Hydrophobic Channel Research Articles

Sticky Business: Correlating Oligomeric Features of Class B Scavenger Receptors to Lipid Transport.

Atherosclerotic plaques result from imbalanced lipid metabolism and maladaptive chronic immune responses. Class B scavenger receptors are lipid transporters and regulators of their metabolism. The purpose of this review is to explore recent structural findings of these membrane-associated receptors, with particular focus on their higher-order oligomeric organization and impact on lipid transport. Class B scavenger receptors have evidence for oligomerization, with recent efforts placed on identifying residues and motifs responsible for mediating this process. The first studies correlating scavenger receptor oligomerization to function are described. This review highlights two emerging hypotheses regarding the function of scavenger receptor oligomerization. The first is a hydrophobic channel created by self-association of receptors to promote transport. The second hypothesis suggests that homo-oligomerization stabilizes receptors, prevents internalization and thereby promotes transport indirectly. Novel computational and in vitro experimental techniques with purified receptors are also described.

Tillandsia-Inspired Asymmetric Covalent Organic Framework Membranes for Unidirectional Low-Friction Water Collection.

Friction plays a pivotal role in many phenomena of physical chemistry and has long been in the focus of research thereof. As a crucial parameter, frictions in membranes' inner and/or outer surfacecan be minimized toreducesolvent inlet pressure and enlarge inner pore fluid flux, ideally reachingnear frictionless transport of water at nanoscale. Inspired by the leaf structure of Tillandsia, a porous membrane with a rough surface and a hydrophilic inlet together with hydrophobic pore channels was designed and fabricated, based on covalent organic frameworks (COFs). Combined with COFs' inherent highly oriented pore structures, theas-madeasymmetric membranes through chemical etching can minimize the solvent critical intrusion pressure andenableinner pore low friction water transport. Ultimately, obtained COF membranes succeeded intrappingfog from air and achieved a water harvesting rate(WHR) of 1570 mg cm-2h-1, together with small molecular pollutants filtratedoffin the meantime. Intriguingly, the synthesized asymmetric COF membranes illustrated unidirectional low friction water collecting and transporting features, the successful imitation of T. macdougallii. This work presentsapractical strategy to construct functional porous membranes for low friction water collection and transport,and created a model paradigm todesign fluid transporting pore channels.

Tillandsia‐Inspired Asymmetric Covalent Organic Framework Membranes for Unidirectional Low‐Friction Water Collection

Friction plays a pivotal role in many phenomena of physical chemistry and has long been in the focus of research thereof. As a crucial parameter, frictions in membranes’ inner and/or outer surface can be minimized to reduce solvent inlet pressure and enlarge inner pore fluid flux, ideally reaching near frictionless transport of water at nanoscale. Inspired by the leaf structure of Tillandsia, a porous membrane with a rough surface and a hydrophilic inlet together with hydrophobic pore channels was designed and fabricated, based on covalent organic frameworks (COFs). Combined with COFs’ inherent highly oriented pore structures, the as‐made asymmetric membranes through chemical etching can minimize the solvent critical intrusion pressure and enable inner pore low friction water transport. Ultimately, obtained COF membranes succeeded in trapping fog from air and achieved a water harvesting rate (WHR) of 1570 mg cm‐2 h‐1, together with small molecular pollutants filtrated off in the meantime. Intriguingly, the synthesized asymmetric COF membranes illustrated unidirectional low friction water collecting and transporting features, the successful imitation of T. macdougallii. This work presents a practical strategy to construct functional porous membranes for low friction water collection and transport, and created a model paradigm to design fluid transporting pore channels.

