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The behavior of colloidal particles with a hard core and a soft shell has attracted the attention for researchers in the physical-chemistry interface not only due to the large number of applications, but also owing to the unique properties of these systems, both in bulk and at interfaces. The adsorption at the two-phase boundary can provide information about the molecular arrangement. Thus, by Langevin Dynamics simulations, we have employed a recently obtained core-softened potential to analyze the relation between adsorption, structure and dynamic properties of the polymer-grafted nanoparticles near a solid repulsive surface. Two cases were considered: flat or structured walls. At low temperatures, a maximum is observed in the adsorption. It is related to a fluid to clusters transition and with a minimum in the contact layer diffusion - which is explained by the competition between the scales in the core-softened interaction. Due to the long range repulsion, the particles stay at the distance correspondent to this length scale at low densities, and overcome the repulsive barrier as the packing increases. However, by increasing the temperature, the gain in kinetic energy allows the colloids to overcome the long range repulsion barrier even at low densities. As a consequence, there is no competition and no maximum was observed in the adsorption.

In this work we measured, by using a direct approach, the equilibrium solubility of recombinant Aβ40 peptide to be S ​= ​0.36 ​± ​0.15 ​μM in aqueous solution of 20 ​mM sodium phosphate buffer at pH 7.4. Microfluidic diffusional sizing (MDS) and mass spectrometry (MALDI-TOF/TOF) with isotope standard were used to quantify the concentration of soluble Aβ40 species coexisting with formed fibrils. A sample set of Aβ40 at different concentrations was incubated at 37 ​°C under quiescent conditions and for different incubation times. After incubation, the samples were centrifuged and the concentration of Aβ40 in the supernatant was determined. This allowed us to also determine the metastable zone in supersaturated Aβ40 monomer solutions, as a function of the observation time, as well as the monomer concentration coexisting with formed fibrils. Moreover, the hydrodynamic radius (R_H) of the Aβ40 species detected in the supernatant at different time points was also measured, and showed a constant value of ∼1.8 ​nm, consistent with random coil Aβ40 monomers.

In a dual-functional photocatalytic reaction system with coupled selective organic reductions and oxidation reaction, both the photogenerated electrons and holes can be simultaneously utilized to generate value-added products, make the overall process more valuable from a sustainability and economic perspective. Herein, CdS&P25–Ni₂P (SPN) has been synthesized, which realized the selective transformation of organic compounds coupled with hydrogen evolution under visible light condition. The traditional sacrificial agent oxidation reaction is replaced by the dehydrogenation half reaction of aromatic alcohol with higher additional value, where high efficiency photocatalytic reaction can be realized. The effects of solvent, substituents, component of photocatalyst, co-catalyst loading and other factors on this reaction were explored. Under the optimal conditions, the substrate was almost completely transformed within 5 ​h, and the hydrogen production rate can reach 1.148 ​mmol·g_cat⁻¹·h⁻¹. Through compare the research of different reaction systems, different possible reaction mechanisms and reaction paths have been proposed. This paper further explores the field of organic value-added transformation coupled with hydrogen production and provides a new strategy for the effective use of photogenerated electrons and holes, which will be inspirational for the future involving catalysis, materials and other fields.

Semiconductor photocatalysts have been utilized to convert solar energy into hydrogen. However, CeO₂ has been rarely reported as a photocatalyst for hydrogen production on account of the rapid photoelectron-hole pair recombination and limited visible light adsorption capacity. In this work, we present the morphology controlling strategy on the purpose of preparing efficient composite semiconductor photocatalysts of CeO₂ with regular shape and reliable performance. The synthesized photocatalysts ZnS/CeO₂ with completely different morphologies structure (ZnS/CeO₂ solid spheres and ZnS/CeO₂ hollow dodecahedra) were obtained by a similar method. The results show that with the expansion of the visible light absorption range and the increase of nano pore porosity, the two photocatalysts ZnS/CeO₂ can afford more active sites and promote the transfer of photogenerated electrons-holes, thus effectively improving the hydrogen production efficiency. Besides, both of the photocatalysts ZnS/CeO₂ exhibit the long term (25 ​h) stability that also indicates a great potential in the photocatalytic water splitting for hydrogen evolution. This work provides a new idea and research method for further research on hydrogen production from photolysis of water.

