Small-angle X-ray scattering analysis of poly(amic acid) dispersed in a liquid matrix to understand the size control of polyimide nanoparticles.

Poly(amic |acid) |nanoparticles |prepared |by ||precipitation |polymerization with a dispersant were evaluated by small-angle X-ray scattering (SAXS) and field-emission scanning electron microscopy (FE-SEM). The particle size evaluation of poly(amic acid) nanoparticles in the liquid phase by SAXS was performed to gain insight into the size control of poly(amic acid) nanoparticles, and showed good agreement with visual observation by FE-SEM, explaining the effect of the dispersant in obtaining polyimide nanoparticles with small particle size. This indicates that the particle size is maintained without change during the solvent evaporation process. The polyamide nanoparticles controlled by the dispersant effect maintained their size after imidization, and polyimide nanoparticles with a minimum radius of about 60 nm were prepared.

Carboxyalkylated Lignin as a Sustainable Dispersant for Coal Water Slurry.

Coal water slurry (CWS) has been considered a cleaner and sustainable alternative to coal. However, the challenging suspension of coal particles in CWS has created a major obstacle to its use in industry. This study presents a novel approach to enhance the stability and rheological properties of coal water slurry (CWS) through the utilization of carboxyalkylated lignin (CL) as a dispersant. The generated CL samples had high water solubility of around 9 g/L and a charge density of around 2 mmol/g. All CLs were able to stabilize the coal suspension, and their performance decreased due to the increase in the alkyl chain length of carboxyalkylated lignin. Carboxymethylated lignin (CL-1) improved the stability of the coal suspensions with the lowest instability index of less than 0.6. The addition of CLs reduced the contact angle of the coal surface from 45.3° to 34.6°, and the increase in the alkyl chain length hampered its effect on contact angle changes. The zeta potential measurements confirmed that the adsorption of CL enhanced the electrostatic repulsion between coal particles in suspensions, and the zeta potential decreased with the increased alkyl chain length of CLs due to increased steric hindrance. The rheology results indicated that CLs demonstrated shear thinning behavior. This innovative method showcases the affinity of carboxyalkylated lignin to improve the performance of CWS, offering an environmentally friendly alternative for producing a cleaner product, i.e., sustainable coal water slurry, with improved suspension stability.

Acute gastrointestinal symptoms associated with oil spill exposures among U.S. coast guard responders to the Deepwater Horizon oil spill.

PURPOSE: Research investigating gastrointestinal (GI) symptoms from oil spill-related exposures is sparse. We evaluated prevalent GI symptoms among U.S. Coast Guard responders deployed to the Deepwater Horizon oil spill cleanup. METHODS: Crude oil (via skin contact, inhalation, or ingestion routes), combined crude oil/oil dispersant exposures, other deployment exposures, deployment characteristics, demographics, and acute GI symptoms during deployment (i.e., nausea/vomiting, diarrhea, stomach pain, and constipation) were ascertained cross-sectionally via a post-deployment survey (median time between deployment end and survey completion 185 days) (N = 4885). Log-binomial regression analyses were employed to calculate prevalence ratios (PRs) and 95 % confidence intervals (CI). Effect modification was evaluated. RESULTS: In adjusted models, responders in the highest (versus lowest) tertile of self-reported degree of skin contact to crude oil were more than twice as likely to report nausea/vomiting (PR=2.45; 95 %CI, 1.85-3.23), diarrhea (PR=2.40; 95 %CI, 2.00-2.88), stomach pain (PR=2.51; 95 %CI, 2.01-3.12), and constipation (PR=2.21; 95 %CI, 1.70-2.89). Tests for trend were statistically significant (p < 0.05). Results were similar for crude oil exposure via inhalation and ingestion. Higher PRs for all symptoms were found with combined crude oil/dispersant exposure than with crude oil exposure alone. CONCLUSIONS: These results indicate positive associations between self-reported crude oil and combined crude oil/oil dispersant exposures and acute GI symptoms.

Preparation of Modified Polycarboxylate by Pyrrolidone for Using as a Dispersant in Cobalt Blue Nano-Pigment Slurry.

