Concentrated Dispersions Research Articles

Quantitative Analysis Village Spatial Morphology Using “SPSS + GIS” Approach: A Case Study of Linxia Hui Autonomous Prefecture

This research comprehensively analyzes the spatial morphology of 177 traditional villages within Linxia Hui Autonomous Prefecture, Gansu Province. The study delineates these characteristics utilizing a combination of five quantitative measured indices—ratio, boundary, saturation, building density, and dispersion coefficients. Leveraging sophisticated analytical techniques facilitated by “SPSS + GIS” integration, the investigation systematically explores the intricate details of village spatial form. Their overarching distribution patterns, and the determinant factors influencing them, provide insights across both granular and broad-scale dimensions. The aim is to establish a robust quantitative data analysis framework, facilitating a precise description of traditional villages’ spatial dynamics. The findings categorize the spatial morphology of Linxia’s traditional villages into three distinct types: linear multi-point concentration, dense clustering, and irregular dispersion. Common traits among these categories include widespread dispersal, small settlements, and a mix of dwellings. Spatial distribution patterns vary, with dense clusters forming an “olive-shaped” trend in the southeast–northwest direction, while irregularly dispersed villages develop along mountains and valleys, exhibiting multi-core structures. Additionally, linear multi-point concentrated villages display a random, multi-point distribution interspersed with dense clusters. The survival strategies of these commercial, subsistence, and resource-based villages are shaped by a confluence of factors such as elevation, river proximity, ancient road networks, and the interplay between Han Chinese and Tibetan cultural influences. The implications of this study are significant for understanding traditional village dynamics, promoting sustainable development, and refining quantitative methods for rural studies.

Preparation of high-purity SiO2 by S-HGMS coupled with mixed-acid leaching: A case study on hematite tailings from Ansteel, China

Hematite tailings (HTs) are rich in silica and are used as replacements for fine aggregates in the preparation of construction materials. However, there is scope for a more effective utilization of the valuable elements present in HTs. In this paper, a process for preparing high-purity SiO2 using HTs procured from Ansteel (China) is proposed. HTs were treated using the superconducting high-gradient magnetic separation (S-HGMS) technology, where the silica as part of the nonmagnetic fraction was obtained in the form of a high-silica concentrate, which was then subjected to mixed-acid leaching to dissolve impurities to achieve refined purification. The optimum process conditions for S-HGMS were determined, and the response surface methodology was applied to optimize the process parameters of the mixed-acid leaching process. The process indicators of the mixed-acid leaching step included the leaching time, leaching temperature, and molar ratio of the mixed acids. The optimum process conditions for S-HGMS were as follows: the magnetic strength-to-velocity ratio in the weak magnetic separation stage was set to 0.034 T·s/m whereas it was maintained at 0.076 T·s/m in the strong magnetic separation stage; the pulp concentration was 40 g/L, the pulp velocity was 500 mL/min, and the dispersant concentration was 1 mg/g. Under these conditions, the high-silica pulp was processed. The corresponding SiO2 grade increased from 71.788 % to 95.260 %, and its recovery and yield reached 56.330 % and 42.450 %, respectively. The SiO2 content in the sample increased from 95.260 % to 99.961 %. Further, the mechanisms of the S-HGMS and mixed-acid leaching were revealed. The proposed process is environmentally friendly and operationally inexpensive. It can reduce the amount of HTs by 42.450 %, and the obtained high-purity silica product has high economic value and good industrialization prospects.

Synthesis of concentrated colloidal dispersion of zinc-based spinel nanoparticles via liquid-phase crystallization from “double-hydroxide-like” metal hydroxides

We demonstrate a liquid-phase crystallization of interdispersed metal hydroxides nanoparticles (NPs) (diameter < 10 nm), toward the versatile syntheses of highly concentrated colloidal dispersions of spinel oxides. ZnGa2O4 was chosen as a representative system to demonstrate our strategy. Heating of precursory wetgels of hydroxide NPs, interdispersed in a quasi-double-hydroxide-state, induced the crystallization at 60–80 °C into ZnGa2O4 NPs with a size of single nanometer. X-ray absorption fine structure (XAFS) analysis reveals that octahedrally coordinated Zn2+ in the hydroxide NPs decreased as the result of the crystallizations, and the amount of tetrahedrally coordinated Zn2+ increased. By the chelation of acetylacetone (acac) to tetrahedrally coordinated zinc species in crystalline oxides NPs, deflocculation of the wetgel was induced and then acac worked as a dispersion stabilizer. The present method can be also applied to ZnAl2O4 and ZnFe2O4 NPs, allowing to yield the colloidal dispersions of spinel oxides NPs with a size of single nanometers in diameter with high dispersion stability (over 1 week) under highly concentrated conditions (ca. 20–40 g/L).

