Dual Pores Research Articles

Tailored Cellulose Gel Electrolytes with Dual Pores, Aligned Channels, and Dendrite Mitigation for Improved K/Zn Dual-Ion Battery

Tailored Cellulose Gel Electrolytes with Dual Pores, Aligned Channels, and Dendrite Mitigation for Improved K/Zn Dual-Ion Battery

Paradigm for Determining the Optimal Ultradeep and Super‐thick Saline Aquifer for High‐TDS Mine Water Geological Storage

AbstractSaline aquifers are the most popular waste and CO2 injection and storage reservoirs worldwide. This project proposes that several optimal injection positions should be investigated as hydraulic pressure‐focused positions, in order to relieve the high demands of pump performance. The comprehensive indices (Fi) representing the injectivity of different burial depths were obtained by using information entropy, based on the mercury injection experimental data of 13 rock samples. The results demonstrated that the burial depths of No. 4, No. 1 and No. 2 in the Liujiagou Formation were the most suitable positions for hydraulic focused injection, which means the upper 30 m thickness could be regarded as the hydraulic focused range in the saline aquifer with an average thickness of 400 m. In addition, some laboratory experiments and in situ tests were carried out for the purpose of certifying and analyzing results, including SEM, XRD, brittleness index and logging. The results suggested that the rock samples at the No. 4, No. 1 and No. 2 burial depth ranges have loose microstructure, weak cementation, as well as dual pores and fractures. The lithology is mainly quartz and feldspar, but the clay mineral content is high (10%–25%), which is positive for dissolution. The lithology is suitable for hydraulic fracturing to form extended cracks and micro‐fissures during high‐TDS (total dissolved solids) mine water injection, because of the high brittleness index. Finally, a theoretical and technical framework for high‐TDS mine water injection was established, based on operating pilot engineering. Some theoretical defects and drawbacks learned from the field practices were summarized and solutions proposed. The research in this study could provide guidance and a paradigm for the inexpensive treatment of high‐TDS mine water by injection and storage.

Large scalable, anti-ultraviolet, strong cellulose film with well-defined dual-pores for longtime daytime radiative cooling

Passive daytime radiative cooling technology, which reflects sunlight and emits thermal radiation simultaneously, shows great potential in releasing global warming and energy consumption. Particularly, cellulosic cooling materials, with the advantages of high infrared emissivity, eco-friendly, and easy processing, have gained great attention. However, the poor solar reflectance and the poor durability related to UV and mechanical properties still limited its broad applications. In this work, we developed a novel cellulose composite film (CCF) with a well-defined, hierarchical micro/nanostructure via a rational solvent-induced phase separation technology for efficient and longtime daytime radiative cooling. TiO2@PT synthesized via facile ball milling process was used to serve as a dual functional modifier, which can improve the optical, mechanical properties, and anti-UV function of the cellulose-based daytime radiative cooler. Benefiting from the hierarchical dual pores, formed tough interface, and assembled anti-UV functional network, the as-prepared CCF displayed ultrahigh solar reflectance of 97.6 % and enhanced Young's modulus and tensile strength increase by 13 and 4.4 times, respectively. Most importantly, the solar reflectance of CCF is maintained constant after continuous UV tests for 720 h. The work provides a general strategy to simultaneously enhance both the mechanical stability and the UV durability of polymer-based PDRC materials toward large-scale applications.

4-Cyanophenol herbicide sensor using multi-walled carbon nanotube embedded dual-microporous polypyrrole nanoparticles as metal-free and environmentally friendly hybrid electrode.

A highly sensitive 4-cyanophenol (4-CP) sensor was fabricated using multi-walled carbon nanotube (MWCNT)-embedded dual-microporous polypyrrole nanoparticle-modified screen-printed carbon electrodes (SPCE/DMPPy/MWCNT). The well-defined dual pores of DMPPy and MWCNT (~ 0.53 and ~ 0.65nm) acted as good analyte absorption agents (shortening the ion diffusion path) and conducting agents (reducing the internal electron-transfer resistance). This enhanced electrical conductivity resulted in the improved electro-oxidation of 4-CP. A higher sensitivity (19.0 μA μM-1cm-2) and lower limit of detection (0.8nM) were achievedwith a wide detection range of 0.001-400µM (R2 = 0.9988). The proposed sensor exhibited excellent recovery of 4-CP in real-world samples. Therefore, the SPCE/DMPPy/MWCNT sensor is regardedhighly suitable for rapidly detecting 4-CP.

