Increase In Dielectric Permittivity Research Articles

Dielectric Property Tuning via Electric Field Alignment in Mxene (Ti3C2)-Based Polymer Nanocomposites

Orientation control is crucial for fine-tuning the functional properties of two-dimensional (2D) nanomaterials. MXene (Ti3C2) alignment has drawn significant attention lately as the targeted properties can be controlled by manipulating the structural anisotropy. However, controlled MXene nanosheet orientation inside the polymer matrix is a complex and less understood mechanism. In this study, we applied an in-plane electric field to align the MXene nanosheets vertically inside the semicrystalline polyvinylidene fluoride (PVDF) (Tg⁓ -35°C) matrix in situ, where the amorphous phase assisted the electric field alignment at room temperature. These vertical orientations of the nanosheets were confirmed directly using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Our study reveals a significant correlation between MXene-orientation and dielectric property enhancement. PVDF- 5 wt.% MXene demonstrated the highest dielectric permittivity increase of ⁓500% because of the maximum surface polarization of the nano-capacitors inside the matrix. Interestingly, the loss value shows a sharp jump after the 5 wt. % MXene concentration, demonstrating a percolative network formation. Notably, our nanocomposite exhibited a low loss before (0.07) and after (0.66) applying the electric field, even at a high MXene concentration (20wt.%). Finally, to understand the effect of polymer domain structure on the electric field-induced orientation effect, we conducted a comparative study between non-ferroelectric poly vinyl alcohol (PVA) and ferroelectric (PVDF) polymer-based MXene nanocomposites. Interestingly, we observed a synergistic effect of the polymer chain and MXene orientation on the permittivity enhancement in the ferroelectric polymer-based nanocomposites at both high and low frequencies. This study provides fundamental insights for designing hybrid solid-state dielectric films for next-generation flexible electronics.

New Series of Hydrogen-Bonded Liquid Crystal with High Birefringence and Conductivity.

Liquid crystals with high dielectric anisotropy, low operational thresholds, and significant birefringence (Δn) represent a key focus in soft matter research. This work introduces a novel series of hydrogen-bonded liquid crystals (HBLCs) derived from 4-n-alkoxybenzoic, 4-alkoxy-3-fluorobenzoic derivatives (nOBAF), 4-alkoxy-2,3-fluorobenzoic derivatives (nOBAFF), and 2-fluoro-4-nitrobenzoic acid. The HBLCs were characterized using Fourier transform infrared spectroscopy, and their thermal behavior was evaluated via differential scanning calorimetry. Optical observations were conducted using polarized optical microscopy. The results indicate that mixtures containing benzoic acid with a bilateral fluorine substituent exhibit both SmA and SmC phases, while those with a unilateral fluorine substituent exhibit nematic and SmA phases. Moreover, an increase in the length of the alkoxy chain results in an expanded mesophase temperature range. This study demonstrates that the presence of a fluorine substituent and the incorporation of an NO2 group in the molecular structure result in an increase in dielectric permittivity, DC conductivity, dielectric anisotropy, and birefringence.

Nanoscale dielectric properties of TiO2 in SiO2 nanocomposite deposited by hybrid PECVD method

In this paper, nanocomposites (TiO2 in SiO2) are produced by an advanced hybrid aerosol-PECVD method based on direct liquid injection of a non-commercial colloidal solution in an O2 / hexamethyldisiloxane (HMDSO) low-pressure plasma. Dielectric properties are investigated at nanoscale using techniques derived from Atomic Force Microcopy in terms of relative dielectric permittivity, charge injection and transport. Results show that a concentration in TiO2 up to 14% by volume makes it possible to increase the relative dielectric permittivity up to 4.8 while maintaining the insulating properties of the silica matrix. For a TiO2 concentration in the range 15%–37% by volume, the relative dielectric permittivity increases (up to 11 for 37% TiO2 by volume) and only few agglomerated nanoparticles lowering the insulating properties are observed. For TiO2 concentration above 40% by volume, the relative dielectric permittivity still increases but the quantity of agglomerated nanoparticles is very high, which greatly increases the charge transport dynamic and degrades the insulating properties. Finally, 37% of TiO2 by volume in the SiO2 matrix appears to be the best compromise, between high dielectric permittivity and low leakage current for the MIM applications aimed.

