Heterogeneous Surface Research Articles

Femtosecond laser turn droplets controllable bouncing

Droplets controllable bouncing on solid surfaces plays a vital role in microfluidic operation, liquid collection, and chemical micro reaction applications, which has attracted widespread attention. However, strategies to realize controllable bouncing of droplets on solid surface are still elusive and nanofabrication patterning methods are generally complex and time consuming. Here, we propose a simple and fast method to fabricate heterogeneously wettable surfaces on aluminum sheets by femtosecond laser processing followed by wax treatment. The surface is comprised of superhydrophobic regions with a water contact angle (WCA) of ∼ 159.5°and superhydrophilic regions with a WCA of ∼ 1.8°. The heterogeneous wettability in specific designs can control droplet bouncing motions when impacting the surface. Therefore, the liquid droplets are regulated to rotate and controllably bounce for achieving various functions, including climbing, combining, and driving small boats. This work demonstrates a facile way to fabricate patternable heterogeneous wettability surfaces for manipulating droplets and achieving multifunctional bouncing motions. Our simple, effective, and environmentally friendly method holds promise for transformative advancements in electric power generation, pharmaceutical development and manufacturing, as well as the realm of self-driving actuators.

Effects of heterogeneous surface characteristics on hemocompatibility and cytocompatibility of bacterial nanocellulose

The surface properties of cardiovascular biomaterials play a critical role in their biological responses. Although bacterial nanocellulose (BNC) materials have exhibited potential applications in cardiovascular implants, the impact of their surface characteristics on biocompatibility has rarely been studied. This study investigated the mechanism for the biocompatibility induced by the physicochemical properties of both sides of BNC. With greater wettability and smoothness, the upper BNC surface reduced protein adsorption by 25 % compared with the lower surface. This prolonged the plasma re-calcification time by 14 % in venous blood. Further, compared with the lower BNC surface, the upper BNC surface prolonged the activated partial thromboplastin time by 5 % and 4 % in arterial and venous blood, respectively. Moreover, the lower BNC surface with lesser rigidity, higher roughness, and sparser fiber structure promoted cell adhesion. The lower BNC surface enhanced the proliferation rate of L929 and HUVECs cells by 15 % and 13 %, respectively, compared with the upper BNC surface. With lesser stiffness, the lower BNC surface upregulated the expressions of CD31 and eNOS while down-regulating the ICAM-1 expression - This promoted the proliferation of HUVECs. The findings of this study will provide valuable insights into the design of blood contact materials and cardiovascular implants.

Pre-emergence herbicides widely used in urban and farmland soils: fate, and potential human and environmental health risks

We determined the distribution, fate, and health hazards of dimethenamid-P, metazachlor, and pyroxasulfone, the effective pre-emergence herbicides widely used both in urban and agricultural settings globally. The rate-determining phase of sorption kinetics of these herbicides in five soils followed a pseudo-second-order model. Freundlich isotherm model indicated that the herbicides primarily partition into heterogeneous surface sites on clay minerals and organic matter (OM) and diffuse into soil micropores. Principal component analysis revealed that soil OM (R2, 0.47), sand (R2, 0.56), and Al oxides (R2, 0.33) positively correlated with the herbicide distribution coefficient (Kd), whereas clay (R2, ‒ 0.43), silt (R2, ‒ 0.51), Fe oxides (R2, ‒ 0.02), alkaline pH (R2, ‒ 0.57), and EC (R2, ‒ 0.03) showed a negative correlation with the Kd values. Decomposed OM rich in C=O and C–H functional groups enhanced herbicide sorption, while undecomposed/partially-decomposed OM facilitated desorption process. Also, the absence of hysteresis (H, 0.27‒0.88) indicated the enhanced propensity of herbicide desorption in soils. Leachability index (LIX, < 0.02–0.64) and groundwater ubiquity score (GUS, 0.02‒3.59) for the soils suggested low to moderate leaching potential of the herbicides to waterbodies, indicating their impact on water quality, nontarget organisms, and food safety. Hazard quotient and hazard index data for human adults and adolescents suggested that exposure to soils contaminated with herbicides via dermal contact, ingestion, and inhalation poses minimal to no non-carcinogenic risks. These insights can assist farmers in judicious use of herbicides and help the concerned regulatory authorities in monitoring the safety of human and environmental health.Graphical abstract

