Non-porous Materials Research Articles

Recovery and Visualisation of Methamphetamine-Contaminated Fingermarks from Non-Porous Surfaces

Introduction: Fingermarks left at a crime scene can indicate the presence of an individual and his/her involvement in the crime. Fingermarks, usually invisible, can appear on any surface and may be contaminated by any exogenous substances, including drug substance. Recovery of fingermarks contaminated by drug substance is crucial to link an individual with the drug-related crimes. Hence, this study was aimed to investigate the recovery and visualisation of methamphetamine-contaminated fingermarks from various non-porous surface materials. Methods: In this study, fingermarks were deposited on 11 types of surface materials varied by the presence of methamphetamine contamination, immediacy of deposition, and their concentration levels. Each fingermark was then developed using white and black fingerprint powders, graded, and compared based on the different settings. Results: Application of fingerprint powder was good in developing fingermarks; however, its suitability depends on the nature of the surface materials. Black fingerprint powder produced better visualisation where the fingermarks on all the 11 surface materials tested in this study were successfully recovered compared to white fingerprint powders. Methamphetamine-contaminated fingermarks could still be recovered using the fingerprint powder dusting method, but the fingermark grade was reduced due to the presence of exogenous substance. Conclusion: To conclude, the recovery and visualisation of methamphetamine-contaminated fingermarks on non-porous surfaces were successfully carried out through the application of fingerprint powder. A more severe contamination might lead to lower fingermark grade showing lesser ridge details.

Carbons Derived from Agave tequilana Fibers as Efficient Sulfur Supports for High‐Performance Lithium–Sulfur Batteries

The fabrication of cathodes with carbonized Agave tequilana bagasse for Li–S batteries is performed for the first time. Three porous carbonaceous structures are developed and studied to elucidate the best carbon textural properties in terms of their surface area and pore size distribution: hierarchical porosity, highly microporous, and nonporous material, for sulfur hosting in Li–S cathodes. N2 physorption, scanning electron microscopy, infrared spectroscopy, and potentiometric titrations analysis are performed to determine the textural, morphology, and physicochemical properties. The fabricated coin cells, CR2032, with cathodes made of mesoporous carbons, display a high discharge current (≈1600 mAh g−1), superior performance, and cyclability up to 250 cycles. The performance of batteries is found to be strongly influenced by surface area and pore size of the carbon materials. The carbonized tequila bagasse hosting sulfur can be very useful to fabricate cathodes for Li–S batteries with high initial capacity and cycling stability.

Biological Activity of Poly(1,3-propanediol citrate) Films and Nonwovens: Mechanical, Thermal, Antimicrobial, and Cytotoxicity Studies.

Polymers are of great interest for medical and cosmeceutical applications. The current trend is to combine materials of natural and synthetic origin in order to obtain products with appropriate mechanical strength and good biocompatibility, additionally biodegradable and bioresorbable. Citric acid, being an important metabolite, is an interesting substance for the synthesis of materials for biomedical applications. Due to the high functionality of the molecule, it is commonly used in biomaterials chemistry as a crosslinking agent. Among citric acid-based biopolyesters, poly(1,8-octanediol citrate) is the best known. It shows application potential in soft tissue engineering. This work focuses on a much less studied polyester, poly(1,3-propanediol citrate). Porous and non-porous materials based on the synthesized polyesters are prepared and characterized, including mechanical, thermal, and surface properties, morphology, and degradation. The main focus is on assessing the biocompatibility and antimicrobial properties of the materials.