Direct Construction of 2D Conductive Metal-Organic Frameworks from a Nonplanar Ligand: In Situ Scholl Reaction and Topological Modulation.

Two-dimensional conductive metal-organic frameworks (2D c-MOFs) are an emerging class of promising porous materials with high crystallinity, tunable structures, and diverse functions. However, the limited topologies and difficulties in synthesizing suitable organic linkers remain a great challenge for 2D c-MOFs synthesis and applications. Herein, two layered 2D c-MOF polymorphs with either a rhombus structure (sql-TBA-MOF) or kagome structure (kgm-TBA-MOF) were directly constructed via in situ Scholl reaction and coordination chemistry from a flexible and nonplanar tetraphenylbenzene-based ligand (8OH-TPB) in a one-pot manner. Interestingly, the kgm-TBA-MOF comprising hexagonal and triangular dual pores exhibit higher conductivities of 1.65 × 10-3 S/cm at 298 K and 3.33 × 10-2 S/cm at 353 K than that of sql-TBA-MOF (4.48 × 10-4 and 2.90 × 10-3 S/cm, respectively). Moreover, the morphology and topology can be modulated via the addition of ammonium hydroxide as modulator. The present work provides a new pathway for design, synthesis, and topological regulation of 2D c-MOFs.

Hydraulic conductivity and X-ray diffraction tests of unsaturated bentonites with a multi-ring and their predictions by pores distributions

Following instantaneous profiling method, a new multi-ring was applied in wetting apparatus to ascertain water diffusivities of three bentonites (MX-80, Kunigel-V1, and Kunibon). Hydraulic conductivities of unsaturated bentonites were calculated combining water diffusivities and soil water retention curves (SWRC). Basal spacings were achieved by sending slices from the multi-ring to X-ray diffraction (XRD) tests. A dual pores system was proposed: 1) micro pore (inter-layer pores); and 2) macro pore (inter-particle pores and inter-aggregate pores). By discussing water flow mechanisms in bentonite, it was supposed that: moveable waters flow through macro pore. Porosity and tortuosity of saturated macro pore were used instead of porosity and tortuosity of saturated total pore in traditional Kozeny-Carmen (KC) equation, which was designated as modified KC eq. A new relative permeability was raised for predicting unsaturated bentonites hydraulic conductivities. Macroporosity and macrovolumetric water content were obtained from estimated basal spacing during saturation. Comprehensive comparisons between experimental database and predictions were conducted. Results revealed that the modified KC equation can predict both saturated and unsaturated hydraulic conductivities better.

A T‐Junction Dual Nanopore for Single Nanoparticle Analysis

Label‐free detection methods such as resistive pulse sensing (RPS) have become a pivotal platform for the characterizations of nanoscale objects, providing real‐time monitoring and single‐molecule resolution. Major challenges for RPS platforms include the short translocation time of nanoscale objects passing through the pore and limited dynamic range due to the need for particle sizes to be within 10−90% of the pore size. These issues severely limit the fidelity of the measured signals, particularly when measuring unknown samples. Herein, a T‐junction‐shaped dual pore system that slows down the motion of translocating nanoparticles is proposed, and that allows particle translocations to be unambiguously allocated to one of the two pore structures. Moreover, because the two pore structures are of different sizes, the size range of particles that may be measured without clogging is increased. The prepared dual pores afford to measure the size features and surface charge properties of nanoparticles with high accuracy. Importantly, the dual‐pore system enables the study of the dynamic motion behaviors of adjacent nanoparticles. The application of these dual pores for characterizing the protein corona of bioparticles is exemplified.