Enhanced dielectric properties of Sr2+ and Zr4+ doped BaTiO3 colossal permittivity metamaterials

BaTiO3, as one of the most important functional materials of perovskite structure, is widely used in the electronic industry. However, the dielectric permittivity of BaTiO3 remains relatively low, which greatly limits its practical application in metamaterials with colossal dielectric permittivity. In this work, (Ba100−xSrx)(Ti100−yZry)O3 composite ceramics are fabricated via the solid sintering method. Surprisingly, the dielectric properties of (Ba100−xSrx)(Ti100−yZry)O3 composite ceramic materials are strongly dependent on the occupancy of Sr2+ and Zr4+ at the A-sites and B-sites, respectively. Consequently, via adjusting the doping amount of SrTiO3 and BaZrO3, a greatly enhanced dielectric permittivity of 28287 (65 °C, 1 kHz), along with a high breakdown strength of 84.47 kV/cm is achieved in (Ba90Sr10)(Ti90Zr10)O3 composite ceramics, which are 2144% and 13 % higher than those of (Ba99Sr1)(Ti99Zr1)O3 composite ceramics, respectively. Moreover, the reasons for the significant increase in dielectric permittivity are identified through finite element simulations, and the breakdown mechanism of composite ceramic materials is explored. This work provides a facile approach to constructing high dielectric permittivity composite ceramics, the (Ba100−xSrx)(Ti100−yZry)O3 composite ceramics have broad application prospects in electronics and electrostatic energy storage capacitors.

BZT substitution effect on the characteristics of (1-x) MT – x BZT composite ceramics synthesized by the sol–gel method

This paper addresses a crucial gap in the effect of adding BaZr0.1Ti0.9O3 (BZT) on the structural, microstructural, dielectric, and electrical properties of MgTiO3 (MT) material. These ceramics with the chemical composition (1-x) MT – x BZT were synthesized with different compositions ranging from × = 0.0 to 1.0 with a 0.1 step using the sol–gel reaction process. The X-ray diffraction (XRD) results and Rietveld refinement analysis showed the formation of a tetragonal phase with the P4mm space group for the BZT sample and a hexagonal phase with the R-3 space group for MT ceramics, without any secondary phases. However, (1-x) MT – x BZT composites with × ranging from × = 0.1 to 0.9, showed a coexistence of tetragonal (P4mm) and hexagonal (R-3) phases. Scanning Electron Microscopy (SEM) was used to investigate the morphology and grain size of the compounds. The SEM results revealed a clear decrease in grain growth for x = 0.6 of BZT content with the higher density. Furthermore, the dielectric properties of these composites were studied by impedance spectroscopy, which showed a single diffuse dielectric phase transition for all the BZT-MT composites. There was a clear increase in dielectric permittivity (εr′) value with the increase of the BZT content. This broad phase transition is highly desired and has not been observed in previous studies. The obtained composite ceramics could open the way to lead new applications in microelectronic devices.

CdTe quantum dot-polymer stabilized blue phase liquid crystal nanocomposite with wide blue phase and improved electro-optical responses

In the present work, a hybrid blue phase liquid crystal material exhibiting more than 40K wide blue phase temperature range has been prepared and investigated its optical, electro-optical and dielectric properties. The hybrid material was prepared by introducing cadmium telluride quantum dots in polymer stabilized blue phase liquid crystals. The blue phase temperature range of hybrid material was also compared with other blue phase liquid crystal systems (polymer stabilized blue phase liquid crystals, quantum dots doped pure blue phase liquid crystals), which indicated that the thermal stability is significantly augmented in hybrid materials. Further, the substantial reduction in operating voltage (12.5%), improvement in transmittance and Kerr constant with three-fold increase in dielectric permittivity in quantum dots doped polymer stabilized blue phase liquid crystals were observed as the other important findings of present work. The examined hybrid materials with wide blue phase temperature range and superior electro-optical properties are expected to be important for various photonic applications.