The role of solvent interfacial structural ordering in maintaining stable graphene dispersions

Liquid phase exfoliation is the most promising method for the low-cost, scalable production of two-dimensional nanosheets from their bulk counterparts. Extensive exfoliation occurs in most solvents due to the huge amount of energy introduced by sonication or shear mixing. However, the subsequent dispersion is not always stable, with extensive reaggregation occurring in some solvents. Identifying the optimal solvent for a particular layered material is difficult and requires a fundamental understanding of the mechanism involved in maintaining a stable dispersion. Here, we use molecular dynamics calculations to show that when graphene is immersed in a solvent, distinct solvation layers are formed irrespective of the choice of solvent and their formation is energetically favourable for all considered solvents. However, energetic considerations such as these do not explain the experimental solvent-dependence of the dispersion concentration. Instead, we find that solvents with high diffusion coefficients parallel to the graphene layer result in the lowest experimental concentration of graphene in solution. This can be explained by the enhanced ease of reaggregation in these solvents. Solvents with smaller diffusion coefficients result in higher experimental graphene concentrations as reaggregation is prevented. In the low diffusion limit, however, this relationship breaks down. We suggest that here the concentration of graphene in solution depends primarily on the separation efficiency of the initial exfoliation step. Based on this, we predict that the concentration of exfoliated graphene in solvents such as benzaldehyde and quinoline, which have low diffusion constants, can be increased dramatically by careful tuning of the experimental sonication parameters.

A novel crosstalk-free piezoresistive/self-capacitive bimodal sensor for human-robot collaboration

In practical applications of collaborative robots, proximity and pressure sensing capabilities are crucial for ensuring the safety and effectiveness of interaction. This paper proposes a novel method of integrating a bimodal sensor that uses a piezoresistive membrane as a self-capacitive electrode, overcoming the current challenges in integration and signal independence. By optimizing the graphene dispersion concentration, the prepared piezoresistive membrane can meet the initial resistance requirements of the self-capacitive electrode and the high sensitivity requirements of piezoresistive sensing. Experimental trials conducted to characterize the sensor focus on its sensitivity (8.49 MPa−1 /2.75% cm−1), response time, and repeatability for both pressure and proximity sensing. Results indicate successful dual-mode detection with crosstalk-free between the two sensing modalities, achieved by evaluating proximity performance under different pressure conditions. Furthermore, a practical application of a 6-array e-skin mounted on a robotic arm is demonstrated, enabling proximity pause and pressure-based servo position control. This innovative approach enhances the robot’s sensing ability and promotes safer and more efficient collaboration between humans and machines.

Enhancing flammable gas dispersion and explosion prediction: A novel hybrid analytical-numerical approach with exploCFD

The analysis of explosion consequences involves two primary approaches: analytical methods and Computational Fluid Dynamics (CFD). Analytical methods offer a simplified one-dimensional model of overpressure, while CFD provides a more detailed numerical analysis capturing asymmetric and inhomogeneous overpressure distribution. However, CFD simulations can be computationally demanding and require additional sub-grid models to enable calculations to be carried out in realistic timeframes. Both approaches have large irreducible uncertainty. The hybrid analytical-numerical approach aims to simplify and speed up the calculation process, yet producing results that remain within this irreducible uncertainty. This study describes the theoretical basis and demonstrates the successful implementation of the hybrid methodology in exploCFD for predicting flammable gas dispersion and explosions with special focus on hydrogen. The methodology combines analytical source terms with numerical simulations, capturing the inhomogeneity of explosion overpressure distribution in realistic explosion cases, and gas release dispersion cases, which can only be achieved by taking obstacles and obstructions into account. We then compare the predictions of exploCFD with dispersion and explosion experiments with experimental results, with a special focus on Hydrogen. The focus on hydrogen utilization in recent years necessitates the development of predictive capabilities to assess the consequences of hydrogen-fuelled accidents in industrial facilities due to its unique properties. The methodology exhibits good agreement with experiment, for maximum and transient overpressure readings as well as dispersion concentrations. The study demonstrates that exploCFD's hybrid methodology is well-suited for modeling flammable gas releases, particularly hydrogen, and simulating explosion events resulting from the ignition of premixed gas clouds. This approach offers a superior alternative to more time-consuming and costly purely numerical methods, as well as crude analytical methods still in use today.

