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The low-pressure gas in the vacuum plume produced by the chemical thrusters contaminates the spacecraft when adsorbed on the low-temperature surface. To provide theoretical support for further research on gaseous plume pollutants, the adsorption isotherms of low-pressure H2O were measured by a quartz crystal microbalance (QCM) at temperatures ranging from 233 to 273 K. The measured isotherms are similar to the type-I and type-II isotherms and have been correlated by various models (e.g., the Langmuir, Dubinin-Radushkevich, Brunauer-Emmett-Teller (BET), and universal models). It shows that the universal model has a great advantage in predicting the adsorption at a specific temperature point in our study. To estimate the adsorption at the continuous temperature range, the critical parameters of the multi-Langmuir model were expressed in semiempirical formulas. Since the normalized isotherms of H2O at different temperatures converge well, a simplified multi-Langmuir (SML) model was proposed. The experimental results at the temperature and pressure ranges we explored are consistent with the results predicted by the SML model, suggesting that the SML model is more suitable and convenient to predict the low-pressure adsorption of H2O for a continuous low-temperature range. Moreover, the low-pressure adsorption behaviors of H2O and CO2 on the low-temperature surface are compared and discussed.

Plasmon resonance energy transfer (PRET) in hybrid plasmonic-molecular systems has a broad range of applications from catalysis to analytical/biochemical/biophysical imaging and sensing. Herein, we experimentally and theoretically probed the influence of the distance (d) between the plasmonic nanoparticle and the conjugated molecules on the PRET efficiency (ηPRET) using two PRET systems, which involved tetramethylrhodamine (TAMRA) or Cy3 molecules as acceptors and single spherical gold nanoparticles (AuNPs) as donors. The double-stranded DNA (dsDNA) sequences precisely adjusted within 12.0 nm were utilized as a donor-acceptor spacer. Then, the ηPRET of the two systems under varied d-values was available from the reduction of the scattering intensity of AuNPs. Both experimental and quasi-static approximation data show that ηPRET displays a d-value-dependent decay function. This study would provide new insights into optimal PRET-based chemical/biochemical sensors.

Biofunctionalized nanomaterials have been extensively studied as a tool for a wide range of applications in biomedical fields. Despite many existing strategies to conjugate proteins to colloidal pa...

This paper deals with the densities of aqueous solutions of N-methylacetamide (NMA) in the range of concentrations x (starting from 0.0095 to 0.699) at T = 278.15, 288.15, 298.15, 308.15, 323.15, a...

Polydopamine (PDA) has a wide range of applications in biomedicine due to its high biocompatibility and surface chemistry and because of the presence of many functional groups in it, enabling further modification. As a catechol-like material, it has chelation properties for various types of metal ions, including iron. Here, we developed a procedure that uses PDA as a template to grow iron structures β-FeOOH directly on its surface. The innovative approach of this work relies on that these structures can be obtained in neutral conditions and selective iron-ion source. The influence of iron-ion source, environment, and solution concentration on the structure and amount of resulting material is presented. The growth has been characterized over time, taking into account their photothermal, magnetic, and colloidal stability properties. Moreover, we shed new light on understanding the interaction of PDA with iron ions for the growth of iron-based nanostructure on polydopamine particles. Finally, we predict that PDA@β-FeOOH nanoparticles could be a promising material in dual therapy merging photothermal therapy (PTT) treatment and magnetic resonance imaging (MRI) contrast agents.

This work determined isothermal work function changes as a function of oxygen activity, p(O2), for the Fe-O2 system within the stability range of the FeO phase at elevated temperatures (948 K – 122...

Hydrogen sensors are of tremendous technological demand, which requires more selective and responsive sensors over a wide concentration range (ppm to percentage). Here, we report a giant enhancemen...