There has been an increasing number of studies in magnetic nanoparticles with auspicious applications in medicine. Among the oxides of magnetic nanoparticles, iron oxide has emerged as an indispensable tool in nanotechnology, particularly bio-nanotechnology. This is attributed to its exceptional properties such as size, shape, magnetism, and biocompatibility. In this review, iron oxide nanoparticles were exploited in different model organisms ranging from prokaryotes to eukaryotes, elucidating their cellular functions relative to their antibacterial activity, drug delivery, and toxicity.

The Hydrophilic-Lipophilic Difference (HLD) model can be described by additive contributions accounting for the effect of the oil and surfactant nature, temperature, ionic strength, and so on. The first step to build an HLD framework for a surfactant class is to have Winsor III phase equilibria in a restricted range of formulation variables. In this respect, anionic and nonionic surfactants are well suited for an HLD study. On the contrary, it is difficult achieve for pure cationic surfactant Winsor III phase equilibria without the addition of alcohols and this has precluded the extension of the HLD to cationic surfactants.

In the present contribution, we first propose a system based on a blend of single-tailed and double-tailed cationic surfactant to study the oil contribution, and then we afforded the determination of the surfactant contribution trough an experimental approach (the “HLD-titration”) that is especially tailored for systems displaying a wide range of existence of Winsor III phase equilibria.

HLD-titration results confirmed the ionic strength contribution to HLD as a logarithmic function of salinity for cationic-based microemulsions similarly to anionic ones. However, the oil carbon number contribution is almost four-fold larger (k ​= ​0.7 ​± ​0.1) with respect to anionic surfactants. A clearing point was observed in correspondence of the Winsor III phase equilibria under stirring. This approach allows us the determination of the so-called characteristic curvature (Cc), i.e. the term describing the surfactant nature contribution to the film curvature, of the cationic surfactant. Finally, the method was adopted to determine Cc values of 7 quaternary ammonium surfactants differing in the polar heads nature and further three amine oxide surfactant at pH ​= ​1 where they are protonated.

Hypothesis

High molecular weight polymers are widely used in oilfield applications, such as in chemical enhanced oil recovery (cEOR) technique for hydrocarbon recovery. However, during flow in a porous rock, polymer retention is usually a major challenge, as it may result in the decrease of polymer concentration or lead to plugging of pores with significant permeability reduction and injectivity loss. Hence, an understanding of the retention mechanisms will have a profound effect in optimizing the process of polymer flooding, in particular, for carbonate rocks, which hold more than half of the world's oil reserves. Therefore, in this study, the retention of hydrolysed polyacrylamide (HPAM) polymer, a commonly used chemical for EOR, is investigated during flow in Estaillades carbonate rock.

Experiments

A novel approach of investigating HPAM retention in Estaillades carbonate rock was carried out using Atomic force microscopy (AFM). Since Estaillades carbonate rock is ∼98% calcite, HPAM retention was first characterised on a cleaved flat calcite mineral surface after immersing in HPAM solution. Afterwards, HPAM was flooded in Estaillades carbonate to observe the effect of flow dynamics on the retention mechanisms.

Findings

We find that the dominant mechanism for retention of HPAM on calcite after fluid immersion is polymer adsorption, which we believe is driven by the electrostatic interaction between the calcite surface and the solution. The thickness of the adsorbed layer on calcite is beyond 3 ​nm suggesting it is not adsorbed only flat on the surface. Different types of adsorbed layers were formed representing trains, and the more extended loops or tails with the largest polymer layer thickness about 35 ​nm, representing the longer loops or tails. Layers of this thickness will begin to impair the permeability of the rock. However, in Estaillades, thicker adsorbed layers are observed in different regions of the rock surface ranging between 50 and 350 ​nm. We suggest that this is due to either mechanical entrapment and/or polymer entanglement during flow in Estaillades carbonate rock, which will cause the major permeability impairment in porous rocks.