Light-induced dynamics of liquid-crystalline droplets on the surface of iron-doped lithium niobate crystals

We investigated the effect of a photovoltaic field generated on the surface of iron-doped lithium niobate crystals on sessile droplets of a ferroelectric nematic liquid crystalline and a standard nematic liquid crystalline material present on this surface. When such an assembly is illuminated with a laser beam, a wide range of dynamic phenomena are initiated. Droplets located outside the laser spot are dragged in the direction of the illuminated area, while droplets located inside the illuminated region tend to bridge each other and rearrange into tendril-like structures. In the ferroelectric nematic phase (NF), these processes take place via the formation of conical spikes evolving into jet streams, similar to the behavior of droplets of conventional dielectric liquids exposed to overcritical electric fields. However, in contrast to traditional liquids, the jet streams of the NF phase exhibit profound branching. In the nematic phase (N) of both the ferroelectric nematic and the standard nematic material, dynamic processes occur via smooth-edged continuous features typical for conventional liquids subjected to under-critical fields. The difference in dynamic behavior is attributed to the large increase of dielectric permittivity in the ferroelectric nematic phase with respect to the dielectric permittivity of the nematic phase.

Anomalous Phase Transition, Polarization Switching, and Relaxation in a Novel Composite Consisting of Dimethylammonium Aluminum Sulfate Hexahydrate and Oxidized Multiwalled Carbon Nanotubes

A novel ferroelectric composite consisting of dimethylammonium aluminum sulfate hexahydrate (CH3)2NH2Al(SO4)2·6H2O and oxidized multiwalled carbon nanotubes was developed to investigate its dielectric relaxation, phase transition, and ferroelectric switching behaviors. Experimental methods combined with theoretical analyses were employed. The results showed that the filler of oxidized multiwalled carbon nanotubes caused the freezing of domain-wall motion in (CH3)2NH2Al(SO4)2·6H2O at 98.2 K, leading to a decrease in dielectric constant, dielectric loss, and the polarization. In addition, an increase in dielectric permittivity and dielectric loss was found at higher temperatures. The role of hydroxyl groups incorporated in the carbon nanotubes after its oxidation was responsible for the obtained anomalies.

Structural and Electrical Properties of Glass-Ceramic Ferroelectric Composite Materials

Introduction. Materials exhibiting high dielectric permittivity are relevant for use in modern ultrahigh-frequency electronics. Among them, ferroelectrics with high dielectric nonlinearity present particular interest. The electrical strength of ferroelectric materials can be increased using modern composite structures based on mixing ferroelectries and linear dielectrics - materials exhibiting simultaneously low dielectric permittivity and high electrical strength. This approach provides for the opportunity of creating new multicomponent materials with previously unattainable properties and adjusting their component composition, inclusion size and electrical properties across a wide range. In this work, on the basis of porous potassium-iron-silicate glass (KFS) obtained by ion exchange, glass-ceramic materials containing barium titanate were synthesized for use at ultrahigh frequencies.Aim. Production of glass composites by low-temperature sintering of pre-synthesized BaTiO3 (BTO) and potassium-iron-silicate glass, as well as characterization of their structural and electrical properties at ultrahigh frequencies (microwave).Materials and methods. The crystal structure and phase composition of the obtained films were studied by X-ray diffraction using a DRON-6 diffractometer by the emission spectral line CuKα1 (λ = 1.5406 Å). The dielectric permittivity (ε) of microwave samples was evaluated by the Nicholson-Ross method at room temperature using an Agilent E4980A LCR-meter.Results. According to X-ray diffraction analysis, the synthesized samples are a mixture of KFS glass, ferroelectric BaTiO3 and dielectric barium polytitanates; the ratio of the latter determines the electrical properties of the composites. Depending on the content of barium titanate, the studied samples demonstrate a dielectric constant from 50 to 270 at a dielectric loss level of 0.1...0.02. The samples subjected to annealing in an oxygen medium showed an increase in dielectric permittivity by 10.25 % and an increase in controllability with a decrease in dielectric losses by an average of two times.Conclusion. The composite composition of 70 wt % BTO /30 wt % KFS was found to be the most promising in terms of structural and electrical properties. This composite showed an increase in dielectric permittivity by 25 % and a significant increase in nonlinearity, at the same time as reducing losses by more than two times as a result of annealing in an oxygen medium.

