Particle Size Research Articles

Assessing processability of milled HME extrudates: Consolidating the effect of extrusion temperature, drug loading, and particle size via Non-dimensional cohesion

The downstream processability of Hot Melt Extrusion (HME) Amorphous Solid Dispersions (ASD), an underexplored topic of importance, was assessed through a multi-faceted particle engineering approach. Extrudates, comprised of griseofulvin (GF), a model poorly water-soluble drug, and hydroxypropyl cellulose (HPC), were prepared at four drug concentrations and three HME temperature profiles to yield cases with and without residual crystallinity and subsequently milled to five sieve cuts ranging from < 45 μm to 355 – 500 μm. Solid state characterization was performed with XRPD, FT-IR, and TGA. Particle scale properties of the milled extrudates were evaluated including particle size, density, surface energy, and morphologies imaged via SEM. It was observed that regardless of sieve cut size, drug concentration and HME conditions impacted the flowability trends, quantified via Flow Function Coefficient (FFC) and bulk density. As a novelty, the effects of various process parameters and drug loadings were consolidated into a dimensionless interparticle cohesion measure, granular Bond Number (Bog), to better correlate them with bulk powder properties. The significant contrast in particle morphologies, particle size, and densities among selected cases demonstrated that particle size alone should not be the sole consideration when correlating particle scale to bulk powder scale properties of milled extrudates. Instead, the HME temperature profile and ASD drug loading may be more suitable parameters affecting the bulk powder properties of the milled extrudates.

Formulation of Solid Lipid Nanoparticles Loaded with Rosiglitazone and Probiotic: Optimization and In-vitro Characterization.

In the present study, solid lipid nanoparticles loaded with Rosiglitazone and probiotics were prepared via solvent emulsification diffusion method which is patented. As a lipid and surfactant, Gleceryl monostearate and Pluronic -68 were used in the formulation process. During characterization, it was determined that ingredient quantity variations significantly impacted Rosiglitazone loading capacity, particle size, polydispersity index, etc. In an optimized formulation of RSG-PB loaded SLNs, spherical particles with a mean particle size of 147.66 ± 1.52 nm, PDI of 0.42 ± 0.02, and loading capacity of 45.36 ± 0.20 were identified. Moreover, the developed SLNs had the potential to discharge the drug for up to 24 hours, as predicted by Higuchi's pharmacokinetic model. The SLNs were stable at 25°C/60%RH for up to 60 days. There was little to no change in particle size, PDI, or loading capacity. In addition, the number of probiotic bacteria was determined using the standard plate count procedure. Further, the antioxidant effect of the prepared formulation is evaluated using the DPPH assay method. This study concludes that the method used to fabricate RSG-probiotic-loaded SLNs is straightforward and yields favorable results regarding various parameters, including sustained release property, particle size, PDI, and percent drug loading stability. Furthermore, DPPH radical scavenging activity shows the high antioxidant potential of RSG-PB SLNs when compared to RSG and probiotics alone.

Particle size control and performance analysis of the ammonium perchlorate-based molecular perovskite energetic material

To solve the problem of high mechanical sensitivity and difficulty in coating caused by large crystal particles of ammonium perchlorate-based molecular perovskite energetic material (H2dabco)[NH4(ClO4)3] (DAP-4), we conducted research on the particle size regulation and performance of it. Firstly, we determined the solubility of DAP-4 in six commonly used organic solvents using a static method. And based on this data, an UDAP-4 (D50 = 6.19 μm) was successfully prepared. The characterization results of UDAP-4 revealed that UDAP-4 exhibits a decrease in thermal decomposition peak temperature (Tp) by 19 °C compared to the raw material, along with an 87.92kJ/mol reduction in activation energy (Ea). The studies on different particle sizes indicate that UDAP-4 maintains good thermal stability while significantly enhancing safety performance. UDAP-4 shows an over 20J increase in impact sensitivity, and a 12N increase in minimum frictional load. And the smaller the particle size, the lower the sensitivity. These findings provide a reference for further secure applications of DAP-4 in an academic context.