Droplet absorption and spreading into thin layers of polymer hydrogels

From biological tissues to microactuators and absorption of solvents into layers of paint, macroscopically non-porous materials with the capacity to swell when in contact with a solvent are ubiquitous. In these systems, owing to strong solid–fluid interactions, chemically driven flows can yield large geometric changes. We study experimentally and theoretically the canonical problem of the swelling of a thin hydrogel layer by a single water drop. Using a bespoke experimental set-up, we observe fast absorption leading to a radially spreading axisymmetric blister. We use a fully three-dimensional linear poroelastic framework with nonlinear kinematic equations to obtain governing equations, which we then reduce with thin-layer scalings to a one-dimensional nonlinear diffusion equation for the evolution of the blister geometry. In the limits of large and small deformations, the evolution of the blister characteristic height and radius are self-similar, following power laws in time. Our experimental measurements show that the evolution of the blister is broadly within the theoretical predictions in the large and small deformation regimes. In the general intermediate deformation regime, the measurements are well captured by our reduced one-dimensional diffusion model, which does not require the sophisticated and computationally expensive numerical approaches necessary for the original two-dimensional nonlinear coupled transport problem. By adapting modelling techniques from the fluid dynamics of thin porous elastic layers to a polymer swelling problem, our modelling framework extends the range of polymer swelling problems that can be treated with semi-analytical methods. Moreover, our detailed experimental data can serve as a test case for future nonlinear poroelastic frameworks of swelling polymer materials.

Biodegradable iron-based foams prepared by the space holder technique using urea

Iron-based degradable biomaterials have attracted much attention as next-generation bone implants due to their excellent mechanical properties and good biocompatibility. Many studies are now focusing on the preparation and detailed study of porous versus non-porous degradable materials. Porous degradable biomaterials have many advantages over the non-porous ones owing to their structure, which allows easier bone tissue ingrowth. The aim of this work was to prepare Fe-based biodegradable porous materials in a cost-effective way via powder metallurgy technique using urea space holders. Five different samples with increasing space holder weight ratio (up to 20 wt%) were prepared. Surface morphology and sample structure were studied using the optical microscopy, Raman spectroscopy, and scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX). Electrochemical corrosion rate analysis confirmed that the samples corroded faster with increasing number of pores. With an increasing amount of urea, the number of pores increased proportionally, which can potentially be used to tune the corrosion rate. However, mechanical integrity of the samples was not maintained when more than 10 wt% of space holder was used.Graphical abstract

Comparative analysis of interaction of ionic liquids with porous and non-porous electrode materials

Fascinating properties of ionic liquids such as their higher ionic conductivity, lower vapor pressure, high thermal and electrochemical stability, make them promising candidates as electrolytes for novel energy storage devices. Interaction of ionic liquids (ILs) as electrolytes with electrode is crucial for optimizing the efficiency of energy storage devices. Herein, we report the interaction mechanism of ionic liquids 1-3 dimethylimidazolium halide (1,3-DMIX) on porous covalent triazine frameworks (CTF-0) and non-porous carbon nitride (C4N) electrode materials. Molecular electrostatic potential (MEP) analysis is performed for the prediction of interacting sites on studied electrolytes and electrode materials. Significant changes in geometric and electronic parameters are observed upon interaction of ionic liquid electrolytes with C4N and CTF-0. The nature of interaction between ionic liquids and electrode surfaces is evaluated through Quantum theory of atoms in molecules (QTAIM) and non-covalent index (NCI) analyses which reveal that there exist only the non-covalent interactions (van der Waals) between them. Frontier molecular orbitals (FMO) analysis shows a significant decrease in energy gap upon interaction of ILs with CTF-0, which results in increase in electrical conductivity. Overall, porous CTF-0 electrode material displays greater interaction with the considered ILs as compared to non-porous C4N electrode material. This study will provide a way for experimentalist to explore ionic liquids and carbon nitride or covalent triazine framework as electrolyte–electrode systems which can be used further in energy storage devices like fuel cells, solar cells, ion batteries, and supercapacitors.