Toward multifunctionality of PEO/PMMA/MMT hybrid polymer nanocomposites: Promising morphological, nanostructural, thermal, broadband dielectric, and optical properties

Different compositional ratio organic polymer blend (PB) matrices of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) and these matrices with inorganic montmorillonite (MMT) nanoclay dispersed PEO/PMMA/MMT hybrid polymer nanocomposites (HPNCs) were prepared through solution-cast followed by melt-press technique. The structures and properties of these PB and HPNCs were comprehensively characterized using several advanced techniques: scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, broadband dielectric spectroscopy (2×101–109 Hz), and ultraviolet–visible (UV–Vis) spectroscopy. The effects of PEO/PMMA blend compositional ratio and the MMT nanofiller concentration on the homogeneity, nano- to micro-sized structures of these PBs and the hybrid composites, variation in intercalated MMT structures, melting temperature of PEO crystallites, and degree of crystallinity were explored. Dielectric dispersion and relaxation processes, electrical conductivity, UV–Vis absorbance with energy band-gap, and other optical parameters of these nanocomposites were influenced by the amounts of constituents and polymer–polymer and polymer–nanofiller interphases in these PB and HPNC materials. The dielectric results showed that these materials were low-permittivity nanodielectrics over a wide radio-frequency range (∼105–109 Hz), but a considerable increase in dielectric permittivity with the decrease in frequency from 105 to 2×101 Hz was predominantly governed by the interfacial polarization which confirmed them as tunable-type dielectrics. The promising multifunctional macro-scale properties and their relationship with the nano-scale structural variables indicated that these state-of-the-art engineered HPNCs were flexible and tunable nanodielectrics and also controllable optical properties smart-materials for advances in polymer-based device technologies.

A grease for domain walls motion in HfO2-based ferroelectrics

A large coercive field E C of HfO2 based ferroelectric devices poses critical performance issues in their applications as ferroelectric memories and ferroelectric field effect transistors. A new design to reduce E C by fabricating nanolaminate Hf0.5Zr0.5O2/ZrO2 (HZZ) thin films is used, followed by an ensuing annealing process at a comparatively high temperature 700 °C. High-resolution electron microscopy imaging detects tetragonal-like domain walls between orthorhombic polar regions. These walls decrease the potential barrier of polarization reversal in HfO2 based films compared to the conventional domain walls with a single non-polar spacer, causing about a 40% decrease in E C. Capacitance versus electric field measurements on HZZ thin film uncovered a substantial increase of dielectric permittivity near the E C compared to the conventional Hf0.5Zr0.5O2 thin film, justifying the higher mobility of domain walls in the developed HZZ film. The tetragonal-like regions served as grease easing the movement of the domain wall and reducing E C.

Structure, thermal, optical and dielectric properties of SnO2 nanoparticles-filled HDPE polymer

The present study deals with the structural, thermal, optical and electrical properties of a new combination of nanocomposites with high-density polyethylene (HDPE) polymer and SnO2 nanoparticle filler. The structural and morphological change with SnO2 concentration (0.5, 1, 2, 3, 5, 10, 20 wt%) were investigated with Rietveld refinement of X-ray diffraction, FTIR, FESEM and Raman spectroscopy. It was found from the XRD refinement that a monotonic decrease in lattice volume and lattice paraments of HDPE with filler addition up to 5 wt % and non-uniform change in cell parameters at filler concentrations above 5 wt% due to the agglomeration of nanoparticles. The FTIR and Raman spectra analysis also supported the uniform dispersion of nanoparticles in the polymer below 5 wt% filler concentrations. The DSC and TGA studies proved that the addition of low concentrations of SnO2 nanofillers could significantly enhance the degradation temperature. The accelerated thermal aging studies using UV spectroscopy confirmed the improved thermal stability of nanocomposites. The optical and dielectric studies demonstrate the effective tailoring of these properties by changing the volume fraction of SnO2 nanoparticles. UV spectroscopy studies showed the higher UV-light shielding performance of nanocomposites than the pure HDPE polymer. The dielectric behaviour follows the percolation phenomenon and the critical volume fraction is found to be 1%. The rate of increase of dielectric permittivity of nanocomposites is around 17% with 20 wt % filler loading. The polymer nanocomposites with improved and tunable thermal, optical and dielectric properties benefit insulation and UV shielding applications.

Experimental studies on mechanical and dielectric behavior of Glycerol filled Silicone rubber composites

In this study, Silicone rubber composites are prepared with Glycerol filler in three different volume fractions. The samples developed are subjected to mechanical and dielectric testing. The tensile strength increases first and later decreases with Glycerol loading whereas compression strength decreases with Glycerol loading. Modulus of elasticity in tension and compression both decreases with the increase of Glycerol loading. Dielectric permittivity, dissipation factor and conductivity are increases with the increase of Glycerol loading. The Silicone Rubber (SR) composite with 15% volume of Glycerol filler shown a maximum reduction in modulus of elasticity of 29% (in tension) and 16.8% (in compression), and maximum improvement in the dielectric permittivity of 112% compared to neat silicone rubber. The reduction in modulus of elasticity with an increase in dielectric permittivity with an increase in Glycerol loading suggests that this material is a potential candidate for materials to be used in soft dielectric sensors and actuator applications.

