Ionic Fluids Research Articles

Ion transport in surface functionalized SnO2 nanoparticles dispersed imidazolium ionanofluids: Decoupling from structural relaxation

The focus of the present work is the study of conductivity and structural relaxation dynamics of a series of ionanofluids, prepared by dispersing different extents of ionic liquid tethered SnO2 nanoparticles, i.e., nanoscale hybrid ionic fluid, (NHIF) in imidazolium ionic liquid host. Measurements have been made using temperature dependent dielectric spectroscopy and differential scanning calorimetry (DSC). Our study reveals that with increasing NHIF content in the host, the ion conductivity relaxation becomes increasingly faster than the structural relaxation at any measured temperature. For 20.0 wt% NHIF the structural relaxation time is longer than the conductivity relaxation times by more than six decades in the vicinity of the glass transition temperature (Tg), i.e. the decoupling index Rt(Tg) is >6. In contrast to the host ionic liquid, the observed unusual behaviour with increasing NHIF content is appropriately correlated to the corresponding depression of crystallinity and a sharp rise in fragility index in ionanofluids. The study suggests that the conjunction of ionic liquid tethered nanoparticles and ionic liquid provides a promising way to design highly conductive ionanofluids solvents with numerous application perspectives.

Fluid-fluid phase behaviour in the explicit solvent ionic model: Hard spherocylinder solvent molecules

We study a fluid-fluid phase transition of the explicit solvent model represented as a mixture of the restricted primitive model (RPM) of ionic fluid and neutral hard spherocylinders (HSC). To this end, we combine two theoretical approaches, i.e., the scale particle theory (SPT) and the associative mean spherical approximation (AMSA). Whereas the SPT is sufficient to provide a rather good description of a reference system taking into account hard-core interactions, the AMSA is known to be efficient in treating the Coulomb interactions between the ions. Alternatively, we also use the mean spherical approximation (MSA) for comparison. We restrict our attention to the HSC with aspect ratios L2/σ2 = 5 and 10, when the diameter of RPM particles is set to σ1 = σ2. We find the conditions at which the fluid-fluid phase transition is accompanied by the isotropic-nematic phase transition occurring in the solvent component. Furthermore, the effect of asphericity of solvent molecules on the fluid-fluid phase transition is studied by considering an “equivalent” mixture in which the HSC particles are replaced by hard spheres (HS) of the same volume. We discuss an importance of accounting for the association effects which appear between oppositely charged ions.

Molecular streaming and its voltage control in ångström-scale channels.

Over the past decade, the ability to reduce the dimensions of fluidic devices to the nanometre scale (by using nanotubes1-5 or nanopores6-11, for example) has led to the discovery of unexpected water- and ion-transport phenomena12-14. More recently, van der Waals assembly of two-dimensional materials15 has allowed the creation of artificial channels with ångström-scale precision16. Such channels push fluid confinement to the molecular scale, wherein the limits of continuum transport equations17 are challenged. Water films on this scale can rearrange into one or two layers with strongly suppressed dielectric permittivity18,19 or form a room-temperature ice phase20. Ionic motion in such confined channels21 is affected by direct interactions between the channel walls and the hydration shells of the ions, and water transport becomes strongly dependent on the channel wall material22. We explore how water and ionic transport are coupled in such confinement. Here we report measurements of ionic fluid transport through molecular-sized slit-like channels. The transport, driven by pressure and by an applied electric field, reveals a transistor-like electrohydrodynamic effect. An applied bias of a fraction of a volt increases the measured pressure-driven ionic transport (characterized by streaming mobilities) by up to 20 times. This gating effect is observed in both graphite and hexagonal boron nitride channels but exhibits marked material-dependent differences. We use a modified continuum framework accounting for the material-dependent frictional interaction of water molecules, ions and the confining surfaces to explain the differences observed between channels made of graphene and hexagonal boron nitride. This highly nonlinear gating of fluid transport under molecular-scale confinement may offer new routes to control molecular and ion transport, and to explore electromechanical couplings that may have a role in recently discovered mechanosensitive ionic channels23.

