A5049565522- Force Microscopy Techniques and Applications
- Polymer Surface Interaction Studies
- Adhesion, Friction, and Surface Interactions
- Lipid Membrane Structure and Behavior
- Surfactants and Colloidal Systems
- Supramolecular Self-Assembly in Materials
- Advanced Sensor and Energy Harvesting Materials
- Hydrogels: synthesis, properties, applications
- Nanomaterials and Printing Technologies
- Lubricants and Their Additives
- Polymer composites and self-healing
- Pickering emulsions and particle stabilization
- Dendrimers and Hyperbranched Polymers
- Fluid Dynamics and Thin Films
- RNA Interference and Gene Delivery
- 3D Printing in Biomedical Research
- Innovative Microfluidic and Catalytic Techniques Innovation
- Advanced biosensing and bioanalysis techniques
- Photoreceptor and optogenetics research
- Food Chemistry and Fat Analysis
- Nanopore and Nanochannel Transport Studies
- Polymer Nanocomposites and Properties
- Conducting polymers and applications
- Diatoms and Algae Research
- Photochromic and Fluorescence Chemistry
University of Bristol
2015-2024
At Bristol
2014-2018
Weizmann Institute of Science
2006-2009
University of Oxford
2002-2009
University of Sheffield
2009
University of Toronto
2006
University of South Australia
2002-2004
The very low sliding friction at natural synovial joints, which have coefficients of mu < 0.002 pressures up to 5 megapascals or more, has date not been attained in any human-made joints between model surfaces aqueous environments. We found that water bearing polyzwitterionic brushes were polymerized directly from the surface can values as 0.0004 high 7.5 megapascals. This extreme lubrication is attributed primarily strong hydration phosphorylcholine-like monomers make robustly attached...
Polymers offer the advantage that they may independently combine desirable supramolecular structure with useful local monomeric properties to yield optimal performance of different tasks. Here we utilise remarkable lubricating both dense polymer brushes, and hydration sheaths about charges via emerging paradigm lubrication, design a grafted-from polyzwitterionic brush system, where each monomers has similar highly-hydrated phosphorylcholine headgroups phosphatidylcholine lipids. Such...
The molecular mechanisms for aqueous boundary lubrication are very different from those in the classic lubrication, originating fluidity of hydration shells surrounding surfactant and lipid headgroups. We discuss important structural criteria effective lubricants, highlight strategy reinforcing interfacial structure via synergistic interactions between amphiphilic polymers lipids/surfactants. It is proposed that energetic considerations elastic deformations stalk model cell membrane fusion...
Rigid polyurethane foams (RPUFs) are among the most used polymeric materials due to their tailorable properties. Greener and biobased polyol sources for synthesising RPUFs have been recently prototyped because of ever-growing demand more sustainable solutions. Castor Oil has also rapidly become one successful alternatives replace fossil-based components. This study extensively investigates three types developed from commercially available Oil-based resins, correlating properties across...
Direct measurements of a long-range force between charged solid surfaces in nonpolar liquid are presented for the first time. Measurements were made mica solutions anionic surfactant sodium di-2-ethylhexylsulfosuccinate (AOT) at millimolar concentrations n-decane using surface apparatus which has been modified to improve its sensitivity detecting weak and force. Modifications include magnetic drive system, use cantilever spring with mounted vertical configuration, detailed consideration...
We have measured normal and lateral interactions across a range of different liquids between mica surfaces using surface force balance (SFB). The were prepared either by melt cutting Pt wire standard procedures in our laboratories or tearing sheets (that had not been exposed to Pt) off from freshly cleaved sheet mica. AFM micrographs revealed the substantial absence nanoparticles on cut torn-off surfaces. Normal-force versus surface-separation (D) profiles shear D measurements for purified...
This paper presents measurements, using the surface force balance (SFB), of normal and shear forces in aqueous solutions between polyelectrolyte layers grown directly on mica substrates (grafted-from). The grafting-from was via surface-initiated atom transfer radical polymerization (surface-initiated ATRP) a positively charged methacrylate monomer. X-ray reflectometry measurements confirm successful formation by this method. Surface-inititated ATRP has advantages that polymer chains can be...
Controlling polymer thin-film morphology and crystallinity is crucial for a wide range of applications, particularly in organic electronic devices. In this work, the crystallization behavior model polymer, poly(ethylene oxide) (PEO), during spin-coating studied. PEO films were spun-cast from solvents possessing different polarities (chloroform, THF, methanol) probed via situ grazing incidence wide-angle X-ray scattering. The was found to follow solvent polarity order (where chloroform < THF...
Understanding surface structure of graphene is important for its integration into composite materials. Here, we have used synchrotron X-ray reflectivity (XRR) to study the commercially available samples (prepared via chemical vapor deposition, and marketed as monolayers) on SiO2/Si at different temperatures. photoelectron spectroscopy, photoemission electron microscopy atomic force (AFM) were employed evaluate composition morphology layer. Our results indicate that characterized consisted...
Despite extensive studies with many experimental techniques, the morphology and structure of self-assembled aggregates quaternary alkyl ammonium bromides (CnTABs; where n denotes number hydrocarbons in surfactant tail) at solid–liquid interface remains controversial, results from atomic force microscopy (AFM) imaging pointing to a variety surface such as cylinders micelles, whilst measurements neutron reflectivity (NR) reporting bilayer structures. Using home-built liquid cell that employs...
In this work, stability of poly(butadiene)-poly(ethylene oxide) (PBD-PEO) polymersomes, self-assembled from two polymers with different molecular weights (PBD32-PEO21 and PBD125-PEO80) in either pure H2O or phosphate buffered saline (PBS), is studied. Polymersome dispersions usually show large polydispersity, it thus desirable to separate different-sized vesicles if a narrow size distribution required, e.g. for model systems certain applications. This typically achieved by extrusion through...
Flexible polyurethane foam composites with enhanced stiffness and energy dissipation have been prepared via a facile layer-by-layer assembly approach.The composite foams consisted of naturally abundant nanoclay/chitosan multilayers (up to six) deposited onto the struts dip-coating.The were characterised using infrared spectroscopy, scanning electron microscopy, elemental mapping μ-CT scanning.Quasi-static mechanical compression 6 bilayers showed 202% increase in 33% enhancement damping loss...
Conducting polymers have shown great potential for application in electronic devices. A major challenge such applications is to control the supramolecular structures these materials form optimise functionality. In this work we probe structure of oligo(aniline) thin films (of sub-μm thickness) drop cast on a silicon substrate using synchrotron surface diffraction. Self-assembly was induced through doping with an acid surfactant, bis(ethyl hexyl) phosphate (BEHP), resulting formation...