Poor Dispersion Research Articles

Commercially important mangrove crabs are more susceptible to microplastic contamination than other brachyuran species

Brachyuran crabs are ecologically and economically important macrofauna in mangrove habitats. However, they are exposed to various contaminants, including plastics, which bioaccumulate in relation to their feeding modes. Setiu Wetlands is a unique place on the east coast of Peninsular Malaysia where different ecosystems such as mangroves, lagoon, beaches, etc., are duly connected and influencing each other. In recent years, the shifted river mouth has threatened these wetlands, causing severe hydrodynamic changes in the lagoon, especially in the core mangrove zone. The present study tested microplastics (MPs) contamination in the mangroves through brachyuran crabs as indicators. Three sampling sites, namely Pulau Layat, Kampung Pengkalan Gelap, and Pulau Sutung were chosen. The four abundant crab species Parasesarma eumolpe, Metaplax elegans, Austruca annulipes, and Scylla olivacea, which display different feeding behaviours were collected from all sites covering the dry (Feb–Mar 2021) and the wet (Dec 2021–Jan 2022) seasonal periods. There were significant differences in the seasonal abundance of MPs among crab species. The highest accumulation of MPs in the crab stomachs in the dry season could be linked to subdued water circulation and poor material dispersion. Besides the lower MPs in the wet period due to improved water exchange conditions, its significant presence in the stomachs of S. olivacea indicates the role of its feeding behaviour as a carnivore. In addition, the micro-Fourier transform infrared spectroscopy (micro-FTIR) revealed the widespread occurrence of polymers such as rayon and polyester in all species across the sites. Given the fact that crabs like S. olivacea are commercially important and the ones contaminated with MPs can cause detrimental effects on the local community's health, further managerial actions are needed to assure sustainable management of the Setiu Wetlands.

Superior Interfacial Contact Yields Efficient Electron Transfer Rate and Enhanced Solar Photocatalytic Hydrogen Generation in M/C3N4 Schottky Junctions.

Various literature studies (Table 6) have reported that dispersion of metal nanoparticles (NPs) on graphitic carbon nitride g-C3N4 (M/CN) has considerably improved the photocatalytic hydrogen yield. It is understood that metal NPs create active sites on the surface of CN and act as a cocatalyst. However, the precise changes induced by different metal NPs on the surface of CN still elude us. Here, we report a thorough understanding and comparison of the morphology, metal-support interactions, interfacial charge transfer kinetics, and band characteristics in different M/CN (M = Pt, Pd, Au, Ag, Cu) correlated with photocatalytic activity. Among all metals, Pt/CN was found to be the best performer both under sunlight and UV-visible irradiation. Under sunlight, maximum H2@ 2.7 mmol/h/g was observed over Pt/CN followed by Pd/CN > Au/CN > Ag/CN > Cu/CN ≈ CN. The present study revealed that among all metals, Pt formed superior interfacial contact with g-C3N4 as compared to other metals. The maximum Schottky barrier height (Φb,Pt) of 0.66 V was observed at Pt/CN followed by Φb,Au/CN (0.46 V) and Φb,Pd/CN (0.05 V). The presence of electron-deficient Pt in Pt-XPS, decrease in the intensity of d-DOS of Pt near the Fermi level in VB-XPS, increase in CB tail states, and cathodic shift in Vfb in MS plots sufficiently confirmed strong metal-support interactions in Pt/CN. Due to the SPR effect, Au and Ag NPs suffered from agglomeration and poor dispersion during photodeposition. Finely dispersed Pt NPs (2-4 nm, 53% dispersion) successfully competed with shallow/deep trap states and drove the photogenerated electrons to active metallic sites in a drastically reduced time period as investigated by femtosecond transient absorption spectroscopy. Typically, an interfacial electron transfer rate, KIET,avg, of 2.5 × 1010 s-1 was observed for Pt/CN, while 0.087 × 1010 s-1 was observed in Au/CN. Band alignment/potentials at M/CN Schottky junctions were derived and most favorable in Pt/CN with CB tail states much above the water reduction potential; however, in the case of Pd, these extend much below the H+/H2 potential and hence behave like deep trap states. Thus, in Pd/CN (τ0 = 4200 ps, 49%) and Ag/CN (3870 ps, 53%), electron deep trapping dominates over charge transfer to active sites. The present study will help in designing futuristic new cocatalyst-photocatalyst systems.

