A5018760067- Surfactants and Colloidal Systems
- Phase Equilibria and Thermodynamics
- Spectroscopy and Quantum Chemical Studies
- Advanced Polymer Synthesis and Characterization
- Lipid Membrane Structure and Behavior
- Material Dynamics and Properties
- Pickering emulsions and particle stabilization
- Electrostatics and Colloid Interactions
- Photochemistry and Electron Transfer Studies
- Carbon Dioxide Capture Technologies
- Nuclear Physics and Applications
- Ionic liquids properties and applications
- Analytical Chemistry and Chromatography
- Chemical and Physical Properties in Aqueous Solutions
- Proteins in Food Systems
- RNA Interference and Gene Delivery
- Liquid Crystal Research Advancements
- Polymer Surface Interaction Studies
- NMR spectroscopy and applications
- Porphyrin and Phthalocyanine Chemistry
- Supramolecular Self-Assembly in Materials
- High Temperature Alloys and Creep
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Polymer Nanocomposites and Properties
Rutherford Appleton Laboratory
2013-2023
Science and Technology Facilities Council
2000-2021
Forschungszentrum Jülich
2004-2020
Heinz Maier-Leibnitz Zentrum
2020
Lawrence Berkeley National Laboratory
2020
Institute of Engineering
2020
Didcot Community Hospital
2015-2017
Oxfam
1978-2016
Dutch Research Council
2014
Cardiff University
2004-2010
The aggregation behavior in aqueous solutions of three ionic liquids based on the 1-alkyl-3-methylimidazolium cation has been investigated by means surface tension, conductivity, and small-angle neutron scattering (SANS) measurements. From analysis SANS data, models for shapes sizes aggregates have proposed: short-chain 1-butyl-3-methylimidazolium tetrafluoroborate [C4mim][BF4] system can be best modeled treating it as a dispersion polydisperse spherical that form above critical...
Phase stability and small-angle neutron scattering (SANS) data show that surfactant-stabilized nanodomains of a typical ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4]) may be dispersed by the nonionic surfactant Triton-X100 in cyclohexane. Analyses these SANS are consistent with formation liquid-in-oil microemulsion droplets.
Small-angle diffraction with a pulsed neutron source, using time-of-flight analysis to separate neutrons of different wavelengths, offers very wide simultaneous Q range coupled good resolution. Data reduction allow for wavelength-dependent effects may be achieved as matter routine. The cold flux available from accelerator-based sources does not yet fully match that the most intense reactor sources. Simulations show performance proposed future instrumentation would largely complementary best...
We present experiments and theory on the melt dynamics of monodisperse entangled polymers H-shaped architecture. Frequency-dependent rheological data a series polyisoprene H-polymers are in good agreement with tube model that combines path-length fluctuation (like star polymer melts) at high frequency, reptation self-entangled "cross-bars" low frequencies linear melts). account explicitly for mild polydispersity. Nonlinear step-strain transient shear extension confirm presence relaxation...
Droplet attraction: Surfactants responsive to magnetic fields are reported for the first time. This new class of ionic liquid surfactants (MILSs; see picture) shows remarkable effects on surface and interfacial tension allows access magneto-responsive emulsions methods separation, recovery, catalysis, potential magnetophoretic applications. Detailed facts importance specialist readers published as ”Supporting Information”. Such documents peer-reviewed, but not copy-edited or typeset. They...
Small-angle neutron scattering and surface tension have been used to characterize a class of surfactants (SURFs), including surfactant ionic liquids (SAILs). These SURFs SAILs are based on organic anions (single-tail dodecyl sulfate, DS, double-chain aerosol-OT, AOT, the trichain, TC) with substituted quaternary ammonium cations. This can be obtained by straightforward chemistry, being cheaper more environmentally benign than standard cationic SAILs. A surprising aspect results is that,...
Establishing structure–property relationships in the black insoluble eumelanins, key determinants of human pigmentation and skin photoprotective system, is a considerable conceptual experimental challenge current drive for elucidation biological roles these biopolymers their application as advanced materials organoelectronics. Herein, we report new breakthrough toward this goal by first detailed investigation on nanoscale level oxidative polymerization 5,6-dihydroxyindole (DHI), model...
An overview is provided of the 15 neutron beam instruments making up initial instrument suite European Spallation Source (ESS), and being made available to user community. The ESS source consists a high-power accelerator target station, providing unique long-pulse time structure slow neutrons. design considerations behind structure, moderator geometry layout are presented. 15-instrument two small-angle instruments, reflectometers, an imaging beamline, single-crystal diffractometers; one for...
The Loq small angle neutron scattering (SANS) instrument at ISIS target station one (TS1) has proved an extremely popular and immensely productive SANS facility over the last 20 years. is routinely operated with a 25 Hz disc chopper removing alternate pulses from 50 source to provide usable wavelength range of 2.2 10 Å. Scattered neutrons are recorded on 0.64 m square 3He multiwire proportional counter (Ordela 2661N) fixed ∼ 4 sample, total flight path 15 decoupled liquid hydrogen moderator...
The aim was to identify why Aerosol-OT is such an efficient surfactant for forming microemulsions, and in pursuit of this, 11 Aerosol-OT-related compounds have been investigated. These surfactants were from two separate homologous series, with either linear or branched hydrocarbon tails. Hence, it possible examine the effect chain structure on packing curved interfacial films at oil−water interfaces. With dichain compounds, water-in-oil microemulsion phases could be formed only presence a...
