4 research outputs found
Mechanistic Investigation of Inclusion Complexes of a Sulfa Drug with α- and β‑Cyclodextrins
Molecular
encapsulation is extremely important in pharmaceutical
and drug delivery science. In this article, one of the most important
sulfa drugs, namely, sulfacetamide sodium, has been probed in the
solution and solid phases for encapsulation within the cavities of
α- and β-cyclodextrins. Various physicochemical techniques
were employed to establish the outcome of the work. The isothermal
titration calorimetric method was used to evaluate the stoichiometry,
association constant, and thermodynamic parameters with high accuracy.
The solid inclusion complexes were analyzed by spectroscopic techniques
to ascertain the encapsulation of the investigated drug within the
cavities of α- and β-cyclodextrins. This phenomenon of
drug inclusion is exceedingly significant for its stabilization against
external hazards, such as oxidation, sensitization, and photolytic
cleavage, for the proficient and accurate regulatory release of an
essential amount of drug at the targeted site for a period of time
and for the prevention of overdose when applied as an ophthalmic solution
and ointment
High Energy Density Achieved in Novel Lead-Free BiFeO<sub>3</sub>–CaTiO<sub>3</sub> Ferroelectric Ceramics for High-Temperature Energy Storage Applications
The
development of high-performance electrostatic energy storage
dielectrics is essential for various applications such as pulsed-power
technologies, electric vehicles (EVs), electronic devices, and the
high-temperature aviation sector. However, the usage of lead as a
crucial component in conventional high-performance dielectric materials
has raised severe environmental concerns. As a result of this, there
is an urgent need to explore lead-free alternatives. Ferroelectric
ceramics offer high energy density but lack stability at high temperatures.
Here we present a lead-free (1 – x)BiFeO3–xCaTiO3 (x = 0.6, 0.7, and 0.8; BFO-CTO) ceramic capacitor with low dielectric
loss, high thermal stability, and high energy density up to ∼200
°C. The introduction of CTO (x = 0.7) to the
BFO matrix triggers a transition from the normal ferroelectrics to
the relaxor ferroelectrics state, resulting in a high recoverable
energy density of 1.18 J cm–3 at 190 °C with
an ultrafast dielectric relaxation time of 44 μs. These results
offer a promising, environmentally friendly, high-capacity ceramic
capacitor material for high-frequency and high-temperature applications
A Distinctive PdCl<sub>2</sub>‑Mediated Transformation of Fe-Based Metallogels into Metal–Organic Frameworks
Simple,
efficient conversion of viable Fe<sup>3+</sup>-based metallogels into
Fe-metal–organic frameworks (MOFs) has been achieved by PdCl<sub>2</sub>-mediated gel degradation. The metallogels and the resulting
MOFs have been characterized, and a probable mechanism for the event
has been elucidated
Multistimuli-Responsive Interconvertible Low-Molecular Weight Metallohydrogels and the in Situ Entrapment of CdS Quantum Dots Therein
Two
low molecular weight metallohydrogels (ZALA and CALA) have
been synthesized from an amino-acid-based ligand precursor (LA) and
two different metal salts [zinc acetate dihydrate (ZA) and cadmium
acetate dihydrate (CA), respectively. These two hydrogels show a unique
chemically stimulated interconversion to each other via a reversible
gel–sol–gel pathway. This programmable gel–sol
reversible system satisfies logic operations of a basic Boolean logic
(INHIBIT) gate. Also, these hydrogels can be degraded into different
MOF phases at room temperature spontaneously or in the presence of
chloride and bromide salts (NaCl and NaBr.). CdS quantum dots can
be grown inside the CALA gel matrix (CdS@CALA) in the presence of
small amount of Na<sub>2</sub>S. This CdS doped gel exhibits time
dependent tunable emission (white to yellow to orange) as a consequence
of a slow agglomeration process of the entrapped quantum dots inside
the gel matrix. This luminescence property also reflects the corresponding
gel derived MOFs (obtained either by self-degradation of CdS@CALA
or via anion induction) as well. This, to the best of our knowledge,
is probably the simplest way to make a CdS quantum dot based composite
material where CdS is entrapped within the gel and the gel-derived
MOF matrix