A conceptual design approach for mega-latticed structures based on combinatorial equilibrium modelling

In this paper, a novel equilibrium-based form-finding approach for a mega-latticed structure is presented based on vector-based 3D graphic statics and the Combinatorial Equilibrium Modelling (CEM). This approach can be effectively applied to the conceptual design phase of the structures with various design objectives under conservative loads. It allows us to adjust the design parameters in real time during the design phase and to obtain the resultant forms immediately. Based on a certain selection strategy, the forms have a better state of internal membrane forces compared to the original spherical structure. An ANSYS Parameter Design Language (APDL)-based automatic geometric modelling method for mega-latticed structures with various surface forms is developed. The proposed method solves the problem that the existing modelling methods are only available for spherical structures. It is highly applicable for modelling mega-latticed structures with spherical, cylindrical, and other heterogeneous surfaces. Furthermore, a complete design workflow that combines the proposed form-finding approach (for conceptual design), the automatic geometric modelling method (for transformation), and the finite element method (for deepening design and analysis), is discussed. This paper provides a reference for the design of mega-latticed structures and similar truss-based spatial structures.

Sustainable adsorption of methylene blue (MB) dye using individual and combined ratios of Trigonella foenum-graecum (F) seed galactomannan and Linum usitatissimum (L) seed

Abstract This study explores the adsorption of methylene blue (MB) dye from aqueous solution using different forms of fenugreek galactomannan and linseed (both individually and in combination) as an adsorbent. Characterization study of adsorbents reveal the involvement of carboxyl, hydroxyl and amine groups in MB adsorption taking place on the amorphous and porous surface of the adsorbent. BET surface area of the adsorbent (F+L) was found to be 394 m2/g. Different parameters including pH, adsorbent dose, adsorbate concentration, adsorption time and temperature were studied. Results of the study shows 86.62, 86.94, 88.04, 88.24, 88.56 and 89.09% of MB dye adsorption with F, L, F + L (1:1), F + L (1:2), F + L (2:1) and F + L (2:2) under optimized conditions. Maximum adsorption take place at pH 12, i.e., highly basic medium. Isothermal study shows the fitness of the experimental data to Langmuir isotherm model. Kinetic modeling shows that both physical and chemical interactions are involved in dye adsorption. Further, thermodynamic study confirms the spontaneity, endothermicity and feasibility of the process. Overall, current research involves the use of low-cost raw material for MB dye removal that aids in waste management and in promoting sustainability.

Single-domain antibodies reveal unique borrelicidal epitopes on the Lyme disease vaccine antigen, outer surface protein A (OspA).

Camelid-derived, single-domain antibodies (VHHs) have proven to be extremely powerful tools in defining the antigenic landscape of immunologically heterogeneous surface proteins. In this report, we generated a phage-displayed VHH library directed against the candidate Lyme disease vaccine antigen, outer surface protein A (OspA). Two alpacas were immunized with recombinant OspA serotype 1 from Borrelia burgdorferi sensu stricto strain B31, in combination with the canine vaccine RECOMBITEK Lyme containing lipidated OspA. The phage library was subjected to two rounds of affinity enrichment ("panning") against recombinant OspA, yielding 21 unique VHHs within two epitope bins, as determined through competition enzyme linked immunosorbent assays (ELISAs) with a panel of OspA-specific human monoclonal antibodies. Epitope refinement was conducted by hydrogen exchange-mass spectrometry. Six of the monovalent VHHs were expressed as human IgG1-Fc fusion proteins and shown to have functional properties associated with protective human monoclonal antibodies, including B. burgdorferi agglutination, outer membrane damage, and complement-dependent borreliacidal activity. The VHHs displayed unique reactivity profiles with the seven OspA serotypes associated with B. burgdorferi genospecies in the United States and Europe consistent with there being unique epitopes across OspA serotypes that should be considered when designing and evaluating multivalent Lyme disease vaccines.

Magnetic graphene derivates for efficient herbicide removal from aqueous solution through adsorption.