Synthesis of pure fine AlN powder via CRN using nitridation promoter

Aluminum nitride (AlN) was synthesized using fine α-Al2O3 and carbon black through carbothermal reduction-nitridation (CRN) for heat dissipation applications in high-power electronics and electric vehicles. Pure AlN powder having a mean particle size of 0.52 μm was synthesized by CRN at 1650°C for 6h under 10L/min N2 flow. Because further reduction in particle size is needed to confer sinterability, the effects of various nitridation promoters, i.e., CaF2, AlF3, Y(NO3)3, Ca(NO3)2, and Mg(NO3)2 on decreasing the particle size were examined. The promoters containing Ca, Y, or Mg facilitate AlN conversion, while AlF3 retards it, revealing different particle morphologies. Addition of Ca(NO3)2 showed complete AlN conversion with a mean particle size of 0.38 μm after CRN at 1550°C for 10h. On the other hand, the addition of Mg(NO3)2 also revealed 100% AlN but coarser particle size of 0.45 μm along with more uniform particle size distribution. Intermediate phases generated by the reaction with promoter could be removed by optimizing the conditions for solid-state reaction to synthesize a pure fine AlN powder.

Effects of solutes and additives on ice growth prevention in ice slurry production

Ice slurry is a promising functional fluid with high thermal energy density and high heat transfer rate. However, large ice particles in the ice slurry can cause blocking of tubes during ice slurry flow. Therefore, it is preferable to use fine ice particles to prepare ice slurry in many fields. In this study, ice slurries were generated from supercooled solutions containing additives, such as anti-freeze protein and polyvinyl alcohol, to prevent the increase in the ice particle size in the formation process of the ice slurry. The concentration of the solute and amount of the additive were varied as experimental parameters, and the size of the ice particles was evaluated. The average area of the ice particles decreased with the addition of the additives. In particular, anti-freeze protein was effective for generating fine ice particles in the ice slurry. However, the effects of the additives became weaker for higher concentration of the solute, and the size of the ice particles was almost the same regardless of the concentration of the solute and the amount of the additive. Moreover, it was found that particular properties, such as the freezing-point depression, kinematic viscosity of the solution, and effective latent heat of fusion, did not affect the size of the ice particles in the ice slurry generation process.

Transport and retention mechanisms of highly suspended biochar in aquifer media

Biochar-based in-situ reaction zones are promising methods for groundwater remediation. However, the transport and retention of biochar in aquifer media remain unclear. Herein, biochar with high suspensibility was developed through nitrogen doping. A linear regression was used to analyze the relationship between particle size, concentration, time, and suspension rate. Seepage column experiments were conducted to investigate the transport and retention mechanisms of biochar in the aquifer medium. The ratio of biochar particle size (dp) to medium particle size (Dp) affected the permeability coefficient. At a 3.0 g/L injected concentration, hydraulic conductivity decreased within 3.3 × 10−3 ≤ dp/Dp ≤ 8.4 × 10−3. Within 9.7 × 10−3 ≤ dp/Dp ≤ 1.9 × 10−2, hydraulic conductivity first increased and then decreased. Within 2.5 × 10−2 ≤ dp/Dp ≤ 5.7 × 10−2, hydraulic conductivity slightly increased and then stabilized. This study confirms that nitrogen-doped biochar is an excellent remediation material for in-situ reaction zone.

Preparation and evaluation of Puerarin-loaded PLGA nanoparticles for improving oral bioavailability in SD rats

BackgroundPuerarin (Pue) is an isoflavone compound with significant therapeutic effect on cardiovascular diseases, but its poor water solubility and low oral bioavailability limit clinical application. MethodsIn this study, Pue was prepared into PLGA nanoparticles (Pue-PLGA NPs) by emulsion solvent volatilization method. The morphology, particle size, Zeta potential, X-ray diffraction (XRD), and fourier transform infrared (FTIR) of the NPs were characterized. Additionally, their stability and in vitro release were evaluated. SD rats were orally administered wtih Pue and Pue-PLGA NPs, and a high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to determine the concentration of blood samples and to investigate the pharmacokinetic behaviour of Pue and Pue-PLGA NPs in rats. ResultsThe NPs were observed by transmission electron microscopy (TEM) as regular spheroids and uniformly dispersed. The average particle size of the NPs was (167.1±5.26）nm, the Zeta potential was (-29.88±2.46)mV, the encapsulation rate was (83.12 %±4.73 %) and the drug loading capacity was (7.75 %±1.81 %). The results of in vitro release showed that the drug was released slowly and continuously from the NPs, reaching the release platform in 24 h, and the cumulative release amount was (88.55±2.86) %. The pharmacokinetic results showed that the AUC0–24, AUC0-∞, Cmax, Tmax, t1/2, MRT0–24 and MRT0-∞ of Pue-PLGA NPs were 2.196, 1.978, 1.327, 1.5, 1.385, 3.915 and 3.140 times of Pue, respectively. The relative bioavailability was (197.82±25.28) %. ConclusionThese results indicated that the prepared nanoparticles had small particle size, high encapsulation rate, drug loading capacity and good slow-release effect, and could significantly improve the oral bioavailability of Pue in rats.

