DGEBA, improved intermolecular crosslinking and glass transition temperature, and yielded mechanically stronger polymerized materials than materials obtained using ESO. Other benefits of the EGS resin blend systems were significantly reduced viscosities compared to either DGEBA or ESO-blended DGEBA counterparts. Therefore, EGS that is derived from renewable sources has improved potential for fabrication of structural and structurally complex epoxy composites, e.g., by vacuum-assisted resin transfer molding.
TL;DR: In this article, the effects of annealing time and temperature on the crystallinity of injection-molded poly(lactic acid) (PLA) were investigated using differential scanning calorimetry and wide-angle x-ray diffraction.
Abstract: The effects of annealing time and temperature on the crystallinity of injection-molded poly(lactic acid) (PLA) were investigated using differential scanning calorimetry and wide-angle x-ray diffraction. Differential scanning calorimetry, tensile test, and dynamic mechanical analysis showed that an increase in crystallinity in the PLA parts from the annealing treatment offers several benefits such as a higher glass transition temperature, better heat resistance, and greater storage modulus and tensile strength. Based on the experimental data, the degree of crystallinity, annealing time, and annealing temperature were found to closely follow the time–temperature superposition relationship. Namely, a master curve could be constructed based on either the Williams–Landel–Ferry equation or the Arrhenius relationship by shifting the crystallinity isotherms in the logarithmic scale horizontally along the log-time axis. This relationship provides a quantitative guideline for annealing postinjection-molded PLA parts to improve the heat resistance and mechanical properties. An increase of over 17% and 26% in tensile strength was achieved at an annealing temperature of 80°C for 30 min and 65°C for 31 h, respectively. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers
TL;DR: Measurements of the third-order nonlinear dielectric susceptibility are deduced and a surprisingly simple correlation of E(T) and N(corr)(T) is found, providing strong evidence that the noncanonical temperature development of glassy dynamics is caused by a temperature-dependent energy barrier arising from the cooperative motion of ever larger numbers of molecules at low temperatures.
Abstract: The slowing down of molecular dynamics when approaching the glass transition generally proceeds much stronger than expected for thermally activated motions. This strange phenomenon can be formally ascribed to a temperature-dependent activation energy E(T). In the present work, via measurements of the third-order nonlinear dielectric susceptibility, we deduce the increase of the number of correlated molecules N(corr) when approaching the glass transition and find a surprisingly simple correlation of E(T) and N(corr)(T). This provides strong evidence that the noncanonical temperature development of glassy dynamics is caused by a temperature-dependent energy barrier arising from the cooperative motion of ever larger numbers of molecules at low temperatures.
TL;DR: In this paper, the thermal conductivity of five semi-crystalline and four amorphous polymers was determined within a wide range of temperature, starting at room temperature and going up to temperatures above the polymer melting point.
TL;DR: In this paper, the authors develop quantitative relationships between interfacial surface energy parameters and the dispersion and Tg shifts of PNCs through systematic experiments on an array of hybrid systems spanning a wide range of interfacial interactions.
Abstract: Developing structure–property relationships between the filler/matrix interface chemistry and the dispersion and interface properties of polymer nanocomposites (PNC) is critical to predicting their bulk mechanical, electrical, and optical properties. In this paper we develop quantitative relationships between interfacial surface energy parameters and the dispersion and Tg shifts of PNCs through systematic experiments on an array of hybrid systems spanning a wide range of interfacial interactions. We use four different matrices of surface energies varying from polar to nonpolar (poly(2-vinylpyridine) (P2VP), poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), and polystyrene (PS)), filled with three monofunctional-silane modifications of colloidal silica nanospheres (octyldimethylmethoxysilane, chloropropyldimethylethoxysilane, and aminopropyldimethylethoxysilane). We hypothesize the ratio of the work of adhesion between filler and polymer to the work of adhesion of filler to filler (WPF/WFF...
TL;DR: In this article, low molecular weight acrylated poly(ethylene glycol) (PEG) was grafted onto poly(lactic acid) (PLA) via a reactive blending to improve its plasticity.
TL;DR: In this article, a mesoscale model, shear transformation zone dynamics (STZ dynamics), is employed to investigate the connections between the structure and deformation of metallic glasses.
TL;DR: In conclusion, vitrification plays a dominant role in stabilization at glass transition temperatures up to 10 to 20°C above storage temperature, depending on whether trehalose or inulin is used.
TL;DR: In this paper, broadband dielectric spectroscopy (BDS) was used to investigate the filler effect on the molecular mobility of polyvinylidene fluoride (PVDF) polymer chains.
Abstract: Polymer nanocomposites based on polyvinylidene fluoride (PVDF) matrix filled with TiO 2 nanoparticles (1%, 2%, 3% and 5% by v/v%) were studied by broadband dielectric spectroscopy (BDS) in order to investigate the filler effect on the molecular mobility of the polymer chains. The formalism of electric modulus was used to analyze the dielectric response, thus three relaxation processes were observed. In fact, the first one, which is around −40 °C at 10 Hz, is attributed to the glass transition at low temperature. As for the second phenomenon, around 30 °C at 10 Hz, it is related to the dipolar relaxations in the crystalline phase. Regarding the third one, around 100 °C at 10 Hz, it can be due to the interfacial polarization (IP). The crystallinity ratio decreases and the electric modulus of the interfacial polarization increases with the increase of the TiO 2 content.