We developed a synthetic strategy to form cyclodextrin-based intrananogap particles (CIPs) with a well-defined ∼1 nm interior gap in a high yield (∼97%), and were able to incorporate 10 different Raman dyes inside the gap using the cyclodextrin-based host-guest chemistry, leading to strong, reproducible, and highly multiplexable surface-enhanced Raman scattering (SERS) signals. The average SERS enhancement factor (EF) for CIPs was 3.0 × 109 with a very narrow distribution of the EFs that range from 9.5 × 108 to 9.5 × 109 for ∼95% of the measured particles. Remarkably, 10 different Raman dyes can be loaded within the nanogap of CIPs, and 6 different Raman dye-loaded CIPs with little spectral overlaps were distinctly detected for cancer cell imaging applications with a single excitation source. Our synthetic strategy provides new platforms in precisely forming plasmonic nanogap structures with all key features for widespread use of SERS including strong signal intensity, reliability in quantification of signal and multiplexing capability.

Deep-sea hydrothermal vents are a source of Fe to the ocean with potential impact on surface ocean primary productivity. Long-range horizontal transport of hydrothermally derived Fe in suspended pa...

Colloidal particles are mostly charged in an aqueous solution because of the protonation or deprotonation of ionizable groups on the surface. The surface charge density reflects a complex interplay of ion distributions within the electric double layer and the surface reaction equilibrium. In this work, we present a coarse-grained model to describe the charge regulation of various colloidal systems by an explicit consideration of the inhomogeneous ion distributions and surface reactions. With the primitive model for aqueous solutions and equilibrium constants for surface reactions as the inputs, the theoretical model is able to make quantitative predictions of the surface-charge densities and zeta potentials for diverse colloidal particles over a wide range of pH and ionic conditions. By accounting for the ionic size effects and electrostatic correlations, our model is applicable to systems with multivalent ions that exhibit charge inversion and provides a faithful description of the interfacial properties without evoking the empirical Stern capacitance or specific ion adsorptions.

Dynamics of the reaction of hydrogen sulfide, H2S(X1A1), with ground-state atomic carbon, C(3Pj), was investigated over the interpolated ab initio-based potential energy surface using the quasi-classical trajectory (QCT) simulation. The reaction probability and total reactive cross section were calculated at a wide range of collision energies from 2.6 to 78.8 kJ mol-1. The total rate constant of the reaction was calculated using collision theory. The energy distribution for the formation of main products (HCS/HSC + H) was also investigated. At 44.6 kJ mol-1 collision energy, approximately 39.5 and 12% of the total available energy were released to translational and rotational energy levels of the HCS + H products, respectively, while for HSC + H, these values were found to be about 61.6 and 25.7% of the total available energy. The remaining total energy was deposited in the vibrational modes of the products.

The exciton migration mechanism in organic photovoltaic devices is still an ambiguity owing to the insufficient understanding of molecular arrangement on a microscopic scale. Herein, we reveal the relationship between the molecular stacking modes and exciton migration for a representative fused-ring electron acceptor, namely, ITIC. The precise molecular stacking patterns are extracted, and directional Coulombic couplings are calculated based on the information of a single-crystal structure, which proves the anisotropic character for exciton motion. The theoretical analysis results indicate ultrafast exciton migration along the head-to-tail stacking directions with maximum migration length of 330 nm in the finite lifetime of 1 ns. Experimentally, the exciton diffusion length is determined to be 183 nm by exciton-exciton annihilation measurement. This work reveals head-to-tail type intermolecular stacking induces strong anisotropic Coulombic coupling, leading to the ultrafast and long-range exciton migration in nonfullerene systems.

Control over the surface roughness of colloidal particles offers exciting opportunities to tailor the properties and the processing of a broad range of soft matter systems. Moreover, identifying surface roughness as a design parameter reveals the possibility to connect seemingly distinct phenomena and materials via the role played by roughness effects. In this feature article, we concisely review some approaches to synthesize and characterize rough colloidal particles, with a focus on model spherical colloids. We then discuss the impact that surface roughness has on both the high-shear rheology of dense suspensions and the stabilization of Pickering emulsions. Commenting on developments of our own research, we aim to offer an original perspective for a property-oriented development of colloidal particles that transcends classical divisions between materials and processes toward innovative solutions.

