Characterization of Process Induced Contamination and Residues on Semiconductor Components Via FTIR and Raman Microanalysis

2001 ◽  
Vol 7 (S2) ◽  
pp. 152-153
Author(s):  
H. Gotts
Keyword(s):  
Molecular Structure ◽  
Yield Enhancement ◽  
Spectroscopic Techniques ◽  
Bulk Materials ◽  
Scanning Calorimetry ◽  
Vis Spectroscopy ◽  
Classical Technique ◽  
Raman Microprobe ◽  
Scanning Electron

FTIR and Raman microanalysis may be used as a powerful combination to determine the identity, and hence infer the source, of contaminant particles which diminish yields of semiconductor components and devices. The complimentarity of these techniques arises from the underlying spectroscopic selection rules.Vibrational spectroscopic techniques are commonly used to characterize the molecular structure of bulk organic materials. These bulk materials typically represent purified fractions of components which may be further investigated with various classical instrumental techniques such as Differential Scanning Calorimetry (DSC), Nuclear Magnetic Resonance (NMR) spectroscopy, UV-Vis spectroscopy. However, these classical technique may have limited value for the interrogation of small impure particles or materials of limited quantity(ng.).Elemental techniques such as Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy are enhanced by the specificity of FTIR Microprobe Spectroscopy and Raman Microprobe Spectroscopy which are now used in process laboratories to characterize and identify particulate and thin film residues with the intent of device yield enhancement.

scholarly journals Synthesis and Characterization of Lateral Fluoro-substituents Liquid Crystals

2021 ◽  
Vol 11 (5) ◽  
pp. 12495-12505
Keyword(s):  
Molecular Structure ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Linkage Group ◽  
Optical Microscope ◽  
Synthesis And Characterization ◽  
Spectroscopic Techniques ◽  
Dielectric Measurements ◽  
Scanning Calorimetry

Lateral difluoro substituent liquid crystal based on a three-aromatic core has been synthesized. It has been designed to correlate the molecular structure and mesomorphism with reference to the difluoro substituent and -COO- linkage group. This compound was characterized by elementary analyses and spectroscopic techniques such as FTIR and 1H-NMR. The synthesis compound's mesomorphic behavior was studied by polarizing optical microscope, differential scanning calorimetry, and dielectric measurements. The recent investigation reveals only SmB phase.

scholarly journals Synthesis, Mesomorphism and the Optical Properties of Alkyl-deuterated Nematogenic 4-[(2,6-difluorophenyl)ethynyl]biphenyls

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4653
Author(s):  
Jakub Herman ◽  
Piotr Harmata ◽  
Michał Czerwiński ◽  
Olga Strzeżysz ◽  
Marta Pytlarczyk ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Optical Properties ◽  
Liquid Crystalline ◽  
Near Infrared ◽  
Synthesis And Characterization ◽  
Molecular Approach ◽  
Scanning Calorimetry

The synthesis and characterization of new deuterated liquid crystal (LC) compounds based on phenyl tolane core is described in this paper. The work presents an alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic and optical properties for compounds which are alkyl-hydrogen terminated and alkyl-deuterium, have been drawn. The compounds are characterized by mass spectrometry (electron ionization) analysis and infrared spectroscopy. They show enantiotropic nematic behavior in a broad temperature range, confirmed by a polarizing thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesized compounds show a significantly reduced absorption in the near-infrared (NIR) and medium-wavelength infrared (MWIR) radiation range, and stand as promising components of medium to highly birefringent liquid crystalline mixtures.

scholarly journals Synthesis, Crystal Structures, and Spectroscopic Characterization of Bis-aldehyde Monomers and Their Electrically Conductive Pristine Polyazomethines

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1498 ◽  
Author(s):  
Abdul Hafeez ◽  
Zareen Akhter ◽  
John F. Gallagher ◽  
Nawazish Ali Khan ◽  
Asghari Gul ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Spectroscopic Characterization ◽  
Spectroscopic Techniques ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Electrically Conductive ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir

Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.