Boosting OECT Performance with PEGylated Gold Nanoparticles in Hydrophobic Channels

AbstractOrganic electrochemical transistors (OECTs) require organic mixed ion‐electron conductors (OMIECs) (i.e., hydrophilic materials supporting electron and ion transportation) as active materials. However, high‐performance OMIECs grafted with hydrophilic side chains are difficult to synthesize and purify, and often suffer from swelling during operation. In contrast, the synthetic pathways toward a broad range of hydrophobic polymeric semiconductors used in classic organic‐field‐effect transistors are well established, and several are even commercially available. Yet, these hydrophobic materials do not intrinsically support ionic transport, limiting their application in OECTs. Here, poly(ethyleneglycol) (PEG)‐coated gold nanoparticles (AuNP) are incorporated into conventional hydrophobic polymeric semiconductors like poly‐3‐hexylthiophene (P3HT), improving not only ionic but also electronic transport. The hydrophilic AuNPs modify P3HT crystallite orientation, shorten lamellar and π–π distances, and create pathways for ion penetration, as evidenced by GIWAXS and AFM studies. With 5 wt% AuNP loading, OECTs achieve µC* of 98 F cm−1 V−1 s−1, comparable to hydrophilic materials. The strategy also works for other polymer systems, offering a facile method to utilize hydrophobic materials in OECTs and boost their performance.

Fluid Classification via the Dual Functionality of Moisture-Enabled Electricity Generation Enhanced by Deep Learning.

Classifications of fluids using miniaturized sensors are of substantial importance for various fields of application. Modified with functional nanomaterials, a moisture-enabled electricity generation (MEG) device can execute a dual-purpose operation as both a self-powered framework and a fluid detection platform. In this study, a novel intelligent self-sustained sensing approach was implemented by integrating MEG with deep learning in microfluidics. Following a multilayer design, the MEG device including three individual units for power generation/fluid classification was fabricated in this study by using nonwoven fabrics, hydroxylated carbon nanotubes, poly(vinyl alcohol)-mixed gels, and indium tin bismuth liquid alloy. A composite configuration utilizing hydrophobic microfluidic channels and hydrophilic porous substrates was conducive to self-regulation of the on-chip flow. As a generator, the MEG device was capable of maintaining a continuous and stable power output for at least 6 h. As a sensor, the on-chip units synchronously measured the voltage (V), current (C), and resistance (R) signals as functions of time, whose transitions were completed using relays. These signals can serve as straightforward indicators of a fluid presence, such as the distinctive "fingerprint". After normalization and Fourier transform of raw V/C/R signals, a lightweight deep learning model (wide-kernel deep convolutional neural network, WDCNN) was employed for classifying pure water, kiwifruit, clementine, and lemon juices. In particular, the accuracy of the sample distinction using the WDCNN model was 100% within 15 s. The proposed integration of MEG, microfluidics, and deep learning provides a novel paradigm for the development of sustainable intelligent environmental perception, as well as new prospects for innovations in analytical science and smart instruments.

RETRACTION: Soft Nanotubes with a Hydrophobic Channel Hybridized with Au Nanoparticles: Photothermal Dispersion/Aggregation Control of C60 in Water

AbstractRETRACTION: K. Ishikawa, N. Kameta, M. Aoyagi, M. Asakawa, T. Shimizu, “Soft Nanotubes with a Hydrophobic Channel Hybridized with Au Nanoparticles: Photothermal Dispersion/Aggregation Control of C60 in Water,” Advanced Functional Materials 23 no. 13 (2012): 1677–1683, https://doi.org/10.1002/adfm.201202160.The above article, published online on 22 October 2012 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors; the journal Editor‐in‐Chief, Jörn Ritterbusch; and Wiley‐VCH GmbH, Weinheim. The retraction has been agreed upon the authors' request following an investigation by the National Institute of Advanced Industrial Science and Technology (AIST), due to image falsification in electron microscopy images. In Figure 1a, the second author used an incorrect scale bar and carelessly placed incorrect scale bars in Figures 1b, 5a, 5b, and 5c. As a result, the research results presented are considered unreliable.

Construction of Stable 2D Cationic Breathing Ni-MOF for Cr(VI) Trapping and Electrochemical Sensing.