2,4-Dichlorophenoxyacetic acid (2,4-D) is an herbicide and is among the most widely distributed pollutant in the environment and wastewater. Herein is presented a complete comparison of adsorption performance between two different magnetic carbon nanomaterials: graphene oxide (GO) and its reduced form (rGO). Magnetic functionalization was performed employing a coprecipitation method, using only one source of Fe2+, requiring low energy, and potentially allowing the control of the amount of incorporated magnetite. For the first time in literature, a green reduction approach for GO with and without Fe3O4, maintaining the magnetic behavior after the reaction, and an adsorption performance comparison between both carbon nanomaterials are demonstrated. The nanoadsorbents were characterized by FTIR, XRD, Raman, VSM, XPS, and SEM analyses, which demonstrates the successful synthesis of graphene derivate, with different amounts of incorporate magnetite, resulting in distinct magnetization values. The reduction was confirmed by XPS and FTIR techniques. The type of adsorbent reveals that the amount of magnetite on nanomaterial surfaces has significant influence on adsorption capacity and removal efficiency. The procedure demonstrated that the best performance, for magnetic nanocomposites, was obtained by GO∙Fe3O4 1:1 and rGO∙Fe3O4 1:1, presenting values of removal percentage of 70.49 and 91.19%, respectively. The highest adsorption capacity was reached at pH 2.0 for GO∙Fe3O4 1:1 (69.98mgg-1) and rGO∙Fe3O4 1:1 (89.27mgg-1), through different interactions: π-π, cation-π, and hydrogen bonds. The adsorption phenomenon exhibited a high dependence on pH, initial concentration of adsorbate, and coexisting ions. Sips and PSO models demonstrate the best adjustment for experimental data, suggesting a heterogeneous surface and different energy sites, respectively. The thermodynamic parameters showed that the process was spontaneous and exothermic. Finally, the nanoadsorbents demonstrated a high efficiency in 2,4-D adsorption even after five adsorption/desorption cycles.

Controlling the Collision Type and Frequency of Single Pt Nanoparticles at Chemically Modified Gold Electrodes.

Studying the electrochemical response of single nanoparticles at an electrode surface gives insight into the dynamic and stochastic processes that occur at the electrode interface. Herein, we investigated single platinum nanoparticle collision dynamics and type (elastic vs inelastic) at gold electrode surfaces modified with self-assembled monolayers (SAMs) of varying terminal chemistries. Collision events are measured via the faradaic current from catalytic reactions at the Pt surface. By changing the terminal, solution-facing group of a thiolate monolayer, we observed the effect of hydrophobicity at the solution-electrode interface on single-particle collisions by employing either a hydrophobic -CH3 terminal group (1-hexanethiol), a hydrophilic -OH terminal group (6-mercaptohexanol), or an equimolar mixture of the two. Changes in the terminal group lead to alterations in collision-induced current magnitude, collisional frequency, and the distinct shape of the collision event current transient. The effects of the terminal group of the SAM were probed by measuring quantitative differences in the events monitored through both the hydrogen evolution reaction (HER) and hydrazine oxidation. In both cases, a platinum nanoparticle (PtNP) favors adsorption to bare and hydrophilic surfaces but demonstrates elastic collision behavior when it collides with a hydrophobic surface. In the case of a mixed monolayer, distinct characteristics of hydrophobic and hydrophilic surfaces are observed. We report how single nanoparticle collisions can reveal nanoscale surface heterogeneity and can be used to manipulate the nature of single-particle interactions on an electrode surface by functionalized self-assembled monolayers.

