scholarly journals Response of Photoluminescence of H-Terminated and Hydrosilylated Porous Si Powders to Rinsing and Temperature

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 366-380
Author(s):  
Kurt Kolasinski ◽  
Joseph Swanson ◽  
Benjamin Roe ◽  
Teresa Lee
Keyword(s):  
Environmental Factors ◽  
Aqueous Solutions ◽  
Phosphate Buffer ◽  
Peak Shape ◽  
Porous Si ◽  
Peak Wavelength ◽  
Vacuum Oven ◽  
Electroless Etching ◽  
Potential Applications ◽  
Pl Intensity

The photoluminescence (PL) response of porous Si has potential applications in a number of sensor and bioimaging techniques. However, many questions still remain regarding how to stabilize and enhance the PL signal, as well as how PL responds to environmental factors. Regenerative electroless etching (ReEtching) was used to produce photoluminescent porous Si directly from Si powder. As etched, the material was H-terminated. The intensity and peak wavelength were greatly affected by the rinsing protocol employed. The highest intensity and bluest PL were obtained when dilute HCl(aq) rinsing was followed by pentane wetting and vacuum oven drying. Roughly half of the hydrogen coverage was replaced with –RCOOH groups by thermal hydrosilylation. Hydrosilylated porous Si exhibited greater stability in aqueous solutions than H-terminated porous Si. Pickling of hydrosilylated porous Si in phosphate buffer was used to increase the PL intensity without significantly shifting the PL wavelength. PL intensity, wavelength and peak shape responded linearly with temperature change in a manner that was specific to the surface termination, which could facilitate the use of these parameters in a differential sensor scheme that exploits the inherent inhomogeneities of porous Si PL response.

scholarly journals Polyanilines as New Sorbents for Hydrocarbons Removal from Aqueous Solutions

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2161
Author(s):  
Cristina Della Pina ◽  
Maria Antonietta De Gregorio ◽  
Pierluisa Dellavedova ◽  
Ermelinda Falletta
Keyword(s):  
Aqueous Solutions ◽  
Environmental Protection ◽  
Surface Properties ◽  
Health Risks ◽  
Water Remediation ◽  
Wastewater Remediation ◽  
Sorption Efficiency ◽  
Potential Applications ◽  
High Sorption ◽  
Green Procedure

Water remediation from hydrocarbons is crucial to reduce health risks. Numerous costly and, sometimes, sophisticated methods were proposed over the years. Herein, an innovative green procedure for porous polyanilines preparation is reported. Polyaniline (PANI) was synthesized by three different approaches ranging from traditional to more eco-friendly ones. Thermal, optical and morphological features of the resulting materials were investigated along with their surface properties. Finally, PANIs were tested as sorbents for hydrocarbons removal from waterbodies. Although an overall fast and high sorption efficiency is always observed, the effective hydrocarbons abatement performed by ‘green’ PANIs is particularly welcome in the context of environmental protection. Moreover, the sorption efficiency retention after five-run recycling tests suggests potential applications in wastewater remediation.

Nitrone formation in phosphate buffer and aqueous solutions: novel chemistry inspired by a natural product

2012 ◽  
Vol 53 (16) ◽  
pp. 2129-2131 ◽  
Author(s):  
Acharavadee Pansanit ◽  
Nattha Ingavat ◽  
Thammarat Aree ◽  
Chulabhorn Mahidol ◽  
Somsak Ruchirawat ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Natural Product ◽  
Phosphate Buffer

The Effect of Hydrogen/ Deuterium Introduction on Photoluminescence of 3C-SiC Crystals

1998 ◽  
Vol 513 ◽  
Author(s):  
B. K. Lee ◽  
A. J. Steckl ◽  
J. M. Zavada ◽  
R. G. Wilson
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Laser Excitation ◽  
Peak Wavelength ◽  
Final Annealing ◽  
Increasing Trend ◽  
Area Increase ◽  
Hydrogen Deuterium ◽  
Pl Intensity ◽  
Post Implantation