In this paper, N-vinylpyrrolidone was copolymerized with acrylic acid and itaconic acid by free radical polymerization, and a series of polyacrylic acid-co-itaconic acid-co-N-vinylpyrrolidone (PAIN) dispersants with different pyrrolidone ligand contents were synthesized and characterized. Then, the cobalt blue nano-pigment slurry (20 wt%) was prepared through a water-based grinding method, and the optimum grinding technology was explored and determined as follows: PAIN2 as a dispersant, a dispersant dosage of 10 wt%, and a grinding time of 480 min. According to this optimum grinding technology, the prepared pigment slurry had a significantly decreased agglomeration, the D90 of which was 82 nm, and separately increased to 130 nm and 150 nm after heat storage for 3 and 7 days, exhibiting excellent heat storage stability. Additionally, its TSI value was also the lowest (1.9%), indicating good dispersion stability. The QCM and adorption capacity measuring results showed PAIN2 had a larger adsorption capacity, and the formed adsorption layer had a higher rigidity and was not easy to fall off. This was caused by both the interaction of carboxyl groups and the pyrrolidone ligand (strong coordination interaction) in PAIN2 with cobalt blue. The XPS and FT-IR measurements further proved the above-mentioned adsorption mechanism.

Compositional change of bacterial communities in oil-polluted seawater amid varying degrees of nanoplankton bacterivory.

Petroleum hydrocarbons are being released into the marine environment continuously. They will undergo weathering and may eventually be biodegraded by bacteria and other microbes. While nanoplankton (2-20 µm) are the major consumers of marine bacteria, their effect on the process of biodegradation of oil hydrocarbons is still debated. A 14-day microcosm experiment was conducted to investigate the effects of crude oil hydrocarbons on nanoplankton bacterivory and bacterial community in coastal waters. The coefficients of population growth (0.56-1.80 d-1 for all treatments considered) and grazing mortality (0.38-1.65 d-1 for all treatment considered) of bacteria estimated with the dilution method did not differ among the treatments of control (Ctrl), low dose chemically dispersed oil (LDOil, 2 µL L-1 of crude oil), and high dose chemically dispersed oil (HDOil, 8 µL L-1 of crude oil). Bacterial abundance ranged between 0.21-0.86 × 106 cells mL-1 on average for all treatments. The lack of drastic increases in the cell density of bacterial cells in the oil-loaded treatments was observed throughout the experiment period. Sequencing analysis of the 16S rRNA gene revealed the progressive changes in the community compositions of bacteria in all treatments. The relatively high abundance of oil-degrading bacteria, including Cycloclasticus and Alcanivorax on Days 3-14 of the experiment reflected the presence of biodegradation of oil in the LDOil and HDOil treatments. Throughout the 14 days, the community composition of bacteria in the LDOil and HDOil treatments became more similar and they both differed from that in the Ctrl treatment. This study concluded that, in oil-polluted seawater, the changes in the bacterial community composition were mainly resulting from the addition of chemically dispersed crude oil.

Molecular simulation of the slurrying mechanism in microplastic semi-coke water slurry.

CONTEXT: This study explores the interaction between particles in microplastic semi-coke water slurry at the molecular level using molecular simulation methods, specifically DFT calculations and MD simulations. In addition, the experiment of slurry preparation was carried out to study the viscosity and stability of the slurry. The electrostatic potential analysis shows that the interaction between microplastics and dispersant molecules occurs on atoms with large electronegativity or oxygen-containing functional groups, and the energy gap of frontier molecular orbitals indicated that PVC interacts most easily with the dispersant (0.39 eV), followed by PS (1.08 eV) and PET (3.65 eV). In addition, it is also noted that due to the steric hindrance effect, the adsorption energy was opposite to the DFT calculation results: PET was - 213.338 kcal/mol (NNO) which was highest, followed by PS (- 107.603 kcal/mol, NNO), and PVC (NNO) was lowest which was - 94.808 kcal/mol. And RDF shows similar results, which the probability of water molecules in the PET system was the highest, followed by PS, and finally, PVC. The MD results are consistent with the viscosity and stability characterization results of the slurry which PET has the lowest viscosity of 87.3 mPa·s. Finally, this study provides new ideas for the treatment of microplastics and the improvement of the performance of semi-coke water slurry and reveals the interaction mechanism between microplastics and semi-coke water slurry. METHODS: All calculations were performed using Materials Studio (MS) version 2020 software, BIOVIA Corporation. The DFT calculation was carried out through the DMol3 module. The DFT calculations include electron density, electrostatics, orbitals, and population analysis. In DMol3 module, the GGA-PBE function was selected to consider gradient changes in density in the simulated calculation. The DFT-D correction was selected, and all electrons were calculated by DNP for accurate core potentials and the DNP file was 4.4. MD simulation was performed through the Forcite module. MD simulation mainly focuses on relative concentration distribution analysis, radial distribution function, and adsorption energy calculation. All molecular geometry optimizations are performed in the Forcite module. In the molecular dynamic part, all simulations used PCFF forcefield. The NVT ensemble was adopted and using the Nosé thermostat.

