A5090366404- Surfactants and Colloidal Systems
- Spectroscopy and Quantum Chemical Studies
- Electrostatics and Colloid Interactions
- Analytical Chemistry and Chromatography
- Polymer Surface Interaction Studies
- Lipid Membrane Structure and Behavior
- Advanced Polymer Synthesis and Characterization
- Environmental Chemistry and Analysis
- Chemical and Physical Properties in Aqueous Solutions
- Photochemistry and Electron Transfer Studies
- Protein purification and stability
- Pickering emulsions and particle stabilization
- Proteins in Food Systems
- Plant Surface Properties and Treatments
- Ionic liquids properties and applications
- Polymer-Based Agricultural Enhancements
- Microfluidic and Capillary Electrophoresis Applications
- Thermodynamic properties of mixtures
- Surface Modification and Superhydrophobicity
- Phase Equilibria and Thermodynamics
- Advancements in Transdermal Drug Delivery
- Supramolecular Self-Assembly in Materials
- Polyamine Metabolism and Applications
- Pesticide and Herbicide Environmental Studies
- nanoparticles nucleation surface interactions
Rutherford Appleton Laboratory
2016-2025
Science and Technology Facilities Council
2017-2024
Harbin Institute of Technology
2022-2024
Northwest A&F University
2024
Hebei University of Technology
2024
Vision Medicals (China)
2024
Shandong Agricultural University
2022-2023
Tohoku University
2023
University of Bath
2022
ISIS Neutron and Muon Source
2022
Histidine, a widely used buffer in monoclonal antibody (mAb) formulations, is known to reduce aggregation. While experimental studies suggest nonelectrostatic, nonstructural (relating secondary structure preservation) origin of the phenomenon, underlying microscopic mechanism behind histidine action still unknown. Understanding this will help evaluate and predict stabilizing effect under different conditions for mAbs. We have all-atom molecular dynamics simulations contact-based free energy...
The rational design of lipid nanoparticles (LNPs) for enhanced gene delivery remains challenging because incomplete knowledge their formulation–structure relationship that impacts intracellular behavior and consequent function. Small-angle neutron scattering has been used in this work to investigate the structure LNPs encapsulating plasmid DNA upon acidification (from pH 7.4 4.0), as would be encountered during endocytosis. results revealed acidification-induced evolution (AISE) on different...
The aggregation properties of three dicationic quaternary ammonium gemini surfactants with the same structure, except spacer group, diethyl ether, six methylene, and p-xylyl, have been studied using electrical conductivity fluorescence. critical micelle concentration (cmc) number (N) were determined, micropolarity microviscosity characterized. ionization degree (α) was obtained by a combination data number. Furthermore, Gibbs free energy micellization (ΔGmic) studied. These results shown...
The interactions between a series of cationic surfactants (alkyltrimethylammonium bromides) (CnTAB) and the anionic polymer sodium poly(styrenesulfonate) (NaPSS) have been studied using surface tension neutron reflectivity. effect surfactant chain length on surfactant/polymer adsorption has lengths from 10 to 16 carbon atoms (i.e. C10TAB C16TAB). plots (γ against ln c) two types shape. C12TAB with NaPSS systems plateaus, while longer C 14TAB C16TAB pronounced hump in at concentrations just...
Neutron reflection (NR) and surface tension (ST) are used to show that there serious limitations in applying the Gibbs equation accurately ST data of cationic surfactants obtain limiting excess, ΓCMC, at critical micelle concentration (CMC). Nonionic impurities C12TABr C16TABr have been eliminated by extensive purification give – ln(concentration) (σ ln c) curves convex with respect c axis around CMC, which is characteristic a finite micellization width. Because NR shows excess often...
Small-angle neutron scattering experiments, supported by molecular dynamics simulations, have been performed on a range of compositions the [C<sub>2</sub>mim]<sub>1−x</sub>[C<sub>12</sub>mim]<sub>x</sub>[Tf<sub>2</sub>N] ionic liquid mixture system.
Antimicrobial peptides are promising alternatives to traditional antibiotics. A group of self-assembling lipopeptides was formed by attaching an acyl chain the N-terminus α-helix-forming with sequence Cx-G(IIKK)yI-NH2 (CxGy, x = 4–12 and y 2). CxGy self-assemble into nanofibers above their critical aggregation concentrations (CACs). With increasing x, CACs decrease hydrophobic interactions increase, promoting secondary structure transitions within nanofibers. activity, determined minimum...
Cationic surfactants have a wide range of applications, often associated with their affinity for solid surfaces and anti-microbial properties. Manipulating adsorption self-assembly properties is key to most this commonly achieved through surfactant mixtures or manipulating headgroup alkyl chain structure. Achieving adjustments structure less common in cationic than anionic surfactants. Ethoxylation provides the ability adjust hydrophilic / hydrophobic balance, as extensively demonstrated
The micellization of six cationic gemini surfactants with various counterions, [C12H25(CH3)2N(CH2)6N(CH3)2C12H25]X2, designated as C12C6C12X2, X = F-, Cl-, Br-, Ac-, NO3-, and 1/2SO42- in aqueous solutions has been investigated by isothermal titration microcalorimetry (ITC) conductivity measurements. interaction these DNA also microcalorimetry. critical micelle concentration (CMC) the degree micellar ionization (α), aggregation (CAC), saturation (C2) aggregation, associated thermodynamic...
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...
Surface tension (ST) and neutron reflection (NR) measurements have been made on a series of mixtures two ionic surfactants, one anionic (SDS) cationic (C12TAB), with the zwitterionic surfactants dodecyldimethylammonium propanesulfonate (C12SB) acetate C12CB. The surfactant SDS interacts equally strongly both zwitterionics C12TAB less strongly. For SDS-C12SB simultaneous fitting ST NR data it possible to use pseudophase approximation an expansion excess free energy, GE, up including quartic...
Micellisation of surfactants in deep eutectic solvents has been recently demonstrated to provide a controllable way modify micelle morphology. Ion-pair interactions between the solvent and surfactant headgroup were identified as affecting micellisation by modifying charge density micelle. Here we explore dodecylsulfate with different counterions (Li+, Cs+, Mg2+, Bmim+, Emim+, cholinium+) dissolved two solvents: choline chloride:urea chloride:glycerol. Surface tension results show counterion...
Abstract The high oil magnetic composite resin, which is a low crosslinking was synthesized by conventional suspension copolymerization in the present work. effect of monomer ratio, crosslinker, initiator, modified Fe 3 O 4 , and reaction time on absorptivity resin defined optimum condition were studied. highest about 20 g/g chloroform 10.5 toluene when extent 5%. Infrared (IR), X‐ray diffractometer (XRD), synthetic themoanalyzer, laser particle size analyzer, vibrating‐sample magnetometer...
We have measured the structure and properties of a series dicationic quaternary ammonium compounds α,ω-bis(N-alkyl dimethyl ammonium)hexane halides (Cn−C6−Cn) for values alkyl chain length n 8, 9, 10, 11, 12, 16, ammonium)diethylether (Cn−C2OC2−Cn) as well C8−C12−C8 C12−C10−C12 at air/water interface. Although critical micelle concentration (CMC) in two decreases normal way, that is, logarithmically, with increasing length, limiting surface tension CMC area per molecule both increase...