Development of Wheatgrass (Triticum aestivum) Extract Loaded Solid Lipid Nanoparticles using Central Composite Design and its Characterization- Its In-vitro Anti-cancer Activity

Background: The prevalence of cancer is around the world and is identified as a multifactorial ailment. One of the most common causes of cancer in the world is oxidative stress, and this can be overcome by taking herbal plant wheatgrass in any form. As colloidal carriers with particle sizes of 50-1,000nm, Solid Lipid Nanoparticles (SLNs) combine the benefits of liposomes, emulsions, and other colloidal systems to deliver drugs at their targets. Objective: Aim and objective of the present work is to formulate wheatgrass extract loaded solid lipid nanoparticles using Central Composite design and to investigate the effect of formulation variables. Using hot homoginization method, the present work aimed to formulate wheatgrass loaded chitosan solid lipid nanoparticles using central composite design and to evaluate the extract potential to treat breast cancer on MCF-7 cell line. Methods: This study investigated the effect of three formulation variables on particle size, namely the sodium alginate concentration, the calcium carbonate concentration, and the homogination time. Extraction of wheatgrass was done in soxhlet extractor, using methanolic extract. The hot homogenization technique was used to prepare Triticum aestivum extract loaded solid lipid nanoparticles (SLNs). Result: For CCD, all formulations were analyzed for particle size, which ranged from 362.5 to 933.8 nm, and for polydispersity index, which ranged from 0.137 to 5.799. Batch code SLN-6 was found to be finest suitable because of maximum loading capacity of 67.76 ±0.17 % (w/w), maximum entrapment efficiency of 65.81 ± 0.11 % (w/w) and minimum particle size of 362.5nm by using sodium alginate as surface stabilizer at homogenization time ~ 5 min and having maximum percentage yield of 43.66%. Conclusion: During characterization studies and MCF-6 cell line studies, it was found that batch code SLN-6 was found to be finest suitable and wheatgrass has anti-oxidant potential, and potent against breast cancer.

Experimental study on the concentration fluctuation of dust particles with different sizes during a dust storm

The particle size distribution (PSD) and concentration fluctuation were analyzed during different stages of a dust event. Our results show that dust smaller than 0.5 μm were dominant during the development stage; dust less than 0.5 μm decreased and dust from 0.5 μm to 10 μm increased in the high and low concentration stage; dust from 0.5 μm to 10 μm decreased and dust less than 0.5 μm increased in the dissipation stage. PSD of the first and fourth stages shows the unimodal distribution, but that of the other stages shows the distribution of 4 peaks. For large scale fluctuation with a period larger than 300 s, the concentration fluctuation of particles with size less than 0.4 μm and size larger than 0.4 μm has a high correlation. For small scale fluctuation with period less than 300 s, some particle size segments have high correlation at different stages, while some particle size segments have poor correlation at different stages. At the same stage, the size of the benchmark particle that is highly correlated in different particle size segments fluctuates with increasing particle size. In addition, the concentration fluctuation in 0.01276 Hz ∼ 0.02084 Hz and 0.00285 Hz ∼ 0.01096 Hz has significant contributions.