Functionalised mesoporous silica nanoparticles with excellent cytotoxicity against various cancer cells for pH-responsive and controlled drug delivery

Mesoporous silica nanoparticles (MSNs) modified with Pt and carboxyl groups were designed and the drug molecule-release behaviour was studied by loading cisplatin as a model anticancer drug. The MSNs had a high surface area (342 m2 g−1) and dual pores (3.3 and 33.4 nm) with a uniform size. The amount of cisplatin loaded in the nanopores was 74.9 mg g−1. Drug release was approximately two times higher under acidic conditions (pH 4.0) than under neutral conditions (pH 7.3). The cell viability was tested using three types of cancer cells (A549, A2780, and MCF-7). When the drug-free samples (Surfactant-extracted MSNs, COOH-MSNs) were applied at a concentration of 500 μg ml−1, the cancer cell death did not show any differences (Cell survival rate of approximately 82.7–85.7%). On the other hand, cancer cell death was more pronounced with excellent performance when drug-loaded MSNs (Pt/COOH-MSNs) were applied at the same concentration (Cell survival rate 3.6% for A549, 15.8% for A2780, 12.8% for MCF-7, respectively). This result may give more generalised insights in developing effective and universal nanocarrier of an anticancer drug by using multiple cell lines instead of using any single cancer cell line.

Tuning Pore Heterogeneity in Covalent Organic Frameworks for Enhanced Enzyme Accessibility and Resistance against Denaturants.

Achieving high-performance biocomposites requires knowledge of the compatability between the immobilized enzyme and its host material. The modular nature of covalent organic frameworks (COFs), as a host, allows their pore geometries and chemical functionalities to be fine-tuned independently, permitting comparative studies between the individual parameters and the performances of the resultant biocomposites. This research demonstrates that dual pores in COFs have profound consequences on the catalytic activity and denaturation of infiltrated enzymes. This approach enforces a constant pore environment by rational building-block design, which enables it to be unequivocally determined that pore heterogeneity is responsible for rate enhancements of up to threefold per enzyme molecule. More so, the enzyme is more tolerant to detrimental by-products when occupying the larger pore in a dual-pore COF compared to a corresponding uniform porous COF. Kinetic studies highlight that pore heterogeneity facilitates mass transfer of both reagents and products. This unparalleled versatility of these materials allows many different aspects to be designed on demand, lending credence to their prospect as next-generation host materials for various enzyme biocomposites catalysts.

Interfacial Synthesis of Conjugated Crystalline 2D Fluorescent Polymer Film Containing Aggregation-Induced Emission Unit.

A fully conjugated 2D fluorescent film containing a tetraphenylethene (TPE) unit is constructed by Glaser-Hay coupling reaction on the surface of copper foil. A large-area, freestanding fluorescent films with an average thickness 4.5 nm can be obtained through the strategy of solid-liquid interfacial synthesis. The film and the pore structure are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS). High-resulution TEM and selected area electron diffraction (SAED) further confirm the dual pores structure with triangular- and hexagonal-shaped pores. The as-prepared 2D films exhibit excellent solid-state fluorescence emission arising from the confinement of TPE units.

Controlling the Structure of Hydroxyapatite Ceramics with Dual Pores Prepared Using Freeze-Casting

A hydrogen peroxide solution in deionized water was used as the pore-forming agent in freeze-casting to fabricate a hydroxyapatite porous ceramic containing both lamellar and spherical macrospores. The influence of the volumetric content of H2O2 in the mixed solvent on the morphology of the porous ceramic was analyzed, and the effect of the solvent cooling speed on the microstructure and pore morphology of the pore ceramic was also investigated. The results show that H2O as the sole pore-forming agent led to the formation of a HA scaffold with only lamellar pores. When 3% (v/v) of H2O2 solution was used, both lamellar and spherical pores were observed. However, when the concentration of H2O2 reached 9% (v/v), only spherical pores were formed in the porous ceramic. The average lamellar spacing and the spherical pore size of the pore ceramic composed of HA decreased with the increase of the cooling speed.