Metal–support interactions over Ni/CeO2–ZrO2 catalysts for ethanol steam reforming and their effects on the coke gasification

In this study, we investigated the metal–support interactions over Ni/CeO2–ZrO2 (Ni/CZ) catalysts for ethanol steam reforming. Different Ni contents (5, 10, and 15 wt%) were loaded onto the CZ support using two catalyst preparation methods, namely one-pot, and successive impregnation methods. Using the one-pot method, the Ni species over the Ni/CZ catalysts strongly interacted with the CZ support, resulting in smaller Ni nanoparticles with abundant oxygen vacancies. In contrast, the successive impregnation method mainly generated an isolated Ni phase at a high Ni content, resulting in large Ni clusters with limited oxygen vacancies. The poor Ni dispersion over the Ni/CZ catalysts prepared by the successive impregnation method induced low ethanol conversions and hydrogen production rates. In addition, the large Ni clusters over the Ni/CZ catalysts prepared by the successive impregnation method achieved a fast-coking behavior, thereby increasing the coke amount. Further, coke gasification was demonstrated to dominate the Ni surface with the Ni/CZ catalysts prepared by the one-pot method because of the high Ni dispersion and abundant oxygen vacancies.

ZIF-8-based dual layer hollow fiber mixed matrix membrane for natural gas purification

To prevent pipe damage and lower operating costs, natural gas must be cleaned of pollutants like carbon dioxide (CO2) and hydrogen sulphide (H2S). High selectivity of the functional material in the mixed matrix membranes (MMMs) allows for a more efficient gas separation compared to traditional polymeric membranes. However, poor dispersion and compatibility between the functional material and the polymer matrix become one of the major problems of MMMs. The use of zeolite imidazole (ZIF-8) in MMMs has been explored for its ability to separate CO2/CH4 due to its versatile gas molecule diameter range and effective CO2 adsorption. In this study, the effects of ZIF-8 at various loadings were examined on the physical and chemical properties of dual layer hollow fiber MMMs and gas separation efficiency. Following the successful production of 86.25 nm ZIF-8 nanoparticles, ZIF-8-based DLHF MMMs were created. The results showed that 0.5 wt% ZIF-8 loading provided the best results, with excellent interaction between the polymer PSf and the inorganic filler ZIF-8, strong heat resistance, and chemical stability. Increased CO2 permeability and CO2/CH4 ideal selectivity by 72.5 % and 1196.2 % respectively, compared to the unmodified membrane. It was inferred through this study that minimal loading of 0.5 wt% ZIF-8 in the DLHF MMMs improved their ability to separate gases, making them a good option for capturing CO2.

Ultrasonic-mediated electrochemical design of graphene/polyacrylonitrile conductive membrane for antifouling and electrofiltration

Electrofiltration using conductive membranes can effectively alleviate membrane fouling. However, poor dispersion and aggregation in water severely constrain the ability of graphene (Gr) to synthesize conductive membranes. Herein, the water-dispersible Gr with high conductivity is tailored by ultrasonic-assisted electrochemical exfoliation and loaded onto the polyacrylonitrile (PAN) membrane by classical vacuum filtering in layers. The customization at 6 V voltage, 40 W ultrasonic power, and 23.87 g/m2 mass loading endows an optimal improvement in membrane pore structure, permeability, mechanical behavior, and electrochemical properties. The graphene/polyacrylonitrile (Gr/PAN) conductive membrane exhibits a high conductivity of 6.43 S/cm and a water flux of 450.19 L m-2h−1. The membrane shows remarkable antifouling capabilities by achieving a 99.8% rejection rate, 89.74% flow rate recovery, and only 10.26% irreversible fouling using yeast as a pollutant model. The normalized flux of the membrane can stay high at 0.41 after electrofiltration for 120 min, outperforming other conductive membranes in comparison. Cyclic electrofiltration of the developed membrane exhibits a 53.85% higher normalized flux than when no electric field is present, demonstrating its potential for long-lasting antifouling under electric fields. This study offered a novel strategy for the straightforward construction of highly functional graphene-based conductive membranes utilized in electrofiltration.