SORI: A softness-rendering interface to unravel the nature of softness perception

Tactile perception of softness serves a critical role in the survival, well-being, and social interaction among various species, including humans. This perception informs activities from food selection in animals to medical palpation for disease detection in humans. Despite its fundamental importance, a comprehensive understanding of how softness is neurologically and cognitively processed remains elusive. Previous research has demonstrated that the somatosensory system leverages both cutaneous and kinesthetic cues for the sensation of softness. Factors such as contact area, depth, and force play a particularly critical role in sensations experienced at the fingertips. Yet, existing haptic technologies designed to explore this phenomenon are limited, as they often couple force and contact area, failing to provide a real-world experience of softness perception. Our research introduces the softness-rendering interface (SORI), a haptic softness display designed to bridge this knowledge gap. Unlike its predecessors, SORI has the unique ability to decouple contact area and force, thereby allowing for a quantitative representation of softness sensations at the fingertips. Furthermore, SORI incorporates individual physical fingertip properties and model-based softness cue estimation and mapping to provide a highly personalized experience. Utilizing this method, SORI quantitatively replicates the sensation of softness on stationary, dynamic, homogeneous, and heterogeneous surfaces. We demonstrate that SORI accurately renders the surfaces of both virtual and daily objects, thereby presenting opportunities across a range of fields, from teleoperation to medical technology. Finally, our proposed method and SORI will expedite psychological and neuroscience research to unlock the nature of softness perception.

Efficient production of isomaltulose using engineered Yarrowia lipolytica strain facilitated by non-yeast signal peptide-mediated cell surface display.

Isomaltulose is a 'generally recognized as safe' ingredient and is widely used in the food, pharmaceutical and chemical industries. The exploration and development of efficient technologies is essential for enhancing isomaltulose yield. In the present study, a simple and efficient surface display platform mediated by a non-yeast signal peptide was developed in Yarrowia lipolytica and utilized to efficiently produce isomaltulose from sucrose. We discovered that the signal peptide SP1 of sucrose isomerase from Pantoea dispersa UQ68J (PdSI) could guide SIs anchoring to the cell surface of Y. lipolytica, demonstrating a novel and simple cell surface display strategy. Furthermore, the PdSI expression level was significantly increased through optimizing the promoters and multi-site integrating genes into chromosome. The final strain gained 451.7 g L-1 isomaltulose with a conversion rate of 90.3% and a space-time yield of 50.2 g L-1 h-1. The present study provides an efficient way for manufacturing isomaltulose with a high space-time yield. This heterogenous signal peptide-mediated cell surface display strategy featured with small fusion tag (approximately 2.2 kDa of SP1), absence of enzyme leakage in fermentation broth and ample room for optimization, providing a convenient way to construct whole-cell biocatalysts to synthesize other products and broadening the array of molecular toolboxes accessible for engineering Y. lipolytica. © 2024 Society of Chemical Industry.

Containment control of networked heterogeneous autonomous surface vehicles: A data‐driven control approach

AbstractIn this article, by creating a novel distributed full‐form dynamic linearization based model‐free adaptive containment control (FFDL‐MFACC) approach, the containment control problem of networked heterogeneous autonomous surface vehicles (ASVs), suffering from complex external disturbances and unavailable kinetic model‐information, is resolved. In light of the data‐driven strategy, a full‐form dynamic linearization‐based data model is efficiently established. Then, by further deploying the commonly used rotation matrix, a distributed FFDL‐MFACC scheme is thereafter developed such that accurate tracking of a predefined convex hull spanned for all follower vehicles can be achieved. Afterwards, a disturbance observer is further designed to accurately estimate the lumped disturbances and the estimation is served as a compensation within the distributed full‐form dynamic linearization. Rigorously theoretical analysis indicates the devised distributed FFDL‐MFACC method can ensure the asymptotic containment tracking of networked heterogeneous ASVs. Finally, simulation results are illustrated to verify the advantages of the devised approach.