Preparation and Optimization of Gemcitabine Loaded PLGA Nanoparticle Using Box-Behnken Design for Targeting to Brain: In Vitro Characterization, Cytotoxicity and Apoptosis Study

Background: Treatment of glioma with conventional approaches remains a far-reaching target to provide the desired outcome. This study aimed to develop and optimize Gemcitabine hydrochloride- loaded PLGA nanoparticles (GNPs) using the Box-Behnken design methodology. The independent variables chosen for this study included the quantity of Polymer (PLGA) (X1), Tween 80 (X2), and Sonication time (X3), whereas the dependent variables were Particle size (Y1) EE % (Y2) and PDI (Y3). The optimized biodegradable nanoparticles were investigated for their anticancer effectiveness in U87MG human glioblastoma cells in vitro. Method: The formulation process involved two steps. Initially, emulsification was carried out by combining the organic polymer solution with the aqueous surfactant solution. Subsequently, in the second step, the organic solvent was evaporated, resulting in the precipitation of the polymer and the formation of nanoparticles. The quantity of PLGA, Tween 80, and PVA (at a constant concentration) was adjusted based on the experimental trial approach. Subsequently, the PLGA-based nanoparticles underwent characterization, wherein their particle size, encapsulation efficiency, polydispersity index (PDI), and cumulative release were assessed. The optimal formulation composition was determined as 200 mg of PLGA, 4 ml of Tween 80, and 2 mg of PVA. Further, the optimized GNPs were evaluated for their anti-cancer effectiveness on U87 MG cells by MTT and apoptosis assay. Results: The results demonstrated that the optimized GNPs exhibited an encapsulation efficiency of 81.66 %, a particle size of 140.1 nm, and a PDI of 0.37. The morphology of the Opt-GNPs was observed to be spherical through transmission electron microscopy (TEM). Conclusion: The Apoptosis study further confirmed the observations of MTT assay as the Opt- GNPs significantly enhanced the apoptosis in U-87 MG cells than the Standard marketed formulation.

Construction and characterization of Laminaria polysaccharide functionalized selenium nanoparticles based on an activity-oriented approach

Laminaria polysaccharides (LP) have been shown to effectively stabilize selenium nanoparticles (SeNPs), forming LP–SeNP complexes with enhanced bioactivity. However, the correlation between their bioactivity and physicochemical properties remains inadequately explored. This study used chemical reduction with LP as stabilizer to investigate how LP-to-selenium mass ratio (LPSMR), reaction time, and temperature influence particle size, selenium content, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of LP–SeNPs. The results showed that enhanced DPPH scavenging correlated with higher selenium content and smaller particle size, primarily modulated by LPSMR and temperature. Under optimal conditions (LPSMR of 1; temperature of 25°C), the resulting LP–SeNPs exhibited uniform morphology with a particle size of 81.41nm and selenium content of 653.91mg/g. This stability was achieved through non-covalent interactions between LP and SeNPs, providing superior light and acid resistance compared to unmodified SeNPs. Notably, LP–SeNPs showed synergistic antioxidant effects, with lower half-maximal inhibitory concentration (IC50) values for scavenging DPPH, hydroxyl, and superoxide anion radicals than LP or SeNPs alone, and enhanced hypoglycemic activity. Cytotoxicity assays confirmed LP–SeNPs had reduced toxicity compared to Na2SeO3 and selenopeptide. These findings provide insights into the structure-activity relationships of LP–SeNPs and support their potential application as antioxidant and hypoglycemic agents.

Analysis of deformation and failure of sediment particle-surrounding rock structure of salt cavern gas storage under the coupled action of temperature and pressure

When gas is injected or produced in the gas storage of salt cavern, the different effects of thermal stress, gas pressure, sediment particles and brine pressure on the cavity wall of salt cavern may cause large deformation and damage in the surrounding rock, which threatens the safe and stable operation of the gas storage of salt cavern. Therefore, based on FLAC3D-PFC3D coupling method, a numerical model of salt cavern gas storage with sediment particles in consideration of temperature was constructed, and the influence of injection-production time effect, sediment particle size and initial porosity on the deformation and failure of sediment-surrounding rock structure is studied. The results show that the tensile contact force chain of sediment is sensitive to the particle size of sediment, but insensitive to the initial porosity of sediment and injection-production conditions; during gas production, the larger the particle size and initial porosity of sediment particles, the greater the vertical displacement of shallow sediment particles, and the opposite results are obtained during gas injection. With the progress of gas production and gas injection, the absolute value of vertical displacement of the roof of the salt cavern increases gradually, and the plastic failure range of surrounding rock expands; for gas production process, the larger the particle size and initial porosity of sediment, the smaller the algebraic value of vertical displacement of surrounding rock at the top of cavity and the smaller the plastic failure range of surrounding rock. For the gas injection process, the larger the particle size and initial porosity of the sediment, the larger the algebraic value of the vertical displacement of the surrounding rock at the top of the cavity and the larger the plastic failure range of the surrounding rock. The results can provide reference for the reasonable setting of injection-production operation parameters of salt cavern gas storage and ensure the safe and stable operation of underground salt cavern gas storage (USCGS).