Effects of dry powder mixing on electrochemical performance of lithium-ion battery electrode using solvent-free dry forming process

This research examines how the morphology of the electrode powder mixture affects the structure and battery performance of lithium-ion battery electrodes fabricated using a dry electrode forming process. We demonstrate that the distribution of conductive and binding additives (CBA) on the active materials (AMs) can be controlled by adjusting the rotation speed of a dry mixer. Furthermore, we show that controlling the distribution of CBA can improve the rate performance of the batteries. The tortuosity of the CBA domain in the electrodes is analyzed from SEM images of electrode cross-sections as electronic and ionic conductive pathways. Low rotation speed dry mixing results in poor dispersion of CBA, leading to the formation of long-range conductive pathways with low tortuosity. Consequently, the capacity at high rates decreases due to fewer short-range conductive pathways between the AM particles. In contrast, high rotation speed dry mixing leads to excessive dispersion of CBA, resulting in high tortuosity in both long-range and short-range conductive pathways. As a result, the capacity decreases due to fewer efficient conductive pathways throughout the electrode. We demonstrate that medium rotation speed dry mixing achieves a favorable balance between short-range and long-range conductive pathways, providing high capacity at high rates.

Complexing with fibrillated glutenin and orange peel pectin improves the aqueous dispersion and storage stability of hesperitin/hesperidin

Hesperitin (Ht) and hesperidin (Hd) have a variety of biological activities, but their applications are limited due to the poor aqueous dispersion, weak stability and low bioavailability. In this study, a complex coacervate, formed by glutenin heated at pH 2, 80 °C for 8 h and orange peel pectin (P), was used as a carrier to enhance the water dispersibility of Ht/Hd, and their release behavior in vitro were investigated. The main driving forces for the complexes of Ht/Hd with glutenin (Glu) or fibrillated glutenin (Glu-F) were hydrogen bonding and hydrophobic forces. However, the enthalpy change of the interaction of the fibrillated glutenin with Ht/Hd was reduced, implying the formation of a more stable Ht/Hd-Glu-F complex. Furthermore, the optimum mass parameter ratio of Ht/Hd:P:Glu-F obtained from orthogonal experiments was 5:4:40 at pH 6. Both Ht and Hd were almost insoluble in water (pH 6), while the formation of the Ht-Glu-F-P and Hd-Glu-F-P complexes increased the solubility of the almost insoluble Ht and Hd to 102.16 ± 4.82 and 220.57 ± 10.82 μg/mL, respectively. After 30 days of storage, the particle size of the emulsions formed by Ht-Glu-F-P and Hd-Glu-F-P complexes increased from 171.90 to 174.84 nm to 231.82 and 219.81 nm, respectively, which had better storage stability than those formed from Ht/Hd-Glu-P complexes. The increased intermolecular repulsion caused by fibrillation modification improved the stability of the delivery system. These results provide a unique method for improving the aqueous dispersion and storage stability of Ht/Hd.

Investigation of Cu-ZnO/SiO2 catalysts for CO2 hydrogenation: Effect of SiO2 support with different porous structure

CO2 hydrogenation is one of the reactions to realize effective utilization of CO2, while Cu-Zn based catalyst is widely adopted for CO2 hydrogenation to value-added chemicals like methanol. However, this process is less efficient since the poor performance of catalyst due to its poor dispersion or sintering issue. In this study, three kinds of SiO2 supports (SBA-15, MCM-41 and Nano-SiO2) with different porous structure were conducted to load same amount of 5.0 wt% Cu-ZnO active component (the molar ratio of Cu/Zn is 2.0), which were further applied for CO2 hydrogenation. All catalysts were characterized chemically, morphologically and structurally by different techniques such as XRD, BET, TEM, H2-TPR and CO2-TPD. The results showed that the structure of three catalysts was basically preserved and the surface aera kept stable after loading active component, while the active component had the best dispersion when SBA-15 was used as the support and space-time yield of methanol is about 705.6 gMeOH•kgCu−1•h−1,which is higher than that of Nano-SiO2-5% (532.9 gMeOH•kgCu−1•h−1) and MCM-41–5% (213.2 gMeOH•kgCu−1•h−1). Due to the confined effect of mesoporous channel structure provided by SBA-15 support, the Cu-Zn interaction could be significantly enhanced with increasement of medium and strong alkaline sites, further improving CO2 activation ability. This work provides a useful strategy to improve the catalytic efficiency of classical Cu-Zn catalyst for the CO2 hydrogenation process.

