2 research outputs found
Small-Angle Neutron Scattering Study of Cyclic Poly(ethylene glycol) Adsorption on Colloidal Particles
The adsorptions of cyclic PEG and
linear PEG on colloidal silica
particles were compared. Their adsorption volume fraction profiles
were generated through model fitting of small-angle neutron scattering
data from the adsorbed polymer layers. The two important parameters
to describe adsorbed polymer layers were discussed in detail. It was
found that the adsorption amounts of cyclic PEGs increased with molecular
weight but were generally higher than their linear counterparts. However,
the root-mean-square layer thickness, δ<sub>rms</sub>, of adsorbed
cyclic PEGs was found to decrease with molecular weight, opposing
adsorbed linear PEGs and the theoretic prediction based on SF model.
This disagreement was ascribed to the topological restriction of cyclic
polymer at low molecular weight. An illustrated structural evolution
with molecular weight for adsorbed polymer at interface was tentatively
proposed based on the observations of this study
Combination of Running-Buffer-Mediated Extraction and Polyamidoamine-Dendrimer-Assisted Capillary Electrophoresis for Rapid and Sensitive Determination of Free Fatty Acids in Edible Oils
A method
was developed for determining free fatty acids in edible
plant oils by incorporation of running-buffer-mediated liquid–liquid
extraction and polyamidoamine-dendrimer-assisted capillary electrophoresis–capacitively
coupled contactless conductivity detection. The recoveries for the
extraction were in the range of 90.1% and 110.3%. Addition of dendrimer
to the running buffer improved the separation of fatty acids. Under
the optimized buffer conditions, i.e., 3 mM pelargonic acid, 39 mM
trisÂ(hydroxymethyl)Âaminomethane, 30 mM polyoxyethylene 23 lauryl ether,
35% acetonitrile, 15% 2-propanol, 2.5% 1-octanol, and 300 μM
polyamidoamine generation 2 at apparent pH 8.53, the 10 model fatty
acids were separated in 18 min with detection limits ranging from
0.46 to 3.28 μM. The successful determination of fatty acids
in real samples suggests that the method is simple, cost-effective,
and easy to operate and is suitable for scanning free fatty acid in
edible plant oils