Pollution of surface water by heavy metal hexavalent chromium ions poses a serious threat to human health; herein, a two-dimensional (2D) cationic breathing Ni-MOF with free nitrate ions between the layers was designed and synthesized according to the characteristics of hexavalent chromium ions, {[Ni(L)2](NO3)2·5H2O}n (L = 1,3,5-tris[4-(imidazol-1-yl)phenyl]benzene). The flexible layer spacing of the 2D breathing Ni-MOF allows the exchange of NO3- by CrO42- without destroying the original structure. Electrostatic and hydrogen bonding interactions between CrO42- and Ni-MOF facilitate its exchange with NO3-. Moreover, CrO42- exhibits a higher binding energy with Ni-MOF compared to NO3-, and the hydrophobic channels of Ni-MOF favor CrO42- trapping due to its lower hydration energy. Consequently, Ni-MOF demonstrates both effective sorption and electrochemical sensing of Cr(VI), achieving a sensitivity of 2.091 μA μM-1 and a detection limit of 0.07 μM.

Computational investigation in inhibitory effects of amantadine on classical swine fever virus p7 ion channel activity

Classical swine fever virus (CSFV) p7 viroporin plays crucial roles in cellular ion balance and permeabilization. The antiviral drug amantadine effectively inhibits viral replication by blocking the activity of CSFV p7 viroporin. However, little information is available for the binding mode of amantadine with CSFV p7 viroporin, due to the lack of a known polymer structure for CSFV p7. In this study, we employed AlphaFold2 to predict CSFV p7 structures. Subsequently, we conducted a docking study to investigate the binding sites of amantadine to CSFV p7. Computational analysis showed that CSFV p7 forms a pore channel in a hexameric structure. Furthermore, molecular dynamics (MD) simulations and mutant analyses further suggest that CSFV p7 likely exists as a hexamer. Docking studies and MD simulations showed that amantadine interacts with the hydrophibic regions of tetramer and pentamer, as well as with the hydrophobic pore channel of the hexamer. Considering the potential hexameric assembly of CSFV p7, along with docking results, MD simulations, and the characteristics of the gated ion channels, we propose a model of CSFV p7 ion channel based on its hexameric configuration. In this model, residues E21, Y25, and R34 are suggested to selectively recruit and dehydrate ions, while residues L28 and L31 likely act as hydrophobic constrictors, thereby restricting the free movement of water. The binding of amantadine to residues I20, E21, V24 and Y25 effectively blocks ion transport. However, this proposed molecular model requires experimental validation. Our findings give a structural insight into the models of CSFV p7 as an ion channel and provide a molecular explanation for the inhibition effects of amantadine on CSFV p7-mediated ion channel conductance.

A novel low-cost and simple fabrication technique for a paper-based analytical device using super glue

BackgroundThe microfluidic paper-based analytical devices (μPADs) have been highly regarded as effective tools that offer a cost-effective and portable solution for point-of-care testing (POCT) and on-site detection. Utilizing paper substrates such as cellulose and nitrocellulose membranes, μPADs have proven beneficial for a range of applications from medical diagnostics to environmental monitoring. Despite their advantages, the fabrication of μPADs often requires sophisticated techniques and equipment, posing challenges for widespread adoption, especially in resource-limited settings. This study addresses the need for a simplified, low-cost method for fabricating μPADs that is accessible without specialized training or equipment. ResultsThis research introduces a novel, efficient method for producing μPADs using 3D-printed slidable chambers and super glue vapor, bypassing traditional, more complex fabrication processes. The method utilizes super glue (ethyl-cyanoacrylate) vapor to create hydrophobic barriers on paper substrates. By optimizing the exposure sequence to super glue and water vapors and the heating conditions, we achieved rapid hydrophobization within 5 min, creating effective hydrophobic barriers and hydrophilic channels on paper substrates. The technique's simplicity allows for use by individuals without specialized training. The practical application of the fabrication method is demonstrated by the fabrication of μPADs that can detect multiple target analytes. We perform the simultaneous detection of glucose, proteins, and also the simultaneous detection of heavy metal ions nickel (Ni2+) and copper (Cu2+), highlighting its potential for broad applications in point-of-care diagnostics. SignificanceThis study is the first to report a method for selective exposure of ethyl-cyanoacrylate vapor for the fabrication of μPADs. This method significantly reduces the complexity, time, and fabrication cost, making it feasible for use in various settings. It also eliminates the need for specialized equipment and can be executed by individuals without specialized training. We believe that the proposed fabrication method contributes to the wider adoption and deployment of μPADs across various sectors.