Outgassing performance of an ionic liquid-based magnetic fluid

In this study, an ionic liquid (IL)-based magnetic fluid (MF) (IMF; IL-based MF) and dispersant was synthesized to create MF seals for rotational mechanisms in high-vacuum chambers, such as those in rotational electron beam mastering systems. The synthesized dispersant dispersed magnetite nanoparticles in pyridinium ionic liquid that is stable under magnetic fields. The outgassing from the IMF was investigated using a quadrupole mass spectrometer during a sliding test under high-vacuum conditions with a pressure of 10−6 Pa. The fragmentation pattern of the outgassing from the IMF was very similar to that of the base IL. Pollution-causing fragments were not detected under vacuum conditions on the order of 10−9 Pa. On the basis of our findings, we anticipate that the IMF is suitable for use in MF seals required in clean, high-vacuum conditions.

Sedimentation Velocity and Potential in Dilute Suspensions of Charge-Regulating Porous Spheres.

The sedimentation of a charge-regulating porous sphere surrounded by an arbitrary electric double layer, which usually models a permeable polyelectrolyte coil or an aggregate of nanoparticles, is analyzed for the first time. The hydrodynamic frictional segments and ionogenic functional groups uniformly distribute in the porous sphere, and a regulation mechanism for the dissociation and association reactions occurring at these functional groups linearly relates the local electric potential to fixed charge density. The linearized electrokinetic equations governing the ionic concentration (or electrochemical potential energy), electric potential, and fluid velocity fields are solved for the case of a small basic fixed charge density by the regular perturbation method. Analytical formulae for the sedimentation velocity of a porous sphere and sedimentation potential of a dilute suspension of porous spheres are then obtained. The charge regulation tends to reduce the electrokinetic retardation to sedimentation velocity and the sedimentation potential (can be as much as 50 and 25%, respectively) compared to the case that the fixed charge density is a constant. Both the electrokinetic retardation to sedimentation velocity and the sedimentation potential vanish at the isoelectric point of the particles. The increase in the bulk concentration of the potential-determining ions crossing the isoelectric point changes signs of the fixed charges and thus causes a reversal in the direction of the sedimentation potential. The effects of charge regulation on the sedimentation of porous particles differ substantially from those of hard particles.

Ionic Fracture Fluid Leak-Off

The study is motivated by monitoring the space orientation of a hydrolic fracture used in oil production. Streaming potential arises due to the leakage of ionic fracking fluid under the rock elastic forces which make the fracture disclosure disappear after pumping stops. The vector of electric field correlates with the fracture space orientation since the fluid leakage is directed normally to the fracture surfaces. We develop a mathematical model for the numerical evaluation of the streaming potential magnitude. To this end, we perform an asymptotic analysis taking advantage of scale separation between the fracture disclosure and its length. The contrast between the virgin rock fluid and the fluid invading from the fracture is proved to be crucial in a build up of a net charge at the invasion front. Calculations reveal that an increase of the viscosity and resistivity contrast parameters results in an increase of the streaming potential magnitude. Such a conclusion agrees with laboratory experiments.

Modeling the Water Solubility in Imidazolium-Based Ionic Liquids Using the Peng–Robinson Equation of State

Ionic liquids (ILs), which are also known as liquid salts or ionic fluids, are organic salts with a low fusion point. They behave as a liquid at low temperature or ambient temperature. Accordingly, they are prominent solvents to be used in the green chemical processes, because of their attractive physicochemical properties such as low vapor pressure, high thermal stability, an excellent solvation behavior, and high gas solubility. Recently, various experimental researches have reported the water solubility in different imidazolium-based ILs at different temperature, pressure, and composition conditions. In this study, we present the modeling of the vapor–liquid equilibrium of the H2O–IL system using the Peng–Robinson cubic equation of state (EoS), coupled with the Wong-Sandler mixing rules; eight binary systems were studied for this purpose. In addition, improved temperature-dependent parameters were introduced into the EoS as those proposed by Stryjek and Vera for water [Can. J. Chem. Eng. 1986, 64, 323]...

Polymer solvation in choline chloride deep eutectic solvents modulated by the hydrogen bond donor

Choline chloride (ChCl) Deep Eutectic Solvents (DESs) are a relatively new class of ionic fluid physicochemically similar to ionic liquids. Their properties, combined with their hydrogen bond - rich bulk nanostructures make them attractive alternatives as molecular solvents for a range of applications. Nevertheless, the solvation structure of molecular and polymer solvents in choline chloride DES remains largely uncharacterised due to the complexity of the DES nanostructure itself. We present a systematic quantum chemical investigation of the solvation structure of poly(ethylene glycol) (PEO) in DES formed by ChCl and urea, ethylene glycol and glycerol hydrogen bond donors. Trends in the solvation structure of PEO correlate with the density of the DES hydrogen bond network, and the extent to which this network can be perturbed by the polymer solute. We show that both of these factors are modulated by the type of hydrogen bond donor itself. Notably, PEO disrupts the urea – choline hydrogen bond network. This disruption leads to a more highly structured solvation environment for the polymer, which is forced into a relatively constrained, coiled morphology. By contrast, the disruption to the hydrogen bond networks in the ethylene glycol and glycerol DES are less significant, leading to a less constrained environment.