A wide range of material properties can be accessed by tuning the size and shape of nanocrystals (NCs). Cations incorporated into the crystal lattice of indium oxide (In2O3) NCs as dopants have bee...

The wealth of structural phases seen in the rare-earth disilicate compounds promises an equally rich range of interesting magnetic properties. We report on the crystal growth by the optical floating zone method of members of the rare-earth disilicate family, R2Si2O7 (with R = Er, Ho, and Tm). Through a systematic study, we have optimized the growth conditions for Er2Si2O7. We have grown, for the first time using the floating zone method, crystal boules of Ho2Si2O7 and Tm2Si2O7 compounds. We show that the difficulties encountered in the synthesis of polycrystalline and single crystal samples are due to the similar thermal stability ranges of different rareearth silicate compounds in the temperature−composition phase diagrams of the R-Si-O systems. The addition of a small amount of SiO2 excess allowed the amount of impurity phases present in the powder samples to be minimized. The phase composition analysis of the powder X-ray diffraction data collected on the as-grown boules revealed that they were of single phase, except in the case of thulium disilicate, which was comprised of two phases. All growths resulted in multigrain boules, from which sizable single crystals could be isolated. The optimum conditions used for the synthesis and crystal growth of polycrystalline and single crystal R2Si2O7 materials are reported. Specific heat measurements of erbium and thulium disilicate compounds confirm an antiferromagnetic phase transition below TN = 1.8 K for D-type Er2Si2O7 and a Schottky anomaly centered around 3.5 K in C-type Tm2Si2O7, with an upturn in C(T)/T below 1 K suggesting the onset of short-range magnetic correlations. Magnetic susceptibility data of E-type Ho2Si2O7 reveals an antiferromagnetic ordering of the Ho spins below TN = 2.3 K.

In this work we investigate the relationship between metal-enhanced fluorescence (MEF) and fluorophore-induced plasmonic current (PC). This is accomplished through measurements of both radiative emission (MEF) and direct electrical current generation between discrete metal nanoparticles upon fluorophore excitation (PC). We have conducted these measurements on silver and gold nanoparticle island films, over a range of nanoparticle sizes and spacing in the films. We have observed an inverse relationship in the magnitude of MEF with PC, where larger and more closely spaced metal nanoparticles are found to result in increased PC and subsequently a decreased MEF. We attribute this effect to the relatively high capacitance and low charging energy of large and closely spaced particles, providing an outlet for plasmon relaxation in the form of electron flow and electrical current generation. These results are significant as they open potential for controlling for and the optimization of both MEF and PC.

Single crystals of Nb2PdxSe5 have been grown covering a broad range of palladium stoichiometries from x = 0.68–0.95 (Pd2 occupancies of 0.36 and 0.90, respectively). Miscibility gaps in the Pd stoi...

A blend of poly(3-hexylthiophene) (P3HT) and poly(n-hexyl isocyanate-block-2-vinylpyridine) (PHIC-b-P2VP) in a common solvent shows the formation of long-range (micrometer-scale) nanowires of P3HT ...

Current combustion technologies used for energy generation are incapable of burning a wide range of liquid fuels without sacrificing combustion efficiency or requiring system modifications. In this...