Advancing paper microfluidics: A strategic approach for rapid fabrication of microfluidic paper-based analytical devices (µPADs) enabling in-vitro sensing of creatinine

Paper-based microfluidic sensors for point-of-care applications represent an exceptional strategy for facilitating rapid sensing within clinical settings. Despite their considerable promise, the ongoing research objective lies in efficiently printing hydrophobic microfluidic channels (µPADs) onto hydrophilic paper while minimizing expenditure. This research paper introduces an advanced, economic, and efficient method for the rapid fabrication of µPADs on paper substrates, enabling immediate colorimetric detection of creatinine in artificial urine using Jaffe’s reagent. The process involves a modified DIY RepRap 3D printer with an integrated technical drawing pen filled with the solution of Polydimethylsiloxane (PDMS) and hexane. This solution creates hydrophobic domain barriers on a flexible nylon-based paper substrate, effectively confining the aqueous medium within the microfluidic channels. We report visual detection of a broad spectrum of creatinine concentrations ranging from 5 mg/dL to 450 mg/dL through the vibrant Janovsky complex appearance on the microfluidic domains. The study identifies the limiting concentration on µPADs as 500 mg/dL. The innovative procedure demonstrates exceptional selectivity, exhibiting a maximum interference of only 0.97 % from potentially interfering substances. This rapid, naked-eye detection of creatinine on nylon 6,6 membranes offers a user-friendly and economical approach, enhancing the capabilities of colorimetric visualization in point-of-care applications.

Hydrophilic/hydrophobic modified microchip for detecting multiple gene doping candidates using CRISPR-Cas12a and RPA

With significant advancements in understanding gene functions and therapy, the potential misuse of gene technologies, particularly in the context of sports through gene doping (GD), has come to the forefront. This raises concerns regarding the need for point-of-care testing of various GD candidates to counter illicit practices in sports. However, current GD detection techniques, such as PCR, lack the portability required for on-site multiplexed detection. In this study, we introduce an integrated microfluidics-based chip for multiplexed gene doping detection, termed MGD-Chip. Through the strategic design of hydrophilic and hydrophobic channels, MGD-Chip enables the RPA and CRISPR-Cas12a assays to be sequentially performed on the device, ensuring minimal interference and cross-contamination. Six potential GD candidates were selected and successfully tested simultaneously on the platform within 1 h. Demonstrating exceptional specificity, the platform achieved a detection sensitivity of 0.1 nM for unamplified target plasmids and 1 aM for amplified ones. Validation using mouse models established by injecting IGFI and EPO transgenes confirmed the platform's efficacy in detecting gene doping in real samples. This technology, capable of detecting multiple targets using portable elements, holds promise for real-time GD detection at sports events, offering a rapid, highly sensitive, and user-friendly solution to uphold the integrity of sports competitions.

Genetic evidence for functional diversification of gram-negative intermembrane phospholipid transporters.

