High‐internal‐phase Pickering emulsions have various applications in materials science. However, the biocompatibility and biodegradability of inorganic or synthetic stabilizers limit their ...applications. Herein, we describe high‐internal‐phase Pickering emulsions with 87 % edible oil or 88 % n‐hexane in water stabilized by peanut‐protein‐isolate microgel particles. These dispersed phase fractions are the highest in all known food‐grade Pickering emulsions. The protein‐based microgel particles are in different aggregate states depending on the pH value. The emulsions can be utilized for multiple potential applications simply by changing the internal‐phase composition. A substitute for partially hydrogenated vegetable oils is obtained when the internal phase is an edible oil. If the internal phase is n‐hexane, the emulsion can be used as a template to produce porous materials, which are advantageous for tissue engineering.
Fit for consumption: Peanut‐protein‐isolate microgel particles existing at the interface and in the continuous phase inhibited the destabilization of high‐internal‐phase (87 % edible oil or 88 % n‐hexane) oil/water Pickering emulsions (see picture). Such emulsions based entirely on natural and nontoxic raw materials could potentially be adapted for multiple applications in food and tissue engineering simply by changing the internal‐phase composition.
Pickering emulsions are an excellent platform for interfacial catalysis. However, developing simple and efficient strategies to achieve product separation and catalyst and emulsifier recovery is ...still a challenge. Herein, we report the reversible transition between emulsification and demulsification of a light‐responsive Pickering emulsion, triggered by alternating between UV and visible light irradiation. The Pickering emulsion is fabricated from Pd‐supported silica nanoparticles, azobenzene ionic liquid surfactant, n‐octane, and water. This phase behavior is attributed to the adsorption of azobenzene ionic liquid surfactant on the surface of the nanoparticles and the light‐responsive activity of ionic liquid surfactant. The Pickering emulsion can be used as a microreactor that enables catalytic reaction, product separation as well as emulsifier and catalyst recycling. Catalytic hydrogenation of unsaturated hydrocarbons at room temperature and atmospheric pressure has been performed in this system to demonstrate product separation and emulsifier and catalyst re‐use.
A light‐responsive Pickering emulsion was designed and prepared, which could be reversibly switched between stable and unstable upon exposure to visible and UV light, respectively. The reversible, light‐responsive phase behavior of the Pickering emulsion enabled its use as a microreactor, allowing highly efficient catalytic hydrogenation, followed by product separation and emulsifier and catalyst recycling.
Aims. To constrain models of high-mass star formation, the Herschel-HOBYS key program aims at discovering massive dense cores (MDCs) able to host the high-mass analogs of low-mass prestellar cores, ...which have been searched for over the past decade. We here focus on NGC 6334, one of the best-studied HOBYS molecular cloud complexes. Methods. We used Herschel/PACS and SPIRE 70−500 μm images of the NGC 6334 complex complemented with (sub)millimeter and mid-infrared data. We built a complete procedure to extract ~0.1 pc dense cores with the getsources software, which simultaneously measures their far-infrared to millimeter fluxes. We carefully estimated the temperatures and masses of these dense cores from their spectral energy distributions (SEDs). We also identified the densest pc-scale cloud structures of NGC 6334, one 2 pc × 1 pc ridge and two 0.8 pc × 0.8 pc hubs, with volume-averaged densities of ~105 cm-3. Results. A cross-correlation with high-mass star formation signposts suggests a mass threshold of 75 M⊙ for MDCs in NGC 6334. MDCs have temperatures of 9.5−40 K, masses of 75−1000 M⊙, and densities of 1 × 105−7 × 107 cm-3. Their mid-infrared emission is used to separate 6 IR-bright and 10 IR-quiet protostellar MDCs while their 70 μm emission strength, with respect to fitted SEDs, helps identify 16 starless MDC candidates. The ability of the latter to host high-mass prestellar cores is investigated here and remains questionable. An increase in mass and density from the starless to the IR-quiet and IR-bright phases suggests that the protostars and MDCs simultaneously grow in mass. The statistical lifetimes of the high-mass prestellar and protostellar core phases, estimated to be 1−7 × 104 yr and at most 3 × 105 yr respectively, suggest a dynamical scenario of high-mass star formation. Conclusions. The present study provides good mass estimates for a statistically significant sample, covering the earliest phases of high-mass star formation. High-mass prestellar cores may not exist in NGC 6334, favoring a scenario presented here, which simultaneously forms clouds, ridges, MDCs, and high-mass protostars.