Toward a mechanistic understanding of wettability alteration in reservoir rocks using silica nanoparticles

Traditional concepts of simple liquid spreading may not apply to nanoparticle-fluids. Most investigations pertaining to the wettability alteration of solid surfaces due to the presence of nanoparticles in the fluid are oversimplified, i.e. nanoparticles dispersed in DI-water and smooth, homogeneous, and clean surfaces have been used. From a practical enhanced oil recovery (EOR) point of view, the nanoparticles must be dispersed in either seawater or high salinity formation water containing diverse types and concentrations of ions. These ions interact with the electrostatic properties of the nanoparticles. Likewise, the oil phase may contain many surface active components like asphaltene and naphthenic acids which can interact with nanoparticles at oil-water and oil-rock interface. In reality, the rock sample is a heterogeneous, non-smooth, mixed-wet substrate with a diverse mineralogical composition. The electrical charge of minerals can vary when contacted with an ionic fluid. This can alter the electrostatic repulsion between substrate and nanoparticles and consequently the substrate can either attract or repel charged particles, including nanoparticles. Hence, the role of nanoparticles must be evaluated considering multicomponent complex fluids and real formation rock. Despite numerous reports regarding the wettability alteration of reservoir rock from oil-wet to water-wet by nanoparticles, some inherent limitations in the wettability alteration experiments prevent conclusions about the performance of nanoparticles in practical complex conditions. For instance, the wettability alteration by nanoparticles is often determined by contact angle measurements. In this method, the substrates are either aged with (immersed in) nanoparticle-fluids before conducting the experiments or contacted with nanoparticle-fluids before attachment of the oil droplet on the rock surface. Hence, in both cases, before initiating the contact angle measurements, the nanoparticles would already exist at the oil-rock interface possibly giving inaccurate measurements. The objective of this work is to investigate the mechanism of wettability alteration by silica nanoparticles pre-existing on the rock interface (conventional contact angle measurements) and using a new displacement contact angle method to better mimic the scenario of injecting a nanoparticle fluid into the reservoir already containing formation brine. The impact of pre-existing nanoparticles at the oil-rock interface (in the conventional contact angle measurements) on the contact angle measurements are examined for simple (n-decane, NaCl brine, and pure substrates) and complex (crude oil, seawater, and reservoir rock) systems on various wetting conditions of substrates (water-wet and oil-wet). The nanoparticles are dispersed in seawater using our H+ protected method [1]. Then, the effect of surface and nanoparticle charge on the contact angle is evaluated by adjusting the aqueous phase salinity. We also differentiate between the disjoining pressure mechanism and diffusion of silica nanoparticles through the oil phase by testing the attachment of nanoparticles on the rock surface.

A Brief Review on Ionic Fluids and its Application in Machining

Abstract In the world of manufacturing, achieving sustainability in machining process is of prime importance. The present known hazards of conventional flood cooling method via mineral oils have made us realize the need to eliminate this ongoing process to ensure safety to operator’s health as well as to pass on a better environment to upcoming generations. Ionic liquids (ILs) are one such class of lubricants that have the potential to replace the mineral oils in machining with their promising properties. The results performed in various works reviewed in this paper have proved ILs to be a potential additive aiding better performance in terms of cutting force, tool wear and surface roughness. Application of ILs + additives (Benzotriazole (BTA) and Tricresyl phosphate (TCP)) in high-speed machining will be newer concept and need to be investigated to study the machinability of hardened steel.

Machinability behavior of Aluminium Alloys: A Brief Study

Abstract Aluminium alloys are the most promising material which provides highest mechanical strength in the field of hard machined material. Owing to its higher strength to weight ratio, it is extensively applied in the aerospace and aeronautical manufacturing enterprises. Over the years, the requirement for eco-friendly and cost-effective machining practices have been developed continuously, and many researchers have shown keen interest for increasing more advanced machining process. During machining of aluminium alloy materials, the appropriate choice of machining process and cooling situations play an imperative role as it affects the performance. The current research article focuses on a comprehensive review of power consumption during machining of aluminium alloy. Additionally, comparisons are performed between Dry and MQL cooling system and critical observation for tool wear, cutting temperature, and surface roughness using various types of cutting insert have been considered. Application of ionic fluids as a coolant for aluminium alloys machining were not found in literature and it can be the novel choice for the researchers to carry out their works. This exploration will definitely provide appropriate selection of cutting conditions during machining of various aluminium alloys for machinist and researchers.