Nanoparticle drug delivery systems encounter many biological barriers, such as the extracellular matrix and mucus gels, that they must bypass to gain access to target cells. A design parameter that has recently gained attention is nanoparticle shape, as it has been shown elongated rod–shaped nanoparticles achieve higher diffusion rates through biological gels. However, the optimal dimensions of rod-shaped nanoparticles to enhance this effect has yet to be established. To systematically approach this, rod-shaped nanoparticles were synthesized by mechanically stretching 100 ​nm, 200 ​nm, and 500 ​nm spherical nanoparticles. Transmission electron microscopy confirmed this procedure yields a significant fraction of elongated rods and remaining spheres could be removed by centrifugation. Fluorescent microscopy and multiple particle tracking analysis was then used to characterize rod-shaped and spherical nanoparticle diffusion in MaxGel®, a model extracellular matrix hydrogel. When dispersed in MaxGel, we found rod-shaped nanoparticles exhibited the greatest enhancement in diffusion rate when their length far exceeds the average hydrogel network size. These results further establish the importance of shape as a design criterion to improve nanoparticle-based drug delivery systems.

Metal oxide composites containing nanostructured carbons have been extensively researched to overcome difficulties such as low intrinsic electronic conductivity, significant irreversible capacity loss, and poor coulombic efficiency in lithium-ion batteries (LIBs). A time-efficient microwave autoclave synthesis technique was approached to fuse V₂O₅ to MWCNT strands. V2O5/MWCNT is a hybrid nanoparticle with crucial features for the electrode needed for a supercapacitor that has been investigated and reported. Due to X-ray diffraction (XRD) peak investigation, the nanoparticles' phase structure, space group, and strain($\epsilon$) have been determined. The particle size was calculated in Debye-Scherrer, modified Scherrer, and uniform deformation modeling (UDM) modes. The interaction between light photons and electrons is thoroughly addressed using UV–Vis technology. Optical constants like refractive index (n), absorption coefficient ($\alpha$), and destructive coefficient (k) is addressed as a result of this. Nanoparticles' dielectric function (${\epsilon }_r$and ${\epsilon }_i$), and direct bandgap have also been reported. Along with V₂O₅/MWCNT's strong Photoluminescence (PL) emission, interpretation of unique optical properties and considerable potential for practical applications have been intensively studied. V₂O₅/MWCNT is confirmed by data acquired by Fourier Transform Infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) for vanadium, oxygen, and carbon. The formation of nanoparticles with the dimensions of V2O5/MWCNT is proven by Scanning Electron Microscopic (SEM) micrographic imagery. A Cyclic Voltammetry (CV) analyzer measures the material's highest specific capacity when exposed to electrochemical action, 632 Fg-1. The median power density (E) is predicted to be 146 Whkg-1, and the power density (P) is 1.52 ​kW kg-1 in the Galvanostatic Charge/Discharging (GCD) rating. These values are beneficial for describing the capabilities of supercapacitors.

One-step emulsification approaches enable prevention of the loss of emulsion droplets associated with two-step emulsification approaches. Stimuli-responsive amphiphilic block copolymers, emulsifiers, and nanoparticles that are responsive to changes in the temperature, pH, presence of CO₂, or presence of salts, can eliminate the requirement for two hydrophilic and lipophilic emulsifiers in the emulsion system. The amphiphilic block copolymers prepared from naturally occurring amino acids and proteins enable targeted delivery of drugs and nutraceuticals with high cellular uptake. Likewise, the presence of impurities, such as salts and redox reactions driven by the presence of iodine, can result in spontaneous emulsification and formation of double emulsions. This timely review focuses on the application of double emulsions for delivery of drugs and nutraceuticals and will provide insights to scientists in the pharmaceutical industry or food nutritionists who consider fortification of food products with micronutrients.