Quantifying vibronic couplings in molecular excited states is crucial for the elucidation of a broad range of photophysical phenomena. In this study, we compare different theoretical approaches for the calculation of reorganization energy, a measure of vibronic coupling strength, and provide a rigorous derivation to show that molecular transition density characterizing electron-hole excitation could be used to quantify the magnitude of reorganization energy. The theory enables a descriptor based on molecular-orbital coefficients and atomic transition densities to quantify the magnitude of reorganization energies in molecular excited states. Applying the approach to low-lying excited states of polyacenes, we demonstrate that transition density distribution explains the difference in the magnitude of the reorganization energy of different excited states. Furthermore, to clarify the applicability of the transition density descriptor in molecular design for small-reorganization energy molecules, we investigate a broad range of molecular chromophores to show the effectiveness of the proposed theory. With this perspective on the relationship between reorganization energy and transition density, we successfully provide a quantitative rule to identify π-conjugated systems with small reorganization energy in the excited state, which should be useful for the development of novel optoelectronic materials.

Oxide-based transparent p–n homojunctions are desirable for the development of transparent electronics. However, most oxide semiconductors are intrinsically n-type and to achieve p-type wide-gap ox...

Essentially all research done to date on the mechanical properties of polymeric semiconductors (e.g., for organic photovoltaics and thin-film transistors) has had the underlying goal of increasing ...

The excited-state dynamics of chromophores in complex environments determine a range of vital biological and energy capture processes. Time-resolved, multidimensional optical spectroscopies provide a key tool to investigate these processes. Although theory has the potential to decode these spectra in terms of the electronic and atomistic dynamics, the need for large numbers of excited-state electronic structure calculations severely limits first-principles predictions of multidimensional optical spectra for chromophores in the condensed phase. Here, we leverage the locality of chromophore excitations to develop machine learning models to predict the excited-state energy gap of chromophores in complex environments for efficiently constructing linear and multidimensional optical spectra. By analyzing the performance of these models, which span a hierarchy of physical approximations, across a range of chromophore-environment interaction strengths, we provide strategies for the construction of machine learning models that greatly accelerate the calculation of multidimensional optical spectra from first principles.

Triplet excited state chemistry has enabled a range of important organic transformations by accessing reaction pathways inaccessible to photoredox chemistry. Such photoreactions are triggered by triplet photosensitizers, which absorb visible-light photons and transfer the energy to the substrate or to a co-catalyst through triplet-triplet energy transfer (TT EnT). The most popular triplet photosensitizers, metal complexes and organic chromophores, have proven useful in a range of pericyclic reactions, bond dissociations, and isomerizations, but they have several characteristics related to their chemical and electronic structure that limit their selectivity, energy efficiency, and sustainability. This Perspective describes some ways that colloidal quantum dots (QDs) address the limitations of molecular photocatalysts for TT EnT-driven organic transformations. These sub-5-nm particles have the large catalytic surface area and electronic/optical tunability of homogeneous catalysts, and the easy separation and surface templating effects of heterogeneous catalysts. Their optical and electronic properties, small singlet-triplet energy splitting, narrow emission line widths, and high photostability enhance their performance as triplet photosensitizers. This Perspective describes these advantages in the context of published and ongoing investigations of TT EnT-driven reactions, and then highlights the advantages and challenges associated with using related emerging materials, specifically lead halide perovskite QDs and quasi-2D nanoplatelets, as photocatalysts for triplet excited state chemistry.

Metastable γ-Ga2O3 nanocrystals have gained growing interest for a broad range of technological applications. However, a precise description of their atomic structure and changes thereof during the...

We explore the range of applicability of the nuclear ensemble method (NEM) for quantitative simulations of absorption spectra and their temperature variations. We formulate a “good practice” for th...