Influence mechanisms of dissolved organic matter and iron minerals on naphthalene attenuation during river infiltration

Natural attenuation of naphthalene (NAP) in riverbank filtration zones is vital for maintaining water quality and is affected by dissolved organic matter (DOM) and iron minerals. However, the effects of DOM and iron minerals on the attenuation of NAP remain unclear. In this study, the attenuation mechanisms of NAP under the influence of DOM and iron minerals were explored in a riverside source area. Field dynamic monitoring data revealed that the NAP concentration in groundwater is mainly influenced by DOM, effective bound‑iron, and the intensity of river water infiltration recharge. Column experiments indicated that DOM with α-Fe2O3 or α-FeO(OH) reduced medium permeability by 8.16 % or 6.85 %, respectively, increasing water retention time. However, they had different effects on the attenuation of NAP. The coexistence of α-Fe2O3 and DOM enhanced NAP attenuation capacity by 9.13 %–45.91 %, while α-FeO(OH) and DOM reduced it by −13.25 % to −24.13 %. These effects were attributed to changes in the medium permeability, particle size, secondary mineral formation, and microbial community structure. Specifically, α-Fe2O3 and DOM reduced medium permeability, increasing the adsorption and biodegradation reaction time of NAP, and promoted secondary mineral (FeCO3) formation, increasing the adsorption capacity of medium for NAP, while α-FeO(OH) and DOM underwent cementation, resulting in larger particles and reduced adsorption capacity for NAP. Additionally, α-FeO(OH) and DOM promoted Shewanlla growth, inhibiting NAP attenuation by competing with NAP-degrading bacteria. These findings improve the understanding of the natural attenuation of polycyclic aromatic hydrocarbons (PAHs) in riverbank filtration, offering a basis for evaluating and controlling PAH pollution risks.

Preparation, characterization and properties of chitosan-coated Epsilon-poly-lysine nanoliposomes in apple juice

Epsilon-poly-lysine (EPL) is widely used in food preservatives. However, EPL can react with components in food substrates, resulting in the formation of precipitates that reduce its antimicrobial properties. Nanoencapsulation is a promising technique and represents a novel approach to enhance EPL activity. In this study, EPL nanoliposomes (EPLLP) were prepared by the thin film hydration method, and chitosan-coated nanoliposomes (CS-EPLLP) were developed by modifying EPLLP with 0.5 mg/mL chitosan. The obtained CS-EPLLP exhibited a spherical morphology with a particle size range of 85.27–89.77 nm, a polydispersity index (PDI) of 0.293–0.301, and an encapsulation efficiency of 83.01 ± 4.00 %. After 30 days of storage, no significant difference in particle size was observed and the PDI was <0.30. The release rate of EPLLP was up to 40 % in 1 h, while that of CS-EPLLP was <20 %. The physical and thermal stability of EPLLP could be effectively improved by chitosan. Moreover, CS-EPLLP could effectively eradicate A. acidocaldarius and A. acidoterrestris in apple juice at concentrations of 2.5 and 0.625 mg/L, respectively. The cytotoxicity test showed that CS-EPLLP exhibited excellent biocompatibility. Therefore, this study has developed a novel nanoliposome material that provides new insights into the control of bacterial contamination in fruit juices.

Selective On-Site Detection and Quantification of Polystyrene Microplastics in Water Using Fluorescence-Tagged Peptides and Electrochemical Impedance Spectroscopy