Adhesion and morphology of mammalian cells on nanoporous and nonporous spherical carbon substrates

Three spherical activated carbons (SACs) were used as substrates for mammalian cell proliferation. SACs were obtained by carbonizing styrene-co-divinylbenzene ion exchangers 35WET, XAD4, or 1200H. The new materials (XAD_C, WET_C, and H_C) were characterized by adsorption–desorption nitrogen isotherms and mercury intrusion porosimetry. XAD_C and WET_C exhibited well-developed BET surface areas, similar total pore volumes, and highly different pore size distributions. H_C was nonporous spherical material—reference material. The XAD_C was meso-macroporous, but the WET_C was micro-mesoporous. All SACs were not cytotoxic toward Leydig TM3 cells. The differences in porous structure and morphology of the carbon scaffolds led to morphological differences in adhered cells. The monolayer of cells was distributed flat over the entire WET_C and H_C surfaces. Leydig TM3 cells adhered to nonporous SAC but were easily washed out due to weak adhesion. The cells adhered in clusters to XAD_C and proliferated in clusters. As microscopic techniques and viability tests demonstrated, only nanoporous carbons provided a good surface for the attachment and proliferation of eukaryotic cells.

Adsorption of Basic Yellow 28 and Basic Blue 3 Dyes from Aqueous Solution Using Silybum Marianum Stem as a Low-Cost Adsorbent.

In the present study, the ability of an adsorbent (SLM Stem) obtained from the stem of the Silybum Marianum plant to treat wastewater containing the cationic dyes basic blue 3 (BB3) and basic yellow 28 (BY28) from aqueous solutions was investigated using a batch method. Then, the SLM Stem (SLM Stem-Natural) adsorbent was carbonized at different temperatures (200-900 °C) and the removal capacity of the products obtained for both dyes was examined again. The investigation continued with the product carbonized at 800 °C (SLM Stem-800 °C), the adsorbent with the highest removal capacity. The dyestuff removal studies were continued with the SLM Stem-Natural and SLM Stem-800 °C adsorbents because they had the highest removal values. The surface properties of these two adsorbents were investigated using IR, SEM, and XRD measurements. It was determined that the SLM Stem-Natural has mainly non-porous material, and the SLM Stem-800 °C has a microporous structure. The optimal values for various parameters, including adsorbent amount, initial dye solution concentration, contact time, temperature, pH, and agitation speed, were investigated for BY28 dye and were 0.05 g, 15 mg/L, 30 min, 40 °C, pH 6 and 100 rpm when SLM Stem-Natural adsorbent was used and, 0.15 g, 30 mg/L, 30 min, 40 °C, pH 10, and 150 rpm when SLM Stem-800 °C adsorbent was used. For BB3 dye, optimal parameter values of 0.20 g, 10 mg/L, 30 min, 25 °C, pH 7, and 100 rpm were obtained when SLM Stem-Natural adsorbent was used and 0.15 g, 15 mg/L, 40 min, 40 °C, pH 10, and 100 rpm when SLM Stem-800 °C adsorbent was used. The Langmuir isotherm described the adsorption process best, with a value of r2 = 0.9987. When SLM Stem-800 °C adsorbent was used for BY28 dye at 25 °C, the highest qm value in the Langmuir isotherm was 271.73 mg/g. When the study was repeated with actual water samples under optimum conditions, the highest removal for the BY28 dye was 99.9% in tap water with the SLM Stem-800 °C adsorbent. Furthermore, the reuse study showed the adsorbent's efficiency even after three repetitions.

Persistence of Coronavirus on Surface Materials and Its Control Measures Using Nonthermal Plasma and Other Agents.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been responsible for the initiation of the global pandemic since 2020. The virus spreads through contaminated air particles, fomite, and surface-contaminated porous (i.e., paper, wood, and masks) and non-porous (i.e., plastic, stainless steel, and glass) materials. The persistence of viruses on materials depends on porosity, adsorption, evaporation, isoelectric point, and environmental conditions, such as temperature, pH, and relative humidity. Disinfection techniques are crucial for preventing viral contamination on animated and inanimate surfaces. Currently, there are few effective methodologies for preventing SARS-CoV-2 and other coronaviruses without any side effects. Before infection can occur, measures must be taken to prevent the persistence of the coronavirus on the surfaces of both porous and non-porous inanimate materials. This review focuses on coronavirus persistence in surface materials (inanimate) and control measures. Viruses are inactivated through chemical and physical methods; the chemical methods particularly include alcohol, chlorine, and peroxide, whereas temperature, pH, humidity, ultraviolet irradiation (UV), gamma radiation, X-rays, ozone, and non-thermal, plasma-generated reactive oxygen and nitrogen species (RONS) are physical methods.

