Showing papers by "Jyh-Ping Hsu published in 2019"
TL;DR: The modeling reveals that for a highly charged nanochannel, a significant increase in the surface charge density amplifies the ion concentration polarization effect, thus weakening the effective salinity ratio across the channel and undermining the osmotic power generated.
Abstract: Nanofluidic osmotic power, which converts a difference in salinity between brine and fresh water into electricity with nanoscale channels, has received more and more attention in recent years. It is long believed that to gain high-performance osmotic power, highly charged channel materials should be exploited so as to enhance the ion selectivity. In this paper, we report counterintuitive surface-charge-density-dependent osmotic power in a single funnel-shaped nanochannel (FSN), violating the previous viewpoint. For the highly charged nanochannel, the performance of osmotic power decreases with a further increase in its surface charge density. With increasing pH (surface charge density), the FSN enables a local maximum power density as high as ∼3.5 kW/m2 in a 500 mM/1 mM KCl gradient. This observation is strongly supported by our rigorous model where the equilibrium chemical reaction between functional carboxylate ion groups on the channel wall and protons is taken into account. The modeling reveals that for a highly charged nanochannel, a significant increase in the surface charge density amplifies the ion concentration polarization effect, thus weakening the effective salinity ratio across the channel and undermining the osmotic power generated.
67 citations
TL;DR: An ultrathin ionomer membrane as an artificial solid-electrolyte interphase filter that minimizes parasitic reactions and enables stable dendrite-free lithium plating-stripping cycles in a carbonate-based electrolyte is reported.
Abstract: High coulombic efficiency and dendrite suppression in carbonate electrolytes remain challenges to the development of high-energy lithium ion batteries containing lithium metal anodes. Here we demonstrate an ultrathin (≤100 nm) lithium-ion ionomer membrane consisting of lithium-exchanged sulfonated polyether ether ketone embedded with polyhedral oligosilsesquioxane as a coating layer on copper or lithium for achieving efficient and stable lithium plating-stripping cycles in a carbonate-based electrolyte. Operando analyses and theoretical simulation reveal the remarkable ability of the ionomer coating to enable electric field homogenization over a considerably large lithium-plating surface. The membrane coating, serving as an artificial solid-electrolyte interphase filter in minimizing parasitic reactions at the electrolyte-electrode interface, enables dendrite-free lithium plating on copper with outstanding coulombic efficiencies at room and elevated (50 °C) temperatures. The membrane coated copper demonstrates itself as a promising current collector for manufacturing high-quality pre-plated lithium thin-film anode. The authors here report an ultrathin ionomer membrane as an artificial solid-electrolyte interphase filter that minimizes parasitic reactions and enables stable dendrite-free lithium plating-stripping cycles in a carbonate-based electrolyte. The protected anodes exhibit outstanding coulombic efficiencies at room and elevated (50 °C) temperatures.
57 citations
TL;DR: In this paper, the performance of a nanochannel having a pH-regulated surface in RED is examined, focusing on the influence of the bulk salt concentration, the distribution of H +, and the nanochannels size and its shape.
46 citations
TL;DR: It is shown that manipulation of surface charge can occur without changing pH of the background electrolyte, which is especially important for applications where maintaining pH at a constant and physiological level is necessary.
Abstract: Surface charge plays a very important role in biological processes including ionic and molecular transport across a cell membrane. Placement of charges and charge patterns on walls of polymer and s...
42 citations
TL;DR: In this paper, the potential applications of biomimetic artificial nanopores in versatile fields capture much attention in the past few decades, and it is known that applying simultaneously an electric poten...
Abstract: The potential applications of biomimetic artificial nanopores in versatile fields capture much attention in the past few decades. Although it is known that applying simultaneously an electric poten...
25 citations
TL;DR: The conductance and the ion selectivity of a conical nanopore surface modified by a polyelectrolyte (PE) layer are studied through adjusting the pH, the bulk salt concentration, and the level of the applied potential bias.
19 citations
TL;DR: In this article, the authors used metal organic framework UiO-66 and NH2 to adsorb phosphoric acid from waste mixed acids from the world's largest semiconductor foundry, a synthetic HNO3 H3PO4 HAc mixture, and 85% of the HPO4 mixture.
Abstract: Streams of waste mixed acids from conventional wet etching processes contain high levels of H3PO4, which warrant recycling. This investigation is the first to use metal organic framework UiO-66 and UiO-66-NH2 to adsorb phosphoric acid from waste mixed acids from the world's largest semiconductor foundry, a synthetic HNO3 H3PO4 HAc mixture, and 85% phosphoric acid. Both UiO-66 and UiO-66-NH2 have high capacities to adsorb H3PO4 in extremely acidic solutions. The Langmuir adsorption capacities (qmax’s) of UiO-66 for waste mixed acids and a synthetic HNO3 H3PO4 HAc mixture on UiO-66 at 25 °C are 3360 and 8,510 mg-H3PO4/g, respectively, and that of 85% phosphoric acid on UiO-66 is 4,790 mg-H3PO4/g. The qmax of UiO-66-NH2 for phosphoric acid from 25% to 75% waste mixed acids is 4550 mg-H3PO4/g, which exceeds that of UiO-66. The corresponding P:Zr ratio for adsorbed MOF is in the range 6.2‒13.5, suggesting that the tested MOF crystals are super-adsorbents of phosphoric acid under extremely acidic conditions.
18 citations
TL;DR: It is shown that the ICR behavior of a branched nanochannel can be modulated satisfactorily by filling highly charged PE and the solution pH, and how the region(s) of a Nanochannel is filled with PE examined.