TL;DR: At low temperatures, the numerical findings are consistent with the existence of a random first-order phase transition rounded by finite size effects.
Abstract: We use computer simulations to investigate the static properties of a simple glass-forming fluid in which the positions of a finite fraction of the particles have been frozen. By probing the equilibrium statistics of the overlap between independent configurations of the liquid, we find strong evidence that this random pinning induces a glass transition. At low temperatures, our numerical findings are consistent with the existence of a random first-order phase transition rounded by finite size effects.
TL;DR: In this article, three different organo-modified clays have been incorporated by sonication into a high performance epoxy resin before the cross-linking reaction, which increased free volume and micro-voids in the samples.
Abstract: Three different organo-modified clays have been incorporated by sonication into a high performance epoxy resin before the cross-linking reaction. The X-ray analysis indicated that, depending on the organoclay type, partially exfoliated and partially intercalated composites have been obtained. As shown by the DSC analysis, the clay addition seems to interact with the cross-linking reaction. The incorporation of organoclay into epoxy increased free volume and micro-voids in the samples. Sorption of water in the composite samples resulted higher than that of the pristine resin, whereas the diffusion coefficient is significantly lower. The lower value of diffusion makes the permeability at ambient conditions lower than the pristine resin. The elastic modulus of the composite sample results higher than that of the pristine resin, especially in the temperature region around the glass transition. The presence of organoclay in epoxy matrix decreased the glass transition temperature, whether the nanocomposites were in a dry or wet condition.
TL;DR: The Random First Order Transition Theory and the Coupling Model successfully predict the large surface-enhancement of mobility and its increase on cooling, but disagree with the experimental observation of the faster surface diffusion of Nifedipine.
Abstract: Surface self-diffusion coefficients have been determined for the organic glass Nifedipine using the method of surface grating decay. The flattening of 1000 nm surface gratings occurs by viscous flow at 12 K or more above the glass transition temperature and by surface diffusion at lower temperatures. Surface diffusion is at least 107 times faster than bulk diffusion, indicating a highly mobile surface. Nifedipine glasses have faster surface diffusion than the previously studied Indomethacin glasses, despite their similar bulk relaxation times. Both glasses exhibit fast surface crystal growth, and its rate scales with surface diffusivity. The observed rate of surface diffusion implies substantial surface rearrangement during the preparation of low-energy glasses by vapor deposition. The Random First Order Transition Theory and the Coupling Model successfully predict the large surface-enhancement of mobility and its increase on cooling, but disagree with the experimental observation of the faster surface di...
TL;DR: This work provides a method to develop the GO-based polyimide composites with superior performances but also conceptually provides a chance to modulate the interfacial interaction between GO and the polymer through designing the chain length of grafting molecules on NH(2)-functionalized GO.
Abstract: This study fabricates amine (NH2)-functionalized graphene oxide (GO)/polyimide(PI) composite films with high performance using in situ polymerization. Linear poly(oxyalkylene)amines with two different molecular weights 400 and 2000 (D400 and D2000) have been grafted onto the GO surfaces, forming two types of NH2-functionalized GO (D400-GO/D2000-GO). NH2-functionalized GO, especially D400-GO, demonstrated better reinforcing efficiency in mechanical and thermal properties. The observed property enhancement are due to large aspect ratio of GO sheets, the uniform dispersion of the GO within the PI matrix, and strong interfacial adhesion due to the chemical bonding between GO and the polymeric matrix. The Young’s modulus of the composite films with 0.3 wt % D400-GO loading is 7.4 times greater than that of neat PI, and tensile strength is 240% higher than that of neat PI. Compared to neat PI, 0.3 wt % D400-GO/PI film exhibits approximately 23.96 °C increase in glass transition temperature (Tg). The coefficient...
TL;DR: Acellular in vitro studies revealed very high bioactivity independent of Cu doping as indicated by the fast formation of a carbonated hydroxyapatite layer on scaffold surfaces after immersion in simulated body fluid (SBF).