Nonporous amorphous superadsorbents for highly effective and selective adsorption of iodine in water

Adsorbents widely utilized for environmental remediation, water purification, and gas storage have been usually reported to be either porous or crystalline materials. In this contribution, we report the synthesis of two covalent organic superphane cages, that are utilized as the nonporous amorphous superadsorbents for aqueous iodine adsorption with the record–breaking iodine adsorption capability and selectivity. In the static adsorption system, the cages exhibit iodine uptake capacity of up to 8.41 g g−1 in I2 aqueous solution and 9.01 g g−1 in I3− (KI/I2) aqueous solution, respectively, even in the presence of a large excess of competing anions. In the dynamic flow-through experiment, the aqueous iodine adsorption capability for I2 and I3− can reach up to 3.59 and 5.79 g g−1, respectively. Moreover, these two superphane cages are able to remove trace iodine in aqueous media from ppm level (5.0 ppm) down to ppb level concentration (as low as 11 ppb). Based on a binding–induced adsorption mechanism, such nonporous amorphous molecular materials prove superior to all existing porous adsorbents. This study can open up a new avenue for development of state–of–the–art adsorption materials for practical uses with conceptionally new nonporous amorphous superadsorbents (NAS).

DEVELOPMENT OF THE METHOD OF DESIGNING THE MICRO SCREW EXTRUDER OF A 3D PRINTER

The article deals with the development of a design method for a 3D printer extruder screw. The key aspects that must be applied during design are described. The main mechanical properties that should be taken into account when designing the screw element of the extruder are given. Various designs of screws, their advantages and disadvantages are considered. A single-screw extruder was selected for a 3D printer, which uses granules, crushed waste polymer materials as raw materials. It is proposed to use a three-zone cylindrical one-way screw with a constant pitch and without a degassing zone of the screw for processing granules or crushed polymer particles. Recommended for screw extruders that do not require high dosing pressure of molten polymer material and that process non-porous homogeneous polymer materials, single-zone screws with a constant pitch and depth of screw cutting. Their use in the processing of cut strips from plastic waste is proposed. The main geometric parameters of the screw with a constant pitch and a variable depth of the screw channel were determined for designing. The diameter for the 3D printer extruder has been selected. Dependencies are given for determining the length of the screw, the pitch of the screw thread, the width of the crest of the turn, the angle of elevation of the screw line of the screw thread, and the depth of the screw channel of the screw. Dependencies are given for determining the boundaries of feeding, plasticizing, and dosing zones. The degree of screw compression was determined for the main polymer materials used in 3D printing. The geometry of screws depending on the degree of compression for different materials is given. A formula is presented for determining the volume performance of a 3D printer extruder depending on the design of the dosing zone and nozzle resistance. The formulas for determining the forward flow constant, the reverse flow constant and the flow constant of the flowing material and the dependence of the coefficients characterizing the design of the auger with a variable cutting depth are presented. The geometric parameters of screws with a constant pitch and depth of screw cutting and expressions for their determination are described.

Sequential Water Sorption/Desorption of a Nonporous Adaptive Organic Ligand Bridged Coordination Polymer for Atmospheric Moisture Harvesting.