Influence of biocide and dispersant additives on the performance and durability of building paints produced with granite waste

Several studies aim to develop sustainable paints with performance and durability comparable to commercial ones. These can involve the reuse of waste as a substitute for conventional pigments and the replacement of organic solvents with aqueous bases. This latter approach contributes to reducing emissions of Volatile Organic Compounds (VOCs); however, it makes the paint more susceptible to biodegradation and instability. In this research, we sought to assess the influence of different concentrations of biocide and dispersant additives on the performance and durability of paints produced with granite waste (GW). The experimental program was divided into two phases. In Phase 1, the optimized mixture of basic components was determined based on the results of abrasion resistance (AR) and hiding power (HP). In this phase, the best proportion of GW, water, and polyvinyl acetate (PVA) resin was obtained, respectively, 44.3%, 35%, and 20.7%. In Phase 2, maintaining the optimized mixture from Phase 1, paints were formulated with the incorporation of biocide (0; 0.050; 0.225; and 0.400%) and dispersant (0; 0.02; 0.76; and 1.50%), and they were analyzed for AR, HP, shelf life, and weather resistance. It was found that the biocide additive did not significantly influence the performance properties, while the dispersant additive reduced the AR of the paint film possibly due to an increase in the pH of the medium. Regarding shelf life, samples with 0.225% biocide were considered more economical and sustainable. In the weather resistance test, none of the samples analyzed showed cracks, peeling, or mold. However, the fading of the paint film was more intense for higher concentrations of dispersant. Thus, the results obtained indicate that biocide additives are promising alternatives to improve the durability of paints based on GW.

Laser-based fabrication of superhydrophobic carbide surfaces from waste plastics

We report a procedure for fabricating superhydrophobic carbides with femtosecond laser-assisted carburization of metals, semiconductors, and oxides from waste plastics. To form a concentrated plastic dispersion, plastic is laser-ablated in toluene. Hydrogenated carbides are synthesized by applying the dispersion drop by drop onto the target surface, and then employing femtosecond laser scanning. Hydrogenated carbides of tungsten, silicon, and zirconium were syntehszied, and they depicted exceptional hydrophobic properties. Hierarchical structuring further promoted the hydrophobicity of these hydrogenated carbides. A water contact angle ∼ 168○ and roll-off angle ∼ 6○ were observed. Further, the samples retained hydrophobicity after 30 days of exposure to ambient air and 100 ○C thermal treatment. Our study holds equal significance from both environmental and technological perspectives, as it not only eliminates the use of fluorinated compounds but also contributes to environmental remediation by converting waste plastics into valuable superhydrophobic carbides.

Molecular rotor as an in-situ fluorescent probe for the degree of polymerization of α-D-1,4-glucans

Various starch synthesis and tailoring processes involve prevailing adjustments in the degree of polymerization (DP) of linear α-D-1,4-glucan chains (LGCs) for the improved functional performances. Previous studies indicated that LGCs might hinder the twisted relaxation of 9-(2-carboxy-2-cyanovinyl)-julolidine (CCVJ, a hydrophilic molecular rotor), highlighting CCVJ as a potential in-situ structural probe for LGC. In this study, glucose and its α-D-1,4 oligomers and polymers with molecular weights ranging from 0.18 kDa to 70.00 kDa were prepared as the model molecules (MM). The fluorescent emission behavior of CCVJ in various concentrations (1–5 g/L) of MM solutions or dispersions were analyzed. Results showed that for the low-DP MMs (≤ 3.98 kDa) with good aqueous stability, CCVJ emission increased by about 20 times with the DP of MMs. In contrast, CCVJ generally emitted weak DP-relevant but glucan content-dependent fluorescence in response to the interaction with high-DP MMs (> 3.98 kDa). Furthermore, a double-logarithmic linear relationship was found between the emission intensity of CCVJ and the molar-based molecular weight of glucan. The result combined with the molecular dynamic simulation suggested that CCVJ underwent surface-to-surface interaction with MMs. This study may contribute to the real-time analysis of the DP of α-D-1,4 oligoglucosides in maltodextrin and starch syrup.