3D snowflake graphene modified α-MnO2 Catalyst: Enhancing the Low-Temperature catalytic activity for VOCs degradation

Manganese oxide is a promising catalyst for volatile organic compounds oxidation with merits of low cost, abundant valence states, diverse crystal forms and morphology, however, its catalytic activity at low temperature (<200 °C) is limited due to the poor dispersion and inferior electron transfer. To solve these problems, a novel 3D snowflake graphene is doped into α-MnO2 to fabricate rGO@α-MnO2 catalyst to enhance the catalytic activity at low temperature. Compared with α-MnO2, the rGO@α-MnO2 catalysts present larger specific surface area and pore volume, which facilitates the adequate contact reaction between active component and VOCs. The unique graphene electronic bridge promotes the electron transfer on rGO@α-MnO2, which results in higher concentration of surface defects and more surface adsorbed oxygen to the catalyst. The performance tests show that the catalyst doped with 4% 3D snowflake graphene has the best activity, which can achieve 90% toluene conversion at 155 °C, and even 100% toluene conversion with 80% CO2 selectivity at 200 °C. In particular, 4%rGO@α-MnO2 demonstrates excellent catalytic stability and moisture resistance, presenting similar catalytic performance after 5 cycles for both the dry and high relative humidity (RH = 85%) conditions. The excellent activity of 4%rGO@α-MnO2 can be attributed to the enhancement of toluene adsorption energy after graphene doping and the defect induced by the interface effect between graphene and (211) facet. In general, 3D snowflake graphene doping provides a convenient and cost-effective method to enhance the low-temperature activity of the α-MnO2 catalyst, presenting great application potential.

TWO-STEP SYNTHESIS AND FORMATION MECHANISM FOR LACUOS NANO-SIZED AGGLOMERATES

We have developed a two-step synthesis method to obtain pure LaCuOS nano-sized agglomerates using La(NO3)3·6H2O, CuSO4·5H2O and NH3·H2O as the starting materials. The result shows that the precursor can be converted into La2O2SO4, La2(SO4)3 and CuO phases at 800 °C for 2 h in air, which was then converted into a pure LaCuOS phase by a reduction at 800 °C for 5 h in a flowing argon and hydrogen atmosphere. The as prepared LaCuOS nano-aggregates have poor dispersion and a wide size distribution range (50–100 nm).

Enhanced elasticity in magnesium nanoparticle reinforced acrylic elastomer

AbstractElastomers are highly potential materials for shock absorption, cushioning, and similar applications. However, for most elastomers, poor strength limits their application. Compounding nanoparticles in the polymer matrix have been vastly explored to improve mechanical strength or introduce electrical, thermal, optical, and magnetic properties to the polymer. However, poor dispersion of nanoparticles in polymer mixture has remained a challenge in nanocomposite production. This study presents a unique approach to improving particle dispersion as well as designing ultra‐soft, light, cost‐effective, and highly compressible nanocomposite elastomers. To this end, magnesium nanoparticles were fabricated by pulsed laser ablation in a non‐ionic surfactant (Triton X‐100) and the mixture was added to an acrylic base polymer chain to design the nanocomposite elastomer. Various nanocomposites were manufactured using different ratios of surfactant and nanoparticle mixtures. The mechanical and optical properties of the composites were investigated. The nanocomposite containing the largest amount of Triton X‐100 and magnesium nanoparticles displayed beyond 50% compressive deformation under only 0.4 MPa load and light absorbance was enhanced in the UV–visible region of the spectra.Highlights Pure Mg nanoparticles were successfully synthesized by PLAL in undiluted Triton X‐100. Nanocomposites displayed very high deformation capacity under small loading. Nanoparticles dispersed in surfactant led to a uniform particle distribution. Absorbance enhanced by surfactant and Mg nanoparticle in UV–visible region. Elasticity modulus tailored up to 60% by surfactant and nanoparticle addition.

Enhancing the Electrical Conductivity and Strength of PET by Single-Wall Carbon Nanotube Film Coating.

