In this study, the polyethylene oxide (PEO)/SiO2 nanoparticles (NPs) nanocomposite films with various SiO2 NPs concentrations were prepared using an in situ formation of NPs in the polymer matrix for ...self‐cleaning antireflected surface applications. The effect of SiO2 NPs in PEO/SiO2 NPs nanocomposite films on the structural, morphological, chemical, thermal, optical, and electrical properties of PEO/SiO2 NPs nanocomposite films was performed. According to the x‐ray diffraction and the differential scanning calorimetry analysis, the crystallinity degree of the nanocomposite films decreases by increasing the SiO2 NPs concentrations. The bandgap energy of PEO/SiO2 NPs nanocomposite films decreases from 3.95 to 3.55 eV as the SiO2 NPs concentration increases up to 10 wt.%. The average electrical conductivity of the PEO/SiO2 NPs nanocomposite films increases from 5.1 × 10−7 to 2.0 × 10−6 S/cm as the SiO2 NPs concentration increases up to 10 wt.%. The refractive index decreases to 1.64 at 550 nm for the PEO/SiO2 NPs nanocomposite films with 10 wt.% of SiO2 NPs, and the water contact angle decreases to around 0° after thermal treatment, which confirms that the PEO/SiO2 NPs nanocomposite films can be used as self‐cleaning antireflected surfaces.
Morphological and particle dispersion of PEO/SiO2 nanocomposite films.
Objectives
: To quantify quercetin, gallic acid, rutin, naringin, and caffeic acid in the rhizome of
Zingiber officinale
different extracts in seven different solvents (methanol, ethanol, ethyl ...acetate, water, dichloromethane, chloroform, and
n
-hexane), for the first time, using HPLC/UV. Also, to study the anticancer activity of
Zingiber officinale
different extracts by evaluating its
in vitro
toxicity on HT-29 colorectal cancer cell line.
Methods
: The fresh and dried rhizomes were extracted using Soxhlet (SOX) and maceration (MAC) methods. Separation of compounds was conducted using HPLC. The cell line used for MTT cell proliferation assay antiproliferative; is HT-29 (HTB-38) colorectal adenocarcinoma.
Results
: The MTT test indicated that powder ginger extracted by MAC or SOX showed high cytotoxicity activity (IC
50
<50) against HT-29 cells, except water using SOX, which showed mild cytotoxicity activity. The fresh ginger extracted by MAC using dichloromethane and those extracted by SOX using ethyl acetate showed strong cytotoxicity activity (IC
50
<50).
Conclusion
: The phenolic and flavonoid contents of ginger can vary depending on the different extracts from ginger plant. Also, HPLC results revealed that quercetin was the highest in all extracts.
A thorough computational study of a thermal degradation mechanism of 2-ethoxyethanol (2-EE) in the gas phase has been implemented using G3MP2 and G3B3 methods. The stationary point geometries were ...optimized at the B3LYP functional utilizing the 6-31G(d) basis set. Intrinsic reaction coordinate analysis was performed to determine the transition states on the potential energy surfaces. Nineteen primary different reaction mechanisms, along with the kinetic and thermodynamic parameters, are demonstrated. Most of the thermal degradation mechanisms result in a concerted transition state step as an endothermic process. Among 11 degradation pathways of 2-ethoxyethanol, the formation of ethylene glycol and ethylene is kinetically significant with an activation energy of 269 kJ mol–1 at the G3B3 method. However, the kinetic and thermodynamic calculations indicate that ethanol and ethanal’s formation is the most plausible reaction with an activation barrier of 287 kJ mol–1 at the G3B3 method. For the bimolecular dissociation reaction of 2-ethoxyethanol with ethanol, the pathway that produces ether, H2, and ethanol is more likely to occur with a lower activation energy of 221 kJ mol–1 at the G3B3 method. Thus, 2-EE has experienced a set of complex unimolecular and bimolecular reactions.
Abstract In this study, the polyethylene oxide (PEO)/SiO 2 nanoparticles (NPs) nanocomposite films with various SiO 2 NPs concentrations were prepared using an in situ formation of NPs in the polymer ...matrix for self‐cleaning antireflected surface applications. The effect of SiO 2 NPs in PEO/SiO 2 NPs nanocomposite films on the structural, morphological, chemical, thermal, optical, and electrical properties of PEO/SiO 2 NPs nanocomposite films was performed. According to the x‐ray diffraction and the differential scanning calorimetry analysis, the crystallinity degree of the nanocomposite films decreases by increasing the SiO 2 NPs concentrations. The bandgap energy of PEO/SiO 2 NPs nanocomposite films decreases from 3.95 to 3.55 eV as the SiO 2 NPs concentration increases up to 10 wt.%. The average electrical conductivity of the PEO/SiO 2 NPs nanocomposite films increases from 5.1 × 10 −7 to 2.0 × 10 −6 S/cm as the SiO 2 NPs concentration increases up to 10 wt.%. The refractive index decreases to 1.64 at 550 nm for the PEO/SiO 2 NPs nanocomposite films with 10 wt.% of SiO 2 NPs, and the water contact angle decreases to around 0° after thermal treatment, which confirms that the PEO/SiO 2 NPs nanocomposite films can be used as self‐cleaning antireflected surfaces.
Abstract
A detailed computational study of the dehydrogenation reaction of
trans
-propylamine (
trans
-PA) in the gas phase has been performed using density functional method (DFT) and CBS-QB3 ...calculations. Different mechanistic pathways were studied for the reaction of
n
-propylamine. Both thermodynamic functions and activation parameters were calculated for all investigated pathways. Most of the dehydrogenation reaction mechanisms occur in a concerted step transition state as an exothermic process. The mechanisms for pathways
A
and
B
comprise two key-steps: H
2
eliminated from PA leading to the formation of allylamine that undergoes an unimolecular dissociation in the second step of the mechanism. Among these pathways, the formation of ethyl cyanide and H
2
is the most significant one (pathway
B
), both kinetically and thermodynamically, with an energy barrier of 416 kJ mol
−1
. The individual mechanisms for the pathways from
C
to
N
involve the dehydrogenation reaction of PA via hydrogen ion, ammonia ion and methyl cation. The formation of α-propylamine cation and NH
3
(pathway
E
) is the most favorable reaction with an activation barrier of 1 kJ mol
−1
. This pathway has the lowest activation energy calculated of all proposed pathways.
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