Modified Clinoptilolite for the Removal of Rhodamine B Dye from Wastewater

This study reveals the modification of the surface area of natural zeolite Clinoptilolite (CLN) by implementing the ion exchange method. The ammonium chloride cation exchange method was adopted and was followed by calcination at 450 °C for 5 h. This procedure helps to increase the surface area of CLN and also enhances its adsorption efficiency. The modifications of the CLN were confirmed by Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) analysis. The efficiency and adsorption capacity of the modified CLN were determined by the adsorption of a Rhodamine B (Rh B) dye from an aqueous medium. The comparative analysis of the adsorption efficiency of raw CLN and the modified CLN revealed an enhanced adsorption of Rh B by the modified CLN at pH = 10. For desorption, different solvents were used. The results showed good desorption in ethanol and methanol, and poor desorption in acidic (HCl) and basic (NaOH) solutions. The kinetic study of the adsorption of Rh B by the modified CLN helped us to conclude that the adsorption follows a pseudo-second-order kinetics. For the surface study and to understand the mechanism of adsorption, several isotherm models were applied to the adsorption data at equilibrium. The data showed consistency with the Freundlich adsorption isotherm confirming that the process took place at its heterogeneous surface. The experimentally calculated adsorption capacity of the modified CLN was 2.81 mg g−1, showing a comparable value to certain other common adsorbents. Therefore, the modified CLN may also be considered a cost-effective and promising adsorbent for the removal of Rh B dye from wastewater.

Ecofriendly Application of Calabrese Broccoli Stalk Waste as a Biosorbent for the Removal of Pb(II) Ions from Aqueous Media

A new biosorbent obtained from Calabrese broccoli stalks has been prepared, characterised and used as an effective, low-cost and ecofriendly biomass to remove Pb(II) from aqueous solutions, without any complicated pretreatment. Structural and morphological characterisation were performed by TGA/DGT, FTIR and SEM/EDX; the main components are hemicellulose, starches, pectin, cellulose, lignin and phytochemicals, with important electron donor elements (such as S from glucosinolates of broccoli) involved in Pb(II) sorption. The biosorbent showed values of 0.52 and 0.65 g mL−1 for bulk and apparent densities, 20.6% porosity, a specific surface area of 15.3 m2 g−1, pHpzc 6.25, iodine capacity of 619 mg g−1 and a cation exchange capacity of 30.7 cmol kg−1. Very good sorption (88.3 ± 0.8%) occurred at pH 4.8 with a biomass dose of 10 g L−1 after 8 h. The Freundlich and Dubinin–Radushkevich isotherms and the pseudo-second-order kinetic models explained with good fits the favourable Pb(II) sorption on the heterogeneous surface of broccoli biomass. The maximum adsorption capacity was 586.7 mg g−1. The thermodynamic parameters evaluated showed the endothermic and spontaneous nature of the Pb(II) biosorption. The chemical mechanisms mainly involved complexation, ligand exchange and cation–π interaction, with possible precipitation.

The amine-functionalized alumina captures CO2 directly from the ambient air in the rotating adsorption bed

Global warming presents formidable challenges, prompting the exploration of Direct Air Capture (DAC) as a promising solution. This study employed the ultrasonic impregnation method to load polyethyleneimine (PEI) onto cost-effective millimeter-sized spherical γ-Al2O3 microspheres, thereby preparing an efficient amine-modified adsorbent. Characterization reveals a uniform dispersion of PEI, resulting in an adsorbent with an effective pore structure, enhancing CO2 diffusion. The adsorption experiment combines DAC with high gravity technology, best conditions at a PEI load of 16.37%, high gravity factor of 2.67, and gas flow rate of 30 L/min. Under these conditions, an impressive adsorption capacity of 41.75 mg/g was achieved, marking an increase of 12.11 mg/g compared to the traditional fixed-bed method. The amine efficiency also reaches 0.25. The Freundlich model outperforms the Langmuir model in fitting isotherm curves, suggesting that the experimental data align with the characteristics of a heterogeneous surface and multilayer adsorption. The fitting results of kinetic models further show that RAB's adsorption rate constant has a significantly better fitting value compared to traditional fixed bed methods. The research provides valuable insights for the application and development of DAC technology, enabling new possibilities for future carbon capture and emission reduction efforts.

