Solvent Contamination Determined by UV Reflection

1985 ◽  
Vol 28 (5) ◽  
pp. 23-26
Author(s):  
Edward Murphy
Keyword(s):  
Room Temperature ◽  
Ultraviolet Absorption ◽  
Simple Test ◽  
Reflection Spectroscopy ◽  
Cleaning Solvents ◽  
Uv Reflection

Commercial organic cleaning solvents, unless specially prepared, may increase contamination of an item rather than clean it. A simple test to determine the presence or absence of a contaminant in a solvent can be performed by using ultraviolet-reflection spectroscopy. The procedure consists of immersing a quartz-paper coupon in a small quantity of the solvent to be tested, then evaporating the solution to dryness in a vent hood at room temperature. Prior to immersion, clean quartz paper typically reflects 70 to 90% of the ultraviolet in a range from 200 to 360 nm. If the filaments of the quartz-paper coupon have had any contaminant from the solvent deposited on their surfaces, the multi reflections produce an extensive ultraviolet absorption.

The Near-ultraviolet Absorption Spectrum of Diimide in Liquid Ammonia and its Decomposition between −65 and −38 °C

1974 ◽  
Vol 52 (13) ◽  
pp. 2513-2515 ◽  
Author(s):  
R. A. Back ◽  
C. Willis
Keyword(s):  
Absorption Spectrum ◽  
Gas Phase ◽  
Room Temperature ◽  
Liquid Ammonia ◽  
Vibrational Structure ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum ◽  
First Order ◽  
Rapid Decomposition ◽  
Near Ultraviolet

The near-ultraviolet absorption spectrum of diimide in liquid ammonia at −50 °C is shifted about 500 Å to the red compared with the gas-phase spectrum, with λmax = 4000 Å. The spectrum is also broadened and the vibrational structure largely obscured. It is suggested that hydrogen bonding is responsible for these changes.Diimide is much more stable in liquid ammonia between −65 and −38 °C than in the gas phase at room temperature. A first-order decay is observed with Arrhenius parameters of A = 1.9 × 103 s−1 and E = 6.6 kcal/mol; this is always preceded by a more rapid, higher-order initial decay which may be related to the rapid decomposition observed during vaporization.

Research on Inhibition Marine Microbial Adherence of a Novel Nano-TiO2 Coating on Aluminum

2012 ◽  
Vol 557-559 ◽  
pp. 1687-1690
Author(s):  
Tong Liu ◽  
Qiang Li
Keyword(s):  
Sol Gel ◽  
Gene Segment ◽  
Dip Coating ◽  
Aluminum Surface ◽  
Reflection Spectroscopy ◽  
X Ray Diffraction ◽  
Anodized Aluminum ◽  
X Ray ◽  
Uv Reflection ◽  
Microbial Adherence

A novel nano-TiO2 coating is prepared by vacuum dip-coating TiO2 sol–gel onto the anodized aluminum surface. The particles of TiO2 anatase is filled into the Al2O3 nano-pores formed by anodization. The structure and composition of the coatings are characterized by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The preponderant bacterium is identified as Pseudomonas lindanilytica strain IPL-1 through analysis of the sequences of S16 nRNA gene segment. In addition, the electrochemical results show that the TiO2 coatings significantly reduce the corrosion rate of Al substrates. The UV reflection spectroscopy is used to determine and analyze that the nano-TiO2 coatings could improve the light photo catalytic activity which decreases microbial influencing corrosion acceleration inhibition (MICI).

Detection of Polytetrafluoroethylene Coating Deposition in Carbon Composite Paper Surface PEMFC Using FTIR-ATR

2016 ◽  
Vol 880 ◽  
pp. 114-118 ◽  
Author(s):  
Dita Rama Insiyanda ◽  
Fredina Destyorini ◽  
Nanik Indayaningsih
Keyword(s):  
Room Temperature ◽  
Polymeric Materials ◽  
Carbon Composite ◽  
Attenuated Total Reflectance ◽  
Reflection Spectroscopy ◽  
Chemical Profiling ◽  
Non Invasive ◽  
Polymeric Substrates ◽  
Different Content ◽  
Composite Paper

Spectroscopy Fourier Transform Infrared (FTIR) – Attenuated Total Reflectance (ATR) used to study the surface of polymeric materials on polymeric substrates using a sensitive technique for chemical profiling, study of reflection spectroscopy, and a non-invasive. In this study we will investigate of Polytetrafluoroethylene (PTFE) deposition in carbon composite paper without damaging its structure by FTIR-ATR. Carbon composite paper was prepared by mixing the carbon material from coconut fiber and polymer binder in xylen as solvent, casted on glass substrate, and then rolled to make a sheet. Coating process was done by dipped the carbon composite paper in the PTFE suspension with different content of 10 wt%, 20 wt% and 30 wt% for 30 minutes and dried at room temperature for one night and heated at 150°C for 30 minutes, and finally heated at 350°C for 30 minutes to melt the PTFE. All samples were analyzed by using FTIR-ATR and SEM-EDS. Deposition of PTFE with different content in carbon composite papers could be observed by FTIR-ATR. The peaks located at near 1205 cm-1 and 1154cm-1 with different intensity for each PTFE contents. FTIR-ATR could be used as a pre-detection method of PTFE deposition in carbon composite paper before using SEM-EDS, because FTIR-ATR would be reflected at the highly reflective surface.

Cure Characterization in Diamine-Cured Epoxy and Polyimide by UV Reflection Spectroscopy

1995 ◽  
Vol 28 (7) ◽  
pp. 2506-2511 ◽  
Author(s):  
Jae-Woong Yu ◽  
Chong Sook Paik Sung
Keyword(s):  
Reflection Spectroscopy ◽  
Cure Characterization ◽  
Uv Reflection

Ultraviolet Absorption Spectra of Selected Unsaturated Carbonyl and β-Dicarbonyl Compounds at High Temperatures

1969 ◽  
Vol 23 (5) ◽  
pp. 532-535 ◽  
Author(s):  
W. W. Haskell ◽  
I. A. Read
Keyword(s):  
Gas Phase ◽  
Absorption Spectra ◽  
High Temperatures ◽  
Total Pressure ◽  
Room Temperature ◽  
Ultraviolet Absorption ◽  
Effect Of Temperature ◽  
Dicarbonyl Compounds

The gas-phase absorption spectra of 2-methylpent-2-ene-4-one, 2-methylpent-l-en-3-one, trans-pent-3-en-2-one, pent-l-en-3-one, 2-methylpent-2-enal, 4-methylpent-2-enal, methacrolein, acrolein, acetylacetone, and 4-methylpentan-3-onal have been determined at 525°C and at a total pressure of 28.5 atm. The effect of temperature on the absorption has been investigated and, for comparison, the absorption spectra have also been determined in cyclohexane solution at room temperature.

Room-Temperature Near-Field Reflection Spectroscopy of Single Quantum Wells

1997 ◽  
Vol 164 (1) ◽  
pp. 541-546 ◽  
Author(s):  
W. Langbein ◽  
J. M. Hvam ◽  
S. Madsen ◽  
M. Hetterich ◽  
C. Klingshirn
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Near Field ◽  
Single Quantum ◽  
Reflection Spectroscopy
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