Preparation and Characterization of Blended Composite Membranes

2012 ◽  
Vol 488-489 ◽  
pp. 506-510 ◽  
Author(s):  
Sikander Rafiq ◽  
Zakaria Man ◽  
Abdulhalim Maulud ◽  
Nawshad Muhammad ◽  
Saikat Maitra
Keyword(s):  
Spectroscopic Analysis ◽  
Sol Gel ◽  
Composite Membranes ◽  
Hybrid Membranes ◽  
Ftir Analysis ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Thermal Stability Of ◽  
Scanning Electron

Composite membranes were prepared by incorporating inorganic silica nanoparticles into blends of polysulfone/polyimide (PSF/PI) membranes via sol-gel route. Morphological structures of the developed membranes were carried out by scanning electron microscopy (SEM). Spectroscopic analysis of the hybrid membranes were done by fourier transform infrared spectroscopy (FTIR) analysis. Differential scanning calorimetry (DSC) analysis shows that the glass transition temperature (Tg) increased from 209oC to 238oC in the hybrid membranes followed by thermogravimetric analysis (TGA) that showed significant improvement in thermal stability of the developed membranes.

Synthesis and Characterization of Nanostructured TiO2-SnO2 Composite

2014 ◽  
Vol 975 ◽  
pp. 233-237
Author(s):  
Joelma C. S. Breve ◽  
Dayse I. dos Santos
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Thermal Analysis ◽  
Gas Sensors ◽  
Catalytic Properties ◽  
Rutile Phase ◽  
Synthesis And Characterization ◽  
Vis Spectroscopy ◽  
Scanning Electron

Nanostructured composites based on titanium dioxide have been studied in order to improve optical and photo-catalytic properties, as well as their performance in gas sensors. In this work, titanium and tin dioxides were simultaneously synthesized by the polyol method resulting in TiO2 platelet coated with SnO2 nanoparticles as was observed by scanning electron microscopy. The thermal analysis showed that the combined synthesis promotes more easily the crystallization of the TiO2 rutile phase. The composite obtained after heat treatment at 500 °C showed to be formed of almost only rutile phases of both oxides. The optical properties analyzed by UV-Vis spectroscopy showed that the combined oxides have higher absorbance, which reinforces a model found in the literature based on the flow of photo-generated electrons to the conduction band of SnO2 delaying the recombination of charges.

scholarly journals Preparation and Characterization of Levofloxacin-Loaded Nanofibers as Potential Wound Dressings

2017 ◽  
Vol 63 (2) ◽  
pp. 66-69 ◽  
Author(s):  
Noémi Pásztor ◽  
Emőke Rédai ◽  
Zoltán-István Szabó ◽  
Emese Sipos
Keyword(s):  
Electron Microscopy ◽  
Electrospun Nanofibers ◽  
Electrospinning Process ◽  
Wound Dressings ◽  
Dissolution Testing ◽  
Electrospun Nanofiber ◽  
Scanning Calorimetry ◽  
Rapid Release ◽  
Scanning Electron

Abstract Objective: The study aimed at obtaining and characterizing levofloxacin-loaded, poly(ε-caprolactone) electrospun nanofiber formulations to be used as antibacterial wound dressings. Methods: Drug-loaded nanofibers were obtained by the electrospinning process and their morphology was determined using scanning electron microscopy. Structural analysis of the prepared nanofibers was carried out using differential scanning calorimetry and dissolution testing was performed in order to determine drug release. Results: Both nanofiberous formulations (containing 20 % and 50 % w/w levofloxacin) showed dimensions in the range of few hundred nanometers. Thermograms indicated that the formulation containing 20% levofloxacin was totally amorphized, showing a rapid release of the active, in 20 minutes. Conclusions: The poly(ε-caprolactone)-based electrospun nanofibers, containing levofloxacin presented suitable characteristics for obtaining potential antibacterial wound dressings.

scholarly journals Structural stability of biofilms produced from silkworm cocoon fibers

2021 ◽  
pp. 54-54
Author(s):  
Souza Felício ◽  
Henrique Santana
Keyword(s):  
Conformational Changes ◽  
Casting Process ◽  
Scanning Calorimetry ◽  
Molecular Conformations ◽  
Freeze Dried ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Silkworm Cocoon ◽  
Band Characteristic