17 citations
TL;DR: In this paper, transition metal carbide and transition metal nitride coatings are adopted to protect metallic bipolar plates in the cathodic environment of proton exchange membrane fuel cell (PEMFC) and first-principle calculations are conducted using CrN, TiC and TiN as examples.
17 citations
TL;DR: It is shown that through adjusting the base opening radius and the surface curvature of a nanochannel, its ICR behavior can be tuned effectively and provide necessary information for designing relevant devices.
Abstract: Bioinspired, artificial functional nanochannels for intelligent molecular and ionic transport control have versatile potential applications in nanofluidics, energy conversion, and controlled drug release. To simulate the gating and rectification functions of biological ion channels, we model the electrokinetic ion transport phenomenon in an asymmetric double-gated nanochannel having a pH-regulated, zwitterionic surface. Taking account of the effect of electroosmotic flow (EOF), the conductance of the nanochannel and its ion current rectification (ICR) behavior are investigated and the associated mechanisms interpreted. In particular, the influences of the solution pH, the bulk salt concentration, and the base opening radius and the surface curvature of the nanochannel on these behaviors are examined. We show that through adjusting the base opening radius and the surface curvature of a nanochannel, its ICR behavior can be tuned effectively. In addition to proposing underlying mechanisms for the phenomena observed, the results gathered in this study also provide necessary information for designing relevant devices.
11 citations
01 Mar 2019
TL;DR: It is shown that the ICR ratio for the case where pH is lower than the isoelectric point (IEP) of the nanopore surface is different both quantitatively and qualitatively from that for the Case where pH > IEP, and that the performance of ion separation can be improved by tuning the fluid viscosity.
Abstract: Extending previous electrokinetic analyses based on a Newtonian fluid to power-law fluids, we investigate the behaviors of the ion current rectification (ICR) and the ion selectivity S of a conical nanopore having a pH-regulated surface. The bulk salt concentration Cbulk, the solution pH, and the power-law index n are examined in detail for their influences on these behaviors. We show that the ICR ratio for the case where pH is lower than the isoelectric point (IEP) of the nanopore surface is different both quantitatively and qualitatively from that for the case where pH > IEP. The relative magnitude of the ICR ratio as n varies depends largely on the level of Cbulk. In contrast, S (pH IEP), where | S | decreases with increasing Cbulk and/or decreasing n. In addition, S is very sensitive to n, for example, a decrease of n from 1.0 (Newtonian fluid) to 0.9 (pseudoplastic fluid) can yield a 245% increase in S at Cbulk = 100 mM. Implying that the performance of ion separation can be improved by tuning the fluid viscosity. Mechanisms are proposed for explaining the observed behaviors in the ICR ratio.
Journal Article•
TL;DR: In this article, the role of applied pH, electric potential gradients, and the grafting density of polyelectrolyte chains played in the performance of ion current rectification of a cylindrical nanopore.
Abstract: The potential applications of biomimetic artificial nanopores in versatile fields capture much attention in the past few decades. Although it is known that applying simultaneously an electric potential and a pH gradient can improve appreciably the performance of the ion current rectification of a nanopore, the underlying mechanisms are still not understood comprehensively. Adopting a cylindrical nanopore functionalized with homogeneous (single) pH-tunable polyelectrolyte brushes, these mechanisms are discussed in this study. In particular, the roles that the applied pH, electric potential gradients, and the grafting density of the polyelectrolyte chains played are examined in detail. We show that homogeneously modified nanopores can also exhibit ion current rectification behavior that is only seen in nanopores functionalized with two or more kinds of polyelectrolytes. Several interesting results are also observed. For example, if the applied pH gradient is sufficiently strong, the preferential direction of the ionic current can be tuned by the level of the applied electric potential; if it is sufficiently weak, an increase in the grafting density of the polyelectrolyte chains can make that preferential direction reversed. These results provide not only explanation for the behaviors associated with the transport of ions in nanopores but also a reference for designing relevant devices.
TL;DR: The ability of CE to analyze the charge variation during guided differentiation of iPSCs with drug carriers is shown, and the CE method can be promising in evaluating the formation of matured neurons from iPSC.
Abstract: The capillary electrophoresis (CE) technique has been widely used to improve our understanding of biochemistry, and has become one of the best choices to address critical issues in neurobiology. In this study, doubled-emulsified solid lipid nanoparticles (DESLNs) grafted with PPFLMLLKGSTR (PM12) were fabricated to carry retinoic acid (RnA) and nerve growth factor (NGF), and to differentiate induced pluripotent stem cells (iPSCs) into nerve cells. The membrane charge of differentiated neuron-like cells was investigated using a high-performance CE. We found that surface PM12 enhanced the uptake of RnA- and NGF-loaded DESLNs (RnA-NGF-DESLNs) via strong interaction with cellular integrin α3β1 and α5β1, as evidenced by immunofluorescence assay. Further, highly expressed βIII-tubulin, a typical neuronal marker, suggested the improved neurite outgrowth of differentiating iPSCs. The enhanced electrophoretic mobility also demonstrated the reproduction of neurons from iPSCs treated with various kinds of DESLNs. After longer induction, the major CE elution peak appeared in shorter time, evidencing an increase in electrostatic potential (more negative) and effective neuronal regeneration. Induction with PM12-RnA-NGF-DESLNs to differentiate iPSCs resulted in the largest electrophoretic mobility (more negative), zeta potential and membrane charge. Thus, this study showed the ability of CE to analyze the charge variation during guided differentiation of iPSCs with drug carriers, and the CE method can be promising in evaluating the formation of matured neurons from iPSCs.