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Pickering emulsions stabilized by naturally derived or biodegradable particles
Emulsions are used widely in formulated consumer products, paints and coatings, foods, and pharmaceutical preparations to name just a few examples. Frequently surfactants are employed as emulsifiers, but the use of particles, including nanoparticles, can offer advantages. Naturally derived, or synthetic, particles that are biodegradable can reduce end-of-life environmental impact, while offering a
Model-dependent small-angle scattering for the study of complex organic materials
Background: Small-angle scattering (SAS) is a powerful technique capable of determining the sample averaged structure of systems within sizes ranging from 1 nm to ~500 nm. This is particularly useful when applied to the study of self-assembled organic systems. Objective: This review article introduces the method of model-dependent analysis of small angle scattering. Method: The underlying mathemat
An acid-compatible co-polymer for the solubilization of membranes and proteins into lipid bilayer-containing nanoparticles
The fundamental importance of membrane proteins in drug discovery has meant that membrane mimetic systems for studying membrane proteins are of increasing interest. One such system has been the amphipathic, negatively charged poly(styrene-co-maleic acid) (SMA) polymer to form "SMA Lipid Particles" (SMALPs) which have been widely adopted to solubilize membrane proteins directly from the cell membra
Influence of Poly(styrene-co-maleic acid) Copolymer Structure on the Properties and Self-Assembly of SMALP Nanodiscs
Polymer stabilized nanodiscs are self-assembled structures composed of a polymer belt that wraps around a segment of lipid bilayer, and as such are capable of encapsulating membrane proteins directly from the cell membrane. To date, most studies on these nanodiscs have used poly(styrene-co-maleic acid) (SMA) with the term SMA-lipid particles (SMALPs) coined to describe them. In this study, we have
Unravelling cationic cellulose nanofibril hydrogel structure : NMR spectroscopy and small angle neutron scattering analyses
Stiff, elastic, viscous shear thinning aqueous gels are formed upon dispersion of low weight percent concentrations of cationically modified cellulose nanofibrils (CCNF) in water. CCNF hydrogels produced from cellulose modified with glycidyltrimethylammonium chloride, with degree of substitution (DS) in the range 10.6(3)-23.0(9)%, were characterised using NMR spectroscopy, rheology and small angle
Decyltrimethylammonium Bromide Micelles in Acidic Solutions : Counterion Binding, Water Structuring, and Micelle Shape
Wide-angle neutron scattering experiments combined with empirical potential structural refinement modeling have been used to study the detailed structure of decyltrimethylammonium bromide micelles in the presence of acid solutions of HCl or HBr. These experiments demonstrate considerable variation in micelle structure and water structuring between micelles in the two acid solutions and in comparis
Thermal stability, storage and release of proteins with tailored fit in silica
Biological substances based on proteins, including vaccines, antibodies, and enzymes, typically degrade at room temperature over time due to denaturation, as proteins unfold with loss of secondary and tertiary structure. Their storage and distribution therefore relies on a “cold chain” of continuous refrigeration; this is costly and not always effective, as any break in the chain leads to rapid lo
Microwave-assisted deep eutectic-solvothermal preparation of iron oxide nanoparticles for photoelectrochemical solar water splitting
Here, we present a new microwave-solvothermal method for the preparation of iron oxide nanostructures using deep eutectic solvents as a more sustainable reaction medium. By varying the synthesis temperature and solvent water fraction, the methodology offers control over iron oxide phase, size, and morphology, using efficient, rapid (10 minute) microwave heating. Synthesis with pure DES gives small
The Effect of Water upon Deep Eutectic Solvent Nanostructure : An Unusual Transition from Ionic Mixture to Aqueous Solution
The nanostructure of a series of choline chloride/urea/water deep eutectic solvent mixtures was characterized across a wide hydration range by neutron total scattering and empirical potential structure refinement (EPSR). As the structure is significantly altered, even at low hydration levels, reporting the DES water content is important. However, the DES nanostructure is retained to a remarkably h
Sulfur-Doped Cubic Mesostructured Titania Films for Use as a Solar Photocatalyst
