cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.5286/isis.e.rb1610042
title: Structure and interactions in model and real anti-reflective coatings

description: This proposal seeks to exploit contrast variation SANS to study a multi-component system, spanning a wide range of colloidal length scales. The multi-component system under question is a model antireflective (AR) coating formulation, comprised of silica-polymer core-shell nanocomposites. To be clear, these are core-shell nanocomposites with silica shells (5- 10 nm) and a polymer latex cores (~ 60 nm diameter, cryo-TEM and DLS). Core-shell nanocomposites are grown by addition of a silicon alkoxide to methacrylate-based polymer latex in the presence of a background equilibrium cationic co-polymer (Co-Pol), which is always present in this process and critically acts as the site of silication for core-shell particles. The proposal centres around a contrast-match study of the copolymer with the polymer latex and core-shell particles in turn, to probe interactions.
DOI: 10.5286/isis.e.rb1610150
title: Neutron scattering to characterise protein interactions with solid-liquid interfaces at different densities in bioprocessing

description: Objectives of this proposal aim to shed light on how adsorption processes such as protein A chromatography, used to purify biologics, affect protein propensity for aggregation. Protein A chromatography has been found to increase the aggregation rate of an IgG4 subsequently exposed to low pH. Loading a low concentration of IgG onto the resin increased aggregation rates further. Using neutron reflectivity, we wish to study the conformation of IgG4 when adsorbed to immobilised protein A. We wish to examine whether the conformation or orientation of the adsorbed molecules is affected by either the density of immobilised ligands, or the concentration of protein bound. It is hypothesised that intermolecular forces and rotational freedom affect the structural integrity of the adsorbed proteins, and their orientation in relation to the adsorbent surface, thus influencing aggregation phenomena.
DOI: 10.5286/isis.e.rb1610188
title: Comparasion of the Formation of Linear/Linear interpolymer complex and Linear/Cyclic interpolymer complex

description: Polymers with specific functional groups on their main chains or side chains can interact with each other either in solution or in bulk, forming interpolymer complexes, for example, polyacrylic acid (PAA) chains and poly-N-isopropylacrylamide (PNIPAM), which form hydrogen bonding between them. Factors affecting the structures of interpolymer complexes have been studied extensively, including pH value, chain length, temperature, salt concentration, monomer ratio etc. However, the influence of topological structure on the formation of interpolymer complexes has not been well studied. As well known, the topological structure of polymers could be essential to their physical properties.Therefore,we would like to investigate the conformation of the interpolymer complex formed by linear/linear and linear/cyclic polymers using neutron scattering technique,with the ability to contrast match.
DOI: 10.5286/isis.e.rb1610306
title: The structure of the Bam complex, the Gram-negative outer membrane protein folding machinery

description: The proteins of the outer membrane of Gram-negative bacteria are critical for bacterial survival, from providing basic physiological functions, to impairing virulence and multidrug resistance. The Bam complex has been found to be essential for folding these proteins into the outer membrane. The process by which this is achieved is unknown. Key to this understanding is the knowledge of the structure of the complex and its individual components. We aim to continue our investigation of the Bam complex by studying the complete BamABCDE complex for the first time and in particular identify the location of BamE. To do this we will use Small Angle Neutron Scattering and specific deuteration, in concert with previously collected SANS datasets of the BamCDE and BamABCD sub complexes, to probe the structure of the full Bam complex for first time
DOI: 10.5286/isis.e.rb1610346
title: Structure of B2O3-GeO2 glass by neutron diffraction with isotope substitution

description: The composition dependent structure of glasses in the B2O3-GeO2 system will be measured by employing the method of neutron diffraction with Ge isotope substitution. This system is one of the few oxide glass-forming materials that comprises solely network-forming cations, and the local motifs in the pure component B2O3 and GeO2 glasses are rather different, i.e. BO3 planar triangles versus GeO4 tetrahedra, respectively. The B2O3-GeO2 system is therefore a prototype for investigating the effect of mixing different network forming cations. The neutron diffraction results will give detailed information on the coordination environments of both Ge and B, and will be combined with the results from other techniques in order to build a complete picture of the structure and how this affects the material properties.
DOI: 10.5286/isis.e.rb1610354
title: Film formation and water uptake in macroRAFT latices studied by contrast variation SANS