Single-wall carbon nanotubes (SWCNTs) with excellent physicochemical properties are considered a promising candidate for the electrical and mechanical reinforcements of polymers. However, the poor dispersion of SWCNTs in plastics seriously limits their application and their achieved performance enhancement. Here, we coat a freestanding, highly conductive SWCNT film onto the surface of a polyethylene terephthalate (PET) film by a hot-pressing method. Due to the uniform SWCNT network structure and strong interfacial interaction, the SWCNT/PET hybrid film showed notably enhanced electrical and mechanical properties even though with a very low SWCNT weight fraction of 0.066%. The surface square resistance of the SWCNT/PET film decreased to 120-140 Ω/□ from 1016 Ω. In addition, Young's modulus and tensile strength of the SWCNT/PET film reached 4.6 GPa and 148 MPa, which are 31.3 and 24.4%, respectively, higher than the pure PET film. The SWCNT/PET film shows excellent mechanical durability and thermal stability, demonstrating its potential use as an antistatic material.

Preparation and properties of high vinyl polybutadiene/sepiolite nanocomposites using a sepiolite immobilized Mo‐based catalyst

AbstractThe preparation of polymer/nanoclay nanocomposite has received much attention in recent years from both academic researchers and industry. The addition of nanoclay in polymer matrix could prepare material with improved performance and reduced cost. However, nanocaly is easy to agglomerate resulting in poor dispersion in the matrix. In this work, we proposed the immobilized catalyst prepared by coordination between molybdenum pentachloride (MoCl5) and hydroxyl groups on the nano sepiolite. The obtained sepiolite immobilized catalyst was used for the in situ polymerization of butadiene. The butadiene monomers were diffused into the tiny holes and channels of the sepiolite and sepiolite dispersed uniformly by the effect of in situ polymerization. The immobilization of sepiolite improves the dispersity of MoCl5 during polymerization and further enhances the activity of the catalyst. The coordination between sepiolite and MoCl5 results in a slight drop in vinyl content, and the molecular weight distribution remain unchanged. The flame retardant property of the nanocomposite was further investigated, and the result shows that the addition of sepiolite could increase the Oxygen index. This novel composite with well‐dispersed sepiolite and high content of vinyl can be further applied to flame‐retardant elastic materials.

The Morphologically Controlled Synthesis and Application of Mesoporous Alumina Spheres.

The control of alumina morphology is crucial yet challenging for its various applications. Unfortunately, traditional methods for preparing alumina particles suffer from several limitations such as irregular morphology, poor dispersibility, and restricted application areas. In this study, we develop a novel method for preparing spherical mesoporous alumina using chitin and Pluronic P123 as mixed templates. The effects of reaction temperature, time, and the addition of mixed templates on the phase structure, micromorphology, and optical absorption properties of the samples were investigated. The experimental results indicate that lower temperature and shorter reaction time facilitated the formation of spherical mesoporous alumina with excellent CO2 adsorption capacity. The periodic density functional theory (DFT) calculations demonstrate that both the (110) and (100) surfaces of γ-Al2O3 can strongly adsorb CO2. The difference in the amount of CO2 adsorbed by Al2O3 is mainly due to the different surface areas, which give different numbers of exposed active sites. This approach introduces a novel strategy for utilizing biological compounds to synthesize spherical alumina and greatly enhances mesoporous alumina's application efficiency in adsorption fields. Moreover, this study explored the electrochemical performance of the synthesized product using cyclic voltammetry, and improved loading of electrocatalysts and enhanced electrocatalytic activity were discovered.

Highly efficient and durable syngas production over one-step synthesized synergistic oxygen carriers in biomass chemical looping gasification

Biomass chemical looping gasification (BCLG) gives a promising platform for cost-effective and low-polluting syngas production. To overcome the cumbersome process and poor dispersion of two-step synthesized synergistic oxygen carriers (OCs), NiO-LaFeO3 synergistic OCs were synthesized in one-step by sol–gel method with the found best Ni introduction amount of 0.5. The high lattice oxygen mobility and powerful oxidation capacity derived from the Ni-Fe synergistic effect made it perform better in the BCLG reaction. Due to the extraordinary stability of crystalline phase and oxygen activity, its reactivity did not suffer from any degradation during the 50 long-time redox cycles over 2750 min under the optimal working conditions of the ex-situ configuration, mutual mode and steam/biomass mass ratio of 5.0. The gas yield, carbon conversion, syngas selectivity and H2/CO ratio were constantly maintained around 1846.45 mL/g, 86.74%, 79.96% and 2.0, respectively. This study provides a feasible technical route for highly efficient and durable syngas production.

