Molecular Sieve Thin Films via Laser Ablation

1994 ◽  
Vol 351 ◽  
Author(s):  
Kenneth J. Balkus ◽  
Scott J. Riley ◽  
Bruce E. Gnade
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Film Formation ◽  
Aluminum Phosphate ◽  
Effective Technique ◽  
Solid Films ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

ABSTRACTLaser ablation has become widely recognized as an effective technique for the preparation of thin solid films. We have employed an excimer laser (KrF, 248 nm) to deposit well dispersed thin films of aluminum phosphate molecular sieves on a titanium nitride substrate. Results for the ablation of AIPO4-5, AIPO4-H3 and AIPO4-H1 molecular sieve targets are presented. The laser power and repetition rate as well as substrate distance and temperature affect the thin film formation. A subsequent hydrothermal post treatment of the ablated films was found to enhance the surface crystallinity. The molecular sieve thin films were characterized by XRD, SEM, XRF, and FT-IR spectroscopy.

Molecular Sieve Based Chemical Sensors

1994 ◽  
Vol 351 ◽  
Author(s):  
Laura J. Sottile ◽  
Kenneth J. Balkus ◽  
Scott J. Riley ◽  
Bruce E. Gnade
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Titanium Nitride ◽  
Hydrothermal Treatment ◽  
Chemical Sensors ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Aluminum Phosphate ◽  
Shape Selectivity ◽  
Target Molecules

ABSTRACTBy virtue of their shape selectivity and stability, molecular sieves are ideal components for discriminating chemical sensors. In this paper we report the preparation of capacitance type sensors based on aluminum phosphate molecular sieves. Thin films of the molecular sieves AlPO4-5, A1PO 4-H3 and AlPO4-H1, which cover a range of pore dimensions, were deposited on titanium nitride coated silicon wafers by laser ablation. A subsequent hydrothermal treatment followed by a Pd/Au coating and the application of standard photoresist/masking techniques were used to generate the capacitors. The molecular sieves exhibit significant changes in capacitance upon exposure to target molecules, including CO2, CO, N2, H2O and toluene.

A Novel Approach to Photoacoustic FT-IR Spectroscopy: Rheo-Photoacoustic Measurements

1989 ◽  
Vol 43 (8) ◽  
pp. 1387-1393 ◽  
Author(s):  
William F. McDonald ◽  
Hans Goeitler ◽  
Marek W. Urban
Keyword(s):  
Molecular Structure ◽  
Thin Films ◽  
Fourier Transform ◽  
Acoustic Waves ◽  
Polymeric Materials ◽  
Photoacoustic Signal ◽  
Novel Approach ◽  
Ft Ir ◽  
Property Changes ◽  
Ft Ir Spectroscopy

A new rheo-photoacoustic Fourier transform infrared cell has been developed to perform stress-strain studies on polymeric materials. The rheo-photoacoustic measurements lead to the enhancement of the photoacoustic signal and allow one to monitor the effect of elongational forces on the molecular structure of polymers. Propagating acoustic waves are detected as a result of the deformational changes and thermal property changes upon the applied stress. Applications of this technique to fibers, films, and adhesion of thin films are presented.

Effects of added phthalate plasticizers on photodegradation of irradiated poly (α-methylstyrene) films

2015 ◽  
Vol 35 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Afrah E. Ramadhan
Keyword(s):  
Dibutyl Phthalate ◽  
Irradiation Time ◽  
Broad Band ◽  
Dioctyl Phthalate ◽  
Solid Films ◽  
Polymeric Chains ◽  
Ft Ir ◽  
The Stability ◽  
Monomer Fluorescence ◽  
Ft Ir Spectroscopy

Abstract The effects of UV irradiation and blending on the stability of poly (α-methylstyrene) (PαMS) in solid films were studied at different intervals of irradiation time in the presence of air, by absorption, emission and Fourier transform infrared (FT-IR) spectroscopy. The increase in irradiation time caused an increase in the intensity of the absorption band of the polymer, and an increase in the intensity of absorption of a new broad band at a longer wavelength, thus indicating the possibility of photodegradation of polymeric chains. The influence of added plasticizers, dimethyl terephthalate (DMT), diethyl terephthalate (DET), dibutyl phthalate (DBP), dioctyl phthalate (DOP) and dioctyl terephthalate (DOT) on photoquenching of the polymer fluorescence band was also investigated, and found to increase the photoquenching processes with increase in the amount of added plasticizers. By contrast, the intensity of excimer and monomer fluorescence bands was also found to decrease with increase in irradiation times. These changes may be attributed to the formation of new photoproducts which resulted from the photodegradation and photooxidation of irradiated polymeric chains. In addition, the observed increase in the intensities of the carbonyl and hydroxyl regions of the FT-IR spectra provides evidence for the photooxidation of polymeric chains. The increase in the intensity of some bands and the disappearance of new bands indicate the photodegradation of polymeric chains.