In this study, we developed a method for the on-site selective detection and quantification of microplastics in various water matrices using fluorescence-tagged peptides combined with electrochemical impedance spectroscopy (EIS). Among the types of plastics found in seawater, polystyrene (PS) microplastics were selected. Fluorometry, scanning electron microscopy (SEM), and Raman spectroscopy were used to verify the specific interaction of these peptides with PS spherical particles of different sizes (ranging from 0.1 to 250µm). Principal component analysis (PCA) was employed to determine the effects of temperature (25-65 °C), incubation time (5 and 10minutes), and particle size on plastic-peptide bonding efficiency, based on fluorescence intensity. For each water type (pure, tap, NaCl (0.5M), and seawater), EIS plots (Nyquist and Bode) were generated. Significant factors affecting the EIS response, including particle size, shape, and material, were analyzed by measuring electrical parameters for different microplastic concentrations (50 ppb to 20 ppm). The EIS parameters changed with increasing plastic concentration, determining a limit of detection (LOD) of 50 ppb (ng/mL) for pure and tap water and 400 ppb for saline water, as the lowest concentration producing a significant change in EIS parameters compared to the baseline. The sensor proved highly effective for detecting microplastics in low ionic strength environments such as pure and tap water. However, in high ionic strength environments like saline and seawater, the detection capability diminished, likely due to the masking effect of ions on the EIS response.

Fabrication and evaluation of chitosan-coated nanostructured lipid carriers for co-delivery of paclitaxel and PD-L1 siRNA

This study aimed to develop a nanostructured lipid carrier (NLC) capable of co-delivering paclitaxel (PTX) and programmed death-ligand 1 (PD-L1) small interfering RNA (siRNA) to enhance PTX bioavailability and bolster immunity through PD-L1 knockdown. We prepared a PTX-loaded NLC (P-NLC) and coated it with positively charged chitosan (Chi) to create P-NLC-Chi, which was subsequently conjugated to siRNA (P-NLC-Chi-siRNA). The P-NLC-Chi formulation was optimized using the Box–Behnken design. P-NLC-Chi measured 123.8 ± 0.52 nm (zeta potential, 22.71 ± 0.49 mV). By verifying the gel retardation assay and observing changes in the zeta potential, the optimal binding ratio of NLC to PD-L1 siRNA was identified as 50:1. The P-NLC-Chi-siRNA particle size was 181.97 ± 0.67 nm, with a zeta potential of 18.66 ± 0.23 mV. siRNA stability was observed in serum over a 24-h period. Enhanced cytotoxicity and intracellular uptake of the complex were evident in breast cancer cells and breast cancer-resistant cells (MCF-7 and MCF-7/ADR cells, respectively). Evaluation of P-glycoprotein-mediated efflux demonstrated that NLC mitigated drug efflux in MCF-7/ADR cells. Subcutaneous injection of P-NLC-Chi-siRNA into tumor-bearing BALB/c nude mice injected with MCF-7/ADR cells revealed a reduction in tumor size. In vitro and in vivo experiments indicated a significant reduction in PD-L1 mRNA expression levels. Additionally, an in vivo study revealed tumor-specific CD4 + and CD8 + T cell responses within the tumor tissue following the injection of P-NLC-Chi-siRNA. Our findings suggest that Chi-coated NLC for the co-delivery of PTX and PD-L1 siRNA has great potential as an innovative delivery system for chemoimmunotherapy.

The rational design of ratiometric probe based on fluorescence carbon dots and its PVA film platform for the detection of Hg2+: tunable mechanism and the performance

Carbon dots (CDs) are recognized as sensitive probes for the detection of Hg2+ due to their remarkable fluorescent properties and ease of synthesis. However, drawbacks such as high costs, intricate synthesis, and non-portability hinder their broader applications. This study reported the synthesis of tunable multicolor CDs, including blue (B-CDs), green (G-CDs), and orange (O-CDs), by using hydrothermal methods while adjusting precursors and temperature. The observed fluorescence redshift from B-CDs to G-CDs or O-CDs arose from interactions among particle size, sp² conjugation, and surface oxidation, while the redshift from G-CDs to O-CDs was linked to surface fluorophores. Moreover, a ratiometric probe was developed by mixing B-CDs (response signal) and O-CDs (reference signal). Hg2+ significantly quenched B-CDs fluorescence due to static quenching from electron transfer. The probe demonstrated excellent stability and sensitivity, with limits of detection (LOD) of 4.8nM in the 0-0.6μM range and 9.2nM in a broader range (0-50μM). A portable smartphone-assisted detection platform was further developed by integrating the probe into polyvinyl alcohol (PVA) hydrogel. Both methods manifested the capability to accurately quantify Hg2+ in real water samples. This research provides innovative strategies for multicolor CDs and a sensing platform for rapid on-site Hg2+ detection.