description: Latex is made from tiny polymer particles in water. Latex films are used in paints and to manufacture adhesives & inks. Latex is good for the environment, as it does not emit harmful organic solvents and meets strict EC regulations. Usually latex contains a type of soap molecule (surfactant) needed in its manufacture. Sadly, the surfactant is the source of problems in latex films, allowing water to absorb and leading to corrosion of underlying surfaces, eg steel. A new type of latex, developed in Lyon, is made with specially-designed molecules attached to the polymer particles, which eliminate the surfactants. We propose neutron scattering to look inside a wet latex film as it dries to see the fate of the stabilising molecules. It will also reveal where water goes when absorbed inside a dry film. This will lead to eco-friendly coatings that will block all water from passing through.
DOI: 10.5286/isis.e.rb1620027
title: OSTEOMETRICS IN BURNED HUMAN SKELETAL REMAINS: ESTIMATING HEAT-INDUCED DIMENSIONAL CHANGES IN BONES BY NEUTRON SPECTROSCOPY

description: This study aims at developing a reliable method for probing heat-induced diagenesis in human bones, by INS spectroscopy. The results thus gathered, coupled to Raman and FTIR data, will lead to an improved understanding of the changes undergone by bone upon burning events, allowing a reliable assessment of their effect on the metric dimensions of human skeletal remains. A quantitative relationship between spectroscopic parameters, macroscopic dimensional changes in burned bones and specific burning conditions (e.g. temperature and duration) is sought, which will be of the utmost relevance in forensic contexts (namely for the analysis of burned human remains from crime scenes), as well as in archaeological settings. This is a continuation proposal from a successful experiment  the first INS analysis of human bones burned under controlled conditions (RB1520001).
DOI: 10.5286/isis.e.rb1620134
title: Controlled release from lipid-alkylglycoside vesicles, as triggered by amylase mediated degradation of oligomeric alkylglycoside

description: The consumer demands for functional food have increased the interest for encapsulation of bioactive compounds in the food industry. Encapsulation is crucial, since these compounds need to be protected from the environment and to be released at a given stage (and location) of the gastrointestinal tract. The liposome concept is versatile, since its features can be tuned to address the needs for encapsulation as well as targeting. We aim to develop a liposome carrier containing a novel alkylglycoside surfactant (C16G8, 8 glucose unit head group and 16 carbons in the saturated alkyl chain). When the length of the alkylglycoside head-groups is decreased by amylases, the vesicle integrity is impacted, which leads to a controlled release of vesicle content. We intend to study unilamellar vesicles prepared with DMPC and different concentration of C16G8 and then investigate the effect of amylase.
DOI: 10.5286/isis.e.rb1620171
title: INS Study of Deep Eutectic Solvents

description: Deep Eutectic Solvents (DESs) are emerging as low-cost and environment-friendly solvents for industrial process. DESs are formed by the association of a hydrogen bond-capable with a hydrogen bond donor molecule. In the eutectic composition, the mixture has a melting point much lower than either of the individual components. The nature of the hydrogen bond network among these constituents is expected to play a significant role in the definition of its properties as solvent. In this way, the study of hydrogen bond networks in DESs will ultimately allow the design of solvents suitable for specific applications. The hydrogen-bond network in DESs mixtures with different composition will be assessed through INS spectroscopy. INS allows the observation of both the low wavenumber H motions and the high wavenumber N-H/O-H stretching and bending modes.
DOI: 10.5286/isis.e.rb1620197
title: Structure-property relation in integer-spin quantum magnets

description: Our objective is to determine how changes in symmetry affect the magnetic ground state of spin-1 magnets. Low-dimensional S=1 systems are believed to support rich phase diagrams with multiple possible ground states, some displaying quantum states of matter of much current interest. However, these theoretical models are yet to be thoroughly tested experimentally. Using coordination chemistry, we have created two polymorphs of a quasi-one-dimensional magnet and two polymorphs of a quasi-two dimensional magnet. We propose to determine the ground state magnetic structure of three of these (one is already scheduled to be characterised at WISH) in order to discover how changes in symmetry, in these otherwise identical materials, dictate their magnetic properties. We will also measure a related material that is believed to sit at the boundary between order and disorder at low temperatures.
DOI: 10.5286/isis.e.rb1620423
title: Antiferromagnetic domain manipulation in hematite thin films studied by neutron diffraction