ABSTRACTThe effect of the incorporation and annealing of deuterium in 3C-SiC on its photoluninescence is reported. A 3C-SiC crystal has been implanted with 100 keV deuterium and subsequently annealed at temperatures between 1015 °C and 1220 °C for 1 to 5 minutes. SIMS depth profiles indicate hydrogen is strongly trapped by defects generated through ion bombardment, but a gradual damage repairing occurs during annealing. Photoluminescence was measured with 488 nm Ar laser excitation for sample temperatures from 89 K to 400 K. The PL peak wavelength of 540 nm at room temperature has shifted to 538 nm at 89 K. The peak PL intensity decreases with measurement temperature while its full width at half maximum (FWHM) exhibits an increasing trend. PL data were taken at five annealing stages. The post-implantation peak PL intensity and its integrated area increase initially with annealing temperature and time. After the final annealing at 1218 °C for 2 minute, PL intensity and its integrated area exhibit a decrease in level.

A WIDE-SPECTRUM ANTIBIOTIC PRODUCED BY A SPECIES OF SORANGIUM

1966 ◽  
Vol 12 (2) ◽  
pp. 221-230 ◽  
Author(s):  
E. A. Peterson ◽  
D. C. Gillespie ◽  
F. D. Cook
Keyword(s):  
Low Temperature ◽  
Aqueous Solutions ◽  
Phosphate Buffer ◽  
Wide Spectrum ◽  
Active Material ◽  
Gram Negative Bacteria ◽  
Alkaline Ph ◽  
Gram Negative ◽  
Ether Extraction ◽  
High Degree

A soil-borne myxobacter identified as a species of Sorangium produced a potent antibiotic capable of inhibiting growth of a wide variety of microorganisms including Gram-positive and Gram-negative bacteria, fungi, actinomycetes, and yeasts. The active material was readily isolated from culture fluids of the organism by ether extraction or by adsorption on a resin. A high degree of purity was achieved chromatographically. Acetone, methanol, or aqueous solutions of the antibiotic were stable when stored at low temperature (4 °C). At 70 °C it was unstable in phosphate buffer but retained its activity in iris buffer at neutral and alkaline pH.

scholarly journals Fluorescence Quantum Yields and Lifetimes of Annatto Aqueous Solutions Dependent on Hydrogen Potential: Applications in adulterated milk

2021 ◽  
pp. 100080
Author(s):  
Tácio T.S. Santos ◽  
Larissa R. Lourenço ◽  
Sthanley R. de Lima ◽  
Luiz R. Goulart ◽  
Djalmir N. Messias ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Potential Applications

scholarly journals THE EFFECT OF POLY (ETHYLENE GLYCOL) ON THE PHOTOLUMINESCENCE PROPERTIES OF CARBON DOTS FROM CASSAVA PEELS SYNTHESIZED BY HYDROTHERMAL METHODS

2019 ◽  
Vol 4 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Permono Adi Putro ◽  
Liszulfah Roza ◽  
Isnaeni Isnaeni
Keyword(s):  
Ethylene Glycol ◽  
Carbon Dots ◽  
Time Decay ◽  
Poly Ethylene Glycol ◽  
Peak Wavelength ◽  
Time Resolved ◽  
Before And After ◽  
Pl Intensity ◽  
Poly Ethylene ◽  
Cassava Peels

Carbon dots (C-dots) have been successfully synthesized from cassava peels using the hydrothermal method. The C-dots are further passivated using poly (ethylene glycol) (PEG) with a variation of the volume of 0.5 ml, 1.0 ml, and 1.5 ml. The properties of photoluminescence C-dots before and after PEG were characterized using photoluminescence (PL) and time-resolved photoluminescence (TRPL) spectrophotometers. PEG succeeded in influencing PL C-dots properties, such as peak wavelength, PL intensity, and electron time decay. The addition of 0.5 ml of PEG to C-dots is the optimum condition and best with the peak wavelength, the PL intensity and, time decay electron is 507.52 nm, 5302 a.u, and 3.794031133 ns, respectively.

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