예술 및 음악과 융합할 수 있는 재료로서의 나노 유체에 대한 연구

Nano science and nanotechnology has convergence with sports, music, and arts beyond convergence with other scientific technologies, and comes to develop into a totally new area. Ferrofluids feature the creation of the magnetic field induced shape on the ferrofluid surface, combination of drops, and magnetic microconvection. Because of its small particles size, a ferrofluid has been developed as a promising new nanomaterial the beginning. Ferrofluids are more applied to diverse areas, such as dynamic loudspeakers, computer hardware, dynamic sealing, and bioengineering because of their unique properties. The research method is as follows.BR Firstly, introduction of the background and scope of the study. The basic theories for ferrofluid science and examples of convergent work with ferrofluids are known and published.BR Secondly, the classification of magnetic fields are introduced. There are generally two type of magnetic fields which are magnetorheological fluids and ferrofluids. A ferrofluid is a colloidal suspension of magnetic particles with a very tiny size in a liquid carrier. A ferrofluid is different from MRF with regard to its fluidity even if subjected to strong magnetic fields.BR Thirdly, A key to the application of ferrofluids is colloidal stability. The stability is determined by the balance of multiple types of energy (attractive and repulsive forces) which are the factors to prevent separation for a given time after the disappearance of exterior magnetic fields and thermal energy. If average thermal energy exceeds a total of interaction, negligible agglutination arises. There are two types of ferrofluid which are water-based ionic fluid and organic media based ferrofluid. To use ferrofluid to convergent with arts or other areas, important factors are low viscosity, low vapor pressure and chemical inertness of carrier liquids and surfactants.BR Finally, There are many areas which convergent with ferrofluid to invent totally new work and to sell fantastical products which never meet before. Those areas are arts, music, sculpture, and commercial products. According to the development the nanotechnology, the convergence of ferrofluid with arts or other areas will be accelerate and develop further and intensively.

Does capillary evaporation limit the accessibility of nonaqueous electrolytes to the ultrasmall pores of carbon electrodes?

Porous carbons have been widely utilized as electrode materials for capacitive energy storage. Whereas the importance of pore size and geometry on the device performance has been well recognized, little guidance is available for identification of carbon materials with ideal porous structures. In this work, we study the phase behavior of ionic fluids in slit pores using the classical density functional theory. Within the framework of the restricted primitive model for nonaqueous electrolytes, we demonstrate that the accessibility of micropores depends not only on the ionic diameters (or desolvation) but also on their wetting behavior intrinsically related to the vapor-liquid or liquid-liquid phase separation of the bulk ionic systems. Narrowing the pore size from several tens of nanometers to subnanometers may lead to a drastic reduction in the capacitance due to capillary evaporation. The wettability of micropores deteriorates as the pore size is reduced but can be noticeably improved by raising the surface electrical potential. The theoretical results provide fresh insights into the properties of confined ionic systems beyond electric double layer models commonly employed for rational design/selection of electrolytes and electrode materials.

Expansion and shrinkage of the electrical double layer in charge-asymmetric electrolytes: A non-linear Poisson-Boltzmann description