Moisture harvesters with favourable attributes such as easy synthetic availability and good processability as alternatives for atmospheric moisture harvesting (AWH) are desirable. This study reports a novel nonporous anionic coordination polymer (CP) of uranyl squarate with methyl viologen (MV2+ ) as charge balancing ions (named U-Squ-CP) which displays intriguing sequential water sorption/desorption behavior as the relative humidity (RH) changes gradually. The evaluation of AWH performance of U-Squ-CP shows that it can absorb water vapor under air atmosphere at a low RH of 20 % typical of the levels found in most dry regions of the world, and have good cycling durability, thus demonstrating the capability as a potential moisture harvester for AWH. To the authors' knowledge, this is the first report on non-porous organic ligand bridged CP materials for AWH. Moreover, a stepwise water-filling mechanism for the water sorption/desorption process is deciphered by comprehensive characterizations combining single-crystal diffraction, which provides a reasonable explanation for the special moisture harvesting behaviour of this non-porous crystalline material.

Waste Biomass Originated Biocompatible Fluorescent Graphene Nano-Sheets for Latent Fingerprints Detection in Versatile Surfaces

In recent years, the application of biocompatible and non-toxic nanomaterials for the detection of fingerprints has become the major interest in the forensic sector and crime investigation. In this study, waste chickpea seeds, as a natural resource, were bioprocessed and utilized for the synthesis of non-toxic graphene nano-sheets (GNSs) with high fluorescence. The graphene GNS were synthesized via pyrolysis at high temperatures and were characterized by TEM, XPS, fluorescence and UV-Vis spectroscopy, and FTIR analysis. The GNS exhibited excitation-independent emission at about 620 nm with a quantum yield of over 10% and showed more distinct blue light under a UV lamp. Biocompatibility of the synthesized GNS in terms of cell viability (88.28% and 74.19%) was observed even at high concentrations (50 and 100 mg/mL), respectively. In addition, the antimicrobial properties of the synthesized GNS-based coatings were tested with the pathogenic strain of Bacillus cereus via live/dead cell counts and a plate counting method confirming their biocompatible and antimicrobial nature for their potential use in safe fingerprint detection. The developed chickpea-originated fluorescent GNS-based spray coatings were tested on different surfaces, including plastic, glass, silicon, steel, and soft plastic for the detection of crime scene fingerprints. Results confirmed that GNS can be used for the detection of latent fingerprints on multiple non-porous surfaces and were easy to detect under a UV lamp at 395 nm. These findings reinforce the suggestion that the developed fluorescent GNS spray coating has a high potential to increase sensitive and stable crime traces for forensic latent fingerprint detection on nonporous surface material. Capitalizing on their color-tunable behavior, the developed chickpea-originated fluorescent GNS-based spray coating is ideal for the visual enhancement of latent fingerprints.

Variability in Donor Lung Culture and Relative Humidity Impact the Stability of 2009 Pandemic H1N1 Influenza Virus on Nonporous Surfaces.

Respiratory viruses can be transmitted by multiple modes, including contaminated surfaces, commonly referred to as fomites. Efficient fomite transmission requires that a virus remain infectious on a given surface material over a wide range of environmental conditions, including different relative humidities. Prior work examining the stability of influenza viruses on surfaces has relied upon virus grown in media or eggs, which does not mimic the composition of virus-containing droplets expelled from the human respiratory tract. In this study, we examined the stability of the 2009 pandemic H1N1 (H1N1pdm09) virus on a variety of nonporous surface materials at four different humidities. Importantly, we used virus grown in primary human bronchial epithelial cell (HBE) cultures from different donors to recapitulate the physiological microenvironment of expelled viruses. We observed rapid inactivation of H1N1pdm09 on copper under all experimental conditions. In contrast to copper, viruses were stable on polystyrene plastic, stainless steel, aluminum, and glass, at multiple relative humidities, but greater decay on acrylonitrile butadiene styrene (ABS) plastic was observed at short time points. However, the half-lives of viruses at 23% relative humidity were similar among noncopper surfaces and ranged from 4.5 to 5.9 h. Assessment of H1N1pdm09 longevity on nonporous surfaces revealed that virus persistence was governed more by differences among HBE culture donors than by surface material. Our findings highlight the potential role of an individual's respiratory fluid on viral persistence and could help explain heterogeneity in transmission dynamics. IMPORTANCE Seasonal epidemics and sporadic pandemics of influenza cause a large public health burden. Although influenza viruses disseminate through the environment in respiratory secretions expelled from infected individuals, they can also be transmitted by contaminated surfaces where virus-laden expulsions can be deposited. Understanding virus stability on surfaces within the indoor environment is critical to assessing influenza transmission risk. We found that influenza virus stability is affected by the host respiratory secretion in which the virus is expelled, the surface material on which the droplet lands, and the ambient relative humidity of the environment. Influenza viruses can remain infectious on many common surfaces for prolonged periods, with half-lives of 4.5 to 5.9 h. These data imply that influenza viruses are persistent in indoor environments in biologically relevant matrices. Decontamination and engineering controls should be used to mitigate influenza virus transmission.