Decoupling rheology from particle concentration by charge modulation: Aqueous graphene-clay dispersions

HypothesisAqueous graphene dispersions are usually obtainable by treating the surface of graphene chemically or physically. In these dispersions, the rheological properties (e.g., viscosity) are governed by a direct coupling to the graphene concentration, which limits their applicability. An alternative approach for dispersing graphene is trapping them in a viscoelastic-network formed by a co-dispersed charged fibrous-clay, Sepiolite. Contrary to surface treatment, the rheological properties of these dispersions are set by the clay particles. The rheology of charged-colloidal dispersions is governed by various parameters, including interparticle interactions. Hence, the rheology of the dispersion could be modulated by changing the clay surface charge without compromising the dispersed graphene concentration. ExperimentalThe surface charge of Sepiolite was modulated either by charge-screening (by NaCl added to the solution) or by surface-charging (by attachment of highly charged ions, e.g., HexaMetaPhosphate, HMP−) and the effect on rheology and graphene concentration was assessed. In particular, loading the dispersion with HMP− yielded low viscosity, storage, and loss moduli (two orders of magnitude lower than the corresponding HMP−-free dispersion) while the graphene concentration was maintained. We demonstrate that by this charge-modulation approach, reaching the rheological requirements of different applications without compromising on graphene concentration is plausible.

Study on dynamic mechanism of controllable SWCNTs arrays prepared by self-assembly

Single walled carbon nanotubes (SWCNTs) are seamless hollow tubular structures formed by a layer of graphite curled along a specific spiral vector. Individual SWCNT is restricted by the inconvenient manipulation in its nanoscale, and unable to maximize its functionality in the macro field. As a result, the two-dimensional array is the most basic structure for manufacturing SWCNTs devices in practical application. However, the fidelity of the array pattern and the distribution morphology of individual SWCNT in the large-scale array directly affect its performance, which also poses a challenge to the research on assembly methods and their underlying mechanisms. In this paper, the dynamic mechanism of controllable SWCNTs arrays prepared by self-assembly method has been studied from molecular dynamics to hydrodynamic by a combination of experiments and simulations. Some key factors limiting the fidelity of the arrays and the distribution morphology of individual SWCNT in the array, such as the self-assembly template, the concentration of the SWCNTs dispersion, are investigated and optimized by experiments. Finally, inspired by the results of the mechanism research, a blade-coating procedure is applied in self-assembly process to improve the alignment of SWCNTs in the array. The improved alignment of SWCNTs arrays are verified through morphology analysis and volt-ampere (V-A) characteristics compared with the SWCNTs randomly distributed arrays. The explicitly results are not only helpful to understand dynamic phenomena during self-assembly process and the influencing factors of the self-assembly method but also will provide meaningful guidance in the design, fabrication of SWCNTs arrays to prevent distortion in large scale and further promote their industrial application in manufacturing next-generation micro-nano devices.

Formulating, assessing and using shear thickening fluids for cork helmet liners

In this work, an assessment of different environmentally friendly formulations for shear thickening fluids (STFs) is performed. These formulations consist of concentrated dispersions of particles of precipitated calcium carbonate (PCC) in glycerin varying mass concentrations combined with four particle aspect ratios. A full rheological characterization is developed under simple shear (steady and oscillatory tests, i.e., SAOS and LAOS) and elongational flows. The study allows not only to select the most convenient particle aspect ratio and concentration of PCC, but also to observe a clear viscoelastic behaviour that shows unexpectedly “Beads On A String” (BOAS) structures under extensional flow, which is characteristic of polymer solutions. It is reported for the very first time that a continuous shear thickening fluid exhibits an increasing relaxation time with the extension rate within the thickening region. Based on the rheological information, the best formulation was used to develop reinforced cork composites that were implemented in cork helmet liners. The impact performance of the STF-cork helmet liners was better than commercial helmet liners without hard shell and for a reduction of 36% in thickness.

Small but salient: Minority shareholders’ innovation attention in interactive online platforms and corporate innovation

We examine the impact of minority shareholders’ innovation attention on corporate innovation. The catering hypothesis suggests that firms cater to minority shareholders by increasing only innovation quantity. The monitoring hypothesis argues that innovation attention has monitoring effect and thus motivates managers to pursue both innovation quantity and quality. Using a large sample of Chinese firms and minority shareholder postings on two official interactive online platforms, we document that innovation attention positively impacts innovation quantity and quality. The findings support the monitoring hypothesis. Our findings are robust to alternative innovation metrics and innovation attention, and after accounting for endogeneity. Additional analyses suggest that: (1) the effect is more salient for firms with more dispersed ownership concentration, higher innovation pressure, and greater degree of information asymmetry, (2) lowered agency cost due to minority shareholder attention is the transmission channel for the results, and (3) conditional on a firm’s performance, a high innovation attention from minority shareholders reduces the CEO turnover-performance sensitivity and stock turnover, which is consistent with the notion that minority shareholders’ innovation questions help raise the innovation failure tolerance to drive more innovation quantity and quality.