Water-accommodated fractions of crude oil and its mixture with chemical dispersant impairs oxidase stress and energy metabolism disorders in Oryzias melastigma embryos.

In this study, marine medaka (Oryzias melastigma) embryos were exposed to different concentrations of water-accommodated fractions (WAFs) and chemically enhanced water-accommodated fractions (CEWAFs) of Oman crude oil for 14 d by semi-static exposure methods. The effects on growth and development and energy metabolism process were evaluated. Results showed that embryo survival and hatchability were decreased in a dose-dependent manner with an increase in the concentration of petroleum hydrocarbon compounds, whereas the malformation exhibited a dose-dependent increase. Compared to the control, the adenosine triphosphate (ATP) content and Na+-K+-ATPase (NKA) activities of embryos exposed to both WAFs and CEWAFs were reduced, while intracellular reactive oxygen species (ROS) levels and NADH oxidase (NOX) activities were increased. Our study demonstrated that exposure to crude oil dispersed by chemical dispersant affected the growth and development of marine medaka embryos, caused oxidative stress while produced a series of malformations in the body and dysregulation in energy metabolism. In comparison, the toxic effects of chemically dispersed crude oil might be more severe than the oil itself in the equivalent diluted concentration treatment solution. These would provide more valuable and reliable reference data for the use of chemical dispersants in oil spills.

Development and Geometrical Considerations of Unique Conductive and Reversible Carbon-Nanotube Hydrogel without Need for Gelators.

We propose a new type of CNT hydrogel that has unique conductive and reversible characteristics. We found in previous studies that CNT dispersions became gelatinous without any gelators when a specific CNT was combined with a specific dispersant. This hydrogel has conductive properties derived mainly from the CNTs it contains; and even after gelation, it can be returned to a liquid state by ultrasonic irradiation. Furthermore, the liquid is gelable again. In this study, we prepared several types of CNTs and several types of dispersants, experimentally verified the possibility of gelation by combining them, and geometrically investigated the gelation mechanism to determine how this unique hydrogel is formed. As a result, we found that the experimental results and the theory examined in this study were consistent with the combination of materials that actually become hydrogels. We expect that this study will allow us to anticipate whether or not an unknown combination of CNTs and dispersants will also become gelatinous.

Neutrophil Extracellular Traps-Inspired Bismuth-Based Polypeptide Nanonets for Synergetic Treatment of Bacterial Infections.

Excessive use of antibiotics and the formation of bacterial biofilms can lead to persistent infections caused by drug-resistant bacteria, rendering ineffective immune responses and even life-threatening. There is an urgent need to explore synergistic antibacterial therapies across all stages of infection. Drawing inspiration from the antibacterial properties of neutrophil extracellular traps (NETs) and integrating the bacterial biofilm dispersal mechanism involving boronic acid-catechol interaction, the multifunctional bismuth-based polypeptide nanonets (PLBA-Bi-Fe-TA) are developed. These nanonets are designed to capture bacteria through a coordination complex involving cationic polypeptides (PLBA) with boronic acid-functionalized side chains, alongside metal ions (bismuth (Bi) and iron (Fe)), and tannic acid (TA). Leveraging the nanoconfinement-enhanced high-contact network-driven multiple efficiency, PLBA-Bi-Fe-TA demonstrates the excellent ability to swiftly capture bacteria and their extracellular polysaccharides. This interaction culminates in the formation of a highly hydrophilic complex, effectively enabling the rapid inhibition and dispersion of antibiotic-resistant bacterial biofilms, while Fe-TA shows mild photothermal ability to further assist fluffy mature biofilm. In addition, Bi is beneficial to regulate the polarization of macrophages to pro-inflammatory phenotype to further kill escaping biofilm bacteria. In summary, this novel approach offers a promising bionic optimization strategy for treating bacterial-associated infections at all stages through synergetic treatment.