Dielectric Relaxation Dynamics and Polaronic Tunneling Conduction Mechanism of Electrical Conductivity of Fe2O3‐Doped PbO–ZrO2–SiO2 Glass Ceramics

This study consists of comprehensive investigations on dielectric permittivity (ε′), electric moduli (M′, M″), impedance (Z), and conductivity (σac) spectra over broad regions of frequency and temperature of lead zirconium silicate glass ceramics mixed with different concentrations of Fe2O3. The observed increase in dielectric permittivity with the content of Fe2O3 is attributed to the increasing presence of iron ions in octahedral positions. Electric moduli plots with frequency (ω) and temperature (T) exhibit dipolar effects. These effects are quantitatively analyzed by Cole–Cole plots; the analysis indicates the distribution of relaxation times. Probable dipoles for these effects are identified and discussed. AC conductivity (σac) shows a rising trend with an increase in Fe2O3 beyond 0.2 mol%, and this increase is attributed to the polaron exchange among Fe2+ and Fe3+ ions. The conduction mechanism is well explained using a polaron tunneling model in the middle‐frequency and high‐temperature regions.

Superior optical and dielectric properties of ultrasonic-assisted solution-cast prepared PMMA/MMT nanocomposite films

Poly(methyl methacrylate) (PMMA) and montmorillonite (MMT) nanoclay based PMMA/MMT nanocomposite films were prepared by solution-cast (SC) and ultrasonic-assisted SC (USA-SC) methods, and characterized for structural, thermal, optical, and dielectric properties. The x-ray diffraction patterns evidenced that the amount of MMT exfoliated nanoplatelets and tactoids in the nanocomposites are significantly affected by the preparation methods. Differential scanning calorimetry thermograms showed lowering of glass transition temperature of these nanocomposites as compared to the neat polymer matrix. The ultraviolet–visible spectroscopic measurements explained that the SC prepared PMMA/MMT films have high absorbance in comparison to host matrix which further enhanced when the film thickness was increased. However, in comparison to the SC prepared nanocomposite films, the USA-SC prepared films have low absorbance in the visible region which remained independent of the film thickness. Each nanocomposite film exhibited two different energy bandgaps which confirm their use as multifunctional bandgap tuner in optoelectronic devices. The dielectric relaxation spectroscopy in the frequency range from 20 Hz to 1 MHz revealed that the USA-SC prepared PMMA/MMT film has about nine per cent increase of dielectric permittivity at all the frequencies without alteration in dielectric loss when compared with the PMMA film, confirming its great potential as nanodielectric for advances in flexible microelectronic device technology.

PVA/MMT and (PVA/PVP)/MMT hybrid nanocomposites for broad-range radio frequency tunable nanodielectric applications

Electrical and electronic device applications of the hybrid nanocomposite materials are primarily identified from their frequency dependent dielectric properties. In this context, herein, we report the complex dielectric permittivity of poly(vinylalcohol)(PVA)/montmorillonite(MMT) and PVA/poly(vinylpyrrolidone)(PVP)/MMT nanocomposites with varying MMT nanoclay amounts up to 10 wt% and the frequency from 1 MHz to 1 GHz, in order to address their nanodielectric uses in biodegradable electronic devices operative at ultrahigh frequencies. These melt compounded prepared hybrid polymer nanocomposites (PNCs) showed an increase in dielectric permittivity by about 20% at 1 MHz when the MMT concentration was increased, and a gradual decrease with the rise in frequency which revealed their nanofiller concentration and frequency tunable nanodielectric behaviour. The PVA/MMT nanocomposites have high dielectric permittivity as compared to that of the (PVA/PVP)/MMT nanocomposites confirming that the dielectric properties of these PNCs can also be controlled by considering an appropriate composition polymer blend matrix.