The outer membrane of gram-negative bacteria is a barrier to chemical and physical stress. Phospholipid transport between the inner and outer membranes has been an area of intense investigation and, in E. coli K-12, it has recently been shown to be mediated by YhdP, TamB, and YdbH, which are suggested to provide hydrophobic channels for phospholipid diffusion, with YhdP and TamB playing the major roles. However, YhdP and TamB have different phenotypes suggesting distinct functions. It remains unclear whether these functions are related to phospholipid metabolism. We investigated a synthetic cold sensitivity caused by deletion of fadR, a transcriptional regulator controlling fatty acid degradation and unsaturated fatty acid production, and yhdP, but not by ΔtamB ΔfadR or ΔydbH ΔfadR. Deletion of tamB recuses the ΔyhdP ΔfadR cold sensitivity further demonstrating the phenotype is related to functional diversification between these genes. The ΔyhdP ΔfadR strain shows a greater increase in cardiolipin upon transfer to the non-permissive temperature and genetically lowering cardiolipin levels can suppress cold sensitivity. These data also reveal a qualitative difference between cardiolipin synthases in E. coli, as deletion of clsA and clsC suppresses cold sensitivity but deletion of clsB does not. Moreover, increased fatty acid saturation is necessary for cold sensitivity and lowering this level genetically or through supplementation of oleic acid suppresses the cold sensitivity of the ΔyhdP ΔfadR strain. Together, our data clearly demonstrate that the diversification of function between YhdP and TamB is related to phospholipid metabolism. Although indirect regulatory effects are possible, we favor the parsimonious hypothesis that YhdP and TamB have differential phospholipid-substrate transport preferences. Thus, our data provide a potential mechanism for independent control of the phospholipid composition of the inner and outer membranes in response to changing conditions based on regulation of abundance or activity of YhdP and TamB.

Low-Temperature-Tolerant Aqueous Proton Battery with Porous Ti3C2Tx MXene Electrode and Phosphoric Acid Electrolyte

Supercapacitors have long suffered from low energy density. Here, we present a high-energy, high-safety, and temperature-adaptable aqueous proton battery utilizing two-dimensional Ti3C2Tx MXenes as anode materials. Additionally, our work aims to provide further insights into the energy storage mechanism of Ti3C2Tx in acid electrolytes. Our findings reveal that the ion transport mechanism of Ti3C2Tx remains consistent in both H2SO4 and H3PO4 electrolytes. The mode of charge transfer depends on its terminal groups. Specifically, the hydrogen bonding network formed by water molecules adsorbed by hydroxyl functional groups under van der Waals forces enables charge transfer in the form of naked H+ through the Grotthuss mechanism. In contrast, the hydrophobic channel formed by oxygen and halogen terminal groups facilitates rapid charge transfers in the form of hydronium ion via the vehicle mechanism, owing to negligible interfacial effect. Herein, we propose an aqueous proton battery based on porous hydroxy-poor Ti3C2Tx MXene anode and pre-protonated CuII[FeIII(CN)6]2/3∙4H2O (H-TBA) cathode in a 9.5 M H3PO4 solution. This proton battery operates through hydrated H+/H+ transfer, leading to good electrochemical performance, as evidenced by 26 Wh kg−1 energy density and 162 kW kg−1 power density at room temperature and an energy density of 17 Wh kg−1 and a power density of 7.4 kW kg−1 even at −60 °C.

Genetic evidence for functional diversification of gram-negative intermembrane phospholipid transporters.

The outer membrane of Gram-negative bacteria is a barrier to chemical and physical stress. Phospholipid transport between the inner and outer membranes has been an area of intense investigation and, in E. coli K-12, it has recently been shown to be mediated by YhdP, TamB, and YdbH, which are suggested to provide hydrophobic channels for phospholipid diffusion, with YhdP and TamB playing the major roles. However, YhdP and TamB have different phenotypes suggesting distinct functions. We investigated these functions using synthetic cold sensitivity (at 30 °C) caused by deletion of yhdP and fadR, a transcriptional regulator controlling fatty acid degradation and unsaturated fatty acid production, but not by ΔtamB ΔfadR or ΔydbH ΔfadR,. Deletion of tamB suppresses the ΔyhdP ΔfadR cold sensitivity suggesting this phenotype is related to phospholipid transport. The ΔyhdP ΔfadR strain shows a greater increase in cardiolipin upon transfer to the non-permissive temperature and genetically lowering cardiolipin levels can suppress cold sensitivity. These data also reveal a qualitative difference between cardiolipin synthases in E. coli, as deletion of clsA and clsC suppresses cold sensitivity but deletion of clsB does not despite lower cardiolipin levels. In addition to increased cardiolipin, increased fatty acid saturation is necessary for cold sensitivity and lowering this level genetically or through supplementation of oleic acid suppresses the cold sensitivity of the ΔyhdP ΔfadR strain. Although indirect effects are possible, we favor the parsimonious hypothesis that YhdP and TamB have differential substrate transport preferences, most likely with YhdP preferentially transporting more saturated phospholipids and TamB preferentially transporting more unsaturated phospholipids. We envision cardiolipin contributing to this transport preference by sterically clogging TamB-mediated transport of saturated phospholipids. Thus, our data provide a potential mechanism for independent control of the phospholipid composition of the inner and outer membranes in response to changing conditions.