Optimized Design of Material Preparation for Cotton Linters-Based Carbon Black Dispersion Stabilizers Based on Response Surface Methodology.

Carbon black particles possess dimensions on the nanometer or sub-nanometer scale. When utilized, these particles have a tendency to aggregate, which compromises their stability under storage conditions. To address this issue, a dispersant was prepared using cotton short fibers as raw materials through etherification and graft polymerization with acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as raw materials. The dispersant was then used to disperse carbon black to test its dispersing performance. A response surface optimization test was utilized to ascertain the influence of AMPS monomer mass, AM monomer mass, and potassium persulfate (KPS) initiator mass on the dispersibility of carbon black during dispersant preparation, and a set of optimal preparation conditions were obtained. The dispersion stability of carbon black in water was assessed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), elemental analysis (EA), thermogravimetric analysis (TG), zeta potential analysis, high magnification scanning electron microscopy (SEM), and contact angle measurements. Results revealed that the optimum mass ratio of carboxymethyl cellulose (CMC) to AMPS to AM was 1:0.69:1.67, with the KPS initiator comprising 1.56% of the total monomer mass. By incorporating the dispersant at a concentration of 37.50%, the particle size of carbon black particles was observed to decrease from 5.350 µm to 0.255 µm, and no agglomeration of carbon black particles occurred even after 3 weeks of storage.

Application of biofilm dispersion-based nanoparticles in cutting off reinfection.

Bacterial biofilms commonly cause chronic and persistent infections in humans. Bacterial biofilms consist of an inner layer of bacteria and an autocrine extracellular polymeric substance (EPS). Biofilm dispersants (abbreviated as dispersants) have proven effective in removing the bacterial physical protection barrier EPS. Dispersants are generally weak or have no bactericidal effect. Bacteria dispersed from within biofilms (abbreviated as dispersed bacteria) may be more invasive, adhesive, and motile than planktonic bacteria, characteristics that increase the probability that dispersed bacteria will recolonize and cause reinfection. The dispersants should be combined with antimicrobials to avoid the risk of severe reinfection. Dispersant-based nanoparticles have the advantage of specific release and intense penetration, providing the prerequisite for further antibacterial agent efficacy and achieving the eradication of biofilms. Dispersant-based nanoparticles delivered antimicrobial agents for the treatment of diseases associated with bacterial biofilm infections are expected to be an effective measure to prevent reinfection caused by dispersed bacteria. KEY POINTS: • Dispersed bacteria harm and the dispersant's dispersion mechanisms are discussed. • The advantages of dispersant-based nanoparticles in bacteria biofilms are discussed. • Dispersant-based nanoparticles for cutting off reinfection in vivo are highlighted.

Sonochemical decomposition effects of nickelocene aiming for low-temperature and dispersant-free synthesis of nickel fine particle.