Particle-stabilized oil foams Binks, Bernard P.; Vishal, Badri
Advances in colloid and interface science,
20/May , Volume:
291
Journal Article
Peer reviewed
The area of oil foams although important industrially has received little academic attention until the last decade. The early work using molecular surfactants for stabilisation was limited and as ...such it is difficult to obtain general rules of thumb. Recently however, interest has grown in the area partly fuelled by the understanding gained in the general area of colloidal particles at fluid interfaces. We review the use of solid particles as foaming agents for oil foams in cases where particles (inorganic or polymer) are prepared ex situ and in cases where crystals of surfactant or fat are prepared in situ. There is considerable activity in the latter area which is particularly relevant to the food industry. Discussion of crude oil/lubricating oil foams is excluded from this review.
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•Oil foams can be stabilized by suitable hydrophobic solid particles.•They can also be stabilized by surfactant/fat crystals prepared in situ.•Oleogels may be aerated to produce very stable oil foams.•Oil foams stabilized by surfactant/fat crystals are thermo-responsive destabilizing around the melting point of the crystals.•A summary of the various techniques being used to study oil foams is included.
It is a dream that future synthetic chemistry can mimic living systems to process multistep cascade reactions in a one-pot fashion. One of the key challenges is the mutual destruction of incompatible ...or opposing reagents, for example, acid and base, oxidants and reductants. A conceptually novel strategy is developed here to address this challenge. This strategy is based on a layered Pickering emulsion system, which is obtained through lamination of Pickering emulsions. In this working Pickering emulsion, the dispersed phase can separately compartmentalize the incompatible reagents to avoid their mutual destruction, while the continuous phase allows other reagent molecules to diffuse freely to access the compartmentalized reagents for chemical reactions. The compartmentalization effects and molecular transport ability of the Pickering emulsion were investigated. The deacetalization-reduction, deacetalization-Knoevenagel, deacetalization-Henry and diazotization-iodization cascade reactions demonstrate well the versatility and flexibility of our strategy in processing the one-pot cascade reactions involving mutually destructive reagents.
Context.
Polarised emission from non-spherical dust grains contains information about the alignment of these dust grains and traces the structure of the interstellar magnetic field.
Methods.
We ...post-processed a set of Milky-Way-like galaxies from the Auriga project, assuming a dust mix consisting of spheroidal dust grains that are partially aligned with the model magnetic field. We constrained our dust model using
Planck
353 GHz observations of the Milky Way. This model was then extrapolated to shorter wavelengths that cover the peak of interstellar dust emission and to observations of arbitrarily oriented nearby Milky-Way-like galaxies.
Results.
Assuming an intrinsic linear polarisation fraction that does not vary significantly with wavelength for wavelengths longer than 50 micron, we predict a linear polarisation fraction with a maximum of 10 − 15% and a median value of ≈7% for face-on galaxies and ≈3% for edge-on galaxies. The polarisation fraction anti-correlates with the line of sight density and with the angular dispersion function which expresses the large-scale order of the magnetic field perpendicular to the line of sight. The maximum linear polarisation fraction agrees well with the intrinsic properties of the dust model. The true magnetic field orientation can be traced along low density lines of sight when it is coherent along the line of sight. These results also hold for nearby galaxies, where a coherent magnetic field structure is recovered over a range of different broad bands.
Conclusions.
Polarised emission from non-spherical dust grains accurately traces the large-scale structure of the galactic magnetic field in Milky-Way-like galaxies, with expected maximum linear polarisation fractions of 10 − 15%. To resolve this maximum, a spatial resolution of at least 1 kpc is required.
Hospitalization places patients at elevated risk for the development of “nosocomial” or hospital acquired complications, ranging from multidrug resistant infections to delirium and physical ...deconditioning. Adverse nosocomial psychological effects of hospitalization may also exist. This paper introduces a nosocomial based stress model, conceptualizing hospitalization as a unique period of biopsychosocial vulnerability, due to physiologic effects of acute illness and psychosocial variables of the hospital experience.
A research synthesis and narrative review was performed to evaluate evidence supporting this model, integrating existing knowledge of the psychological and physiological effects of acute life threatening events, with known sequelae associated with hospitalization.
Psychosocial factors during hospitalization may act as independent predictors of recovery following hospitalization, moderating variables impacting ongoing physiologic changes due to acute illness, and/or dynamic bidirectional elements, influencing medical and psychological outcomes in the near and long-term setting.
The Nosocomial Stress model provides a novel framework to understanding the biopsychosocial interactions between the psychological and physiologic processes associated with illness and hospitalization. Based on this model, a research agenda is proposed to assess the contributions of acute illness, the hospital experience, and their interactions on the recovery of patients following hospitalization.
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