Using X-ray computed tomography and pore-scale numerical modeling to study the role of heterogeneous rock surface wettability on hydrogen-brine two-phase flow in underground hydrogen storage

Underground hydrogen storage (UHS) is receiving increasing attention to address the challenges in hydrogen storage. A crucial aspect of UHS is understanding the transport of hydrogen in subsurface porous media. In this work, hydrogen core flooding experiments were conducted in a sandstone sample and then the pore-scale distribution of hydrogen and brine was visualized using high-resolution X-ray micro-computed tomography (micro-CT). After CT image processing, we measured the surface contact angles (CAs) on rock surfaces and found that the measured CAs followed a log-normal distribution. To investigate the influence of rock surface wettability on the transport properties in the hydrogen-brine-sandstone system, the lattice Boltzmann (LB) method was used to simulate two-phase flows with different surface CA distributions; hydrogen-brine relative permeability and capillary pressure curves through the primary drainage, imbibition, and secondary drainage processes were obtained by LB simulations. X-ray CT scanning showed that hydrogen resided in both large pores and small pores and pore throats after the primary drainage process (i.e., hydrogen displacing brine), whereas after the imbibition process (i.e., brine displacing hydrogen) hydrogen stayed primarily in large pores where the capillary pressure barriers were low. The LB two-phase flow modeling illustrated that water’s relative permeability increased whereas hydrogen’s relative permeability decreased when the core flooding moved from primary drainage to imbibition; in contrast, when the core flooding moved from imbibition to secondary drainage, water’s relative permeability decreased whereas hydrogen’s relative permeability increased. Decreasing the surface CA increased the capillary pressure and reduced the hydrogen residual rate, which indicates high hydrogen retrievability and thus is favorable for UHS practice. The change in CA’s standard deviation did not cause noticeable changes in water’s relative permeability curves, whereas it resulted in noticeable changes in hydrogen’s relative permeability curves. This work is the first study that utilizes X-ray micro-CT scanning and pore-scale multiphase flow modeling to quantitatively and comprehensively investigate hydrogen-brine two-phase flow properties under different rock surface wettability distributions. The research findings from this study will advance the understanding of hydrogen transport in an underground storage system and provide essential data for large-scale field studies in UHS.

Surface Heat Monitoring with High-Resolution UAV Thermal Imaging: Assessing Accuracy and Applications in Urban Environments

The urban heat island (UHI) effect, where urban areas experience higher temperatures than surrounding rural regions, necessitates effective monitoring to estimate and address its diverse impacts. Many existing studies on urban heat dynamics rely on satellite data with coarse resolutions, posing challenges in analyzing heterogeneous urban surfaces. Unmanned aerial vehicles (UAVs) offer a solution by providing thermal imagery at a resolution finer than 1 m. Despite UAV thermal imaging being extensively explored in agriculture, its application in urban environments, specifically for surface temperatures, remains underexplored. A pilot project conducted in Athens, Georgia, utilized a UAV with a FLIR Vue Pro R 640 thermal camera to collect thermal data from two neighborhoods. Ground data, obtained using a handheld FLIR E6-XT infrared imaging camera, were compared with UAV thermal imagery. The study aimed to assess the accuracy of the UAV camera and the handheld camera for urban monitoring. Initial testing revealed the handheld’s accuracy but tendency to underpredict, while UAV camera testing highlighted considerations for altitude in both the rjpg and tiff image pixel conversion models. Despite challenges, the study demonstrates the potential of UAV-derived thermal data for monitoring urban surface temperatures, emphasizing the need for careful model considerations in data interpretation.

Synthesis and characterization of citric acid-modified chitosan Schiff base with enhanced antibacterial properties for the elimination of Bismarck Brown R and Rhodamine B dyes from wastewater

In this study, a new chitosan Schiff base with surface modification using citric acid was synthesized for efficient removal of pernicious dyes, namely Bismarck Brown R (BBR) and Rhodamine B (RhB), from wastewater. The physicochemical properties of the modified chitosan Schiff base were comprehensively investigated. Adsorption studies demonstrated that BBR adsorption occurred through monolayer formation, while RhB adsorption proceeded via multilayer formation on the heterogeneous surface. The synthesized adsorbent exhibited exceptional dye removal efficiency, with a Langmuir saturation capacity of 348 ± 11.0 mg.g−1 for BBR and 145 ± 18.44 mg.g−1 for RhB. Isotherm data fitting revealed consistency with the Langmuir isotherm model for BBR and the Freundlich isotherm model for RhB. Notably, the modified chitosan Schiff base showcased enhanced antibacterial properties, effectively inhibiting both gram-positive and gram-negative bacteria. The study's findings underscore the potential of this novel chitosan-based Schiff base as an efficient adsorbent for the removal of various dyes from wastewater, emphasizing its versatility and practical applicability in water treatment processes.