Sonochemical decomposition effects of nickelocene, which sublimates easily were investigated to synthesize dispersant-free nickel fine particles at low temperature. In a hydrazine monohydrate and 2-propanol mixed solvent, the reduction of nickelocene was promoted by ultrasound irradiation, and nickel fine particles were synthesized while precluding the sublimation of nickelocene. Unlike the common hydrazine reduction of nickel salts, which requires multiple-step reactions, nickelocene was reduced directly without forming intermediates. The effect of the water-bath temperature (20-60 °C) was investigated, where larger fine particles were synthesized using a higher water-bath temperature (60 °C). When irradiated at 20 °C, the reduction rate of nickelocene was low, leading to the formation of nickel fine particles and organic nanoparticles via the reduction and decomposition of nickelocene. The ultrasound frequency was also investigated, where fine nickel particles were synthesized using low-frequency ultrasound irradiation. The formation of high-temperature hotspots led to the diffusion and growth of nickel on the surface of the nickel fine particles; therefore, raspberry-like nickel fine particles were synthesized. In this study, the difficult-to-handle nature of nickelocene, owing to its sublimation properties, was easily overcome by ultrasound irradiation. Instantaneous and localized reactions at hotspots contributed to inhibiting particle growth. Furthermore, Ni fine particles were synthesized via a direct reduction pathway, which differs from previous reactions. This method represents a new, dispersant-free, low-temperature process for synthesizing Ni fine particles.

Bioemulsifier production by Acinetobacter venetianus AMO1502: Potential for bioremediation and environmentally friendly applications.

At the best conditions of the bioprocess (30 °C, pH 7.0, 3.0 g/L NaCl) were obtained 0.66 g/L cell concentration, 3.3 g/L of bioemulsifier, which showed high emulsifying activity (53 % ± 2), reducing the surface tension of the water in 47.2 % (38 mN/m). The polymeric structure of the purified bioemulsifier comprised a carbohydrate backbone composed of hexose-based amino sugars with a monomeric mass of 1099 Da, structurally similar to emulsan. A. venetianus bioemulsifier is non-phytotoxic (GI% > 80 %) against Ocimum basilicum and Brassica oleracea and non-cytotoxic (LC50 5794 mg/L) against Artemia salina, being safe local organisms in comparison to other less eco-friendly synthetic emulsifiers. This bioemulsifier effectively dispersed spilled oil in vitro (C22-C33), reducing oil mass by 12 % (w/w) and dispersing oil in a displacement area of 75 cm2 (23.8 % of the spilled area). Thus, the isolated A. venetianus AMO1502 produced a bioemulsifier potentially applicable for environmentally friendly oil spill remediation.

Study on Mudcake disintegration in clayey strata during shield tunneling: Effects of dispersants and bentonite slurry.

While tunnel boring machines (TBMs) tunneling in clayey strata, the adhered excavated soil on the cutterhead and cutting tools tends to form mudcake after compaction and consolidation. Mudcake can obstruct the cutterhead openings and rendering the cutting tools ineffective, leads to a substantial reduction in advance rate. Dispersants are recognized as an effective method for the disintegration of mudcakes. A novel set of equipment, comprising a mudcake compression device and a mudcake disintegration apparatus, is developed for assessing mudcake disintegration properties. The results showed that mudcakes underwent a tripartite disintegration process in water, including an initial stage, a rapid disintegration stage, and a stable stage. In the initial stage, the mudcakes absorbed water before disintegration, resulting in marginal changes in the weight of the disintegrated mudcakes. In the rapid disintegration stage, the weight of the disintegrated mudcakes increased quickly. During the stable stage, the weight of the disintegrated mudcakes remained relatively constant. The submersion of mudcakes in a dispersant solution substantially increased the rate of disintegration. Greater dispersant concentration corresponded to an increase in the disintegration rate. No weight gain was observed in mudcakes during the initial disintegration stage. When mudcakes disintegrated in a bentonite slurry, the weight of the disintegrated mudcakes initially decreased and then stabilized. The weight of the disintegrated mudcakes turned negative, indicating an increase in the weight of mudcakes. This suggested that bentonite significantly hindered mudcake disintegration.

Understanding the Effect of Dispersant Rheology and Binder Decomposition on 3D Printing of a Solid Oxide Fuel Cell.