Biofilms were obtained from cocoons of the silkworm, Bombyx mori, involving the removal of sericin, extraction and solubilization of fibroin fibers, dialysis of fibroin dispersions and preparation of biofilms by the casting process. Biofilm transparency was verified by UV-Vis spectroscopy and thermal stability by thermogravimetric/differential scanning calorimetry (TG/DSC). Soon after preparation, the solidification of the fibroin solution prepared from the cocoons and extracted by the Ajisawa method was monitored until the biofilm stabilized, using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR FT-IR) as a function of time. The results showed that there is a change in the conformation from the silk I structure (?-helix) to silk II (?-sheet). In order to improve the characterization of the biofilms obtained by the Ajisawa method and LiBr solubilization of fibroin fibers, Raman spectroscopy was used to verify stabilization of the different possible molecular conformations for the fibers in these materials, by comparison with the cocoon spectra and those of the solid (freeze-dried hydrogel) precipitated by dialysis for 72 h. By comparing the Raman spectra of the biofilms in terms of the intensities of the broadened band characteristic of amide I, it was possible to assess the conformational changes in both materials based on possible transitions between ?-sheet conformations and flexible ?-helix and ?-turn structures. The results showed a dispersion of these conformations in the biofilms generated and in the solid freeze-dried hydrogel spectrum, and the ?-sheet conformation was found to be predominant. The TG and DSC curves showed that the materials with higher ?-sheet content exhibited higher thermal resistance. Thus, the data obtained further elucidate the properties of these materials which are widely used in various processes.

scholarly journals Synthesis and characterization of four new lanthanide complexes coordinate with β-diketone ligands and 1,10-phenanthroline or 2,2-dipyridine

2020 ◽  
Vol 9 (11) ◽  
pp. e45791110207
Author(s):  
Yuri Johann Vilar de Brito ◽  
Crislene Rodrigues da Silva Morais ◽  
Yohanna Jamilla Vilar de Brito ◽  
Daniella Cibele Bezerra
Keyword(s):  
Electron Microscopy ◽  
Lanthanide Complexes ◽  
Synthesis And Characterization ◽  
Direct Reaction ◽  
Scanning Calorimetry ◽  
Solubility Test ◽  
Microscope Images ◽  
Scanning Electron

In this work the complexes Ln(β-dik)3L (where Ln= Nd+3 e Er+3, β-dik= 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Btfa) and L= 1,10-Phenanthroline (Phen) or 2,2’-Bipyridyl (Bipy)), were synthesized from the direct reaction of LnCl3 with β-diketone and the ligands. The purpose was to create new lanthanide complexes with perspectives of use in markers. After the syntheses, the complexes were characterized by Solubility Test, Scanning Electron Microscopy (SEM) and the thermal properties of compounds were studied using Thermogravimetry Analisys (TGA), Differential Scanning Calorimetry (DSC) and Determination of Melting/Decomposition Intervals. Based on the verified properties, the solubility test found that the complexes are not soluble in chloroform and water. The microscope images showed an excellent crystallization of the complexes. The complexes are stable up to 120°C, after this temperature they show a peak in the DSC referring to the fusion and the beginning of decomposition. The values of activation energy suggests the following decreasing order of stability: Er(Btfa)3Phen>Nd(Btfa)3Phen>Er(Btfa)3Bipy>Nd(Btfa)3Bipy.

Preparation and Characterization of Hydrogels Based on Chitsoan/Polyvinyl Alcohol Blends

2015 ◽  
Vol 1105 ◽  
pp. 203-207
Author(s):  
Mohammed Amine Zitouni ◽  
Sofia Borsali Kara Slimane
Keyword(s):  
Weight Ratio ◽  
Poly Vinyl Alcohol ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
Intermolecular Hydrogen Bonds ◽  
Sem Images ◽  
Structure Morphology ◽  
Ft Ir ◽  
Scanning Electron

In this study, a series of poly (vinyl alcohol) (PVA)/chitosan (CS) hydrogels with different weight ratio of PVA to CS were prepared by freezing-thawing (F-T) method. The structure, morphology, and crystallinity of hydrogels were investigated by Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). FTIR demonstrated the presence of strong intermolecular hydrogen bonds between CS and PVA molecules. SEM images showed that the higher the chitosan, the greater the porous size of the hydrogel and DSC confirmed that crystallinity is higher when PVA is more in hydrogel. The mechanical properties of these hydrogels were studied by rheometry. The study of swelling ability demonstrated that the hydrogel developed with PVA and Cs was more swellable than that with PVA only because of its cross-linking interaction with PVA.

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