8 research outputs found
A solvent-free composite polymer/inorganic oxide electrolyte for high efficiency solid-state dye-sensitized solar cells
Numerical and experimental investigation of the diffusional release of a dispersed solute from polymeric multilaminate matrices
Trimethylsulfonium Lead Triiodide: An Air-Stable Hybrid Halide Perovskite
We
report on the synthesis, characterization, and optoelectronic properties
of the novel trimethylsulfonium lead triiodide perovskite, (CH<sub>3</sub>)<sub>3</sub>SPbI<sub>3</sub>. At room temperature, the air-stable
compound adopts a hexagonal crystal structure with a 1D network of
face-sharing [PbI<sub>6</sub>] octahedra along the <i>c</i> axis. UV–vis reflectance spectroscopy on a pressed pellet
revealed a band gap of 3.1 eV, in agreement with first-principles
calculations, which show a small separation between direct and indirect
band gaps. Electrical resistivity measurements on single crystals
indicated that the compound behaves as a semiconductor. According
to multi-temperature single-crystal X-ray diffraction, synchrotron
powder X-ray diffraction, Raman spectroscopy, and differential scanning
calorimetry, two fully reversible structural phase transitions occur
at −5 and ca. −100 °C with reduction of the unit
cell symmetry to monoclinic as temperature decreases. The role of
the trimethylsulfonium cation regarding the chemical stability and
optoelectronic properties of the new compound is discussed in comparison
with APbI<sub>3</sub> (A = Cs, methylammonium, and formamidinium cation),
which are most commonly used in perovskite solar cells
Preparation and In Vitro Evaluation of a New Fentanyl Patch Based on Functional and Non-functional Pressure Sensitive Adhesives
In this study, some single-layer and double-layer transdermal drug delivery systems (TDDSs) with different functional and non-functional acrylic pressure-sensitive adhesives (PSAs) were prepared. For this purpose, fentanyl as a drug was used. The effects of PSAs type, single-layer and double-layer TDDSs on skin permeation and in vitro drug release from devices were evaluated using a hydrodynamically well-characterized Chien permeation system fitted with excised rat abdominal skin. The adhesion properties of devices such as peel strength and tack values were obtained as well. It was found that TDDS with –COOH functional PSA showed the lowest steady-state flux. Double-layer TDDS displayed a constant flux up to 72 h. In double- and single-layer devices after 1 and 3 h, respectively, drug release followed Higuchi’s kinetic model. Formulations with the highest percentage of –COOH functional PSA have displayed the lowest flux. The double-layer TDDSs with non-functional PSA demonstrated the suitable skin permeation rate close to Duragesic® TDDS and suitable adhesion properties