Sulfur-doped titania thin films with cubic mesostructures were prepared by dip coating via the evaporation induced self-assembly route. The effect of sulfur doping on structure, morphology, porosity, optical properties, and photocatalytic activity of the mesoporous films was studied. Compared to undoped titania films, the S-doped films showed better long-range ordering, bigger pore size, higher po
Coarse-grained empirical potential structure refinement : Application to a reverse aqueous micelle
Conventional atomistic computer simulations, involving perhaps up to 106 atoms, can achieve length-scales on the order of a few 10s of nm. Yet many heterogeneous systems, such as colloids, nano-structured materials, or biological systems, can involve correlations over distances up 100s of nm, perhaps even 1 μm in some instances. For such systems it is necessary to invoke coarse-graining, where sin
Free-Standing Phytantriol Q224 Cubic-Phase Films : Resistivity Monitoring and Switching
Phytantriol Q224 cubic phase, as a bicontinuous meso-structured material stable in contact with aqueous electrolyte, has found applications in drug delivery and cosmetics and is employed here as a free-standing film separating two aqueous compartments in order to study i) ion conductivity (at low potential bias within ±0.8 V), ii) conductivity switching effects (at high potential bias beyond ±0.8
Deep eutectic-solvothermal synthesis of nanostructured ceria
Ceria is a technologically important material with applications in catalysis, emissions control and solid-oxide fuel cells. Nanostructured ceria becomes profoundly more active due to its enhanced surface area to volume ratio, reactive surface oxygen vacancy concentration and superior oxygen storage capacity. Here we report the synthesis of nanostructured ceria using the green Deep Eutectic Solvent
Atomistic modelling of scattering data in the ollaborative Computational Project for Small Angle Scattering (CCP-SAS)
The capabilities of current computer simulations provide a unique opportunity to model small-angle scattering (SAS) data at the atomistic level, and to include other structural constraints ranging from molecular and atomistic energetics to crystallography, electron microscopy and NMR. This extends the capabilities of solution scattering and provides deeper insights into the physics and chemistry o
Evidence of Lipid Exchange in Styrene Maleic Acid Lipid Particle (SMALP) Nanodisc Systems
Styrene-alt-maleic acid lipid particles (SMALPs) are self-assembled discoidal structures composed of a polymer belt and a segment of lipid bilayer, which are capable of encapsulating membrane proteins directly from the cell membrane. Here we present evidence of the exchange of lipids between such "nanodiscs" and lipid monolayers adsorbed at either solid-liquid or air-liquid interfaces. This behavi
Sagnac interferometer for two-dimensional spectroscopy in the pump-probe geometry
An intrinsically phase-stable Sagnac interferometer is introduced for enhanced sensitivity detection in partially collinear two-dimensional spectroscopy. The sensitivity and phase accuracy of the apparatus are demonstrated on the dye IR-26 in the short-wave IR.
Massive open online courses in chemistry : A comparative overview of platforms and features
Open-access, online educational platforms launched in the last decade are receiving growing attention from both academia and the general public. A special class of such courseware known as MOOCs (massive open online courses) allows enrollment of up to hundreds of thousands of students from all over the world. This report reviews and compares currently available chemistry MOOCs as well as other Web
Broad spectral photocurrent enhancement in Au-decorated CdSe nanowires
Metal-semiconductor hybrid nanostructures promise improved photoconductive performance due to plasmonic properties of the metal portions and intrinsic electric fields at the metal-semiconductor interface that possibly enhance charge separation. Here we report gold decorated CdSe nanowires as a novel functional material and investigate the influence of gold decoration on the lateral facets on the p
A new route to produce efficient surface-enhanced Raman spectroscopy substrates : Gold-decorated CdSe nanowires
Surface-enhanced Raman spectroscopy is a popular tool for the detection of extremely small quantities of target molecules. Au nanoparticles have been very successful in this respect due to local enhancement of the light intensity caused by their plasmon resonance. Furthermore, Au nanoparticles are biocompatible, and target substances can be easily attached to their surface. Here, we demonstrate th