Nuclear Magnetic Resonance for Targeted Metabolomics and Biochemical Sensor

NMR spectroscopy is quantitative, highly reproducible, non-selective and non-destructive. However, NMR costs and complexity hinder a use as point-of-care and biochemical sensor instrumentation. Low field NMR (LF-NMR) is an inexpensive and low footprint technique to obtain physical, chemical, electronic and structural information on small molecules, but suffers from poor spectral dispersion, especially when applied to the analysis of mixtures. Subspectral editing employing optimal control pulses is a suitable approach to cope with the severe signal superpositions in complex mixture spectra at low field.&#x0D; We have calculated the optimal control pulse shapes at 0.5 T NMR frequency using the Krotov algorithm. Downsizing the complexity of the algorithm from exponential to polynomial is shown to be possible by using a system approach with each system corresponding to a (small) molecule. In this way compound selective excitation pulses can be calculated. The signals of substructures of the cyclopentenone molecule were excited using optimal control pulses calculated by the Krotov algorithm demonstrating the feasibility of subspectral editing. Likewise, for a mixture of benzoic acid and alanine, editing of the signals of either benzoic acid or alanine employing optimal control pulses was shown to be possible.&#x0D; The obtained results are promising and can be extended to the targeted analysis of complex mixtures such as biofluids or metabolic samples at low field strengths opening access for benchtop NMR to point of care settings. Moreover, the LF-NMR was improved to allow a unique detection and reliable quantification of metabolites in biofluids like blood, urine, cerebrospinal fluid, or even tissue. In contrast to standard large scale NMR equipment the portable LF-NMR allows for an analysis of the chemical composition of biofluid samples directly at the patient (point-of-care).&#x0D; LF-NMR can be freely programmable for detecting and detecting and sensing sets of small molecules which deliver information on the health status of a person. Such an analytical tool would be useful for the prediction, diagnosis, monitoring and prognosis of diseases, and for supervision of therapeutic interventions.

A novel strategy to functionalize styrene butadiene rubber toward enhanced interfacial interaction with silica

AbstractIncorporation of nanofillers (such as silica) into elastomer matrix is the most common strategy to prepare high‐performance rubber products. However, the poor dispersion of nanofillers in non‐affinity rubber materials and the weak interfacial interaction significantly limit the processing and mechanical properties. To reduce the polarity difference and enhance the interfacial interaction between silica and styrene butadiene rubber (SBR), we prepared a hydroxyethyl acrylate‐grafted SBR (SBR‐g‐HEA) through the redox initiator system, and subsequently fabricated SBR‐g‐HEA/silica nanocomposites by simple mechanical blending. The effects of reaction conditions on the grafting rate were studied in detail. ATR‐FTIR and 1H‐NMR collectively confirmed the successful grafting of HEA groups on SBR molecular chains, and the grafting fraction could be regulated from 0% to 2.5%. Scanning electron microscope (SEM) and rubber processing analyzer (RPA) showed that the incorporation of HEA could significantly improve the dispersion of silica nanoparticles in SBR matrix. Notably, the resulting SBR‐g‐HEA exhibited significantly enhanced attributes when compared to their unmodified counterparts, including superior mechanical properties, improved wear resistance, and reduced heat generation. The strategy proposed here provided insights toward the fabrication of non‐affinity rubber/filler nanocomposites for high‐performance rubber products and green tire.

Protein Adsorption and Its Effects on Electroanalytical Performance of Nanocellulose/Carbon Nanotube Composite Electrodes.