Designing sandwich-structured Ag–SnO2 contact materials: Overcoming the trade-off between erosion resistance and mechanical properties

Designing a second-phase enhancement system for SnO2 microstructures always plays a major role in improving the electrical contact performance of Ag–SnO2 contacts. This study fabricated sandwich-structure Ag–SnO2 contacts to overcome the trade-off between the erosion resistance and mechanical properties of Ag–SnO2 contacts via electrospinning with spark-plasma sintering; subsequently, the influence of SnO2 interlayers on the arc-erosion behaviour and mechanical characteristics of the contacts was investigated. The sandwich structure facilitated a reduction in the hill-and-valley morphology of the contact surface during repetitive erosion; fibrous SnO2 restricted the fluid evaporation of Ag, while SnO2 interlayers dispersed molten bridges, thereby improving the erosion resistance of the system. In parallel, 3D models of the sandwich-structured Ag–SnO2 contacts were reconstructed to investigate the evolution of their mechanical characteristics. Experimental and simulation indicated that the dispersion of stress concentration and reduction in surface deformation induced by the interface effect were the mechanical enhancement mechanisms, while the improvement of impact and wear resistances was attributed to the intensified support provided by the SnO2 interlayers on the matrix surface. Moreover, the synergistic interactions between Ag and SnO2 interlayers mitigated crack initiation and fracture propagation, thereby improving the fracture resistance of the contact matrix. These insights led to a feasible strategy for designing the microstructures of Ag-based contact materials.

The effect of welding deformation on the equivalent structural stress of dissimilar girth welded joint

Weld distortion refers to the phenomenon of shrinkage around the weld seam and warping of the outer weldment edges. This leads to a deviation from the original straight force transfer path in the joint, resulting in higher stress concentration. The weld root's stress concentrations can cause significant fatigue issues in dissimilar girth welded joints. However, previous evaluation methods have generally overlooked the impact of the welding process on fatigue assessment. To address this gap, this paper proposes integrating welding deformation into the fatigue life calculation process for welded joints made of G20Mn5 cast steel. In this study, a welding calculation program was developed to accurately simulate joint deformation using a two-curvature conical heat source model. Subsequently, high-frequency fatigue test data from scaled specimens of four types of joints were analyzed. The original equivalent structural stress fatigue data were corrected by taking into account the initial condition of weld deformation. This correction resulted in a reduction in the scatter of the fatigue data. Furthermore, the study also analyzed the welding deformation differences and the dispersion of stress concentration in scaled specimens caused by welding inhomogeneity.

Surface-tension change of graphene-based water nanofluid and its effects on heat-transfer process

Nanofluids with high thermal conductivities are gaining attention for heat-exchange applications, particularly in boiling processes. Nanofluid heat-transfer efficiency is significantly influenced by the surface tension (ST) and wettability patterns of the nanofluid. This study investigated graphene-based water nanofluids prepared from three different viscoelastic polymer solutions. The effects of the dispersant, graphene concentration, and temperature on the ST were investigated, and the wetting behavior of nanofluids on stainless steel and polypropylene random surfaces was determined. The results indicated that the ST of the nanofluids exhibited a negative correlation with the dispersant concentration and temperature. Additionally, the inclusion of graphene reduced the ST in xanthan-gum systems but increased it in sodium carboxymethyl cellulose and polyethylene-oxide systems. Overall, the nanofluids exhibited a lower ST than water. The decrease in the nanofluid ST is ascribed to the development of a rigid network resulting from the co-adsorption of graphene nanoparticles and the dispersant at the gas–liquid interface. Furthermore, graphene has been demonstrated to enhance the wettability of the base fluids of various materials. A decrease in ST led to increased frictional resistance; however, this was counteracted by an increase in the contact angle, resulting in an overall reduction in frictional resistance. Moreover, reducing the ST can improve the fluid boiling heat transfer. Therefore, these nanofluids exhibited the dual effect of reduced flow resistance and enhanced heat-transfer efficiency. This study offers valuable insights into the behavior of nanofluids and their potential applications in areas such as energy storage and spacecraft thermal management.