The ability to control excitons in semiconductors underlies numerous proposed applications, from excitonic circuits to energy transport. Two dimensional (2D) semiconductors are particularly promising for room-temperature applications due to their large exciton binding energy and enormous stretchability. Although the strain-induced static exciton flux has been observed in predetermined structures, dynamic control of exciton flux represents an outstanding challenge. Here, we introduce a method to tune the bandgap of suspended 2D semiconductors by applying a local strain gradient with a nanoscale tip. This strain allows us to locally and reversibly shift the exciton energy and to steer the exciton flux over micrometer-scale distances. We anticipate that our result not only marks an important experimental tool but will also open a broad range of new applications from information processing to energy conversion., United States. Army Research Office. Multidisciplinary University Research Initiative (Grant W911NF-18-1-0431), National Science Foundation (U.S.). Emerging Frontiers & Multidisciplinary Activities. Quantum Optoelectronics, Magnetoelectronics and Plasmonics in 2-Dimensional Materials Heterostructures (Award Abstract 1542863), CREST (Grant JPMJCR15F3)

The bias and temperature dependence of both dark and photoinduced currents in carbon-based molecular junctions were examined over a wide range of oligomeric layer thickness (d) values from 4 to 60 ...

Droplet impact on arbitrary inclined surfaces is of great interest for applications such as antifreezing, self-cleaning, and anti-infection. Research has been focused on texturing the surfaces to alter the contact time and rebouncing angle upon droplet impact. In this paper, using propagating surface acoustic waves (SAWs) along the inclined surfaces, we present a novel technique to modify and control key droplet impact parameters, such as impact regime, contact time, and rebouncing direction. A high-fidelity finite volume method was developed to explore the mechanisms of droplet impact on the inclined surfaces assisted by SAWs. Numerical results revealed that applying SAWs modifies the energy budget inside the liquid medium, leading to different impact behaviors. We then systematically investigated the effects of inclination angle, droplet impact velocity, SAW propagation direction, and applied SAW power on the impact dynamics and showed that by using SAWs, droplet impact on the nontextured hydrophobic and inclined surface is effectively changed from deposition to complete rebound. Moreover, the maximum contact time reduction up to ∼50% can be achieved, along with an alteration of droplet spreading and movement along the inclined surfaces. Finally, we showed that the rebouncing angle along the inclined surface could be adjusted within a wide range.

Inertial microfluidics is a promising approach for particle separation because of the superior advantages of high throughput, simplicity, precise manipulation, and low cost. However, the current obstacle of inertial microfluidics in biological applications is the broad size distribution of biological microparticles. Most devices only work well for a narrow range of particle sizes. For focusing and separating a new set of particles, troublesome and time-consuming design, fabrication, testing, and optimization procedures are needed. As such, it is of particular interest to design a microfluidic device that can be tuned and adjusted to separate particles of various sizes. This paper reports on the proof of concept for a stretchable microfluidic device that can control the length via a stretching platform. By changing the channel dimensions, the device can be adapted to different particle sizes and flow rate ratios. We successfully demonstrate this approach with the separation of a mixture of 10 and 15 μm particles. Stretching the device significantly improves the focusing and separation efficiency of the specific particle sizes. We also show that there is an optimum stretching length, which results in the best separation performance. The proof of concept reported here is the first step toward designing stretchable inertial microfluidic devices that can be implemented for a wide range of biological and medical applications.

Designer nanoparticles with complex morphologies are of growing interest for a wide range of applications, but making them rationally and scalably remains challenging. Here, we demonstrate a retros...

Heterometallic metal organic frameworks (MOF) have attracted huge interest for a wide range of applications including gas storage, separation, and catalysis owing to their tunable electronic and ma...

The effect of deformation on the droplet contact charge electrophoresis (CCEP) was investigated for consistent droplet movement control. Through systematic experiments and numerical simulations, it has been found that overcharging by deformation is up to about 130% of the sphere and is mainly driven by the concentration of the electric field near the tip of the droplet rather than an increase in the surface area. Dimensional analysis revealed a consistent droplet CCEP motion with the electric capillary number range of 0.01-0.09. We also found that the dimensionless droplet charge follows a universal curve proportional to the electric capillary number, regardless of the droplet size, and the weak dependence on the droplet size shown in the experimental results is due to hydrodynamic effects, not electrostatic ones. Changes in droplet velocity distribution with droplet size and the electric capillary number were also investigated. Using the perfect conductor theory and Stokes law, we derived an analytical relationship between the droplet center velocity and the electric capillary number and analyzed the experimental results based on this relationship. This study implies that if proper hydrodynamic correction is applied, the droplet CCEP and its deformation effect can be explained by a perfect conductor theory.

