7 research outputs found
Removal of Pollutants by Ferrihydrite Nanoparticles Combined with Brij L4 Self-Assembled Nanostructures
Release of contaminants such as pharmaceuticals, dyes,
pesticides,
and industrial wastes due to anthropogenic activities is a threat
to human health and the environment. Self-assembled nanostructures
of nonionic surfactants are highly efficient in removing organic and
inorganic pollutants from various environmental media. Here, we present
an evaluation of the pollutant-removal efficiency of Brij L4 nonionic
surfactant as a function of the surfactant concentration and self-assembled
structures. In addition, small-angle X-ray scattering (SAXS) and rheology
were employed to investigate interactions between the Brij L4 isotropic
micellar phase and lyotropic liquid crystals and ferrihydrite nanoparticles
(Fh NPs). Ferrihydrite nanoparticles in the micellar phase destabilized
lyotropic liquid crystals at low surfactant concentrations, while
remaining stable in lyotropic phases at high concentrations. Maximum
pollutant-removal efficiency (22%) was obtained using a self-assembled
nanostructure of pure Brij L4 at 1 wt %. However, Fh NPs are nanoporous
and strongly interact with negatively charged organic matter, enhancing
the pollutant-removal efficiency of 10 wt % Brij L4. We constructed
binary and pseudo-binary phase diagrams at 25 °C of the surfactant
in water and in the presence of ferrihydrite nanoparticles, respectively.
The Brij L4/water binary phase diagram identified rod-shaped structures
at 10 wt % of surfactant. The results of this study identify effective
strategies for formulating highly efficient pollutant-removal systems
using nanotechnology
Multilamellar Vesicle Formation from a Planar Lamellar Phase under Shear Flow
The formation of multilamellar vesicles
(MLVs) from the lamellar phase of nonionic surfactant system C<sub>12</sub>E<sub>5</sub>/D<sub>2</sub>O under shear flow is studied
by time-resolved small angle neutron and light scattering during shear
flow. A novel small angle neutron scattering sample environment enables
the tracking of the lamellae alignment in the velocity–velocity
gradient (1–2) plane during MLV formation, which was tracked
independently using flow small angle light scattering commensurate
with rheology. During the lamellar-to-multilamellar vesicle transition,
the primary Bragg peak from the lamellar ordering was observed to
tilt, and this gradually increased with time, leading to an anisotropic
pattern with a primary axis oriented at ∼25° relative
to the flow direction. This distorted pattern persists under flow
after MLV formation. A critical strain and critical capillary number
based on the MLV viscosity are demonstrated for MLV formation, which
is shown to be robust for other systems as well. These novel measurements
provide fundamentally new information about the flow orientation of
lamellae in the plane of flow that cannot be anticipated from the
large body of previous literature showing nearly isotropic orientation
in the 2,3 and 1,3 planes of flow. These observations are consistent
with models for buckling-induced MLV formation but suggest that the
instability is three-dimensional, thereby identifying the mechanism
of MLV formation in simple shear flow
Characteristics at follow-up by the percentage of total daily caloric intake from dinner.
<p>Characteristics at follow-up by the percentage of total daily caloric intake from dinner.</p
Association between outcomes at follow-up (dependent variables) and the percentage of total daily caloric intake from dinner in multiple logistic regression models.
<p>Association between outcomes at follow-up (dependent variables) and the percentage of total daily caloric intake from dinner in multiple logistic regression models.</p
Baseline clinical and laboratory characteristics by the percentage of total daily caloric intake from dinner.
<p>Baseline clinical and laboratory characteristics by the percentage of total daily caloric intake from dinner.</p
Baseline lifestyle and dietary characteristics by the percentage of total daily caloric intake from dinner.
<p>Baseline lifestyle and dietary characteristics by the percentage of total daily caloric intake from dinner.</p
Complementary X-ray, ellipsometry and neutron data from Non-lamellar lipid assembly at interfaces: controlling layer structure by responsive nanogel particles
Figure S1. Effect of temperature on the lattice parameter, a, of a cubic phase composed of GMO-50/DGMO (40/60 weight ratio) alone (open markers) or containing 10 wt% nanogel (black solid markers). Figure S2. SAXS data for the formulations of nanogels dispersed in lipids (85 wt % lipids composed of GMO-50/DGMO at a 40/60 weight ratio) with 15 wt % ethanol at 25 °C and 40 °C. Figure S3. Spectroscopic ellipsometry parameters, Δ (pink circles) and ψ (black triangles), as a function of wavelength for a film of GMO-50:DGMO (40:60 wt%) on silica. Figure S4. (A) Schematic representation of magnetic contrast surfaces used in this study. Figure S5. Neutron reflectivity data for a spin coated film of GMO-50:DGMO (60:40 wt% ratio) containing nanogel (10wt%) at (A) 25°C and (B) 40°C. Figure S6. Diffraction pattern extracted from the off-specular neutron reflectivity patterns in Figure 6 of lipid-only and lipid-nanogel layers at 25 °C and 40 °C