Bimodal porous TiO2 structures templated by graft copolymer/homopolymer blend for dye-sensitized solar cells with polymer electrolyte

Bimodal porous TiO2 (BP-TiO2) with large surface area, high porosity, good interconnectivity, and excellent light-scattering ability are synthesized via a facile one-step method using a self-assembled blend template consisting of an amphiphilic poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer and a hydrophobic poly(vinyl chloride) (PVC) homopolymer. The hydrophilically surface-modified TiO2 nanoparticles selectively interact with the hydrophilic POEM chains, while the addition of the PVC homopolymer increases the hydrophobic domain size, resulting in the formation of dual pores (i.e., macropores and mesopores). The sizes and numbers of macropores can easily be controlled by changing the molecular weight and amount of the PVC homopolymer. The polymer electrolyte dye-sensitized solar cells (DSSCs) fabricated with BP-TiO2 photoanodes exhibited energy conversion efficiencies of up to 7.6% at 100 mW cm−2, which is much higher than those of mesoporous TiO2 (5.8%) with PVC-g-POEM only and conventional nanocrystalline TiO2 (4.9%) with commercial Dyesol paste. The enhanced energy conversion efficiencies mostly resulted from the light-scattering effects of the macropores, which increased the light-harvesting efficiencies. The improved light-harvesting and photovoltaic performances of the DSSCs were characterized by UV–vis spectroscopy, incident photon-to-current conversion efficiency analysis, electrochemical impedance spectroscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy.

Solar Cells: Honeycomb‐Like Organized TiO2 Photoanodes with Dual Pores for Solid‐State Dye‐Sensitized Solar Cells (Adv. Funct. Mater. 31/2013)

A solid-state dye-sensitized solar cell with 7.4% efficiency is fabricated by J. H. Kim and co-workers using meso/macroscopic, honeycomb-like, organized TiO2 photoanodes. These electrodes have dual pores, high porosity, good interconnectivity, and excellent light scattering properties. On page 3901, an approach to control these structures via a onestep self-assembly of preformed TiO2 nanocrystals and graft copolymers is presented.

Formation of hierarchical LiMn2O4dual‐porous nanostructures by pyrolysis of gel precursor

A precursor-pyrolysing route to fabricate hierarchical LiMn2O4 porous nanostructures is presented. The product was characterised by X-ray powder diffraction, scanning electron microscopy, a transmission electron microscope, a high-resolution transmission electron microscope and a micromeritics analyser. The results show that the resulting material is a honeycomb-like dual-porous structure. One is quasi-hemispherical macropores of several hundred nanometres and the other is slit mesopores of several nanometres. This dual-porous nanostructure is composed of many ultrafine nanocrystallines whose size mainly falls into the range from 3 to 10 nm. Moreover, it has a large Brunauer–Emmett-Teller-specific surface area of 116 m2/g. The formation of such dual pores should be attributed to the Kirkendall effect and surface diffusion.

Honeycomb‐Like Organized TiO2 Photoanodes with Dual Pores for Solid‐State Dye‐Sensitized Solar Cells

AbstractA solid‐state dye‐sensitized solar cell (ssDSSC) with 7.4% efficiency at 100 mW/cm2 is reported. This efficiency is one of the highest observed for N719 dye. High performance is achieved via a honeycomb‐like, organized mesoporous TiO2 photoanode with dual pores, high porosity, good interconnectivity, and excellent light scattering properties. The TiO2 photoanodes are prepared without any TiCl4 treatment via a one‐step, direct self‐assembly of hydrophilically preformed TiO2 nanocrystals and poly(vinyl chloride)‐g‐poly(oxyethylene methacrylate) (PVC‐g‐POEM) graft copolymer as a titania source and a structure‐directing agent, respectively. Upon controlling the secondary forces between the polymer/TiO2 hybrid and the solvent by varying the amounts of HCl/H2O mixture or toluene, honeycomb‐like structures are generated to improve light scattering properties. Such multifunctional nanostructures with dual pores provide good pore‐filling of solid polymer electrolyte with large volume, enhanced light harvesting and reduced charge recombination, as confirmed by reflectance spectroscopy, incident photon‐to‐electron conversion efficiency (IPCE), and electrochemical impedance spectroscopy (EIS) analysis.