Localized surface plasmon resonance (LSPR) modulation appearing in the near-infrared range in doped semiconductor nanocrystals enriches electrochromic performance. Although crystalline and shape anisotropies influence LSPR spectra, study of their impact on electrochromic modulation are lacking. Here, we study how crystalline anisotropy in hexagonal cesium-doped tungsten oxide nanorods and nanoplatelets affects essential metrics of electrochromic modulation—coloration efficiency (CE) and volumetric capacity—using different sizes of electrolyte cations (tetrabutylammonium, sodium, and lithium) as structurally sensitive electrochemical probes. Nanorod films show higher CE than nanoplatelets in all of electrolytes owing to low effective mass along the crystalline c-axis. When using sodium cations, which diffuse through one-dimensional hexagonal tunnels, electrochemical capacity is significantly greater for platelets than for nanorods. This difference is explained by the hexagonal tunnel sites being more accessible in platelets than in nanorods. Our work sheds light on the role of shape and crystalline anisotropy on charge capacity and CE both of which contribute to overall modulation.

A time-dependent postextraction differential acceleration (PEDA) potential was used to temporally focus increasingly heavy ions in a stigmatic imaging mass spectrometer, allowing them to be imaged with high mass and spatial resolutions over a broad mass-to-charge (m/z) range. By applying a linearly rising potential to the ion extraction electrode, sequential m/z ratios were subjected to a changing electric field, allowing their foci to coincide at the detector. Using this approach, at least 75% of the maximum mass resolution was obtained over a 300–600 Da range when the ion microscope was focused around 450 Da, representing more than a 10-fold increase over the conventional single-field PEDA method.

Long-range dopant-dopant coupling in graphene nanoribbon (GNR) has been under intensive study for a very long time. Using a newly developed dopant central insertion scheme (DCIS), we performed first-principles study on multiple H, O, OH, and FeN

We present an experimental and theoretical investigation of the photon interaction with formic acid in the vacuum-ultraviolet energy range. The absolute absorption cross sections and ionization efficiencies were measured in the 11.2-21.4 and 13.5-21.4 eV ranges, respectively, using a double-ion chamber technique. Photoionization and neutral-decay cross sections were derived from these results. From the present ionization cross sections and previously reported ionic dissociative branching ratios, the partial cross sections for dissociating processes were obtained. Theoretically, the photoionization cross sections and the asymmetry parameters of the photoelectron angular distributions for ionization out of the six outermost valence orbitals (10

All-polymer nanocomposites, in which soft, polymer-based nanoparticles are dispersed in the polymer matrix, have received great interest lately due to their potential use in a range of applications...

openaire: EC/H2020/720964/EU//npSCOPE Two-dimensional (2D) materials with nanometer-size holes are promising systems for DNA sequencing, water purification, and molecule selection/separation. However, controllable creation of holes with uniform sizes and shapes is still a challenge, especially when the 2D material consists of several atomic layers as, e.g., MoS2, the archetypical transition metal dichalcogenide. We use analytical potential molecular dynamics simulations to study the response of 2D MoS2 to cluster irradiation. We model both freestanding and supported sheets and assess the amount of damage created in MoS2 by the impacts of noble gas clusters in a wide range of cluster energies and incident angles. We show that cluster irradiation can be used to produce uniform holes in 2D MoS2 with the diameter being dependent on cluster size and energy. Energetic clusters can also be used to displace sulfur atoms preferentially from either top or bottom layers of S atoms in MoS2 and also clean the surface of MoS2 sheets from adsorbents. Our results for MoS2, which should be relevant to other 2D transition metal dichalcogenides, suggest new routes toward cluster beam engineering of devices based on 2D inorganic materials.