Multi Targeted Ligands for Potential Inhibition of Dipeptidyl Peptidase 4, Acetylcholinesterase and Cyclooxygenase 2

Two series of novel compounds were designed by combining indomethacin and ibuprofen with sixteen sulfa drugs. These compounds were systematically evaluated through target fishing using the Pharm Mapper, leading to the identification of DPP-4, AChE, and COX-2 as potential targets. Molecular docking was performed to evaluate the binding affinity of designed compounds against the identified three target proteins. The results revealed that the designed compounds exhibited binding affinities ranging from ~8 to -12kcal/mol, 12 to 13 kcal/mol and 8 to 11kcal/mol for DPP-4, AChE and COX-2 respectively. The binding affinities were found to be comparable or higher than binding affinity of co-crystallized ligand, which was found to be ~10, 12 and 9 kcal/mol respectively. Further investigation into the binding modes of these compounds was carried out. Notably, for DPP-4 complexes, interactions with Arg125, Glu205, and Glu206 were observed which are essential for substrate and inhibitor binding. For AChE complexes, interactions involved crucial His447 residues, essential for acetylcholine hydrolysis. In the case of COX-2, hydrogen bond interaction was noted with Arg120 located at the entrance of the hydrophobic channel. Despite favorable binding potentials, ADME profiling highlighted five compounds (1A, 1F, 1G, 1H, and 1O) with drug-like characteristics but lacking blood-brain barrier permeation ability. Out of five compounds, 1H stood out, demonstrating superior binding affinity and interactions vital residues necessary for catalytic activity of three enzymes. Thus, 1H emerges as a promising candidate for Multi-Targeted Drug-Like (MTDL) development aimed at addressing diabetes mellitus related dementia.

High-performance cellulose nanofibers-based actuators with multi-stimulus responses and energy storage

Smart actuating materials have received tremendous attention due to their promising applications in miniaturized robots, integrated electronics and wearable devices. However, simultaneously achieving sensitive multi-stimuli responsiveness, preferable energy storage capability and adequate mechanical properties by one material in a simple yet efficient way remains a considerable challenge. Herein, we propose a novel multi-responsive nanocomposite film actuator consisting of negatively charged cellulose nanofibers (CNF), polydopamine-chelated MXene-Fe3O4 nanohybrids (PMF) and positively charged carbon nanotubes (CCNT) via a cost-efficient electrostatic self-assembly approach. Benefiting from the laminated porous structure and compositional superiorities, including the water-induced swelling effect of CNF and PMF, conductive CCNT with countless interior hydrophobic channels and magneto-conductive properties of PMF, the optimized nanocomposite film actuator presents a high bending speed (100.5°/s), ultrashort actuation time (2.0 s), long-term stability (1005 cycles) and good magnetic response. These actuators can be assembled into a supercapacitor exhibiting an areal capacitance of 33.5 mF/cm2 at 0.5 mA/cm2 and good cycling stability with a capacitance retention of 80.5 % after 5000 cycles. Furthermore, the actuators are designed as soft robots with different motion modes, mechanical grippers for performing consecutive actions and an integrated circuit system to monitor surrounding humidity changes. This work provides inspiration to develop advanced nanocomposite materials for smart devices that require multifunction integration.