Evolution of throttle-channel dual pores in YSZ ceramic monolith through in situ grown nano carbon wedges

Abstract Interconnectivity of the pore channels and their size distribution in a ceramic monolith influence the flow dynamics of permeating fluid. This work proposes an innovative pore-forming mechanism that begins with the growth of poly(p-phenylene terephthamide) (PPTA) in a ceramic green body of yttrium-doped zirconia (YSZ). The spatial confinement drove the formation of PPTA through an extrusion manner, resulting in submicron PPTA rods embedded in the matrix. Theses rods were carbonized under Ar between 800 and 1200 °C for 2 h before oxidizing atmosphere was introduced to facilitate their removal and sintering of YSZ. This dwelling temperature is crucial to the pore size distribution in the sintered ceramic due to the chemical and dimensional changes of the carbon wedges and YSZ grains. The sintered ceramic is characterized by interconnected throttle-to-channel pore structure, which manifested a marked improvement on fluid permeability and a capability of stretching viscous fluids passing through it.

Zirconia foams prepared by integration of the sol–gel method and dual soft template techniques

This paper presents a new method to produce basic zirconium sulfate foams showing hierarchic porosity, based on a dual pores templating process by oil drops and gas bubbles dispersed into a hydrosol, followed by its fast gelation to form the porous patterned inorganic network. As revealed by mercury porosimetry, the hierarchical structures of final inorganic foams are composed by large gas bubble templated macro-pores (modal size 7–33 μm) and emulsion-templated supermeso-pores of modal size tunable around 3 and 0.4 μm. The relative population and modal pore size of each family and the overall porosity of the final inorganic foam can be varied by adjusting the emulsification and air–liquid foaming stirring speed, and the oil/sol ratio.

Preparation of Biodegradable Polymer Scaffolds with Dual Pore System for Tissue Regeneration

AbstractBiodegradable polymer scaffolds that have dual pores on the matrix were successfully prepared using a combination of gas foaming and phase separation methods. PLLA and PLGA were dissolved in dioxane/water at the ratios of 90/10, 87/13, or 85/15 (v/v), respectively. Sodium bicarbonate was then added to the polymer solution and freezed‐dried, then subjected to a gas foaming process. Dual pore scaffolds have two distinct pore sizes: large pores in 200∼300 µm and small ones in 5∼20 µm, with the interconnected structure. Their porosities were ranged from 92 to 98%, significantly higher than those of unipore scaffold (90%). Two variables, water content (10, 13, and 15%) and freeze‐drying temperature (FDT; −196, −70, and −20 °C), were introduced during the scaffold preparation. Mechanical compressive strength decreased as the polymer solution was gradually diluted with water (100/0 to 85/15, v/v). Earlier weight loss of the different scaffolds was found with FDT at −20 °C but the final result was the same, regardless of different FDTs used. These dual pore polymer scaffolds may thus be useful in tissue engineering applications.

A channel in a transporter

1. Glutamate transporters (or excitatory amino acid transporters (EAAT)) are responsible for removing synaptically released glutamate from the extracellular space. The failure of EAAT to carry out this role will lead to excessive stimulation of glutamatergic receptors, causing excitotoxicity and cell death. 2. Glutamate is cotransported into the cell with three Na+ and one H+, followed by the counter-transport of one K+. In addition, glutamate and Na+ binding activates an uncoupled chloride conductance. Thus, glutamate transporters can function as both a transporter and an ion channel. At present, there is no clear understanding of the structural basis for the dual functions of glutamate transporters and, in the present review, we shall discuss some recent studies that have started to address this question. 3. It is possible to modulate one function of glutamate transporters without affecting the other, which suggests that the two functions have separate molecular determinants, and a number of models have been suggested to account for the dual functions of the EAAT that predict both single and dual pores for transporter function. 4. It appears that the two functions of glutamate transporters arise from separate transmembrane domains. The C-terminal region of the transporters forms the glutamate translocation domain, whereas the second transmembrane domain in the N-terminal half of the protein plays a crucial role in chloride channel function. Although the two functions arise from separate molecular determinants, the two functional domains are likely to be in close proximity. The significance of these observations will be discussed in terms of likely functional models for the transport and channel processes.