The spatial extension or thickness of the electrical double layer determines many thermodynamic and electrokinetic properties of charged colloids in solution. In the classical Debye-Hückel formalism of point ions, the thickness of the electrical double layer around a spherical macroion or next to an infinite planar electrode can be characterized by the bulk Debye length of the supporting ionic fluid. As a result, that approach neglects, at least, the influence of the colloidal charge on the spatial extension of the ionic cloud. Given that the Debye-Hückel formalism of point ions is valid only in the limit of very weak colloidal charges, in this work we use the non-linear Poisson-Boltzmann equation to study the thickness of the electrical double layer near a positively charged electrode in spherical and planar geometries, in the presence of several binary charge-asymmetric −1:z+ point-ions electrolytes with monovalent counterions and multivalent coions. The properties of counterions are maintained fixed, whereas the properties of coions (such as their valence and concentration) are varied fulfilling the bulk electroneutrality condition. The thickness of the ionic cloud is quantified here via the recently introduced capacitive compactness idea (Phys. Chem. Chem. Phys. 20 (2018) 262). Physically, this length represents essentially the separation distance between two electrodes associated to the corresponding effective electrical double layer capacitor, in both planar and spherical geometries. Our numerical calculations show that the capacitive compactness obtained via the non-linear Poisson-Boltzmann equation reduces to the Debye length of the supporting bulk electrolyte at the point of zero charge. In the presence of a charge symmetric −1:+1 electrolyte, the capacitive compactness always decreases as a function of the colloidal charge. Contrastingly, the electrical double layer may expand or shrink as a function of the surface charge density, in the presence of multivalent coions, which is confirmed here by primitive model Monte Carlo simulations. This last non-monotonic behaviour of the capacitive compactness for multivalent coions, depending on the colloidal charge, is related to the microscopic behaviour of the local electric field, the mean electrostatic potential, and the net ionic charge per unit volume close to the colloidal surface. At very large colloidal charges, the capacitive compactness of all −1:z+ electrolytes collapses onto a single curve illustrating the dominance of counterions in the non-linear Poisson-Boltzmann theory.

Salinity effects on soil shrinkage characteristic curves of fine-grained geomaterials

Fine-grained clayey soils are prone to substantial volume changes during desiccation in response to the dynamics of their moisture regime, and are of critical importance in several geotechnical and geo- environmental engineering applications. As such, the complex interactions between the fraction of soil solids and the ionic pore fluid play a critical role in governing such volume changes, and have been the focus in studies dealing with marine geotechnology, mine-tailing ponds, engineered barrier systems, etc. With this in mind, the present investigation evaluates the volume changes and accompanying densification from a saturated slurry state to a constant volume state of a reference fine-grained geomaterial, kaolin, subjected to evaporative dewatering. For this purpose, several parametric studies involving determination of soil shrinkage characteristic curves (SSCCs) of kaolin under the influence of varied salt constituents and concentrations of pore fluid are performed. Furthermore, a critical assessment of SSCCs depicting progressive shrinkage and volume change behaviour of geomaterials is provided, followed by the analysis of experimentally obtained SSCCs of the kaolin to explore the impacts of pore fluid salinity. Moreover, the SSCCs are parameterised with a predictive model and the fitting parameters are used to quantitatively demonstrate the salinity-dependent volume change response of a representative fine-grained porous system.

Describing screening in dense ionic fluids with a charge-frustrated Ising model.

Charge correlations in dense ionic fluids give rise to novel effects such as long-range screening and colloidal stabilization which are not predicted by the classic Debye-Hückel theory. We show that a Coulomb or charge-frustrated Ising model, which accounts for both long-range Coulomb and short-range molecular interactions, simply describes some of these ionic correlations. In particular, we obtain, at a mean field level and in simulations, a non-monotonic dependence of the screening length on the temperature. Using a combination of simulations and mean field theories, we study how the correlations in the various regimes are affected by the strength of the short ranged interactions.

Quasi-incompressible multi-species ionic fluid models

In traditional hydrodynamic theories for ionic fluids, conservation of mass and linear momentum is not properly taken care of. In this paper, we develop hydrodynamic theories for viscous, ionic fluids of N ionic species enforcing mass and momentum conservation as well as considering the size effect of the ionic particles. The theories developed are quasi-incompressible in that the mass-average velocity is no longer divergence-free whenever there exists variability in densities of the fluid components, and the theories are dissipative. We present several ways to derive the transport equations for the ions, which lead to different rates of energy dissipation. The theories can be formulated in either number densities, volume fractions or mass densities of the ionic fluid components. We show that the theory with the Cahn-Hilliard transport equation for ionic species reduces to the classical Poisson-Nernst-Planck (PNP) model with the size effect for ionic fluids when the densities of the fluid components are equal and the entropy of the solvent is neglected. It further reduces to the PNP model when the size effect is neglected. A linear stability analysis of the model together with two of its limits, which are the extended PNP model (EPNP defined in the text) and the classical PNP model (CPNP) with the finite size effect, on a constant state and a comparison among the three models in 1D space are presented to highlight the similarity and the departure of this model from the EPNP and the CPNP model.

Diffusiophoresis of a Charged Porous Particle in a Charged Cavity.