description: We propose to study the antiferromagnetic (AFM) domain structure of 100 nm thick Fe2O3 thin films using WISH. The sample will be magnetically poled to prepare an imbalance in the AFM domain population. By measuring a series of structurally extinct magnetic reflections we are sensitive to the planar orientation of the spins; which allows us to measure the relative populations of the AFM domains. This investigation will develop the understanding of antiferromagnetic domain manipulation of thin films, where this information is essential in development of prototype devices, such as in spin valves. WISH's large detector bank, high Q resolution and excellent collimation make it a unique instrument worldwide for this study. Our results will allow us to refine our film growth programme in the development of spintroics based on antiferromagnetic materials.
DOI: 10.5286/isis.e.rb1620475
title: The Mechanism of Bam Mediated Outer Membrane Protein Folding

description: The proteins of the outer membrane of Gram-negative bacteria are critical for bacterial survival,from providing basic physiological functions, to impairing virulence and multidrug resistance. The Bam complex has been found to be essential for folding these proteins into the outer membrane.The process by which this is achieved is unknown. The structure of the complex and its individual components are now known. We aim to continue our investigation of the Bam complex by studying BamABCDE in complex with stalled folding intermediates. To do this we will use  specific deuteration and neutron reflectometry in concert with previous PNR datasets of the BamABCDE complex bound to a gold surface to probe the structure of the Bam complex as it performs its function.
DOI: 10.5286/isis.e.rb1670533
title: Investigation on spin dynamics of a staircase kagome material by using spin polarized muons
DOI: 10.5286/isis.e.rb1510184
title: Atomic structure of ternary tin phosphate glasses

description: Tin phosphate glasses are the alternative as lead-free glasses with zero photoeleastic constant (PEC) for fibers that are used in sensors of electric current. Since the binary glass with zero PEC is hygroscopic a third component is introduced, here ZnO. The PEC shows a linear dependence for more than 15 mol% ZnO content but it is constant for &lt;5 mol%. The origin of this non-linear change is the topic of the suggested diffraction experiment on glasses xZnO.(66.7-x)SnO.33.3P2O5. The Zn-O and Sn-O first neighbor distances and coordination numbers will be determined. The planned combination with X-ray diffraction will allow resolving both distances. The broad Sn-O peak with about three oxygen neighbors is a difficult subject and needs good resolution and well defined experimental conditions that are possible on GEM. Binary SnO-P2O5 glasses were already measured by us we did not publish yet.
DOI: 10.5286/isis.e.rb1510199
title: Surfactant-Controlled Assembly of Amphiphilic Diblock Polythiophenes

description: Conjugated polythiophenes (PTs) have emerged as a promising class of material in organic solar cells. The device performance depends on the inherently-linked optoelectronic properties and nanoscale morphology of the PT. Hence, there is substantial interest in developing novel approaches to control the morphology of PTs. In this study we will investigate if the co-assembly of cationic, diblock PTs with anionic surfactants can be used to form PT-surfactant complexes with targeted organisation. Using small-angle neutron scattering (SANS) we intend to observe the global and internal structural organisation of the PT-surfactant aggregates formed. Optical spectroscopy will also be used to correlate the aggregate structure with the photophysical properties.
DOI: 10.5286/isis.e.rb1510265
title: Li diffusion in complex olivine, Li(FeMn)PO4

description: This is a part of our Li-diffusion study in battery materials with muSR. In order for balancing safety and energy density, a solid solution system between LiFePO4 and LiMnPO4 has been heavily investigated as a cathode material of an advanced Li-ion battery, because a charged state LiFePO4, i.e. Li1-yFePO4 is very stable even at 150 C and LiMnPO4 has a higher working voltage. Although the diffusion coefficient of Li (D) in LiFePO4 was successfully measured with muSR, it was very difficult for LiMnPO4 due to large Mn moments. However, if we measure D with muSR as a function of x in LiFe1-xMnxPO4, we will extrapolate D for LiMnPO4. Here, D is a very important parameter to determine the total performance of battery and estimate other significant electrochemical properties, such as, a reactive surface area and a concentration of mobile Li.
DOI: 10.5286/isis.e.rb1510281
title: Quantum State Manipulation in PTFE.