Reversible Chromism of Tethered Ruthenium(II) Complexes in the Solid State.

Tethered ruthenium(II) complexes [Ru(η6:κ1-arene:N)Cl2] (where arene:N is 2-aminobiphenyl (1) and 2-benzylpyridine (2)) can convert into their open-tethered chlorido counterparts [Ru(η6-arene:NH)Cl3], 1·HCl and 2·HCl, at room temperature via solid-state reaction in the presence of HCl vapors. The reaction is accompanied by a change in color, is fully reversible, and crystallinity is maintained in both molecular materials. Organoruthenium tethers are presented as nonporous materials capable of capturing and releasing HCl reversibly in the crystalline solid state.

Demonstrating the In Vitro and In Situ Antimicrobial Activity of Oxide Mineral Microspheres: An Innovative Technology to Be Incorporated into Porous and Nonporous Materials.

The antimicrobial activity of surfaces treated with zinc and/or magnesium mineral oxide microspheres is a patented technology that has been demonstrated in vitro against bacteria and viruses. This study aims to evaluate the efficiency and sustainability of the technology in vitro, under simulation-of-use conditions, and in situ. The tests were undertaken in vitro according to the ISO 22196:2011, ISO 20473:2013, and NF S90-700:2019 standards with adapted parameters. Simulation-of-use tests evaluated the robustness of the activity under worst-case scenarios. The in situ tests were conducted on high-touch surfaces. The in vitro results show efficient antimicrobial activity against referenced strains with a log reduction of >2. The sustainability of this effect was time-dependent and detected at lower temperatures (20 ± 2.5 °C) and humidity (46%) conditions for variable inoculum concentrations and contact times. The simulation of use proved the microsphere's efficiency under harsh mechanical and chemical tests. The in situ studies showed a higher than 90% reduction in CFU/25 cm2 per treated surface versus the untreated surfaces, reaching a targeted value of <50 CFU/cm2. Mineral oxide microspheres can be incorporated into unlimited surface types, including medical devices, to efficiently and sustainably prevent microbial contamination.

Steady state thermal analysis of a porous fin with radially outwards fluid flow

Fins are used ubiquitously in engineering devices and systems for enhancement of heat transfer and energy storage. While traditional fins are made of non-porous materials, porous fins with natural convection porous flow orthogonal to the fin direction have also been studied. In contrast to these, there is a lack of work on porous fins in which the fluid flow may be along the direction of the fin. In such a fin, porosity may increase advective heat removal due to increased flow rate but may also impede conductive heat removal due to reduction in effective thermal conductivity. Due to these competing trade-offs, there is a need for comprehensive analysis of thermal performance of such a porous fin. This work derives a solution for the steady-state temperature distribution in a porous fin with advection along the fin direction. It is shown that temperature distribution in such a porous fin is governed by a convection-diffusion-reaction equation. A solution for the temperature distribution is derived in the form of modified Bessel functions of non-zero order. Two distinct fin performance parameters are defined and derived in order to characterize porous fin performance. It is found that thermal properties of the fin as well as ambient convective conditions strongly impact the relationship between fin porosity and fin performance. While in some cases, it is found that an optimum porosity exists that maximizes heat removal, in other cases, the use of a porous fin is found to be not desirable at all. The analysis presented here helps fully understand these trade-offs, and provides useful guidelines for porous fin design for maximum heat removal.