Improving the emulsification characteristics of rapeseed protein isolate by ultrasonication assisted pH shift treatment

Rapeseed protein isolate (RPI) is an important nutrimental macronutrient in human diet due to its abundance in amino acids. However the poor emulsifying attributes of RPI limits its application in food industry, which needs to be overcome for its application in food industry. Ultrasonication-aided pH shift (UpHS) treatment is an efficient method for enhancing the functionality of plant/ food protein. In this work, the emulsification characteristics of RPI modified by UpHS technique under different solubility levels were studied. Results showed that the emulsifying activity and stability of modified RPI were significantly improved by 168.46 % (sample with high solubility treated by Ultrasonication-aided pH 12.5, HSpH 12.5) and 134.5 % (sample with high solubility treated by Ultrasonication-aided pH 1.5, HSpH 1.5), respectively compared with the native sample (P < 0.05), and the emulsifying activity was positively correlated (P < 0.05) with solubility. The emulsification stability under acidic condition was higher than that under alkaline condition (HSpH 12.5 increased by 83.5 %). In addition, the adsorption capacity and zeta potential of RPI were increased to 93.74 % and 13.83 % respectively, whereas the particle size and surface tension were reduced to 41.04 % and 23.63 % respectively. This indicates the changes in the molecular structure of modified rapeseed protein, which improved the emulsifying activity of RPI. Moreover, the interfacial film of emulsions formed by the modified protein had stronger compressive resistance, contributing to the enhanced emulsifying stability of the RPI. These results show that UpHS treatment can effectively improve the emulsification properties of proteins, and can be widely used in food industry.

Permeability estimation from pore to Darcy in cemented granular media using resolved CFD-DEM model

Permeability prediction plays a critical role in many engineering applications that involve fluid flow through porous media. Various factors including pore shape, particle size, polydispersity and compaction levels can significantly impact the flow behavior of a porous medium. Moreover, the influence of cementation should also be considered. In this work, we investigate the effect of particle cementation on the permeability using the three-dimensional resolved CFD-DEM approach. The modified cohesive contact model is utilized to simulate the cementation behavior of particles. The numerical model is initially validated by a laboratory experiment demonstrating similar results for the permeability of the sample with polydisperse particles. Results show that the permeability in both polydisperse and monodisperse particle systems decreases when the cementation of particles increases. Especially, this relationship is observed at higher porosity values. In contrast, in more compacted samples with lower porosity, the cementation effect becomes less. The numerical study also shows that the tortuosity values in both particle systems increase almost linearly with decreasing porosity. However, the strong influence of cementation on tortuosity is noticeable only in a monodisperse particle system dominated by uniform pore shapes with regular fluid paths. A study of fluid flow at different gradation levels reveals that an increase in cementation leads to a significant decrease in the permeability in a sample with larger particles. From the point of view of applying the numerical model to the real reservoir sand sample, the numerical results of permeability align well with the data reported by many studies.

Effect of ultrasonic treatment on the structure and emulsification properties of soybean isolate protein-hyaluronic acid complexes and the stability of their loaded astaxanthin emulsions

The purpose of this work was to prepare an astaxanthin emulsion stabilized by a soybean isolate protein (SPI)-hyaluronic acid (HA) complex and to investigate its protective effect on astaxanthin. In order to examine the impact of various ultrasonic energies (0 W–300 W) on the structural characteristics of the complex and the stability of the emulsion, the SPI-HA complex was created via ultrasonography. The findings demonstrated that ultrasonication may had an impact on the hydrophobic, electrostatic, and hydrogen bonding interactions between SPI and HA, which caused the protein structure to unfold and reveal the interior hydrophobic amino acid residues. Moreover, ultrasonication enhanced the emulsification qualities of SPI-HA complexes by lowering their average particle size. The rheological findings demonstrated that the emulsion's viscosity and energy storage modulus (G′) were considerably decreased by the ultrasonic treatment. The appearance of the emulsions and optical microscopy results further indicated that the emulsions prepared from SPI-HA had superior storage stability, pH stability, and light stability compared to pure SPI. SPI-HA exhibited superior emulsion stability and lower particle size at 150 W ultrasonic power. The AST incorporated in the emulsion was also well protected. The emulsion effectively slows down the degradation of AST. The findings of this study may help create more robust and natural emulsion delivery systems that guarantee the continuous or regulated release of lipophilic bioactive compounds.