Additive manufacturing (AM) is a promising technique to rapidly produce polymeric materials into complex 3-dimensional (3D) geometries. While AM is widespread and relevant for a range of applicatio...

This work reports a radical-enhanced atomic layer deposition (REALD) process using WH2(Cp)2–O*–H* reaction cycles (Cp = cyclopentadienyl group) to grow WO3–x films with a wide range of tunable oxyg...

We report for the first time an excited-state (EX) tuning approach to accurately predict vertical emissions (VEs) based on the study of 36 medium and large organic molecules (∼66 heavy atoms) used ...

Hybridizing the triboelectric and electromagnetic generator shows a great potential in harvesting the water wave energy in a wide frequency range from low to high upon water wave motions. The tribo...

Local hybrid functionals are evaluated in linear-response TDDFT computations for a broad range of excited-state properties including excited-state structures, fluorescence, and phosphorescence energies and the vibronic shape of absorption and phosphorescence spectra. Computation of such properties requires the optimization of excited states, which is facilitated by the recent implementation of excited-state gradients for local hybrid functionals in the TURBOMOLE program (Grotjahn, R.; Furche, F.; Kaupp, M.

The n-type organic semiconductor, β-phase single crystalline dichloro naphthalene diimide, Cl2–NDI, is investigated in a broad frequency range via optical spectroscopy. The temperature-dependent ab...

Polyhydroxyalkanoates (PHAs) have a wide range of applicability due to their biodegradable and biocompatible characteristics. This makes them suitable for their commercialization as an alternative ...

Luminescent metal–organic frameworks (LMOFs) have received considerable attention in recent years because of their enormous potential for a broad range of applications in chemical sensing, energy-e...

The development of room-temperature sensing devices for detecting small concentrations of molecular species is imperative for a wide range of low-power sensor applications. We demonstrate a room-temperature, highly sensitive, selective, stable, and reversible chemical sensor based on a monolayer of the transition-metal dichalcogenide Re0.5Nb0.5S2. The sensing device exhibits a thickness-dependent carrier type, and upon exposure to NO2 molecules, its electrical resistance considerably increases or decreases depending on the layer number. The sensor is selective to NO2 with only minimal response to other gases such as NH3, CH2O, and CO2. In the presence of humidity, not only are the sensing properties not deteriorated but also the monolayer sensor shows complete reversibility with fast recovery at room temperature. We present a theoretical analysis of the sensing platform and identify the atomically sensitive transduction mechanism.

Polymers of intrinsic microporosity (PIMs) have exceptional gas separation performance for a broad range of applications. However, PIMs are highly susceptible to physical aging, which drastically r...

Two-dimensional (2D) materials, such as graphene (GE), hold great potential to be employed as the fundamental building blocks of novel nanofluidic devices for a wide range of applications. Recent advances in experimental techniques are materializing such prospects by enabling the assembly of 2D material-based fluidic channels with heights as small as few Angstroms. Here, we conduct molecular dynamics simulations to probe the effect of the relative misalignment between the walls of the GE fluidic channel with Angstroms height on the resistance to water transport through the channel. Two types of misalignments are studied, namely, translational and rotational misalignments. Our results show that the relative misalignment of the GE lattices can lead to a substantial reduction in the friction between water and the channel walls. Moreover, a dependence of the friction on the degree of misalignment and flow direction is found for the cases with translational misalignment. In contrast, the resistance exerted by the channels with rotational misalignment is found to be independent of the rotation angle (θ) for 0° < θ < 60° but always lower than the perfectly aligned case. We associate such lowering of the resistance to water transport to the corrugation and the anisotropy in the corresponding potential energy landscape associated with each degree of misalignment. The findings, therefore, point to an unprecedented possibility of significantly enhancing the water transport in Angstroms height GE channels by engineering the misalignments of the GE channel walls.