Abstract: Cu-doped 45S5 bioactive glasses with varying Cu contents were fabricated and used to process 3D porous scaffolds via the foam replica technique. Cu-doping results in the weakening of the glass network and a decrease in its glass transition temperature. Acellular in vitro studies revealed very high bioactivity independent of Cu doping as indicated by the fast formation of a carbonated hydroxyapatite layer (CHA) on scaffold surfaces after immersion in simulated body fluid (SBF). The kinetics of the glass-ceramic scaffold's transition to an amorphous calcium phosphate layer (ACP) and the crystallisation of CHA were explored by FT-IR and SEM analyses. The elemental distribution in the scaffold/fluid interface region was monitored by the advanced micro-PIXE-RBS (particle induced X-ray emission/Rutherford backscattering spectrometry) method. Cu-containing glasses showed slower release of Si, Ca and P from the scaffold periphery, whereas traces of Cu were found incorporated in the CaP layer on the scaffold surface. Cu release kinetics from the scaffolds in SBF were found to depend on culturing conditions while highest Cu concentrations of ∼3.1 ppm and ∼4.6 ppm under static and quasi-dynamic conditions, respectively, were observed. Since Cu exhibits potential angiogenic and osteogenic properties, the Cu-containing scaffolds are suggested as promising materials for bone tissue engineering applications.
TL;DR: In this paper, a shape memory composition includes a high temperature ionomer having a glass transition temperature or a melting temperature of 100°C or greater and a modulus at room temperature of 1 x 10 8 Pa or greater.
Abstract: A shape memory composition includes a high temperature ionomer having a glass transition temperature or a melting temperature of 100°C or greater and a modulus at room temperature of 1 x 10 8 Pa or greater, the high temperature ionomer including a polymer with ionic units either within the backbone of the polymer or pendant to the backbone or both. The shape memory composition includes crystalline or glassy domains of a low molecular weight non-polymeric compound dispersed in the high temperature ionomer and interacting the ionic units of the high temperature ionomer to form a secondary network characterized by being a reversible network in that it is compromised by the heating of the low molecular weight non-polymeric compound to change out of its crystalline or glassy phase.
31 Jan 2013
TL;DR: In this article, the authors discuss elastic, anelastic and plastic behaviors of metallic glasses from the atomistic point of view, based upon recent results by simulations and experiments, and suggest that mechanical failure is an intrinsic behavior of metallic glass, a consequence of stress-induced glass transition.
Abstract: Metallic glasses are known for their outstanding mechanical strength. However, the microscopic mechanism of failure in metallic glasses is not well-understood. In this article we discuss elastic, anelastic and plastic behaviors of metallic glasses from the atomistic point of view, based upon recent results by simulations and experiments. Strong structural disorder affects all properties of metallic glasses, but the effects are more profound and intricate for the mechanical properties. In particular we suggest that mechanical failure is an intrinsic behavior of metallic glasses, a consequence of stress-induced glass transition, unlike crystalline solids which fail through the motion of extrinsic lattice defects such as dislocations.
TL;DR: In this article, the effects of aging on nuclei formation were quantitatively probed by analysis of isothermal crystallization at 393 K, using fast scanning chip calorimetry and polarizing optical microscopy.
Abstract: Aging of glassy poly(l-lactic acid) (PLLA) allows formation of crystal nuclei which enhances/accelerates subsequent crystallization at temperatures above the glass transition. The effects of the time and temperature of aging on nuclei formation have quantitatively been probed by analysis of isothermal crystallization at 393 K, using fast scanning chip calorimetry and polarizing optical microscopy. Crystal nuclei begin to form on aging the glass of PLLA at 343 K after about 101 s. The time of nuclei formation increases exponentially with decreasing temperature, so that aging at 323 K requires a minimum time of 104 s, and the extrapolated time for generation of nuclei at 295 K is about 108 s. The aging-controlled increase of the nuclei density in glassy PLLA leads to a distinct decrease of the half-time of crystallization. The half-time of crystallization of nonaged PLLA at 393 K is about 600 s and decreases to less than half of this value due to aging at 343 K for a period of only 103 s. Nuclei formation o...
TL;DR: In this article, the effects of the BaTiO3 nanofiller loading level and the PANI coating on the mechanical properties, rheological behavior, thermal stability, flammability and dielectric properties were systematically studied.
Abstract: Epoxy polymer nanocomposites (PNCs) filled with both barium titanate (BaTiO3) (500 and 100 nm) and conductive polyaniline (PANI) stabilized BaTiO3 nanoparticles (NPs) have been successfully prepared. The effects of the BaTiO3 nanofiller loading level and the PANI coating on the mechanical properties, rheological behavior, thermal stability, flammability and dielectric properties were systematically studied. The viscosity study on the nanosuspensions indicates that the PANI layer on the BaTiO3 nanoparticle surface can promote the network formation of the epoxy resin. The introduction of the PANI layer was found to reduce the heat release rate and to increase the char residue of the epoxy resin. The dynamic storage and loss moduli were studied together with the glass transition temperature (Tg) obtained from the peak of tan δ, and the reduced Tg in the PNCs is associated with the enlarged free volume. The tensile test indicated an improved tensile strength of the epoxy matrix with the introduction of the BaTiO3 NPs. Compared with the cured pure epoxy, the elasticity modulus was increased for all the PNC samples. The fracture surface study revealed an enhanced toughness. Due to the ferroelectric nature of BaTiO3, the real dielectric permittivity increased with increasing the BaTiO3 nanoparticle loading. The PANI layer on the surface of BaTiO3 also enhanced the dielectric permittivity arising from the interfacial polarization formed in the PNCs.