We investigate the shape, dimensions, and transformation pathways of micelles linear sodium alkylbenzenesulfonate (NaLAS), a common anionic surfactant, in aqueous solution. Employing Small Angle Neutron Scattering (SANS) surface tensiometry, we quantify effects surfactant concentration (0.6-15 wt%), temperature (5-40 °C) added salt (≤0.35 M Na2SO4). Spherical form at low NaLAS (≤2.6 wt%) water, become elongated with increasing decreasing temperature. Addition reduces critical micelle (CMC)...

Hydrogel microparticles (HMPs) find numerous practical applications, ranging from drug delivery to tissue engineering. Designing HMPs the molecular macroscopic scales is required exploit their full potential as functional materials. Here, we explore gelation of sodium carboxymethyl cellulose (NaCMC), a model anionic polyelectrolyte, with Fe3+ cations in water. Gelation front kinetics are first established using 1D microfluidic experiments, and effective diffusive coefficients found increase...

We report a small-angle neutron scattering (SANS) study of semidilute aqueous solutions sodium carboxymethyl cellulose (NaCMC), in the presence mono- (Na+) and divalent salts (Mg2+, Ca2+, Zn2+, Ba2+). A degree substitution 1.3 is selected to ensure that, salt-free solution, polymer molecularly dissolved. find that Na+ Mg2+ salt addition yields H-type phase behavior, while Ba2+ instead yield mixed H/L-type behavior dependent on NaCMC concentration (cp), decreasing order required induce...

We comparatively review two versatile approaches employed in the precise formation of polymer particles, with length scales from 10s nm to 100s μm, ternary polymer(s), solvent and nonsolvent mixtures. Flash nanoprecipitation (FNP) utilizes an opposing jet arrangement mix a dilute solution confinement, inducing rapid (∼millisecond) chain collapse eventual precipitation nanoparticles (NPs) 10–1000 diameters. FNP mixtures block copolymers can yield range multiphase morphologies various...

We investigate the structure and interactions of a model anionic/amphoteric mixed surfactant micellar system, namely, sodium dodecyl sulfate (SDS) N,N-dimethyldodecylamine N-oxide (DDAO), employing SANS, FTIR, DLS, pH measurements, in range 0.1–100 mM total concentration 0–100% DDAO. Increasing is found to elongate prolate ellipsoid micelles (RPolar ∼ 25–40 Å), accompanied by up 6-fold increase charge. The synergy, terms charge size, diffusion coefficient, solution pH, headgroup...

The self-assembly of an arylazopyrazole-based photosurfactant (PS), based on cetyltrimethylammonium bromide (CTAB), and its mixed micelle formation with CTAB in aqueous solution was investigated by small angle neutron X-ray scattering (SANS/SAXS) UV-vis absorption spectroscopy. Upon UV light exposure, PS photoisomerizes from E-PS (trans) to Z-PS (cis), which transforms oblate ellipsoidal micelles into smaller, spherical larger shell thickness. Doping resulted at all stoichiometries...

We investigate the formation of poly(vinyl alcohol) microparticles by selective extraction aqueous polymer solution droplets, templated microfluidics and subsequently immersed in a non-solvent bath. The role molecular mass (18-105 kg mol-1), degree hydrolysis (88-99%) thus solubility, initial concentration (0.01-10% w/w) are quantified. Monodisperse droplets with radii ranging from 50 to 500 μm were produced at flow-focusing junction carrier phase hexadecane extracted into ethyl acetate....

We investigate the drying of isolated polymer solution droplets, employing acoustic levitation, and demonstrate spontaneous generation breath figures (BF) on resulting particles capsules (∼5-1000 μm) with controlled surface pore arrays (<1-20 μm). By contrast supported thin films, evaporative cooling experienced by suspended droplets suffices to yield ubiquitous BF formation, owing their thermal insulation synchronous condensation self-assembly water microdroplets, accompanied capsule skin...

We investigate the role of confinement on onset crystallization in subcooled micellar solutions sodium dodecyl sulfate (SDS), examining impact sample volume, substrate surface energy, and roughness. Using small angle neutron scattering (SANS) dynamic light (DLS), we measure temperature upon cooling metastable zone width (MSZW) for bulk 10–30 wt% SDS solutions. then introduce a microdroplet approach to quantify free energy (18–65 mN/m) roughness (Rα ≃ 0–60 μm) kinetics surface-induced through...

We examine the solution structures in a mixed surfactant system of sodium dodecyl sulfate (SDS) and N,N-dimethyldodecylamine N-oxide (DDAO) water, on both sides two-phase boundary, employing dynamic light scattering, small-angle neutron Fourier transform infrared spectroscopy. The precipitate phase boundary was accessed by lowering pH to 8, from its floating 9.5 value, experimentally approached monomeric micellar regions three ways: at fixed DDAO or SDS concentrations (70:30) SDS:DDAO molar...

We investigate the effect of polymer tacticity on phase behavior and separation mixtures by small-angle neutron scattering (SANS). Poly(α-methyl styrene-co-acrylonitrile) (PαMSAN) deuterated poly(methyl methacrylate) (dPMMA) with two degrees syndiotacticity were selected as a model partially miscible blend, one most highly interacting systems known (defined temperature dependence blend's interaction parameter). One-phase (equilibrium) time-resolved, spinodal demixing experiments analyzed de...

We investigate the conformation of poly(2,6-diphenyl-p-phenylene oxide) (PPPO) in good and mixed solvents by small-angle neutron scattering (SANS) across its ternary phase diagram. Dichloromethane was selected as a "good" solvent heptane "poor" whose addition eventually induces demixing polymer precipitation. Below overlap concentration c*, is found to be well described polymer-excluded volume model above Ornstein-Zernike expression with correlation length ξ which depends on...

Poly(methyl methacrylate) (PMMA) and poly(α-methylstyrene-co-acrylonitrile) (PαMSAN) form partially miscible blends with lower critical solution temperature (LCST) behavior. We revisit this system using small angle neutron scattering (SANS), examining the effect of molecular weight (Mw) deuterated PMMA (dPMMA), blend composition (ϕ), (T) in homogeneous region. All data are well-described by Random Phase Approximation (RPA) theory, enabling us to determine thermodynamic structural parameters,...

We examine the formation and growth of isolated myelin figures microscale multilamellar tubules from isotropic micellar solutions an anionic surfactant. Upon cooling, surfactant micelles transform into vesicles (MLVs) whose contact is found to trigger unidirectional myelins. While MLV diameter grows as dMLV ∝ t1/2, myelins grow linearly in time LM t1, with a fixed diameter. Combining time-resolved small-angle neutron scattering (SANS) optical microscopy, we demonstrate that microscopic...

We investigate the thermodynamics of a highly interacting blend poly(cyclohexyl methacrylate)/deuterated poly(styrene) (PCHMA/dPS) with small-angle neutron scattering (SANS). This system is experimentally challenging due to proximity phase boundary (>200 °C) and degradation temperatures. To achieve large wavenumber q-range flux required for kinetic experiments, we employ SANS diffractometer in time-of-flight (TOF) mode at reactor source ancillary microscopy, calorimetry, thermal gravimetric...

We present acoustic levitation combined with polarising optical microscopy (AL-POM). Fatty acid aerosols were probed and a model fit revealed ca. 5–6 orders of magnitude difference in water diffusion coefficient upon phase transition between optically birefringent non-birefringent phases.