The sodium salt of the di-chained anionic surfactant bis-2-ethylhexylsulfosuccinate [Aerosol-OT or Na(AOT)] stabilises essentially monodisperse, spherical water-in-oil microemulsion (w/o) droplets in alkanes over a wide range pressure, temperature and composition. In order to investigate effect change counterion charge size on properties, we have replaced Na+ by doubly charged ions. is then M2+(AOT)2·nH2O: M from series Mg2+, Ca2+, Co2+, Ni2+, Cu2+ Zn2+, n number water ligands associated...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTMicellization of Hydrocarbon Surfactants in Supercritical Carbon DioxideJulian Eastoe, Alison Paul, Sandrine Nave, David C. Steytler, Brian H. Robinson, Emily Rumsey, Matthew Thorpe, and Richard. K. HeenanView Author Information School Chemistry, University Bristol Bristol, BS8 1TS UK Chemical Sciences East Anglia Norwich, NR4 7TJ ISIS, Rutherford Appleton Laboratory Chilton Didcot OX11 0QX Cite this: J. Am. Chem. Soc. 2001, 123, 5,...
Small-angle neutron scattering (SANS) has been used to study the internal structure of poly(lactic acid)−poly(ethylene glycol) (PLA(d)−PEG) block copolymer assemblies, which are being investigated as particulate drug carriers. Three PLA(d)−PEG copolymers with a fixed PEG 5 kDa and fully deuterated PLA(d) either 3, 15, or 45 were synthesized by ring opening polymerization d8-d,l-lactide, using stannous octoate catalyst. These assembled form nanoparticles in aqueous media, following...
A photo-responsive organogel has been made by addition of a novel stilbene-containing photo-surfactant to toluene: exposure UV light led gel-to-sol transition with spatial control.
Aggregate structures in water-in-CO2 microemulsions were studied by high-pressure small-angle neutron scattering (SANS). With liquid CO2 at 15 °C, the partially fluorinated, di-chain surfactant bis(1H,1H,5H-octafluoro-n-pentyl) sodium sulfosuccinate (di-HCF4) stabilized single-phase pressures above ∼400 bar. The maximum water loading (w) investigated was 30 ([water]/[di-HCF4]), representing formation of relatively large droplets microemulsion. Between w = 5 and 30, SANS data consistent with...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructures of metal bis(2-ethylhexylsulfosuccinate) aggregates in cyclohexaneJulian Eastoe, Tom F. Towey, Brian H. Robinson, Jason Williams, and Richard K. HeenanCite this: J. Phys. Chem. 1993, 97, 7, 1459–1463Publication Date (Print):February 1, 1993Publication History Published online1 May 2002Published inissue 1 February 1993https://pubs.acs.org/doi/10.1021/j100109a035https://doi.org/10.1021/j100109a035research-articleACS PublicationsRequest...
Wrapping up water: Two non-fluorinated CO2-philic surfactants are used to generate water in carbon dioxide microemulsion dispersions. Detailed analyses of high-pressure small-angle neutron scattering data provide evidence for formation spherical D2O nanodroplets (red), stabilized by surfactant interfacial monolayers (lines), and dispersed CO2 (yellow the schematic length density (sld) profile). Supporting information this article is available on WWW under...
A simple low-energy two-step dilution process has been applied in oil/surfactant/water systems with pentaoxyethylene lauryl ether (C12E5), dodecyldimethylammonium bromide, sodium bis(2-ethylhexyl)sulfosuccinate, n-dodecyl sulfate-pentanol, and hexadecyltrimethylammonium bromide-pentanol. Appropriate formulations were chosen for the concentrate to be diluted water generate oil-in-water (O/W) emulsions or nanoemulsions. For system of decane/C12E5/water, bluish, transparent nanoemulsions having...
The physicochemical properties of a homologous series sodium p-n-alkylbenzoates have been investigated. objective was to determine whether there is clear transition point from hydrotropic surfactant-like behavior with increasing alkyl chain length n, so as shed light on the aggregation mechanism so-called "hydrotropes". Electrical conductivity measurements were used for first estimation critical concentrations (cac). As classical surfactants, log(cac) depends but two branches observed: one...
The mechanical properties of gels are critical to the final targeted applications. Depending on application, different may be required. Here, we show that strength and ability recover formed using a low molecular weight gelator can controlled by two independent factors (i) volume fraction co-solvent (in this case DMSO) in system (ii) temperature cycle used. These differences correlate with large scale structure network is from self-assembled fibres. This opens up potential prepare very at...
As synthesized, bulk single-walled carbon nanotube (SWNT) samples are typically highly agglomerated and heterogeneous. However, their most promising applications require the isolation of individualized, purified nanotubes, often with specific optoelectronic characteristics. A wide range dispersion separation techniques have been developed, but use sonication or ultracentrifugation imposes severe limits on scalability may introduce damage. Here, we demonstrate a new, intrinsically scalable...
Choline chloride:urea deep eutectic solvent provides a novel media for surfactant self-assembly with micelle morphology tunable by adding water.
Deep eutectic solvents have shown the ability to promote self-assembly of surfactants in solution. However, some differences been found compared with pure water and other polar organic solvents. The behaviour alkyltrimethylammonium bromides choline chloride:glycerol deep solvent has studied by means surface tension, X-ray neutron reflectivity small-angle scattering. were remain active showed comparable critical micelle concentrations same water. Our scattering studies demonstrate that these...