The quasi-steady diffusiophoresis of a charged porous sphere situated at the center of a charged spherical cavity filled with a liquid solution of a symmetric electrolyte is analyzed. The porous particle can represent a solvent-permeable and ion-penetrable polyelectrolyte molecule or floc of nanoparticles in which fixed charges and frictional segments are uniformly distributed, whereas the spherical cavity can denote a charged pore involved in microfluidic or drug-delivery systems. The linearized electrokinetic differential equations governing the ionic concentration, electric potential, and fluid velocity distributions in the system are solved by using a perturbation method with the fixed charge density of the particle and the ζ-potential of the cavity wall as the small perturbation parameters. An expression for the diffusiophoretic (electrophoretic and chemiphoretic) mobility of the confined particle with arbitrary values of a/ b, κ a, and λ a is obtained in closed form, where a and b are the radii of the particle and cavity, respectively; κ and λ are the reciprocals of the Debye screening length and the length characterizing the extent of flow penetration into the porous particle, respectively. The presence of the charged cavity wall significantly affects the diffusiophoretic motion of the particle in typical cases. The diffusio-osmotic (electro-osmotic and chemiosmotic) flow occurring at the cavity wall can substantially alter the particle velocity and even reverse the direction of diffusiophoresis. In general, the particle velocity decreases with an increase in a/ b, increases with an increase in κ a, and decreases with an increase in λ a, but exceptions exist.

The Use of Liquids Ionic Fluids as Pharmaceutically Active Substances Helpful in Combating Nosocomial Infections Induced by Klebsiella Pneumoniae New Delhi Strain, Acinetobacter Baumannii and Enterococcus Species.

This review deals with various microbiological activities of ionic liquids, which constitute the first anti-infective defense against multi-drug-resistant bacteria—with a particular emphasis placed on medicine and pharmacology. The quoted data on the biological activity of ionic liquids including their antimicrobial properties (depending on the type of a cation or an anion) and are discussed in view of possible applications in nosocomial infections. Dedicated attention is given to finding infections with the Klebsiella pneumoniae New Delhi strain, Acinetobacter baumannii, and Enterococcus species, which are responsible for the induction of antibiotic resistance in intensive care units. Diagnosis and treatment using current antibiotics is a significant problem in hospital care, and the relevant burden on the health systems of the European Union member states induces the search for new, effective methods of treatment. Ionic liquids, due to their antibacterial effect, can be considered topical and general medications and may provide the basis for treatment to eliminate the antibiotic resistance phenomenon in the future. At present, the number of infections with resistant pathogens in hospitals and outpatient clinics in the European Union is growing. In 2015–2017, a significant incidence of respiratory and bloodstream infections with bacteria resistant to antibiotics from the 3rd generation group of cephalosporins, glycopeptides, and carbapenems were observed. The paper presents examples of synthesized bifunctional salts with at least one pharmaceutically active ion in obtaining a controlled release, controlled delivery, and biological impact on the pathogenic bacteria, viruses and fungi. The ionic liquids obtained in the presented way may find applications in the treatment of wounds and infections.

Experimental and Computational Studies on the Basic Transmission Properties of Electromagnetic Waves in Softmaterial Waveguides

Conventional waveguides are usually made of metallic materials, and they are effective pathways for the transmission of electromagnetic waves. A “Softmaterial waveguide”, by contrast, is supposed to be made of dielectric material and ionic fluids. In this work, by means of both experiment and computational simulation we examined one kind of softmaterial waveguide, which has the configuration of ionic fluids filled in and out of a dielectric tube. We investigated configurations with varied parameters, i.e., tube thickness from 0.2 mm to 5.0 mm, tube length of 2.0–12.0 cm, ionic concentration covering 4 orders of magnitude from 0.0002–2.0 mol/L, frequency of 10 Hz to 100 MHz for sine wave excitations, pulse duration of 5 ns to 100 ms for excitation pulses. We also mimicked the myelin sheath structure in myelinated axons in simulation. Both experimental and simulation results consistently showed a clear confinement effect for the energy flux of transmitting electromagnetic waves inside the dielectric tube, strongly supporting the model of softmaterail waveguide. The results revealed that the softmaterial waveguide had a low-pass nature, where the intensity of transmitted signals saturated at a duration of 10–100 μs for pulses, or cut off at frequency of 10–100 kHz for sine waves. And, the transmission efficiency increased with the thickness of the dielectric layer, as well as ion concentration of the solution. The results may help for a better understanding various electrical communication behaviors observed in biosystems, where a natural lipid membrane with bilateral fluids was suggested as the efficient pathway for pulsed neural impulses in a way similar to soliton-like electromagnetic pulses transmitting in a softmaterial waveguide.