Accelerated photodegradation of polystyrene by TiO2-polyaniline photocatalyst under UV radiation

Photodegradation of polystyrene (PS) was studied under ultraviolet (UV) radiation, using nano TiO2, surface modified with polyaniline (PANI). X-Ray diffractogram reveals that the crystalline structure of TiO2 remained intact in TiO2-PANI composites. The existence of strong molecular interaction between TiO2 and PANI lead to a decrease in the optical bang gap energy of TiO2 in the composites. PS loaded with TiO2-PANI composites underwent better chain scission and photo-oxidation compared to PS and PS-TiO2 composites, upon UV irradiation. TiO2-PANI composites enhanced the mechanical properties (tensile and flexural) of PS appreciably. Tensile and flexural strengths however decreased with respect to UV exposure time, proving mechanical deterioration of the polymer composites as an outcome of photodegradation. Thermal stability of the composites too decreased upon UV exposure. A decrease in the values of break down voltage as well as increase in dielectric permittivity of the composites upon UV irradiation suggests the formation of charge centers and polarisable species in the polymer matrix. All the polymer composites underwent considerable weight loss due to the formation and evolution of volatile gases, during the course of photodegradation. Suitable mechanism of degradation of PS composites was proposed based on the observed results.

Point defects and their effect on dielectric permittivity in strontium titanate ceramics

The origin of dielectric properties of strontium titanate ceramics is investigated using DFT calculations in periodic system. It was determined that the main factors contributing to the increase in dielectric permittivity are: tetragonal distortion of the normally cubic lattice, and charge imbalance induced displacement of titanium center from its central position. Oxygen vacancies were determined to create significantly larger effects than other types of vacancies, like Ti and SrO. The extent of tetragonal distortion was found to be determined by oxygen vacancy distribution, rather than total concentration: relatively symmetrical distribution of oxygen vacancies resulted in smaller tetragonal distortion of the lattice, and, consequently, smaller increase in dielectric permittivity. Charge imbalance naturally destabilizes the cubic lattice, forcing the Ti-atom out of its central position, resulting in tetragonal lattice with increased dielectric permittivity. The process stabilizes the strontium titanate lattice, while increasing the c/a ratio. Therefore, the dielectric permittivity of strontium titanate can be increased by changes to the system that increase tetragonal distortion of the lattice and/or introduce additional negative charge.

Liquid-crystalline behaviour and electrorheological effect of phthalocyanine-based ionic liquid crystals

ABSTRACT Series of phthalocyanine-based ionic liquid crystals (PILCs) electrorheological (ER) materials were synthesised using brominated polyesters and a phthalocyanine (Pc)-containing monomer, and the chemical structure, liquid-crystalline behaviour, dielectric property and ER performance were characterised. All PILCs showed nematic phase, but some PILCs with more phthalocyanine moieties showed discotic hexagonal columnar mesophase. The dielectric permittivity increase with the increasing temperatures, but decrease with the increase of frequency for these PILCs. The PILCs-based electrorheological fluids (ERFs) contained an integrated character of liquid crystal, poly(ionic liquid) and Pc-base ER suspensions. The ERFs were made by PILC particles and silicone oil, and the ER effect was investigated at controlled test conditions including concentration, electric field strength, temperature and shear rate. When the ERFs were applied an external electric field strength, the shear stress increased instantly, and they showed non-Newtonian behaviour. At the same conditions, the ER effect improved as the measured temperature raised. Furthermore, the ER effect increased with the increase of ionic Pc moieties in the polymer systems. These results were originated from the synergetic effect among the mesogenic orientation and rearrangement of ionic Pc droplets induced by the electric field, forming an alignment-aggregated fibrillation chain.

Confinement-Induced Enhancement of Parallel Dielectric Permittivity: Super Permittivity Under Extreme Confinement.

Enhancement of parallel (x-y plane) dielectric permittivity of confined fluids has been shown previously. However, a theoretical model that explains this enhancement is lacking thus far. In this study, using statistical-mechanical theories and molecular dynamics simulations, we show an explicit relation between the parallel dielectric permittivity, density variations, and dipolar correlations for protic and aprotic fluids confined in slit-like channels. We analyze the importance of dipolar correlations on enhancement of parallel dielectric permittivity inside large channels and extreme confinements. In large channels, beyond the interfacial region, dipolar correlations exhibit bulk-like behavior. Under extreme confinement, the correlations become stronger to the extent that they give rise to a giant increase in the parallel dielectric permittivity. This sudden increase in dielectric permittivity can be a signature of a liquid transition into higher-ordered structures and has important consequences for understanding ion transport, molecular dissociation, and chemical reactions inside nanoconfined environments.