Pulsed Laser Ablation of Low-Density Nanoporous Metal Oxides

1998 ◽  
Vol 526 ◽  
Author(s):  
Mary E. Gimon-Kinsel ◽  
Trinidad Muñoz ◽  
Kenneth J. Balkus
Keyword(s):  
Electron Microscopy ◽  
Laser Ablation ◽  
Metal Oxides ◽  
Hydrothermal Treatment ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Low Density ◽  
Mcm 41

AbstractPulsed laser ablation has been employed to generate thin films of low density metal oxides, including nanoporous molecular sieves. An excimer laser (KrF*, 248 nm) was used to deposit molecular sieve films onto a variety of substrates including polished silicon, platinum, tantalum, titanium nitride, glass, indium-doped tin oxide, copper and Mylar. Recent results for the deposition of microporous UTD-1 and FeAPO-5 as well as mesoporous aluminosilicate MCM-41 and Nb-TMSI molecular sieve films are presented. The order (crystallinity) of the laser deposited films has been shown to be enhanced by a brief post hydrothermal treatment. A vapor phase treatment of the laser deposited FeAPO-5 films allows for increases in film crystallinity without an increase in film thickness. Hydrothermal treatment of laser deposited Nb-TMSI results in “worm hole” pore motif which is new for this composition. Silicate based molecular sieves such as UTD-1 and aluminosilicate MCM-41 require a UV-absorbing guest molecule for laser ablation giving rise to a phenomenon referred to as guest assisted laser ablation (GALA). The molecular sieve films were characterized by x-ray diffraction, scanning electron microscopy and transmission electron microscopy.

Structure of Water Incorporated in Amphoteric Polymer Thin Films as Revealed by FT-IR Spectroscopy

2008 ◽  
Vol 8 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Hiromi Kitano ◽  
Kyoko Nagaoka ◽  
Susumu Tada ◽  
Makoto Gemmei-Ide ◽  
Masaru Tanaka
Keyword(s):  
Thin Films ◽  
Ir Spectroscopy ◽  
Polymer Thin Films ◽  
Structure Of Water ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

scholarly journals Surfactant-dependant thermally induced nonlinear optical properties of l-ascorbic acid-stabilized colloidal GNPs and GNP–PVP thin films

RSC Advances ◽  
2019 ◽  
Vol 9 (27) ◽  
pp. 15502-15512 ◽  
Author(s):  
A. L. Sunatkari ◽  
S. S. Talwatkar ◽  
Y. S. Tamgadge ◽  
G. G. Muley
Keyword(s):  
Thin Films ◽  
Ascorbic Acid ◽  
Nonlinear Optical ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Chemical Reduction Method ◽  
Thermally Induced ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Gold nanoparticle (GNP) colloids stabilized with various concentrations of l-ascorbic acid were synthesized by the chemical reduction method and characterized by UV-Vis spectroscopy, XRD, FT-IR spectroscopy and TEM.

Article

1998 ◽  
Vol 76 (11) ◽  
pp. 1730-1736
Author(s):  
Mathew D Halls ◽  
Ricardo Aroca
Keyword(s):  
Ab Initio ◽  
Normal Modes ◽  
Light Emitting ◽  
Solid Films ◽  
Ft Ir ◽  
First Time ◽  
Mode Assignment ◽  
Transmission And Reflection ◽  
Ft Ir Spectroscopy

The vibrational spectra of one of the most commonly used light-emitting materials for organic electroluminescence (EL) devices, tris(8-hydroxyquinoline)aluminum (Alq3), is presented. The geometry and normal modes of fac-Alq3 isomer in the ground state have been computed for the first time using ab initio methods (HF/6-31G*) to aid in discussion of normal-mode assignment. Normal inelastic scattering excited at 633 nm and low-temperature FT-Raman in addition to the infrared spectra of this material are reported. The vibrational characterization of thin solid films of the material was attempted using transmission and reflection-absorption FT-IR spectroscopy (RAIRS) on smooth silver films.Key words: tris(8-hydroxyquinoline)aluminum, Alq3, ab initio, assignments, infrared, Raman, thin films.

RAMAN, DIELECTRIC AND OPTICAL INVESTIGATIONS OF DLC THIN FILMS

2009 ◽  
Vol 16 (05) ◽  
pp. 731-736 ◽  
Author(s):  
RASOUL MALEKFAR ◽  
HAMID MOTAHARI ◽  
JALAL ROHOLLAHNEJAD ◽  
FATEMEH SAHRAIYAN
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Calculated Data ◽  
Optical Parameters ◽  
Reflection Spectroscopy ◽  
Back Scattering ◽  
Ft Ir ◽  
Sem Imaging ◽  
Ft Ir Spectroscopy

Diamond-like carbon, DLC, thin films which is an amorphous hydrogenated form of carbon, a-C:H , has been synthesized by CVD method. SEM imaging, back-scattering Raman spectroscopy and reflected FT-IR spectroscopy have been used for characterization of the synthesized thin films. Kramers–Kronig dispersion relations have been used for the calculation of dielectric and optical parameters, which include the real and imaginary parts of the refractive and dielectric indices. In Raman spectroscopy, two obvious, wide and almost symmetrical peaks around 1355 cm-1 (D mode) and 1520–1550 cm-1 (G mode), clarify the formation of a-C:H thin film. Reflected spectra of thin films, in the spectral region of 400–4000 cm-1, have been recorded by the near normal FTIR reflection spectroscopy and show some peaks which can be assigned to the bending of sp3 C–C , sp3 or sp2 CH . The calculated data show that dielectric and optical parameters are almost independent of wavenumber.

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