Solid oxide fuel cells (SOFCs) are a green energy technology that offers a cleaner and more efficient alternative to fossil fuels. The efficiency and utility of SOFCs can be enhanced by fabricating miniaturized component structures within the fuel cell footprint. In this research work, the parallel-connected inter-digitized design of micro-single-chamber SOFCs (µ-SC-SOFCs) was fabricated by a direct-write microfabrication technique. To understand and optimize the direct-write process, the cathode electrode slurry was investigated. Initially, the effects of dispersant Triton X-100 on LSCF (La0.6Sr0.2Fe0.8Co0.2O3-δ) slurry rheology was investigated. The effect of binder decomposition on the cathode electrode lines was evaluated, and further, the optimum sintering profile was determined. Results illustrate that the optimum concentration of Triton X-100 for different slurries was around 0.2-0.4% of the LSCF solid loading. A total of 60% of solid loading slurries had high viscosities and attained stability after 300 s. In addition, 40-50% solid loading slurries had relatively lower viscosity and attainted stability after 200 s. Solid loading and binder affected not only the slurry's viscosity but also its rheology behavior. Based on the findings of this research, a slurry with 50% solid loading, 12% binder, and 0.2% dispersant was determined to be the optimal value for the fabricating of SOFCs using the direct-write method. This research work establishes guidelines for fabricating the micro-single-chamber solid oxide fuel cells by optimizing the direct-write slurry deposition process with high accuracy.

Wear Mechanisms, Composition and Thickness of Antiwear Tribofilms Formed from Multi-Component Lubricants.

The antiwear properties of tribofilms formed on steel surfaces lubricated with various multi-component lubricants were investigated at an elevated temperature and under load-speed conditions conducive to sliding in the boundary lubrication regime. The lubricants contained base oil, reduced-level (secondary) zinc dialkyl dithiophosphate (ZDDP), and nitrogenous dispersant. The wear resistance of the tribofilms produced from different oil blends was evaluated in the context of the rate of change in the sliding track volume (wear rate for material loss) and the load-bearing capacity, chemical composition, and thickness of the tribofilms. Surface profilometry and scanning electron microscopy were used to quantify the wear performance and detect the prevailing wear mechanisms, whereas X-ray photoelectron spectroscopy elucidated the chemical composition and thickness of the tribofilms. The oil blends without ZDDP did not produce tribofilms with adequate antiwear properties, whereas the oil blends containing ZDDP and dispersant generated tribofilms with antiwear characteristics comparable to those of tribofilms produced from blends with a higher ZDDP content. Although dispersants can suspend oil contaminants and preserve the cleanness of the sliding surfaces, it was found that they can also reduce the antiwear efficacy of ZDDP. This was attributed to an additive-dispersant antagonistic behavior for surface adsorption sites affecting tribofilm chemistry and mechanical properties. Among the blends containing a mixture of ZDDP and dispersant, the best antiwear properties were demonstrated by the tribofilm produced from the blend consisting of base oil, 0.05 wt% ZDDP, and a bis-succinimide dispersant treated with ethylene carbonate. The findings of this investigation demonstrate the potential of multi-component lubricants with reduced-content ZDDP and nitrogen-based dispersant to form effective antiwear tribofilms.

Multi-site sulfonation of lignin for the synthesis of a high-performance dye dispersant.

Sulfonated lignin-based dye dispersants have intensively attracted attention due to their low cost, renewability and abundant sources. However, their utilization is limited by the low content of sulfonic groups and high content of hydroxyl groups in their complex lignin structure, which results in various problems such as high reducing rate of dye, severe staining of the fibers and uneven dyeing. Here, the multi-site sulfonated lignin-based dispersants were prepared with high sulfonic group content (2.20 mmol/g) and low hydroxyl content (2.43 mmol/g). When using it as the dispersant, the dye uptake rate was improved from 69.23 % to 98.55 %, the reducing rate was decreased from 20.82 % to 2.03 %, the K/S value was reduced from 0.69 to 0.02, and the particle sizes in dye system before and after high temperature treatment were stabilized below 0.5 µm. Besides, the dispersion effect was significantly improved because no obvious separation between dye and water was observed even if without the assistance of grinding process. In short, the multi-site sulfonation method proposed in this work could remarkably improve the performances of the lignin-based dye dispersants, which would facilitate the development of the dye dispersion and the high value utilization of lignin.

Assessment of spilled oil dispersion affected by dispersant: Characteristic, stability, and related mechanism.