Trimethoxy Silyl End-Capped Hyperbranched Polyglycidol/Polycaprolactone Particle Gels for Cell Delivery and Tissue Repair: Mechanical Properties, Biocompatibility, and Biodegradability Studies

This study focuses on the development of new biocompatible and biodegradable particle gel scaffolds based on PCL-HBPG/1SiHBPG triblock copolymers composed of a polycaprolactone (PCL) core and two outer blocks of trimethoxysilyl end-capped hyperbranched polyglycidol (HBPG/1SiHBPG) that have the potential to be used in soft tissue regeneration. The relationship between the gel’s composition, structure, mechanical properties, and performance has been investigated for the first time and the copolymer design parameters have been optimized. The particle gel scaffolds were formed from the concentrated dispersions of the most hydrophobic PCL-45HBPG/1SiHBPG at low temperatures, and were the result of the numerous hydrogen bonds formed from the HBPG/1SiHBPG moieties as well as the formation of siloxane crosslinks (i.e., Si–O–Si bonds). These gels were formed in the physiological temperature range. Gels with a mechanical strength that gradually increases were formed from the physically crosslinked PCL-45HBPG/1SiHBPG particles effectively and safely, in the absence of UV radiation. They feature high elasticity and undergo enzyme-triggered disassembly. The gels are biocompatible and have the potential to invoke cell attachment and differentiation in the absence of exogenous biological stimuli. A successful outcome of this study will be the prospect of a new approach for tissue regeneration that is currently not available.

Antireflective coatings of chitin nanofibers on glass fabricated through electric field deposition

Due to their wide variety of practical applications, antireflective coatings have been studied intensively. In this paper, we developed a novel approach to fabricate antireflective coatings on glass substrate by using charged chitin nanofibers (ChNFs) and electric field deposition. The ChNFs were obtained via ultrasonic treatment of the modified chitin through partial deacetylation, esterification and esterification followed partial deacetylation (dual modification), respectively. The ChNF coatings prepared by applying electric field deposition and using aqueous dispersions of the dual modified ChNFs had antireflective capacity. The effects of electric field intensity, electric field application time and ChNF dispersion concentration on antireflective capacity of the ChNF coatings were studied. The coating obtained by applying 55 V electric field for 5 min and using the dispersion of the dual modified ChNFs with concentration of 0.05 wt% yielded increase in transmittance of a glass substrate (∼ 2.4% at wavelength of 550 nm). The results of this study demonstrate that electric field deposition is a high efficiency and low cost approach to prepare antireflective coatings on large size and nonplanar substrates with charged nanofibers.

Influence of the dispersed silver nanoparticles size and concentration on the properties of 6CB nematic

ABSTRACT We study the effects of concentration and size of the doped silver nanoparticles on material properties of 6CB nematic: 4-hexyl-4’-cyanobiphenyl using electrical, dielectric measurements along with the polarising microscopy methods. We show that the dispersed NPs do not affect the nematic-isotropic liquid transition temperature. We report that the doped NPs decrease the dielectric anisotropy, elasticity and viscosity of the material. We attribute this behaviour to the fact that the dispersed NPs lower the orientational order parameter of the nematic. However, the threshold voltage stays almost unaffected by the doped NPs and the switching-off time is decreased only at certain NPs concentration. Using our measured data, we test the validity of the predicted by the classical Maier-Saupe theory, linear dependence of the elasticity vs the square root of the order parameter. We show that while for the pure sample the mentioned dependence follows the classical prediction, the dispersed samples elasticity shows anomalous behaviour. We report that the mentioned dependence predicted by Gelbart-Ben Shaul theory fits well with the doped samples measured data.

A Review on Oil-Soluble Polyisobutylene-Based Dispersant for Colloidal Stabilization

Oil soluble polymeric-based dispersants have been extensively used in engine oil lubrication formulation due to their inherent properties, such as modifiable viscosity, compatibility, and effectiveness. However, the underlying mechanism of how the dispersant stabilizes soot particles in engine oil is still not fully understood, and discovering this mechanism is crucial for engine oil formulation technology. This review discusses the interactions between colloidal particles induced by two PIBSA-derived dispersants, namely PIBSI and PIBSAE. The effectiveness of these dispersants in stabilizing colloidal particles in oil systems depends on the chemical functional groups present on the main chain. The spectrum of colloidal interactions, ranging from Derjaguin, Landau, Verwey and Overbeek (DLVO) to non-DLVO theory, is predominantly influenced by the equilibrium between dispersant concentration and the overall system viscosity. This phenomenon can eventually reverse colloidal stabilization and result in more serious issues, such as engine wear and tear.