Preparation and performance of coal-based activated carbon based on an orthogonal experimental study

To improve the utilization value of coal resources and optimize the production process of coal-based activated carbon, an L9 (34) orthogonal experiment was designed to study the comprehensive effects of the carbonization temperature, heating rate, activation time and activator type on the specific surface area and iodine value of activated carbon prepared by physical activation, as well as the surface chemical and crystal properties. The results showed that large amounts of C–H and oxygen functional groups from the raw materials were lost in the process of preparing the activated carbon, and CaCO3 generated CaS through a two-step reaction. The raw materials were nonporous or macroporous materials, while the activated carbon developed a microporous structure. The same optimal working conditions were obtained when the iodine value and the specific surface area were used as the optimization target, as follows: 800 °C for carbonization, 10 °C/min for heating rate, 75 min for activation time, and steam + CO2 as the activator. Finally, activated carbon was prepared under the optimal experimental conditions. The results showed that this activated carbon had the highest specific surface area and iodine value. In addition, the iodine value had a good linear relationship with the specific surface area.

Inactivation of SARS-CoV-2 and Other Enveloped and Non-Enveloped Viruses with Non-Thermal Plasma for Hospital Disinfection.

As recently highlighted by the SARS-CoV-2 pandemic, viruses have become an increasing burden for health, global economy, and environment. The control of transmission by contact with contaminated materials represents a major challenge, particularly in hospital environments. However, the current disinfection methods in hospital settings suffer from numerous drawbacks. As a result, several medical supplies that cannot be properly disinfected are not reused, leading to severe shortages and increasing amounts of waste, thus prompting the search for alternative solutions. In this work, we report that non-thermal plasma (NTP) can effectively inactivate SARS-CoV-2 from non-porous and porous materials commonly found in healthcare facilities. We demonstrated that 5 min treatment with a dielectric barrier discharge NTP can inactivate 100% of SARS-CoV-2 (Wuhan and Omicron strains) from plastic material. Using porcine respiratory coronavirus (surrogate for SARS-CoV-2) and coxsackievirus B3 (highly resistant non-enveloped virus), we tested the NTP virucidal activity on hospital materials and obtained complete inactivation after 5 and 10 min, respectively. We hypothesize that the produced reactive species and local acidification contribute to the overall virucidal effect of NTP. Our results demonstrate the potential of dielectric barrier discharge NTPs for the rapid, efficient, and low-cost disinfection of healthcare materials.

A cellular automata framework for porous electrode reconstruction and reaction-diffusion simulation

Due to the high charge transfer efficiency compared to that of non-porous materials, porous electrodes with larger surface area and thinner solid pore walls have been widely applied in the lithium-ion battery field. Since the capacity and charge-discharge efficiency of batteries are closely related to the microstructure of porous materials, a conceptually simple and computationally efficient cellular automata (CA) framework is proposed to reconstruct the porous electrode structure and simulate the reaction-diffusion process under the irregular solid-liquid boundary in this work. This framework is consisted of an electrode generating model and a reaction-diffusion model. Electrode structures with specific geometric properties, i.e., porosity, surface area, size distribution, and eccentricity distribution can be constructed by the electrode generating model. The reaction-diffusion model is exemplified by solving the Fick’s diffusion problem and simulating the cyclic voltammetry (CV) process. The discharging process in the lithium-ion battery are simulated through combining the above two CA models, and the simulation results are consistent with the well-known pseudo-two-dimensional (P2D) model. In addition, a set of electrodes with different microstructures are constructed and their reaction efficiencies are evaluated. The results indicate that there is an optimum combination of porosity and particle size for discharge efficiency. This framework is a promising one for studying the effect of electrode microstructure on battery performance due to its fully synchronous computation way, easy handled boundary conditions, and free of convergence concerns.