description: Discrete energy level form in quantum mechanical systems and if carefully measured the population density of the levels can be probed and manipulated. The consequence of this idea is that it should be possible to build quantum computers by manipulating these levels. However the population density is difficult to measure, we propose to use the commonly formed F-mu-F state in PTFE to form an entangled state using muons. The population of the entangled states can be controlled with RF excitation and importantly the states formed are truly isolated. We will exploit the intensity of the muon beam to create an isolated system and probe the population with high statistics, this is a combination difficult to achieve with other techniques. This is a new technique to investigate a timely and fascinating problem with eventual real world applications.
DOI: 10.5286/isis.e.rb1510328
title: Cationic & Nonionic Micelles in Deep Eutectic Solvents

description: Deep Eutectic Solvents (DES) are molecular mixtures similar to ionic liquids, having melting points below room temperature. DES share many of the features of ionic liquids (low vapour pressure, adjustable polarity, etc) which make them interesting as green solvents while being far less toxic than typical ionic liquids. They are also good solvents for metal salts meaning they have potential as non-aqueous solvents for surfactant templated syntheses of porous inorganic materials which form from water-sensitive precursors. In initial experiments last round we studied an anionic surfactant, SDS in choline chloride:urea DES. Here we propose to extend this study to cationic and nonionic surfactants in in this DES and also in a second DES, malic acid:choline chloride:water, to characterise their self-assembly in these novel media.
DOI: 10.5286/isis.e.rb1510436
title: Polymer-Lipid Nanodisc Self-assembly Processes Using Stop Flow

description: Polymer stabilized lipid nanodiscs offer enormous potential as tools for enabling membrane protein structural studies & biophysics. Polymer stabilized lipid bilayer discs are easily made by adding polymer to a suspension of lipids or disrupted cell membranes, with discs forming within ~5 minutes. It is not clear how the polymer forms discs from these systems, since in vesicles or cell membranes the headgroups are exposed to solution, and the soluble polymer, but in the final discs, the polymer is wrapped around the tail regions of the lipid bilayer. We have also observed that nanodiscs are dynamic, and undergo exchange of lipids between discs or between discs and lipid bilayers on ~10 min timescales. Here we propose to use stop-flow on Sans2d to study nanodisc formation from a solution of vesicles mixed with polymer, and also to probe the kinetics of lipid exchange between nanodiscs.
DOI: 10.5286/isis.e.rb1510507
title: Magnetic excitation of Ca2RuO4 in pressure induced ferromagnetic phase

description: Recently, a novel type of Bose-Einstein condensation (BEC) of spin-orbit excitons has been proposed in Mott insulator   Ca2RuO4. In the recent INS study, we have observed dispersive magnon branch with a gap of 14 meV. The fact that the ground state of Ca2RuO4 can be tuned by a relatively small magnetic field, pressure or chemical doping indicate the near-degeneracy of many possible ground states and quantum critical nature of the system resulting from competition of various effects. Recent pressure dependent transport, magnetization [18], and Raman scattering[19] measurements  has revealed a collapse of the antiferromagnetic insulator phase into a ferromagnetic  metal phase at 5 Kbar. Aim of the proposed experiment is to investigate the magnetic excitations across the pressure induced phase transitionfrom the anti-ferromagnetic to ferromagnetic metallic phase.
DOI: 10.5286/isis.e.rb1520229
title: Neutron diffraction study of local and mesoscopic disorder induced by La and Yb double doping in Ce1-x-yLaxYbyO2-(x+y)/2, using PDF Analysis