Airflow Triggered Water Film Self-Sculpturing on Femtosecond Laser-Induced Heterogeneously Wetted Micro/Nanostructured Surfaces.

Liquid manipulation is essential for daily life and modern industry, and it is widely used in various fields, including seawater desalination, microfluidic robots, and biomedical engineering. Nevertheless, the current research focuses on the manipulation of individual droplets. There are a few projects for water film management. Here, we proposed a facile method of wind-triggered water film self-sculpturing based on a heterogeneous wettability surface, which is achieved by the femtosecond laser direct writing technology and femtosecond laser deposition. Under the conditions of various airflow velocities and water film thicknesses, three distinct behaviors of the water film were analyzed. As a result, when the water film thickness is lower than 4.9 mm, the self-sculpture process will occur until the whole superhydrophobic surface dewetting. Four potential applications are demonstrated, including encryption, oil containers, reconfigurable patterning, and self-splitting devices. This work provides a new approach for manipulating a water film of fluid control engineering.

Enhancing microdroplet array generation via heterogeneous inner surface Modification: Biomimetic & hydrophobic approach

Microdroplet array chips have great potential for biological applications. Both physical structure and chemical material modification are effective surface modification techniques for the generation of droplet arrays. However, single surface modification technique is constrained by either unstable infiltration state transition or the requirement for high surface tension. In this paper, we proposed a heterogeneous inner surface modification technique for an enclosed microdroplet array chip by coupling the physically structured surface modification that accelerates the wetting state of the aqueous solution, and the material-modified surface that can maintain this state, thus keeping the aqueous solution in a stable Wenzel state. This technique provides a stable surface energy difference for enhanced microdroplet array generation. We investigated the influences of variables that affect the heterogeneity of the inner surfaces of the chip, such as the contact angles of the upper and lower surfaces and the size of the micropores on the stability and size of the generated droplet. We also evaluated the compatibility of technique for different types of liquids and biological reagents for the droplet array generation. Furthermore, we demonstrated the potential of the droplet arrays generated in a heterogeneous dual-regulation manner for DNA amplification in loop-mediated isothermal amplification (LAMP).

Experimental kinetics and thermodynamics investigation: Chemically activated carbon-enriched monolithic reduced graphene oxide for efficient CO2 capture

In this research, we have developed solid MGOs by self-assembled reduction process of GO at 90 °C with different weight ratios of oxalic acid (1:1, 1:0.500, and 1:0.250). The as-synthesized monoliths were carbonized (at 600 °C) and chemically activated with varying proportions of NaOH (1:1, 1:2, and 1:3). This materials offer the CO2 adsorption effect under dynamic conditions, fast mass transfer, easy handling, and outstanding stability throughout the adsorption-desorption cycle. FE-SEM, and HR-TEM analyses confirmed the porous nature and shape of the adsorbents, while XPS examination revealed the presence of distinct functional groups on the surface of the monolith. By increasing the mass ratios (MGO:NaOH) from 1:1 to 1:2, the surface areas increased by approximately 2.6 times, ranging from 520.8 to 753.9 m2 g⁻1 (surface area of the untreated MGO was 289.2 m2 g⁻1). Consequently, this resulted in a notable enhancement of 2.10 mmol g⁻1 in dynamic CO2 capture capacity. The assessment encompassed the evaluation of production yield, selectivity, regenerability, kinetics, equilibrium isotherm, and isosteric temperatures of adsorption (Qst). The decrease in CO2 capture effectiveness with rising adsorption temperature indicated an exothermic and physisorption process. The regenerability of 99.1 % at 100 °C and excellent cyclic stability with efficient CO2 adsorption make this monolithic adsorbent appropriate for post-combustion CO2 capture. The significant Qst lend support to the heterogeneity of the adsorbent's surface, and the pseudo-second-order kinetic model along with the Freundlich isotherm model emerged as the most fitting. Therefore, the current investigation shows that the carbon-enriched adsorbents enhance the CO2 adsorption capacity. It may be used as a low-cost pretreatment method on an industrial scale before carbon capture.