Protein fouling is a critical issue in the development of electrochemical sensors for medical applications, as it can significantly impact their sensitivity, stability, and reliability. Modifying planar electrodes with conductive nanomaterials that possess a high surface area, such as carbon nanotubes (CNTs), has been shown to significantly improve fouling resistance and sensitivity. However, the inherent hydrophobicity of CNTs and their poor dispersibility in solvents pose challenges in optimizing such electrode architectures for maximum sensitivity. Fortunately, nanocellulosic materials offer an efficient and sustainable approach to achieving effective functional and hybrid nanoscale architectures by enabling stable aqueous dispersions of carbon nanomaterials. Additionally, the inherent hygroscopicity and fouling-resistant nature of nanocellulosic materials can provide superior functionalities in such composites. In this study, we evaluate the fouling behavior of two nanocellulose (NC)/multiwalled carbon nanotube (MWCNT) composite electrode systems: one using sulfated cellulose nanofibers and another using sulfated cellulose nanocrystals. We compare these composites to commercial MWCNT electrodes without nanocellulose and analyze their behavior in physiologically relevant fouling environments of varying complexity using common outer- and inner-sphere redox probes. Additionally, we use quartz crystal microgravimetry with dissipation monitoring (QCM-D) to investigate the behavior of amorphous carbon surfaces and nanocellulosic materials in fouling environments. Our results demonstrate that the NC/MWCNT composite electrodes provide significant advantages for measurement reliability, sensitivity, and selectivity over only MWCNT-based electrodes, even in complex physiological monitoring environments such as human plasma.

Nano-emulsification method as a strategy for oil soluble corrosion inhibitor transform to water soluble

Corrosion inhibitor is one of the most economical and effective approaches to protecting metal pipes in the oil and gas industries. However, a great amount of corrosion inhibitors such as imidazoline, are difficult to distribute fast due to their poor solubility or dispersibility in water, which results in inhomogeneous concentration distribution and ineffectiveness. In this study, nano-emulsification technique was developed to improve the dispersity of mercaptoacetic acid-modified oleic imidazoline (MOI) in corrosive water. The formulation of nanoemulsion is optimized with the phase inversion temperature (PIT) and droplet diameter. The prepared nanoemulsion which the hydrophilic lipophilic balance value (HLB) was 11.5 and the loading of corrosion inhibitor was 20 wt% exhibited remarkable water dispersion performance and its mean particle size was less than 100 nm. Moreover, its dispersion performance in water was significantly better than that of the paraffin oil system, and was similar in the ethanol system. The inhibition performances and mechanisms of nanoemulsion for L245 carbon steel in the H2S/CO2 containing 5.0 wt% NaCl solution were investigated with weight loss measurements and electrochemical tests. In terms of inhibition efficiency, the corrosion inhibitor encapsulated in nanoemulsion was exceeding 90%, which was comparable to the system employing ethanol and liquid paraffin as solvents. Further experimental results indicated that the nanoemulsion system was more consistent with the Freundlich adsorption model, unlike the other two systems which followed the Langmuir adsorption model. The morphology and composition of corrosion products were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) methods. The SEM and XPS results demonstrated that the nanoemulsion system did not change the material type of corrosion products, but had a visible influence on their morphology. In addition, the inhibition mechanism was also revealed by theoretical calculations. These findings suggest that nano-emulsification technique has the potential to improve the solubility or dispersibility of oil soluble corrosion inhibitor, thereby expanding its application fields.

Chromosome damage in regions with different levels of air pollution.

Air pollution is an important environmental factor influencing human health. In this study, we compared chromosome damage in city policemen from three cities in the Czech Republic: industrial Ostrava characterized by high levels of benzo[a]pyrene, Prague with heavy traffic emitting nitrogen oxides, and relatively clean Ceske Budejovice located in an area with predominantly agricultural activity. Chromosomal aberrations in lymphocytes were evaluated by fluorescence in situ hybridization with painting probes for chromosomes 1, 2, 3, and 4 in spring and autumn. An increase in the frequency of unstable chromosome aberrations, that is, dicentric chromosomes and acentric fragments, was observed in spring samples from Ostrava (p = .014 and p = .044, respectively) and Prague (p = .002 and p = .006, respectively) in comparison with Ceske Budejovice. The difference was significant only for samples taken after the winter period, when the concentration of pollutants in the air increases due to poor dispersion conditions. An increased frequency of dicentric chromosomes was observed in spring compared to autumn in both Ostrava and Prague (p = .017 and p = .023, respectively), but not in Ceske Budejovice. More breakpoints were observed on chromosome 1 than on the other chromosomes examined (p < .001). The number of breakpoints in the heterochromatin region 1p11-q12 was lower than in other parts of chromosome 1 (p < .001), suggesting a protective function of heterochromatin against damage. Our study showed, that air pollution increased the frequency of unstable chromosome aberrations, especially dicentric chromosomes. However, we did not show an effect on stable chromosome rearrangements.