description: The accurate determination of the defect structure of rare earth (RE) doped ceria solid electrolytes is fundamental for the comprehension of oxygen diffusion and charge transport within these materials. The mismatch between Ce4+ and RE3+ ionic radii is supposed to favour the oxygen vacancies and dopant ions clustering limiting the oxygen mobility. To minimize this effect it has been proposed to vary the ?average? ionic radius of RE by a mixture of large and small cation like e.g. La3+ and Yb3+.The aim of the experiment is to clarify the compositional evolution of defect clustering and the oxygen vacancies ordering in RE double-doped ceria. We propose to investigate the Ce1-x-yLaxYbyO2-(x+y)/2 solid solutions by means of PDF technique because it allows to unveil both the local (within few Å) and the mesoscopic (within few nm) disorder induced by doping in these solid solution.
DOI: 10.5286/isis.e.rb1610041
title: Understanding and Controlling Biosurfactant self assembly in solution

description: Biosurfactants are becoming more commonplace in pharmaceuticals, vaccines and other forms of medicines. With the biobased economy growing substantially and pressure to reduce reliance on palm and crude oil derived materials, it is vital that the Home and Personal Care industry develops frameworks for deploying sustainably sourced alternative materials. Biosurfactants tend to be very similar to nonionic and mild anionic surfactants but with significantly higher molecular weights, generally more than double that of the most commonly used conventional surfactants. We have explored many such glycolipids in recent times and in this proposal wish to study the solution microstructure under conditions where the glycolipid self assembles into liquid crystalline like structures. Understanding the shear dependence of the mesophase behaviour is important precursor to commercialisation.
DOI: 10.5286/isis.e.rb1610074
title: SANS characterization of carbonate reservoir formation and evolution

description: Geologists are increasingly realizing the unique perspective that neutron scattering offers for unlocking the complex geologic histories of rocks.  In this study, we propose to answer the question: What controls the formation and evolution of sub-micrometer porosity within carbonate reservoirs?  We will use SANS to systematically assess the sub-micrometer pore size distribution within carbonate reservoir samples formed in a variety of depositional environments and subjected to a range of chemical and temperature/pressure histories in order to categorize the geologic regimes that give rise to individual porosity types.  From these porosity classifications, we can then begin to develop a predictive capacity for where sub-micrometer porosity will exist within carbonate reservoirs, and thereby gain a better understanding of the utility of particular formations for various uses.
DOI: 10.5286/isis.e.rb1610080
title: Ferromagnetic Topological Insulators  A Hot Topic

description: In the quest to find high-temperature ferromagnetic topological insulators (TIs), we have explored different transition-metal and rare-earth doped thin film and bulk samples using x-ray magnetic circular dichroism and polarized neutron reflectometry (PNR) at ISIS. In Cr-doped Sb2Te3 films magnetic transition temperatures of ~180 K have been found, a truly remarkable development compared to the sub-10-K TCs seen before. Unfortunately, there are hints of a second magnetic phase for x &gt; 0.42, which is not detectable in XRD for the low doping concentration samples, and the question is what the magnetic properties of the two phases are and which one is the desired phase for unlocking the exotic TI physics at high temperatures. Here, we propose to carry out a comparative study of V- and Cr-doped Sb2Te3 thin films, supported by magnetometry and structural investigations.
DOI: 10.5286/isis.e.rb1610198
title: Spin dynamics of the Mn12 prototype nanomagnet fully unravelled by 4-dimensional INS

description: Mn12, with an anisotropy barrier close to 65 K, has been for 20 years a prototype nanomagnet, but in spite of a number of investigations  the actual link between the value of the effective barrier and the complex pattern of intra-molecular interactions could not be clarified. Mn12 has already been studied by INS. Although the cross-section is expected to discriminate different parameter sets, the use of powder samples and of variants of Mn12 with several inequivalent isomers, and the lack of PSDs, prevented to individuate the form of the spin-Hamiltonian.We intend to study a recently synthesized variant of Mn12 containing a single high-symmetry isomer, for which high-quality single crystals are available. By exploiting the PSD of LET, we will extract the detailed form factor for several transitions. We expect to make a decisive step-forward in the comprehension of this archetype system.