Oil dispersion, a crucial process in oil transport, involves the detachment of oil droplets from slicks and their introduction into the water column, influencing subsequent oil migration and transformation. This study examines oil dispersion, considering characteristics, stability, and mechanisms, while evaluating the impact of dispersants and salinity. Results show the significant role of surfactant type in dispersants on oil dispersion characteristics, with anionic surfactants exhibiting higher sensitivity to salinity changes compared to nonionic surfactants. The dispersion efficiency varies with salinity, with anionic surfactants performing better in low salinity (<20‰) and nonionic surfactants showing superior performance at 30-35‰ salinities. Rheological analysis illustrates the breakup and coalescence of oil droplets within the shear rates of breaking waves. An increase in interfacial film rigidity impedes the coalescence of oil droplets, contributing to the dynamic stability of the oil-water hybrid system. The use of GM-2, a nonionic dispersant, results in the formation of a solid-like interface, characterized by increased elastic modulus, notably at 20‰ salinity. However, stable droplet size distribution (DSD) at 35‰ salinity for 60 h suggests droplets can remain dispersed in seawater. The enhancement of stability of oil dispersion is interpreted as the result of two mechanisms: stabilizing DSD and developing the strength of viscoelastic interfacial film. These findings offer insights into oil dispersion dynamics, highlighting the importance of surfactant selection and salinity in governing dispersion behavior, and elucidating mechanisms underlying dispersion stability.

Highly Reactive Graphene Dispersant and Its Effective Reinforcement for Phase Change Coatings.

High efficient dispersant that meanwhile possesses additional functions is highly desirable for the fabrication of graphene-based composite. In this paper, a new reactive dispersant, multi-silanols grafted naphthalenediamine (MSiND), is synthesized, which shows superiority compared with conventional dispersants. It can not only stabilize graphene in water at a high concentration of up to 16 mg mL-1, but also simultaneously be applicable for ethanol medium, in which the graphene concentration can be as high as 12 mg mL-1 at the weight ratio of 1:1 (MSiND:graphene). The dispersion is compatible with multi-matrixes and affinity to various substrates. In addition, MSiND exhibits excellent reactivity due to the existence of high-density silanol groups. Tough graphene coatings are constructed on glass slides and non-woven fabric simply by direct painting and dip-coating. Moreover, with the assistance of MSiND, graphene-doped phase-change coatings on hydrophobic non-woven fabric (e.g., functional mask) are prepared via the spray method. The composite coatings show enhanced mechanical strength and excellent energy storage performance, exhibiting great potential in heat preservation and thermotherapy.

Characterization of Ceria Nanoparticles as Abrasives Applied with Defoaming Polymers for CMP (Chemical Mechanical Polishing) Applications.

Chemical mechanical polishing/planarization (CMP) is an essential manufacturing process in semiconductor technologies. This method combines chemical and mechanical forces to smooth the surfaces of wafers. The effectiveness of CMP relies on a carefully chosen slurry, demanding a sophisticated manufacturing technology. This technology must seamlessly integrate both chemical composition and mechanical elements, highlighting the intricate synergy required for successful semiconductor fabrication. Particularly in milling processes, if agglomerated particles due to slurry particle corrosion are present during polishing, uneven polishing, numerous fine scratches occur, leading to an increase in roughness and a deterioration in the quality of the finished surface. In this study, to overcome the issue of particle agglomeration and uneven polishing in commonly used ceria nanoparticle slurries during CMP processes, we investigated the ceria nanoparticle behavior based on styrene-maleic acid (SMA) dispersant polymer applied with three types of defoaming polymers. The investigations are expected to open up the possibility of utilizing ceria nanoparticles with applied defoaming polymer as an abrasive for advanced CMP applications. All samples were characterized by DLS (dynamic light scattering), SEM-EDX (scanning electron microscopy-energy dispersive X-ray spectroscopy), pH, conductivity, viscosity, a 10-day stability test at 60 °C, the AF4 test, and the polishing rate efficiency test. Our research demonstrates a significant improvement achieved through the use of SMA dispersant polymer, resulting in a polishing selection ratio exceeding 80 for oxide and nitride films. The G-336 defoaming polymer utilized here is expected to serve as a viable alternative in CMP processes by providing stable uniformity.