Reticular access to triptycene-based cationic metal–organic frameworks for protein-bound uremic toxins sorption

P-cresyl sulfate (pCS) and indoxyl sulfate (IS), a class of protein-bound uremic toxins, cannot be effectively cleared through hemodialysis treatment due to their strong binding to human serum albumin, posing a potential risk of cardiovascular disease in patients with chronic renal failure. Herein, we designed and prepared novel cationic metal–organic frameworks (MOFs), denoted as ZJU-X18, for the efficient removal of pCS and IS. A triptycene-based rigid trigonal prismatic ligand was utilized to link with Ag+ to yield a rare 4-fold interpenetrated MOF with abundant hydrophobic channels, affording high sorption capacity, excellent selectivity, and decent recyclability toward uremic toxins. Furthermore, the anion-exchange process between ZJU-X18 and uremic toxins is verified through density functional theory (DFT) calculations. This study provides a proactive example of the rational design of cationic MOFs from the perspective of reticular chemistry and demonstrates their promising application in uremia treatment.

Revolutionizing CO2 Electrolysis: Fluent Gas Transportation within Hydrophobic Porous Cu2O.

The success of electrochemical CO2 reduction at high current densities hinges on precise interfacial transportation and the local concentration of gaseous CO2. However, the creation of efficient CO2 transportation channels remains an unexplored frontier. In this study, we design and synthesize hydrophobic porous Cu2O spheres with varying pore sizes to unveil the nanoporous channel's impact on gas transfer and triple-phase interfaces. The hydrophobic channels not only facilitate rapid CO2 transportation but also trap compressed CO2 bubbles to form abundant and stable triple-phase interfaces, which are crucial for high-current-density electrocatalysis. In CO2 electrolysis, in situ spectroscopy and density functional theory results reveal that atomic edges of concave surfaces promote C-C coupling via an energetically favorable OC-COH pathway, leading to overwhelming CO2-to-C2+ conversion. Leveraging optimal gas transportation and active site exposure, the hydrophobic porous Cu2O with a 240 nm pore size (P-Cu2O-240) stands out among all the samples and exhibits the best CO2-to-C2+ productivity with remarkable Faradaic efficiency and formation rate up to 75.3 ± 3.1% and 2518.2 ± 8.1 μmol h-1 cm-2, respectively. This study introduces a novel paradigm for efficient electrocatalysts that concurrently addresses active site design and gas-transfer challenges.

Cyclodextrin nanofilms with hydrophobic and hydrophilic channels for solvent permeation and molecular sieving

Cyclodextrin nanofilms with hydrophobic and hydrophilic channels for solvent permeation and molecular sieving

Fractal Characteristics of Natural Fiber-Reinforced Soil in Arid Climate Due to Cracking

Fractal geometry is a geometry that focuses on irregular geometric forms and can quantitatively describe rough and uneven surfaces and interfaces. As the main material for making natural fiber geotextile, rice straw fiber can reduce the direct impact of rainfall on soil and reduce the intensity of hydraulic erosion. This study investigates whether the use of rice straw fiber as an additive to reinforce arid soil can inhibit moisture evaporation and prevent cracking. Samples with different fiber contents added (0%, 1%, 2%, and 4%) are placed in an environmental chamber to simulate the effects of an arid climatic condition and control the temperature and humidity levels. The cracking process of the samples is recorded by using a digital camera, and the parameters of the evaporation and cracking processes are quantitatively examined through digital image processing. The results show that all of the samples with fiber have a higher residual water content and can retain 31.4%, 58.5%, and 101.9% more water than without the fibers, respectively. Furthermore, both the primary and secondary cracks as well as crack networks are inhibited in samples with a higher fiber content, that is, 2% or 4% fiber contents. The samples reinforced with fiber also have a smaller crack ratio. Compared with the samples without straw fiber, the final crack ratio of the samples with 1%, 2%, and 4% fiber is reduced by 8.05%, 24.09%, and 35.01% respectively. Finally, the final fractal dimensions of the cracks in samples with fiber contents are also reduced by 0.54%, 5.50%, and 6.40% for the samples with 1%, 2%, and 4% fiber, respectively. The addition of natural fiber as an additive to reduce evaporative cracking in soil can: (1) reduce the soil porosity; (2) enhance the binding force between the soil particles; and (3) block the hydrophobic channels. Therefore, the addition of rice straw fiber to soil can effectively reduce soil evaporation and inhibit soil cracking.