3 research outputs found
Molecular Dynamics Study of Carbon Nanotubes/Polyamide Reverse Osmosis Membranes: Polymerization, Structure, and Hydration
Carbon
nanotubes/polyamide (PA) nanocomposite thin films have become very
attractive as reverse osmosis (RO) membranes. In this work, we used
molecular dynamics to simulate the influence of single walled carbon
nanotubes (SWCNTs) in the polyamide molecular structure as a model
case of a carbon nanotubes/polyamide nanocomposite RO membrane. It
was found that the addition of SWCNTs decreases the pore size of the
composite membrane and increases the Na and Cl ion rejection. Analysis
of the radial distribution function of water confined in the pores
of the membranes shows that SWCNT+PA nanocomposite membranes also
exhibit smaller clusters of water molecules within the membrane, thus
suggesting a dense membrane structure (SWCNT+PA composite membranes
were 3.9% denser than bare PA). The results provide new insights into
the fabrication of novel membranes reinforced with tubular structures
for enhanced desalination performance
Concise SAR Exploration Based on the “Head-to-Tail” Approach: Discovery of PI4KIIIα Inhibitors Bearing Diverse Scaffolds
In typical kinase inhibitor programs,
a hinge binder showing best
potency with preferential specificity is initially selected, followed
by fine-tuning of the accompanying substituents on its core module.
A shortcoming of this approach is that the exclusive focus on a single
chemotype can endanger all the analogues in the series if a critical
shortcoming is revealed. Thus, an early evaluation of structure–activity
relationships (SARs) can mitigate unforeseen outcomes within a series
of multiple compounds, although there have been very few examples
to follow such a policy. PI4KIIIα is one of four mammalian phosphatidylinositol-4
kinases and has recently drawn significant attention as an emerging
target for hepatitis C virus (HCV) treatment. In this letter, a novel
“head-to-tail” approach to discover a diverse set of
PI4KIIIα inhibitors is reported. We believe this method will
generate distinct core scaffolds, a rational strategy to circumvent
potential risks in general kinase programs
Antiorganic Fouling and Low-Protein Adhesion on Reverse-Osmosis Membranes Made of Carbon Nanotubes and Polyamide Nanocomposite
We
demonstrate efficient antifouling and low protein adhesion of multiwalled
carbon nanotubes-polyamide nanocomposite (MWCNT-PA) reverse-osmosis
(RO) membranes by combining experimental and theoretical studies using
molecular dynamics (MD) simulations. Fluorescein isothiocyanate (FITC)-labeled
bovine serum albumin (FITC-BSA) was used for the fouling studies.
The fouling was observed in real time by using a crossflow system
coupled to a fluorescence microscope. Notably, it was observed that
BSA anchoring on the smooth MWCNT-PA membrane was considerably weaker
than that of other commercial/laboratory-made plain PA membranes.
The permeate flux reduction of the MWCNT-PA nanocomposite membranes
by the addition of FITC-BSA was 15% of its original value, whereas
those of laboratory-made plain PA and commercial membranes were much
larger at 34%–50%. Computational MD simulations indicated that
the presence of MWCNT in PA results in weaker interactions between
the membrane surface and BSA molecule due to the formation of (i)
a stiffer PA structure resulting in lower conformity of the molecular
structure against BSA, (ii) a smoother surface morphology, and (iii)
an increased hydrophilicity involving the formation of an interfacial
water layer. These results are important for the design and development
of promising antiorganic fouling RO membranes for water treatment